PATENT DOCUMENT

Publication Number: US-12156185-B2
Application Number: US-202117593363-A
Country: US
Kind Code: B2

Title: FR2 type 1 UL gap configuration in dynamic TDD system

Abstract:
Systems and methods for implementing uplink (UL) gaps to facilitate user equipment (UE) calibration are disclosed herein. A UE determines one or more slot patterns of a slot configuration that is repeated during time division duplex (TDD) communication with a base station. The UE determines a UL gap periodicity (defining periods covering an integer number of repetitions of the slot configuration). The UE then performs UE calibration during one or more semi-persistently configured UL slots of a period of the UL gap periodicity that correspond to UL indication(s) in one or more of a common configuration, a dedicated configuration, and/or a slot format indication (SFI) downlink control information (DCI) for the slot pattern(s) of the slot configuration. Methods of identifying particular semi-persistently configured UL slots of a period to use for the UL gap are also discussed. UL slot indications from dynamic DCI are not used for UL gap purposes.

Claims:
The invention claimed is: 
     
       1. A method of a user equipment (UE) that performs time division duplex (TDD) communication with a base station, comprising:
 determining, using configuration information from the base station, a first slot pattern of a slot configuration used during the TDD communication; 
 determining an uplink (UL) gap periodicity, wherein a period of the UL gap periodicity comprises repetitions of the slot configuration during the TDD communication; and 
 performing UE calibration during a plurality of semi-persistently configured UL slots of the period, wherein a number of the plurality of semi-persistently configured UL slots is equal to a UL gap length, and wherein a first UL slot of the plurality of semi-persistently configured UL slots corresponds to the first slot pattern. 
 
     
     
       2. The method of  claim 1 , wherein the plurality of semi-persistently configured UL slots are initial semi-persistently configured UL slots of the period. 
     
     
       3. The method of  claim 1 , wherein the plurality of semi-persistently configured UL slots are initial semi-persistently configured UL slots of the repetitions of the slot configuration. 
     
     
       4. The method of  claim 1 , further comprising determining, using the configuration information, a second slot pattern of the slot configuration, wherein a second UL slot of the plurality of semi-persistently configured UL slots corresponds to the second slot pattern. 
     
     
       5. The method of  claim 1 , wherein the UL gap periodicity is a multiple of a length of the slot configuration. 
     
     
       6. The method of  claim 1 , further comprising receiving, from the base station, a number of the repetitions of the slot configuration of the UL gap periodicity, wherein determining the UL gap periodicity comprises multiplying a length of the slot configuration by a number of the repetitions. 
     
     
       7. The method of  claim 6 , wherein the length of the slot configuration equals a length of the first slot pattern. 
     
     
       8. The method of  claim 6 , wherein the length of the slot configuration equals a sum of a length of the first slot pattern plus a length of a second slot pattern of the slot configuration. 
     
     
       9. The method of  claim 1 , wherein the configuration information includes a common configuration for all UE of a serving cell of the UE indicating the first slot pattern, and wherein the first UL slot corresponds to a first UL slot indication made in the common configuration. 
     
     
       10. The method of  claim 9 , wherein the common configuration indicates a second slot pattern of the slot configuration, and wherein a second UL slot of the plurality of semi-persistently configured UL slots corresponds to a second UL slot indication made in the common configuration and to the second slot pattern. 
     
     
       11. The method of  claim 1 , wherein the configuration information includes a first dedicated configuration for the first slot pattern that is specific to the UE, and wherein the first UL slot corresponds to a first UL slot indication made in the first dedicated configuration. 
     
     
       12. The method of  claim 11 , wherein the configuration information includes a second dedicated configuration for a second slot pattern of the slot configuration, and wherein a second UL slot of the plurality of semi-persistently configured UL slots corresponds to a second UL slot indication made in the second dedicated configuration. 
     
     
       13. The method of  claim 1 , wherein the first slot pattern is further determined using first slot format indication (SFI) downlink control information (DCI) received from the base station, and wherein the first UL slot corresponds to a first UL slot indication made in the first SFI DCI. 
     
     
       14. The method of  claim 13 , wherein a second slot pattern of the slot configuration is determined using second SFI DCI received from the base station, and wherein a second UL slot of the plurality of semi-persistently configured UL slots corresponds to a second UL slot indication made in the second SFI DCI. 
     
     
       15. The method of  claim 1 , wherein the plurality of semi-persistently configured UL slots does not include a UL slot corresponding to a UL slot indication made by dynamic downlink control information (DCI). 
     
     
       16. The method of  claim 1 , wherein the UL gap length is indicated to the UE by the base station. 
     
     
       17. An apparatus of a user equipment (UE) to perform time division duplex (TDD) communication with a base station, comprising:
 one or more processors; and 
 a memory storing instructions that, when executed by the one or more processors, cause the one or more processors to configure the UE to:
 determine, using configuration information from the base station, a first slot pattern of a slot configuration used during the TDD communication; 
 determine an uplink (UL) gap periodicity, wherein a period of the UL gap periodicity comprises repetitions of the slot configuration during the TDD communication; and 
 perform UE calibration during a plurality of semi-persistently configured UL slots of the period, wherein a number of the plurality of semi-persistently configured UL slots is equal to a UL gap length, and wherein a first UL slot of the plurality of semi-persistently configured UL slots corresponds to the first slot pattern. 
 
 
     
     
       18. The apparatus of  claim 17 , wherein the plurality of semi-persistently configured UL slots are initial semi-persistently configured UL slots of the period. 
     
     
       19. The apparatus of  claim 17 , wherein the plurality of semi-persistently configured UL slots are initial semi-persistently configured UL slots of the repetitions of the slot configuration. 
     
     
       20. The apparatus of  claim 17 , wherein the instructions, when executed by the one or more processors, further cause the one or more processors to configure the UE to determine, using the configuration information, a second slot pattern of the slot configuration, wherein a second UL slot of the plurality of semi-persistently configured UL slots corresponds to the second slot pattern.

Description:
TECHNICAL FIELD 
     This application relates generally to wireless communication systems, including systems using time division duplex (TDD) communications that implement uplink (UL) gaps during which user equipment (UE) calibration may be performed. 
     BACKGROUND 
     Wireless mobile communication technology uses various standards and protocols to transmit data between a base station and a wireless communication device. Wireless communication system standards and protocols can include, for example, 3rd Generation Partnership Project (3GPP) long term evolution (LTE) (e.g., 4G), 3GPP new radio (NR) (e.g., 5G), and IEEE 802.11 standard for wireless local area networks (WLAN) (commonly known to industry groups as Wi-Fi®). 
     As contemplated by the 3GPP, different wireless communication systems standards and protocols can use various radio access networks (RANs) for communicating between a base station of the RAN (which may also sometimes be referred to generally as a RAN node, a network node, or simply a node) and a wireless communication device known as a user equipment (UE). 3GPP RANs can include, for example, global system for mobile communications (GSM), enhanced data rates for GSM evolution (EDGE) RAN (GERAN), Universal Terrestrial Radio Access Network (UTRAN), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), and/or Next-Generation Radio Access Network (NG-RAN). 
     Each RAN may use one or more radio access technologies (RATs) to perform communication between the base station and the UE. For example, the GERAN implements GSM and/or EDGE RAT, the UTRAN implements universal mobile telecommunication system (UMTS) RAT or other 3GPP RAT, the E-UTRAN implements LTE RAT (sometimes simply referred to as LTE), and NG-RAN implements NR RAT (sometimes referred to herein as 5G RAT, 5G NR RAT, or simply NR). In certain deployments, the E-UTRAN may also implement NR RAT. In certain deployments, NG-RAN may also implement LTE RAT. 
     A base station used by a RAN may correspond to that RAN. One example of an E-UTRAN base station is an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B (also commonly denoted as evolved Node B, enhanced Node B, eNodeB, or eNB). One example of an NG-RAN base station is a next generation Node B (also sometimes referred to as a or g Node B or gNB). 
     A RAN provides its communication services with external entities through its connection to a core network (CN). For example, E-UTRAN may utilize an Evolved Packet Core (EPC), while NG-RAN may utilize a 5G Core Network (5GC). 
     Frequency bands for 5G NR may be separated into two or more different frequency ranges. For example, Frequency Range 1 (FR1) may include frequency bands operating in sub-6 GHz frequencies, some of which are bands that may be used by previous standards, and may potentially be extended to cover new spectrum offerings from 410 MHz to 7125 MHz. Frequency Range 2 (FR2) may include frequency bands from 24.25 GHz to 52.6 GHz. Bands in the millimeter wave (mmWave) range of FR2 may have smaller coverage but potentially higher available bandwidth than bands in the FR1. Skilled persons will recognize these frequency ranges, which are provided by way of example, may change from time to time or from region to region. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced. 
         FIG.  1 A  illustrates a slot configuration used during time division duplex (TDD) communications, according to an embodiment. 
         FIG.  1 B  illustrates a use of the slot configuration to perform TDD communications that use an uplink (UL) gap, according to an embodiment. 
         FIG.  2 A  illustrates a slot configuration used during TDD communications, according to an embodiment. 
         FIG.  2 B  illustrates a use of the slot configuration to perform TDD communications that use a UL gap, according to an embodiment. 
         FIG.  3 A  illustrates a slot configuration used during TDD communications, according to an embodiment. 
         FIG.  3 B  illustrates a use of the slot configuration to perform TDD communications that use a UL gap, according to an embodiment. 
         FIG.  4 A  illustrates a slot configuration used during TDD communications, according to an embodiment. 
         FIG.  4 B  illustrates a use of the slot configuration to perform TDD communications that use a UL gap, according to an embodiment. 
         FIG.  5 A  illustrates a slot configuration used during TDD communications, according to an embodiment. 
         FIG.  5 B  illustrates a use of the slot configuration to perform TDD communications that use a UL gap, according to an embodiment. 
         FIG.  5 C  illustrates a use of the slot configuration to perform TDD communications that use a UL gap, according to an embodiment. 
         FIG.  5 D  illustrates a use of the slot configuration to perform TDD communications that use a UL gap, according to an embodiment. 
         FIG.  6 A  illustrates a slot configuration used during TDD communication, according to an embodiment. 
         FIG.  6 B  illustrates a use of the slot configuration to perform TDD communications that use a UL gap, according to an embodiment. 
         FIG.  7    illustrates a method of a UE, according to an embodiment. 
         FIG.  8    illustrates an example architecture of a wireless communication system, according to embodiments disclosed herein. 
         FIG.  9    illustrates a system for performing signaling between a wireless device and a network device, according to embodiments disclosed herein. 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments are described with regard to a UE. However, reference to a UE is merely provided for illustrative purposes. The example embodiments may be utilized with any electronic component that may establish a connection to a network and is configured with the hardware, software, and/or firmware to exchange information and data with the network. Therefore, the UE as described herein is used to represent any appropriate electronic component. 
     The enhancement of FR2 coverage in wireless communications systems in order to improve coverage, signal quality, and/or UE performance is of interest, motivated (at least) by a desire for increased power efficiency and/or overall system throughput. In some UEs that operate on FR2, various FR2 enhancements may rely on and/or benefit from the use of a UL gap. The UL gap may represent one or more UL slots during which no UL transmission is actually performed by the UE (or at least where any such UL transmissions would have their power greatly reduced). Then, during this UL gap, the UE may perform calibration and/or measurement over the air and/or through the internal loop of the UE. 
     In a first example of UE calibration using a UL gap, the UL gap may be used at the UE to measure and calibrate a power amplifier (PA) used at the UE. For example, UL gaps may be used to perform a periodic measurement of PA characteristics, such that the UE can make appropriate adjustments over time. 
     In a second example of UE calibration using a UL gap, the UL gap may additionally (or alternatively) be used to perform transceiver calibration. Occasional (re)calibration of a transceiver of the UE may be used to account for runtime impairment profile changes due to, for example, temperature changes at the UE. This transceiver calibration may help realize a maximized beamforming gain of an antenna array of the UE, such that FR2 performance may be improved. 
     In a third example of UE calibration using UL gaps, the UL gap may additionally (or alternatively) be used at the UE to perform transmit (Tx) power management. It may be desirable for the UE to adaptively adjust a Tx power in order to, for example, maximize UL coverage and/or throughput (or alternatively, UL efficiency), all while maintaining compliance with regulatory requirements regarding the power of such transmissions. A corresponding determination of the Tx power to be used/useable by the UE may be affected by/partially determined at the UE in view of environmental factors (such as, e.g., interference due to other transmissions in the area). Accordingly, the UL gap may be used by the UE to measure such environmental factors so the UE can more accurately calibrate its own Tx power. 
     It is contemplated that other examples of UE calibration that could be additionally (or alternatively) performed during one or more UL gaps may occur to one of ordinary skill in the art. In such cases, it is anticipated that the UL gaps disclosed herein could be used for such calibration examples as well. 
     Each of the preceding examples of UE calibration may implement a scheme where the UE sends a calibration signal and receives a return calibration signal (either over the air to a base station, or on the internal loop of the UE between Tx components and receive (Rx) components of the UE). This process may use the hardware for UL transmission. Accordingly, for any UL transmission that is not associated with the UE calibration process that would have otherwise been sent during the time that calibration takes place may be interrupted/affected. As described herein, UL transmissions not comprising part of a UE calibration process may be referred to herein as regular UE transmissions. 
     A provision of a known UL gap allocates time resources during which such an interruption to regular UL transmission (due to UE calibration) is expected/known to occur, thereby promoting organization within the wireless communication system. Systems and methods for predictably providing for/using such a UL gap may therefore be beneficial. 
     A UL gap may be understood to be a “Type 1” UL gap. A Type 1 UL gap may be a UL gap that is known to (and/or determinable by) and used by the UE without first receiving an explicit grant for the UL gap from a base station of the wireless communication system. During a Type 1 UL gap, all UE radio frequency (RF) requirements may apply. In the case of a Type 1 UL gap, it may be beneficial to ensure that the configuration of the UL gap is decided based on interdependent factors, with a goal of a good balance of the gains from UE calibration in view of a power management maximum power reduction (P-MPR). For example, there may be a tradeoff between UL gap overhead and Tx power gain. Since slots used for UL gap slots are used for body proximity sensing (BPS) sensing, there may be a corresponding UL throughput loss associated with this use. For example, Assume x % of a UL resource is used for sensing. In such a case, one might see a throughput loss of x % if no Tx power gain is obtained. On the other hand, with the use of the described UL gap, UE may ultimately be able to transmit with a higher Tx power (over the remaining UL slots not used for the UL gap), achieving better coverage and higher UL throughput. 
     It is contemplated that in some embodiments, a UE may be able to signal to a base station that it is capable of/is using UL gaps as disclosed herein. It is further contemplated that in some embodiments, a base station may be able to signal to a UE that it expects the UE to use UL gaps as disclosed herein. 
     NR provides time division duplex (TDD) configuration schema via which one or more slots (e.g., the symbols of those one or more slots) may be configured. Within each configured slot, each symbol can be formatted for UL, downlink (DL) or as a flexible symbol. A flexible symbol may be a symbol that can be used as either UL or DL (e.g., according to a subsequent configuration/indication for that symbol). Accordingly, a slot may be configured as a UL slot (e.g., all symbols of the slot are UL symbols), a DL slot (e.g., all symbols of the slot are DL symbols), a flexible slot (e.g., all symbols of the slot are flexible symbols) or a special slot (e.g., the symbols of the slot are a mix of symbol types). 
     In some cases, the NR TDD is configured using dynamic scheduling. In dynamic scheduling, the amount and nature of the slots to be used by the UE (e.g., the nature of the symbols of those slots) are dynamically configured on demand by the base station using dynamic downlink control information (DCI) in a physical downlink control channel (PDCCH). 
     In some cases, the NR TDD is configured using semi-persistent (SP) configuration techniques. An SP configuration of the amount and nature of the slots to be used by the UE may be re-used by the UE through time, for example, unless and until an updated SP configuration arrives at the UE. 
     An SP configuration may be a multi-part, hierarchical configuration used to configure one or more slot patterns of a slot configuration used in TDD communications. For a first hierarchical part of the SP configuration, a UE may be provided a common configuration (e.g., in a ‘tdd-UL-DL-ConfigurationCommon’ information element) that indicates one or more slot patterns to be used by the UE as part of a slot configuration used during TDD communications. The common configuration may be applicable to all UE that share the same serving cell of the UE in question. The common configuration may be sent to the UE via a system information block (SIB) (e.g., SIB1) of the base station and/or via dedicated RRC signaling. The common configuration may indicate the locations of any uplink, downlink, flexible, and/or special slots within the configured slot pattern(s). Further, the common configuration may also indicate the locations of any uplink, downlink, or flexible symbols within any special slots of the configured slot pattern(s). Accordingly, at the level of the first hierarchical part, the arrangement of all symbols of all slots in the slot pattern(s) may be fully determined (subject to possible further adjustment, as will be described). A common configuration may be a form of configuration information, as used herein. 
     For a second hierarchical part of an SP configuration, a UE may be provided with a dedicated configuration (e.g., in a ‘tdd-UL-DL-ConfigurationDedicated’ information element) for each of one or more of the slot pattern(s) used by the UE as part of a slot configuration used during TDD communications. The dedicated configuration may be specific to the UE (e.g., not necessarily the same as any other dedicated configuration that may be provided to other UE of the serving cell). The dedicated configuration may be sent to the UE via dedicated RRC signaling. The dedicated configuration may indicate whether any flexible slots/symbols (as configured by the first hierarchical part of the SP configuration) should be used instead in the corresponding a slot pattern as uplink/downlink slots/symbols. A dedicated configuration may be a form of configuration information, as used herein. 
     For a third hierarchical part of an SP configuration, a UE may receive slot format indication (SFI) DCI (e.g., in a group common DCI of format 2_0 that is scrambled by an SFI radio network temporary identifier (SFI-RNTI)) indicating a slot format of one or more slots of one or more of the slot pattern(s) to be used by the UE as part of a slot configuration used during TDD communications. Such an indicated slot format may indicate for a downlink, uplink, or flexible use according to (individually) each symbol in the corresponding slot, and may be communicated according to a predetermined table of possible slot formats indicatable by the SFI DCI. Accordingly, for any such slots so configured by SFI DCI, any flexible symbols still present after the configuration of that slot according to the first hierarchical part (and the second hierarchical part, if performed) may be changed to uplink or downlink symbols to match the slot format for that slot from the SFI DCI. Note that this process may not change any symbols previously configured as UL or DL symbols according to the first hierarchical part (or by the second hierarchical part, if such was performed). An SFI DCI may be a form of configuration information, as used herein. 
     Further details regarding SP configuration as described herein can be found in 3GPP TS 38.213 (version 16.6.0, June 2021), Section 11.1, “Slot Configuration,” which is incorporated herein by reference. 
       FIG.  1 A  illustrates a slot configuration  102  used during TDD communications, according to an embodiment. The slot configuration  102  includes the first slot pattern  104 . As illustrated, the first slot pattern  104  is that of three downlink slots followed by a special slot followed by an uplink slot. The first slot pattern  104  may have been configured according to a first hierarchical part of an SP configuration (e.g., as received in SIB and/or RRC configuration information from the base station). For example, the first slot pattern  104  may be arranged according to a common configuration for the first slot pattern  104  (e.g., as found in a ‘tdd-UL-DL-ConfigurationCommon’ information element). 
     A slot indication, as described herein, may be an indication in information (e.g., configuration information and/or DCI) that specifies a slot format for a slot of, for example, a slot configuration. Accordingly, it may be said that the slot configuration  102  is made up of slots that correspond to slot indications in the common configuration (as such slot indications are reflected in the first slot pattern  104  according to the common configuration). For example, the slot configuration  102  may be made up of the DL slot  106  and the UL slot  108 , each corresponding to UL slot indications of the common configuration (and according to the first slot pattern  104  of the common configuration), along with other slots, as illustrated. 
     The length of the first slot pattern  104  (in time) may be provided in configuration information for the first slot pattern  104  (e.g., as a ‘dl-UL-TransmissionPeriodicity’ parameter), and may be denoted herein as P. As illustrated, in the embodiment of  FIG.  1 A  and  FIG.  1 B , because the slot configuration  102  is coextensive with the first slot pattern  104 , the length of the slot configuration  102  may also be understood by the UE to be P. 
       FIG.  1 B  illustrates a use of the slot configuration  102  to perform TDD communications  110  that use a UL gap, according to an embodiment. As illustrated, the TDD communications  110  proceed according to repetitions of the slot configuration  102  (which is made up of the first slot pattern  104 ). The repetitions of the slot configuration  102  illustrated in the TDD communications  110  may, in some embodiments, be initialized such that the first symbol of every 20/P repetitions of the slot configuration  102  is a first symbol in an even numbered radio frame. 
     The UE may determine a UL gap periodicity. For example, in some cases, the base station may signal the UL gap periodicity to the UE, allowing the UE to make this determination directly based on the signaled value. The signaled value may be an amount of time corresponding to a number of repetitions (denoted herein as N) of the slot configuration of length P in a single UL gap periodicity. In other words, the base station may signal a value for the UL gap periodicity (that is equal to NP) that the UE accordingly determines directly. In other cases, the UE may determine the UL gap periodicity based on its understanding of the length of the slot configuration  102 . In such cases, the base station may signal to the UE the number repetitions of slot configuration in a single UL gap periodicity (e.g., signal to the UE the value of N), and the UE may then calculate the UL gap periodicity using the formula NP. 
     In either case, the UL gap periodicity may be equal to NP. In the embodiment of  FIG.  1 A  and  FIG.  1 B  the periods  116   a ,  116   b , and  116   c  (illustrated in  FIG.  1 B ) of the UL gap periodicity are of length NP. 
     Further, the UE may be able to identify the location(s) of one (or more) of the periods  116   a ,  116   b  and  116   c  within the TDD communications  110 . These locations may be UE-specific (e.g., a first UE may be configured to use different locations for the periods within TDD communications  110  than a second UE also using the TDD communication  110 ). The base station may control these locations for each UE by providing the UE with an offset value. This behavior may allow the base station to co-ordinate multiple UE using the TDD communications  110  (for instance, so that one UE may perform regular UL during a time that a second UE is performing UE calibration). This offset value corresponds to the location where the UE should consider its periods of the TDD communications  110  to begin. Then, once the UE has determined a UL gap periodicity (as described previously), the UE can locate the starting subframe of one of the periods  116   a ,  116   b , and  116   c  using the formula
 
(SFN×10+SubFN)mod(UL gapperiodieity)=Offset,
 
where UL gapperiodicity=NP (as described above), SFN is a system frame number, and SubFN is the subframe within that system frame.
 
     The UE may further determine the value of a UL gap length. In some embodiments, the UL gap length may be determined according to an indication of the UL gap length made by the base station to the UE. 
     A UL gap length may, in some embodiments herein, correspond to a number of semi-persistently configured UL slots of a period of the UL gap periodicity that are to be used for UE calibration purposes. Accordingly, as used herein, reference to semi-persistently configured UL slots of a period of a UL gap periodicity may be understood to refer to a number of UL slots (e.g., up to the UL gap length) of the period that are configured according to an SP configuration for a slot configuration repeated in the period. 
     In the embodiment of  FIG.  1 B , the UE has determined the UL gap length to be equal to four. Accordingly, during each period  116   a ,  116   b , and  116   c  of the UL gap periodicity, four semi-persistently configured UL slots are used for UE calibration purposes according to a UL gap. Note that these have each been denoted ‘G’ (corresponding to the fact that the UE will use each such UL slot as a UL gap for UE calibration) instead of ‘U’ (which might correspond to use of the slot by the UE for regular UL transmission). For example, in  FIG.  1 B , the first semi-persistently configured UL slot  112   a , the second semi-persistently configured UL slot  112   b , the third semi-persistently configured UL slot  112   c , and the fourth semi-persistently configured UL slot  112   d  (denoted ‘G’) within the period  116   b  may be used for UE calibration, while UL slots within the period  116   b  that are not used for UE calibration (such as the UL slot  118 ) remain available for regular UL transmissions. 
     In some cases, the UL gap length may correspond to an initial number of such semi-persistently configuration UL slots of the period. As used herein, reference to initial semi-persistently configured UL slots of a period of the UL gap periodicity may be understood to refer to the initial (e.g., first) number of UL slots of the period (e.g., up to the UL gap length) that are configured according to an SP configuration for a slot configuration repeated in the period. 
       FIG.  1 B  illustrates the use, according to a determination by the UE, of a UL gap according to initial semi-persistently configured UL slots of a period (in part) in relation to the semi-persistently configured UL slots  112   a  through  112   d  of the period  116   b  of the UL gap periodicity. As illustrated, each of the first semi-persistently configured UL slot  112   a , the second semi-persistently configured UL slot  112   b , the third semi-persistently configured UL slot  112   c , and the fourth semi-persistently configured UL slot  112   d  is an initial semi-persistently configured UL slot of the period  116   b.    
     Further, as can be seen, each of the first semi-persistently configured UL slot  112   a , the second semi-persistently configured UL slot  112   b , the third semi-persistently configured UL slot  112   c , and the fourth semi-persistently configured UL slot  112   d  corresponds to the first slot pattern  104 , in that these slots are indicated for UL according to the use of the first slot pattern  104  within the repetitions of the slot configuration  102  in the TDD communications  110 . Further, because the first slot pattern  104  is arranged according to a common configuration, each of the first semi-persistently configured UL slot  112   a , the second semi-persistently configured UL slot  112   b , the third semi-persistently configured UL slot  112   c , and the fourth semi-persistently configured UL slot  112   d  may be understood to correspond to UL slot indications from the common configuration used to generate the first slot pattern  104 , according to an SP configuration. 
     Finally, each period of a UL gap periodicity of the TDD communications  110  may use the same arrangement (according to a use of initial semi-persistently configured UL slots for an UL gap) as the period  116   b . This is illustrated in reference to the UL slot  120  of the period  116   a  (which is a UL slot for regular UL transmission, presuming that four semi-persistently configured UL slots for UE calibration occurred previously during the period  116   a ), and the fifth semi-persistently configured UL slot  114   a  (which may be a first of four initial semi-persistently configured UL slots of the period  116   c  to be used for UE calibration instead of for regular UL transmission). 
       FIG.  2 A  illustrates a slot configuration  202  used during TDD communications, according to an embodiment. The slot configuration  202  includes the first slot pattern  204  and the second slot pattern  206 . As illustrated, the first slot pattern  204  is that of three downlink slots followed by a special slot followed by an uplink slot, and the second slot pattern  206  is that of two downlink slots followed by two special slots followed by an uplink slot. The first slot pattern  204  and the second slot pattern  206  may have been configured according to a first hierarchical part of an SP configuration (e.g., as received in RRC configuration information from the base station). For example, each of the first slot pattern  204  and the second slot pattern  206  may be arranged according to a common configuration for that respective slot pattern in a ‘tdd-UL-DL-ConfigurationCommon’ information element. 
     Further, it may be said that the slot configuration  202  is made up of slots that correspond to slot indications in the common configuration (as such slot indications are reflected in the first slot pattern  204  and the second slot pattern  206  according to the common configuration). For example, the slot configuration  202  may be made of the first downlink DL slot  208  corresponding to a DL slot indication the common configuration (and according to the first slot pattern  204  of the common configuration) and the special slot  210  corresponding to a special slot indication of the common configuration (and according to the second slot pattern  206  of the common configuration), along with other slots, as illustrated. 
     The length of the first slot pattern  204  (in time) may be provided in configuration information for the first slot pattern  204  (e.g., as a ‘dl-UL-TransmissionPeriodicity’ parameter), and may be denoted herein as P. Further, the length of the second slot pattern  206  (in time) may be provided in configuration information for the second slot pattern  206  (e.g., as a ‘dl-UL-TransmissionPeriodicity’ parameter), and may be denoted herein as P 2 . As illustrated, in the embodiment of  FIG.  2 A  and  FIG.  2 B , because the slot configuration  202  is coextensive with the combination of the first slot pattern  204  with the second slot pattern  206 , the length of the slot configuration  102  may accordingly be understood by the UE to be the sum of the length of the first slot pattern  204  and the length of the second slot pattern  206 , or P+P 2 . 
       FIG.  2 B  illustrates a use of the slot configuration  202  to perform TDD communications  212  that use a UL gap, according to an embodiment. As illustrated, the TDD communications  212  proceed according to repetitions of the slot configuration  202  (which is made up of the first slot pattern  204  and the second slot pattern  206 ). The repetitions of the slot configuration  202  illustrated in the TDD communications  212  may, in some embodiments, be initialized such that the first symbol of every 20/(P+P 2 ) repetitions of the slot configuration  202  is a first symbol in an even numbered radio frame. 
     The UE may determine a UL gap periodicity. For example, in some cases, the base station may signal the UL gap periodicity to the UE, allowing the UE to make this determination directly based on the signaled value. The signaled value may be the amount of time corresponding to a number of repetitions (denoted as N) of the slot configuration of length P+P 2  in a single UL gap periodicity. In other words, the base station may signal a value for the UL gap periodicity (that is equal to N(P+P 2 )) to the UE directly. In other cases, the UE may determine the UL gap periodicity based on its understanding of the length of the slot configuration  102 . In such cases, the base station may signal to the UE the number repetitions of slot configuration in a single UL gap periodicity (e.g., signal to the UE the value of N), and the UE may then calculate the UL gap periodicity using the formula N(P+P 2 ). 
     In either case, the UL gap periodicity may be equal to N(P+P 2 ). In the embodiment of  FIG.  2 A  and  FIG.  2 B  the periods  218   a ,  218   b , and  218   c  (illustrated in  FIG.  2 B ) of the UL gap periodicity are of length N(P+P 2 ). 
     Further, the UE may be able to identify the location(s) of one (or more) of the periods  218   a ,  218   b  and  218   c  within the TDD communications  212  using an offset value provided to the UE by the base station, as described above. In such cases, once the UE has also determined the UL gap periodicity, it can locate the starting subframe of one of the periods  116   a ,  116   b , and  116   c  using the formula
 
(SFN×10+SubFN)mod(UL gap periodicity)=Offset,
 
where UL gap periodicity=N(P+P 2 ) (as described above), SPIN is a system frame number, and SubFN is the subframe within that system frame.
 
     The UE may further determine the value of a UL gap length (e.g., according to an indication of the UL gap length made by the base station to the UE). In the embodiment of  FIG.  2 B , the UE has determined the UL gap length to be equal to two. Accordingly, during each period  218   a ,  218   b , and  218   c  of the UL gap periodicity, two semi-persistently configured UL slots are used for UE calibration purposes according to a UL gap. Note that these have been denoted ‘G’ (corresponding to the fact that the UE will use each such UL slot as a UL gap for UE calibration) instead of ‘U’ (which might correspond to use of the slot by the UE for regular UL transmission). For example, in  FIG.  2 B , the first semi-persistently configured UL slot  214   a  and the second semi-persistently configured UL slot  214   b  (denoted ‘G’) may be used for UE calibration, while UL slots within the period  116   b  that are not used for UE calibration (such as the UL slots  220 ) remain available for regular UL transmissions. 
       FIG.  2 B  illustrates the use, according to a determination by the UE, of a UL gap according to initial semi-persistently configured UL slot of a period (in part) in relation to the two semi-persistently configured UL slots  214   a  and  214   b  of the period  218   b  of the UL gap periodicity. As illustrated, each of the first semi-persistently configured UL slot  214   a  and the second semi-persistently configured UL slot  214   b  is an initial semi-persistently configured UL slot of the period  218   b.    
     Further, as can be seen, the first semi-persistently configured UL slot  214   a  corresponds to the first slot pattern  204 , in that this slot is indicated for UL according to the use of the first slot pattern  204  within the repetitions of the slot configuration  202  in the TDD communications  212 . Further, because the first slot pattern  204  is arranged according to a common configuration, the first semi-persistently configured UL slot  214   a  may be understood to correspond to a UL slot indication from the common configuration used to generate the first slot pattern  204  according to an SP configuration. 
     Additionally, as can be seen, the second semi-persistently configured UL slot  214   b  corresponds to the second slot pattern  206 , in that this slot is indicated for UL according to the use of the second slot pattern  206  within the repetitions of the slot configuration  202  in the TDD communications  212 . Further, because the second slot pattern  206  is arranged according to a common configuration, the second semi-persistently configured UL slot  214   b  may be understood to correspond to a UL slot indication from the common configuration used to generate the second slot pattern  206  according to an SP configuration. 
     Finally, each period of a UL gap periodicity may use the same arrangement (according to a use of initial semi-persistently configured UL slots of period for an UL gap) as the period  218   b . This is illustrated in reference to the UL slots  222  of the period  218   a  (which are UL slots for regular UL transmission, presuming that two semi-persistently configured UL slots for UE calibration occurred previously during the period  218   a ), and the third semi-persistently configured UL slot  216   a  and the fourth semi-persistently configured UL slot  216   b  (which may be the two initial semi-persistently configured UL slots of the period  218   c  to be used for UE calibration instead of for regular UL transmission). 
       FIG.  3 A  illustrates a slot configuration  302  used during TDD communications, according to an embodiment. The slot configuration  302  includes the first slot pattern  304 . As illustrated, the first slot pattern  304  is that of four downlink slots followed by a special slot followed by a flexible slot followed by a special slot followed by three uplink slots. The first slot pattern  304  may have been configured according to a first hierarchical part and a second hierarchical part of an SP configuration (e.g., as received in SIB and/or RRC configuration information from the base station), according to configurations provided corresponding to the first and second hierarchical parts. For example, the common configuration  306  may be arranged according to a ‘tdd-UL-DL-ConfigurationCommon’ information element. The dedicated configuration  308  may be arranged according to a ‘tdd-UL-DL-ConfigurationDedicated’ information element corresponding to the first slot pattern  304 . As described above, the dedicated configuration  308  indicates any slots/symbols that should be flexible slots/symbols in the first slot pattern  304  beyond those provided for in the common configuration  306 . Accordingly, the first slot pattern  304  is arrived at  310  through the use of the dedicated configuration  308  to further specify flexible symbols/slots of the common configuration  306 , in the manner illustrated. 
     It may be said that the slot configuration  302  is made up of slots that each correspond to slot indications in one of the common configuration  306  and the dedicated configuration  308 . For example, the slot configuration  302  may be made of the special slot  312  and the UL slot  314  (along with other slots, as illustrated). The special slot  312  corresponds to a special slot indication  316  of the dedicated configuration  308  for that same position (as indicated by an arrow up from the special slot  312  that points at that special slot indication of the dedicated configuration  308 ), while the UL slot  314  corresponds to a UL slot indication  318  in the common configuration  306  found in that same position (as indicated by an arrow up from the UL slot  314  to that points at that UL slot indication of the common configuration  306 ). 
     The length of the first slot pattern  304  (in time) may be provided in configuration information for the first slot pattern  304  (e.g., as a ‘dl-UL-TransmissionPeriodicity’ parameter), and may be denoted herein as P. As illustrated, in the embodiment of  FIG.  3 A  and  FIG.  3 B , because the slot configuration  302  is coextensive with the first slot pattern  304 , the length of the slot configuration  302  may also be understood by the UE to be P. 
       FIG.  3 B  illustrates a use of the slot configuration  302  to perform TDD communications  320  that use a UL gap, according to an embodiment. As illustrated, the TDD communications  320  proceed according to repetitions of the slot configuration  302  (which is made up of the first slot pattern  304 ). 
     The embodiment of  FIG.  3 A  and  FIG.  3 B  uses a slot configuration  302  that is coextensive with a single slot pattern (the first slot pattern  304 ). Accordingly, the embodiment of  FIG.  3 A  and  FIG.  3 B  may be analogous in many ways to the embodiment of  FIG.  1 A  and  FIG.  1 B , which shares the same characteristic. Accordingly, it should be understood, for example, that the repetitions of the slot configuration  302  illustrated in the TDD communications  320  may be initialized such that the first symbol of every 20/P repetitions of the slot configuration  302  is a first symbol in an even numbered radio frame, that the UE may determine a UL gap periodicity that is a multiple of the first slot pattern  304  (denoted herein as NP), and that the UE may be able to identify the location(s) of one (or more) of the periods  326   a ,  326   b , and/or  326   c  of the UL gap periodicity by using a received offset and the formula
 
(SFN×10+SubFN)mod(UL gap periodicity)=Offset
 
(where UL gap periodicity=NP).
 
     The UE may also determine a UL gap length (e.g., according to an indication of the UL gap length made by the base station to the UE). In the embodiment of  FIG.  3 B , the UE has determined the UL gap length to be equal to two. Accordingly, during each period  326   a ,  326   b , and  326   c  of the UL gap periodicity, two semi-persistently configured UL slots are used for UE calibration purposes according to a UL gap. Note that these have been denoted ‘G’ (corresponding to the fact that the UE will use each such UL slot as a UL gap for UE calibration) instead of ‘U’ (which might correspond to use of the slot by the UE for regular UL transmission). For example, in  FIG.  3 B , the first semi-persistently configured UL slot  322   a  and the second semi-persistently configured UL slot  322   b  (denoted ‘G’) may be used for UE calibration, while UL slots within the period  326   b  that are not used for UE calibration (such as the UL slots  328  and the UL slot  334 ) remain available for regular UL transmissions. 
       FIG.  3 B  illustrates the use, according to a determination by the UE, of a UL gap according to initial semi-persistently configured UL slots of a period (in part) in relation to the two semi-persistently configured UL slots  322   a  and  322   b  of the period  326   b  of the UL gap periodicity. As illustrated, each of the first semi-persistently configured UL slot  322   a  and the second semi-persistently configured UL slot  322   b  is an initial semi-persistently configured UL slot of the period  326   b.    
     Further, as can be seen, each of the first semi-persistently configured UL slot  322   a  and the second semi-persistently configured UL slot  322   b  corresponds to the first slot pattern  304 , in that these slots are indicated for UL according to the use of the first slot pattern  304  within the repetitions of the slot configuration  302  in the TDD communications  320 . It can also be seen (with reference back to the dedicated configuration  308   FIG.  3 A ) that each of the first semi-persistently configured UL slot  322   a  and the second semi-persistently configured UL slot  322   b  correspond to UL slot indications from the dedicated configuration  308  that was used to generate the first slot pattern  304  according to an SP configuration. 
     Alternatively to the embodiment illustrated in  FIG.  3 A  and  FIG.  3 B , if, for example, the dedicated configuration  308  had only contained a single UL indication (e.g., in its last specified symbol), the slot configuration  302  would have ultimately ended with only two UL symbols (instead of three). In such a case, the first semi-persistently configured UL slot  322   a  would instead be a flexible slot, and the UL slot  334  would have been used as the second (of the two) initial semi-persistently configured UL slots (which would have corresponded to the illustrated corresponding UL indication in the common configuration  306 , instead of any UL indication in the dedicated configuration  308 ). 
     Returning to the embodiment of  FIG.  3 A  and  FIG.  3 B , each period of a UL gap periodicity may use the same arrangement (according to a use of initial semi-persistently configured UL slots of period for an UL gap) as the period  326   b . This is illustrated in reference to the UL slots  332  of the period  326   a  (which are UL slots for regular UL transmission, presuming that two semi-persistently configured UL slots for UE calibration occurred previously during the period  326   a ), and the third semi-persistently configured UL slot  324   a  and the fourth semi-persistently configured UL slot  324   b  (which may be the two initial semi-persistently configured UL slots of the period  326   c  to be used for UE calibration instead of for regular UL transmission) and the UL slot  330  (which is a UL slot of period  326   c  for regular UL transmission). 
     Persons of ordinary skill in the art, with the benefit of this disclosure, would understand that the use of slot patterns configured according to a first hierarchical part and a second hierarchical part of an SP configuration (an example of which has been presented in relation to the embodiment of  FIG.  3 A  and  FIG.  3 B ) could be extended into embodiments involving more than one configured slot pattern (analogously to content presented in relation to the embodiments of  FIG.  2 A  and  FIG.  2 B  herein). For example, it may be that a slot configuration corresponds to first slot pattern of length P and second slot pattern of length P 2 , giving the slot configuration a length of P+P 2 , and that one (or both) of such slot patterns is configured according to a first hierarchical part and a second hierarchical part of an SP configuration. In such a case, repetitions of such a slot configuration may be initialized such that the first symbol of every 20/(P+P 2 ) repetitions of the slot configuration is a first symbol in an even numbered radio frame, that the UE may determine a UL gap periodicity that is a multiple of the first slot pattern and the second slot pattern (denoted as N(P+P 2 )) and that accordingly comprises repetitions of the slot configuration, and that the UE may be able to identify the location(s) of one (or more) of those periods of the UL gap periodicity by using a received offset and the formula
 
(SFN×10+SubFN)mod(UL gap periodicity)=Offset,
 
but with UL gap periodicity=N(P+P 2 ).
 
     Then, as described herein, initial semi-persistently configured UL slots of such a period may be used for UE calibration. The number of these semi-persistently configured UL slots may be equal to the UL gap length. Further, these semi-persistently configured UL slots may correspond to slots indicated for UL in one or more of the first slot pattern and the second slot pattern. These semi-persistently configured UL slots may accordingly each also be understood to correspond to a UL slot indication in a common configuration for the respective slot pattern, or optionally in a dedicated configuration for the respective slot pattern (if such was provided in relation to the slot pattern), as appropriate, according to an SP configuration. 
       FIG.  4 A  illustrates a slot configuration  402  used during TDD communications, according to an embodiment. The slot configuration  402  includes the first slot pattern  404 . As illustrated, the first slot pattern  404  is that of three downlink slots followed by a special slot followed by two flexible slots followed by four uplink slots. 
     The first slot pattern  404  may have been determined according to the use of a SIB/RRC slot configuration  406  in combination with an SFI DCI  408 . The SIB/RRC slot configuration  406  may have been determined according to a first hierarchical part (and optionally by a second hierarchical part) of an SP configuration (e.g., as these may be received in SIB and/or RRC configuration information from the base station), according common (and optionally dedicated) configurations provided corresponding to the first (and optionally second hierarchical parts). For example, the SIB/RRC slot configuration  406  may be arranged according to a ‘tdd-UL-DL-ConfigurationCommon’ information element (and optionally a ‘tdd-UL-DL-ConfigurationDedicated’ information element) corresponding to the first slot pattern  404 . 
     Then, the UE may receive the SFI DCI  408 . In such a case, the first slot pattern  404  of the slot configuration  402  is arrived at  410  through the use of the SFI DCI  408  to further specify flexible symbols/slots of the SIB/RRC slot configuration  406 , in the manner illustrated. For example, the SFI DCI  408  may make the UL slot indication  416  corresponding to the location of the second special slot, as configured by the SIB/RRC slot configuration  406 , indicating that the UL slot  412  of the slot configuration  402  should instead have a slot format of all uplink symbols. This may be according to a SlotFormatCombination element in the DCI that is configured to all UL symbols. Making the change to that slot as indicated by the SFI DCI  408  results in the first slot pattern  404 . 
     It may be said that the slot configuration  402  is made up of slots that each correspond to a slot of the SIB/RRC slot configuration  406  or a slot indication in the SFI DCI  408 . For example, the slot configuration  402  may be made of the UL slot  412  and the UL slot  414  (along with other slots, as illustrated). The UL slot  412  corresponds to a UL slot indication of the SFI DCI  408  for that same position (as indicated by an arrow up from the UL slot indication  416  that points to the UL slot indication  416  of the SFI DCI  408 ), while the UL slot  414  corresponds to a UL slot of the SIB/RRC slot configuration  406  found in that same position (as indicated by an arrow up from the UL slot  414  that points to the UL slot  418  of the SIB/RRC slot configuration  406 ). 
     The length of the first slot pattern  404  (in time) may be provided in configuration information for the first slot pattern  404  (e.g., as a ‘dl-UL-TransmissionPeriodicity’ parameter), and may be denoted herein as P. As illustrated, in the embodiment of  FIG.  4 A  and  FIG.  4 B , because the slot configuration  402  is coextensive with the first slot pattern  404 , the length of the slot configuration  402  may also be understood by the UE to be P. 
       FIG.  4 B  illustrates a use of the slot configuration  402  to perform TDD communications  420  that use a UL gap, according to an embodiment. As illustrated, the TDD communications  420  proceed according to repetitions of the slot configuration  402  (which is made up of the first slot pattern  404 ). 
     The embodiment of  FIG.  4 A  and  FIG.  4 B  uses a slot configuration  402  that is coextensive with a single slot pattern (the first slot pattern  404 ). Accordingly, the embodiment of  FIG.  4 A  and  FIG.  4 B  may be analogous in many ways to the embodiment of  FIG.  1 A  and  FIG.  1 B , which shares the same characteristic. Accordingly, it should be understood, for example, that the repetitions of the slot configuration  402  illustrated in the TDD communications  420  may be initialized such that the first symbol of every 20/P repetitions of the slot configuration  402  is a first symbol in an even numbered radio frame, that the UE may determine a UL gap periodicity that is a multiple of the first slot pattern  404  (denoted as NP), and that the UE may be able to identify the location(s) of one (or more) of the periods  426   a ,  426   b , and/or  426   c  of the UL gap periodicity by using a received offset and the formula
 
(SFN×10+SubFN)mod(UL gap periodicity)=Offset
 
(where UL gap periodicity=NP)
 
     The UE may also determine a UL gap length (e.g., according to an indication of the UL gap length made by the base station to the UE). In the embodiment of  FIG.  4 B , the UE has determined the UL gap length to be equal to three. Accordingly, during each period  426   a ,  426   b , and  426   c  of the UL gap periodicity, three UL slots are used for UE calibration purposes according to a UL gap. Note that these have been denoted ‘G’ (corresponding to the fact that the UE will use each such UL slot as a UL gap for UE calibration) instead of ‘U’ (which might correspond to use of the slot by the UE for regular UL transmission). For example, in  FIG.  4 B , the first semi-persistently configured UL slot  422   a , the second semi-persistently configured UL slot  422   b , and the third semi-persistently configured UL slot  422   c  (denoted ‘G’) may be used for UE calibration, while UL slots within the period  426   b  that are not used for UE calibration (such as the UL slots  428 ), denoted ‘U’, remain available for regular UL transmissions 
       FIG.  4 B  illustrates the use, according to a determination by the UE, of a UL gap according to initial semi-persistently configured UL slots of a period (in part) in relation to the three semi-persistently configured UL slots  422   a ,  422   b , and  422   c  of the period  426   b  of the UL gap periodicity. As illustrated, each of the first semi-persistently configured UL slot  422   a , the second semi-persistently configured UL slot  422   b , and the third semi-persistently configured UL slot  422   c  is an initial semi-persistently configured UL slot of the period  426   b.    
     Further, as can be seen, each of the first semi-persistently configured UL slot  422   a , the second semi-persistently configured UL slot  422   b , and the third semi-persistently configured UL slot  422   c  corresponds to the first slot pattern  404 , in that these slots are indicated for UL according to the use of the first slot pattern  404  within the repetitions of the slot configuration  402  in the TDD communications  420 , according to an SP configuration. It can also be seen (with reference back to the SFI DCI  408  of  FIG.  4 A ) that the first semi-persistently configured UL slot  422   a  corresponds to the UL slot indication from the SFI DCI  408  that was used to generate the first slot pattern  404 , according to an SP configuration, while the second semi-persistently configured UL slot  422   b  and the third semi-persistently configured UL slot  422   c  correspond instead to the SIB/RRC slot configuration  406  (e.g., each correspond to one of a common configuration and a (possible) dedicated configuration underlying the SIB/RRC slot configuration  406 ). 
     Finally, each period of a UL gap periodicity may use the same arrangement (according to a use of initial semi-persistently configured UL slots of period for an UL gap) as the period  426   b . This is illustrated in reference to the UL slots  432  of the period  426   a  (which are UL slots for regular UL transmission, presuming that semi-persistently configured UL slots for UE calibration occurred previously during the period  426   a ), the fourth semi-persistently configured UL slot  424   a , the fifth semi-persistently configured UL slot  424   b , and the sixth semi-persistently configured UL slot  424   c  (which may be the three initial semi-persistently configured UL slots of the period  426   c  to be used for UE calibration instead of for regular UL transmission) and the UL slot  430  (which is a UL slot of period  426   c  for regular UL transmission). 
     Persons of ordinary skill in the art, with the benefit of this disclosure, would understand that the use slot patterns configured according to a first hierarchical part, optionally a second hierarchical part, and a third hierarchical part of an SP configuration (an example of which has been presented in relation to the embodiment of  FIG.  4 A  and  FIG.  4 B ) could be extended into embodiments involving more than one configured slot pattern (analogously to content presented in relation to the embodiments of  FIG.  2 A  and  FIG.  2 B  herein). For example, it may be that a slot configuration corresponds to first slot pattern of length P and second slot pattern of length P 2 , giving the slot configuration a length of P+P 2 , and that one (or both) of such slot patterns is configured according to a first hierarchical part, optionally a second hierarchical part, and a third hierarchical part of an SP configuration. In such a case, repetitions of such a slot configuration may be initialized such that the first symbol of every 20/(P+P 2 ) repetitions of the slot configuration is a first symbol in an even numbered radio frame, that the UE may determine a UL gap periodicity that is a multiple of the first slot pattern and the second slot pattern (denoted as N(P+P 2 )) and that accordingly comprises repetitions of the slot configuration, and that the UE may be able to identify the location(s) of one (or more) of those periods of the UL gap periodicity by using a received offset and the formula
 
(SFN×10+SubFN)mod(UL gap periodicity)=Offset,
 
but with UL gap periodicity=N(P+P 2 ).
 
     Then, as described herein, initial semi-persistently configured UL slots of such a period may be used for UE calibration. The number of these semi-persistently configured UL slots may be equal to the UL gap length. Further, these semi-persistently configured UL slots may correspond to slots indicated for UL in one or more of the first slot pattern and the second slot pattern. Each of these semi-persistently configured UL slot may correspond to one of a UL slot indication in a common configuration for the respective slot pattern, in a dedicated configuration for the respective slot pattern (if such was provided in relation to the slot pattern), or in an SFI DCI (if such was provided in relation to the slot pattern), according to an SP configuration. 
       FIG.  5 A  illustrates a slot configuration  502  used during TDD communications, according to an embodiment. The slot configuration  502  includes the first slot pattern  504 . As illustrated, the first slot pattern  504  is that of one downlink slot followed by a special slot followed by three uplink slots. The first slot pattern  504  may have been configured according to, for example, an SP configuration method, as described above. 
     The length of the first slot pattern  504  (in time) may be provided in configuration information for the first slot pattern  504  (e.g., as a ‘dl-UL-TransmissionPeriodicity’ parameter), and may be denoted herein as P. As illustrated, in the embodiment of  FIG.  5 A  through  FIG.  5 D , because the slot configuration  502  is coextensive with the first slot pattern  504 , the length of the slot configuration  502  may also be understood by the UE to be P. 
     As will be described herein, each of  FIG.  5 B  through  FIG.  5 D  may use the elements illustrated in  FIG.  5 A . Accordingly, the embodiments of  FIG.  5 B ,  FIG.  5 C , and  FIG.  5 D  each use the slot configuration  502  that is coextensive with a single slot pattern (the first slot pattern  504 ). Accordingly, the embodiment of  FIG.  5 A ,  FIG.  5 B , and  FIG.  5 C  may each be analogous in many ways to the embodiment of  FIG.  1 A  and  FIG.  1 B , which shares the same characteristic. Accordingly, it should be understood, for example, that the repetitions of the slot configuration  502  illustrated in the respective TDD communications of these figures may be initialized such that the first symbol of every 20/P repetitions of the slot configuration  502  is a first symbol in an even numbered radio frame, that the UE may determine a UL gap periodicity that is a multiple of the first slot pattern  504  (denoted herein as NP), and that the UE may be able to identify the location(s) of one (or more) of the periods of the UL gap periodicities shown in these figures by using a received offset and the formula
 
(SFN×10+SubFN)mod(UL gap periodicity)=Offset
 
(where UL gap periodicity=NP).
 
     The UE may also determine a UL gap length (e.g., according to an indication of the UL gap length made by the base station to the UE). In the embodiments of  FIG.  5 B , FIG. and  FIG.  5 D , the UE has determined the UL gap length to be equal to four. Accordingly, during each period of a UL gap periodicity, four semi-persistently configured UL slots are used for UE calibration purposes. 
     However, in the embodiments of  FIG.  5 B ,  FIG.  5 C , and  FIG.  5 D , the UL slots used for a UL gap are not (necessarily) the initial semi-persistently configured slots of the corresponding period of the UL gap periodicity, as in  FIG.  1 B ,  FIG.  2 B ,  FIG.  3 B , and  FIG.  4 B  (though, as can be seen, there may be overlap). Instead, in the embodiments of  FIG.  5 B ,  FIG.  5 C , and  FIG.  5 D , the UE uses one or more sets of initial semi-persistently configured UL slots of individual repetitions of a slot configuration used by a period of the UL gap periodicity. As used herein, reference to initial semi-persistently configured UL slots of a repetition of a slot configuration used by a period of the UL gap periodicity may be understood to refer to the initial (e.g., first) number of UL slots of that repetition of the slot configuration (as configured according to an SP configuration) as used by a period of a UL gap periodicity. Accordingly, in each of  FIG.  5 B ,  FIG.  5 C , and  FIG.  5 D , for the UL gap, A UE uses (up to) a number in of initial semi-persistently configured UL slots of a repetition of the slot configuration of a period of the UL gap periodicity, and, if necessary, repeats this use in subsequent repetition(s) of the slot configuration within that period, until the total number of UL slots so used is equal to the UL gap length. This behavior may represent a “discontinuous UL slot use” for UE calibration. Accordingly,  FIG.  5 B  may be understood to be one possible embodiment according to discontinuous UL slot use using elements from  FIG.  5 A ,  FIG.  5 C  may be understood to be a second possible embodiment according to discontinuous UL slot use using elements from  FIG.  5 A , and  FIG.  5 D  may be understood to be a third possible embodiment according to discontinuous UL slot use using elements from  FIG.  5 A . 
       FIG.  5 B  illustrates a use of the slot configuration  502  to perform TDD communications  510  that use a UL gap, according to an embodiment. As illustrated, the TDD communications  510  proceed according to repetitions of the slot configuration  502  (which is made up of the first slot pattern  504 ). 
     The use of a number m of initial semi-persistently configured UL slots of repetitions of the slot configuration in a period of a UL gap periodicity is illustrated in  FIG.  5 B  (in part) in relation to the four semi-persistently configured UL slots  512   a ,  512   b ,  512   c  and  512   d  of the period  516   b  corresponding to the UL gap periodicity, where m=1. Note that the first semi-persistently configured UL slot  512   a , the second semi-persistently configured UL slot  512   b , the third semi-persistently configured UL slot  512   c , and the fourth semi-persistently configured UL slot  512   d  have each been denoted ‘G’ (corresponding to the fact that the UE will use each such UL slot as a UL gap for UE calibration) instead of ‘U’ (which might correspond to use of the slot by the UE for regular UL transmission). Further, as shown, UL slots within the period  516   b  that are not these semi-persistently configured UL slots (such as the UL slots  518 ), denoted ‘U’, remain available for regular UL transmissions. 
     As can be seen, each of the first semi-persistently configured UL slot  512   a , the second semi-persistently configured UL slot  512   b , the third semi-persistently configured UL slot  512   c , and the fourth semi-persistently configured UL slot  512   d  correspond to the first slot pattern  504 , in that these slots are indicated for UL according to the use of the first slot pattern  504  within the repetitions of the slot configuration  502  in the TDD communications  510 . Further, each of the first semi-persistently configured UL slot  512   a , the second semi-persistently configured UL slot  512   b , the third semi-persistently configured UL slot  512   c , and the fourth semi-persistently configured UL slot  512   d  may correspond to UL slot indications of a common configuration, a dedicated configuration, or an SFI DCI, according to an SP configuration (as described previously). 
     In the embodiment of  FIG.  5 B , the UE uses (up to) one (corresponding to m=1) initial semi-persistent UL slot in each repetition of the slot configuration  502  in the period  516   b  for a UL gap, until the UL gap length of four is reached. For example, as illustrated, the first semi-persistently configured UL slot  512   a  is an initial semi-persistent UL slot of a first repetition of the slot configuration  502  in the period  516   b , the second semi-persistently configured UL slot  512   b  is an initial semi-persistent UL slot of a second repetition of the slot configuration  502  in the period  516   b , the third semi-persistently configured UL slot  512   c  is an initial semi-persistent UL slot of a third repetition of the slot configuration  502  in the period  516   a , and the fourth semi-persistently configured UL slot  512   d  is an initial semi-persistent UL slot of a fourth repetition of the slot configuration  502  in the period  516   b.    
     Finally, each period of a UL gap periodicity in  FIG.  5 B  may use the same arrangement as the period  516   b . This is illustrated in reference to the UL slots  520  of the period  516   a  (which are UL slots for regular UL transmission, presuming that four semi-persistently configured UL slots for UE calibration occurred previously during the period  516   a ), and the fifth semi-persistently configured UL slot  514   a  (which may be an initial semi-persistent UL slot of a repetition of the slot configuration  502  in the period  516   c  to be used for UE calibration instead of for regular UL transmission) and the UL slots  522  (which are UL slots of period  516   c  for regular UL transmission) of the period  516   c.    
       FIG.  5 C  illustrates a use of the slot configuration  502  to perform TDD communications  524  that use a UL gap, according to an embodiment. As illustrated, the TDD communications  524  proceed according to repetitions of the slot configuration  502  (which is made up of the first slot pattern  504 ). 
     The use of a number m of initial semi-persistently configured UL slots of repetitions of the slot configuration in a period of a UL gap periodicity is illustrated in FIG.  5 C (in part) in relation to the four semi-persistently configured UL slots  526   a ,  526   b ,  526   c  and  526   d  of the period  530   b  corresponding to the UL gap periodicity, where m=2. Note that the first semi-persistently configured UL slot  526   a , the second semi-persistently configured UL slot  526   b , the third semi-persistently configured UL slot  526   c , and the fourth semi-persistently configured UL slot  526   d  have each been denoted ‘G’ (corresponding to the fact that the UE will use each such UL slot as a UL gap for UE calibration) instead of ‘U’ (which might correspond to use of the slot by the UE for regular UL transmission). Further, as shown, UL slots within the period  530   b  that are not these semi-persistently configured UL slots (such as the UL slots  532 ), denoted ‘U’, remain available for regular UL transmissions. 
     As can be seen, each of the first semi-persistently configured UL slot  526   a , the second semi-persistently configured UL slot  526   b , the third semi-persistently configured UL slot  526   c , and the fourth semi-persistently configured UL slot  526   d  correspond to the first slot pattern  504 , in that these slots are indicated for UL according to the use of the first slot pattern  504  within the repetitions of the slot configuration  502  in the TDD communications  524 . Further, each of the first semi-persistently configured UL slot  526   a , the second semi-persistently configured UL slot  526   b , the third semi-persistently configured UL slot  526   c , and the fourth semi-persistently configured UL slot  526   d  may correspond to UL slot indications of a common configuration, a dedicated configuration, or an SFI DCI, according to an SP configuration (as described previously). 
     In the embodiment of  FIG.  5 C , the UE uses (up to) two (corresponding to m=2) initial semi-persistent UL slots of each repetition of the slot configuration  502  in the period  530   b  for a UL gap, until the UL gap length of four is reached. For example, as illustrated, the first semi-persistently configured UL slot  526   a  and the second semi-persistently configured UL slot  526   b  are initial semi-persistent UL slots of a first repetition of the slot configuration  502  in the period  530   b , and the third semi-persistently configured UL slot  526   c  and the fourth semi-persistently configured UL slot  526   d  are initial semi-persistent UL slots of a second repetition of the slot configuration  502  in the period  530   b.    
     Finally, each period of the UL gap periodicity may use the same arrangement as the period  530   b . This is illustrated in reference to the UL slots  534  of the period  530   a  (which are UL slots for regular UL transmission, presuming that four semi-persistently configured UL slots for UE calibration occurred previously during the period  530   a ), and the fifth semi-persistently configured UL slot  528   a  and the sixth semi-persistently configured UL slot  528   b  (which may each be an initial semi-persistent UL slot of a first repetition of the slot configuration  502  in the period  530   c  to be used for UE calibration instead of for regular UL transmission) and the UL slot  536  (which is a UL slot of period  530   c  for regular UL transmission) of the period  530   c.    
       FIG.  5 D  illustrates a use of the slot configuration  502  to perform TDD communications  538  that use a UL gap, according to an embodiment. As illustrated, the TDD communications  538  proceed according to repetitions of the slot configuration  502  (which is made up of the first slot pattern  504 ). 
     The use of a number  7   n , of initial semi-persistently configured UL slots of repetitions of the slot configuration in a period of a UL gap periodicity is illustrated in  FIG.  5 D  (in part) in relation to the four semi-persistently configured UL slots  540   a ,  540   b ,  540   c  and  540   d  of the period  544   b  of the corresponding UL gap periodicity, where m=3. Note that the first semi-persistently configured UL slot  540   a , the second semi-persistently configured UL slot  540   b , the third semi-persistently configured UL slot  540   c , and the fourth semi-persistently configured UL slot  540   d  have each been denoted ‘G’ (corresponding to the fact that the UE will use each such UL slot as a UL gap for UE calibration) instead of ‘U’ (which might correspond to use of the slot by the UE for regular UL transmission). Further, as shown, UL slots within the period  530   b  that are not these semi-persistently configured UL slots (such as the UL slots  546 ), denoted ‘U’, remain available for regular UL transmissions. 
     As can be seen, each of the first semi-persistently configured UL slot  540   a , the second semi-persistently configured UL slot  540   b , the third semi-persistently configured UL slot  540   c , and the fourth semi-persistently configured UL slot  540   d  correspond to the first slot pattern  504 , in that these slots are indicated for UL according to the use of the first slot pattern  504  within the repetitions of the slot configuration  502  in the TDD communications  538 . Further, each of the first semi-persistently configured UL slot  540   a , the second semi-persistently configured UL slot  540   b , the third semi-persistently configured UL slot  540   c , and the fourth semi-persistently configured UL slot  540   d  may correspond to UL slot indications of a common configuration, a dedicated configuration, or an SFI DCI, according to an SP configuration (as described previously). 
     In the embodiment of  FIG.  5 D , the UE uses (up to) three (corresponding to m=3) initial semi-persistent UL slots in each repetition of the slot configuration  502  in the period  530   b  for a UL gap, until the UL gap length of four is reached. For example, as illustrated, the first semi-persistently configured UL slot  540   a , the second semi-persistently configured UL slot  540   b , and the third semi-persistently configured UL slot  540   c  are initial semi-persistent UL slots of a first repetition of the slot configuration  502  in the period  544   b , and the fourth semi-persistently configured UL slot  540   d  is an initial semi-persistent UL slot of a second repetition of the slot configuration  502  in the period  544   b  (where only one such slot was used in the second repetition because the UL gap length of 4 is reached with the use of the fourth semi-persistently configured UL slot  540   d ). 
     Finally, each period of the UL gap periodicity may use the same arrangement as the period  544   b . This is illustrated in reference to the UL slots  548  of the period  544   a  (which are UL slots for regular UL transmission, presuming that four semi-persistently configured UL slots for UE calibration occurred previously during the period  544   a ), and the fifth semi-persistently configured UL slot  542   a , the sixth semi-persistently configured UL slot  542   b , and the seventh semi-persistently configured UL slot  542   c  (which may each be an initial semi-persistent UL slot of a first repetition of the slot configuration  502  in the period  544   c  to be used for UE calibration instead of for regular UL transmission) of the period  544   c.    
     In embodiments implementing discontinuous UL slot use (such as those shown in  FIG.  5 B ,  FIG.  5 C , and  FIG.  5 D ), the of a given number m of initial semi-persistent UL slots of applicable repetitions of the slot configuration  502  used by the period  516   b  may be according to a preconfiguration of the UE. In other embodiments, the in may instead be signaled to the UE by the base station. 
     Further, it may be understood that the value of in in such embodiments is to be kept within certain constraints. For example, it may be understood that the value of in should be less than the UL gap length, and that the value of m should be less than or equal to the number of semi-persistently configured UL slots within a period of the UL gap periodicity. 
     Persons of ordinary skill in the art, with the benefit of this disclosure, would understand that the use of slot patterns discussed in  FIG.  5 A  through  FIG.  5 D  could be extended into embodiments involving more than one configured slot pattern (analogously to content presented in relation to the embodiments of  FIG.  2 A  and  FIG.  2 B  herein). For example, it may be that a slot configuration corresponds to first slot pattern of length P and second slot pattern of length P 2 , giving the slot configuration a length of P+P 2  according to an SP configuration. In such a case, repetitions of such a slot configuration may be initialized such that the first symbol of every 20/(P+P 2 ) repetitions of the slot configuration is a first symbol in an even numbered radio frame, that the UE may determine a UL gap periodicity that is a multiple of the first slot pattern and the second slot pattern (denoted as N(P+P 2 )) and that accordingly comprises repetitions of the slot configuration, and that the UE may be able to identify the location(s) of one (or more) of those periods of the UL gap periodicity by using a received offset and the formula
 
(SFN×10+SubFN)mod(UL gap periodicity)=Offset,
 
but with UL gap periodicity=N(P+P 2 ).
 
     Then, as described herein, initial semi-persistently configured UL slots of repetitions of a slot configuration within a period may be used for UE calibration. The number of these semi-persistently configured UL slots may be equal to the UL gap length. Further, these semi-persistently configured UL slots may correspond to slots indicated for UL in one or more of the first slot pattern and the second slot pattern. For example, in cases where a value of m that exceeds the number of semi-persistently configured UL slots of a repetition of a slot configuration that correspond to the first slot pattern, use of (initial) semi-persistent UL slots of that repetition of the slot configuration that correspond to the second slot pattern may be used to reach m. The semi-persistently configured UL slots may also each also be understood to correspond to a UL slot indication in a common configuration for the respective slot pattern, optionally in a dedicated configuration for the respective slot pattern (if such was provided in relation to the slot pattern), or optionally an SFI DCI, as appropriate, according to an SP configuration. 
       FIG.  1 A  through  FIG.  5 B  have described embodiments using slot configurations determined according to SP configuration methods. It is contemplated that one or more slot configurations discussed relative to  FIG.  1 A  through  FIG.  5 B  could also (further) be temporarily changed within TDD communications by the base station via the use of dynamic DCI (e.g., dynamic scheduling DCI). 
     In the case of dynamic DCI, it may be, for example, that in the case that the UE is not configured with/by a SlotFormatIndicator element, and during the flexible symbols configured according to a common configuration (and a dedicated configuration, if used), the UE may a receive physical downlink control channel (PDSCH) or a channel state information reference signal (CSI-RS) in the flexible symbols of a slot if the UE receives a corresponding indication by a DCI format 1_0, DCI format 1_1, or a DCI format 0_1. Alternatively, in such cases, the UE may receive a physical uplink shared channel (PUSCH), a physical uplink control channel (PUCCH), a physical random access channel (PRACH), or a sounding reference signal (SRS) in the flexible symbols of a slot if the UE receives a corresponding indication by a DCI format 0_0, DCI format 0_1, DCI format 1_0, DCI format 1_1, or DCI format 2_3. Such examples of dynamic DCI may operate to dynamically configure a slot for UL use according to a UL slot indication found in the dynamic DCI. 
       FIG.  6 A  illustrates a slot configuration  602  used during TDD communication, according to an embodiment. The slot configuration  602  includes the first slot pattern  604 . As illustrated, the first slot pattern  604  is that of three downlink slots followed by a special slot followed by two flexible slots followed by a special slot followed by three uplink slots. 
     The slot configuration  602  may be determined according to SP configuration methods (e.g., as described in relation to the embodiments disclosed in  FIG.  1 A  through  FIG.  5 B ). For example, the slot configuration  602  may have been determined according to a first hierarchical part, (optionally) by a second hierarchical part of an SP configuration (e.g., as these may be received in SIB and/or RRC configuration information from the base station) and (optionally) a third hierarchical part of an SP configuration (as this may be received in an SFI DCI). 
     Then, the UE may receive the dynamic DCI  606 . In such a case, the modified slot configuration  608  determined through the use of the dynamic DCI  606  to further specify flexible symbols/slots of the slot configuration  602  (or, in other embodiments, to override one or more symbols/slots of the slot configuration  602 ). For example, the dynamic DCI  606  may make the UL slot indication  614  corresponding to the location of the second special slot, as configured by the slot configuration  602 , indicating that the UL slot  610  of the modified slot configuration  608  should instead have a slot format of all uplink symbols. Making the change to that slot as indicated by the dynamic DCI  606  results in the modified slot configuration  608 . 
     It may be said that the slot configuration  602  is made up of slots (in the manner of slot configurations previously described). It may also be said that the modified slot configuration  608  is made up of slots that each correspond to a slot of the slot configuration  602  or a slot indication in the dynamic DCI  606 . For example, the modified slot configuration  608  may be made of the UL slot  610  and the UL slot  612  (along with other slots, as illustrated). As illustrated, the UL slot  610  corresponds to a UL slot indication of the dynamic DCI  606  for that same position (as indicated by an arrow up from the UL slot  610  to the UL slot indication  614  of the dynamic DCI  606 ), while the UL slot  612  corresponds to a UL slot of the slot configuration  602  for that same position (as indicated by an arrow up from the UL slot  612  to the UL slot  616  of the slot configuration  602 ). 
     The length of the first slot pattern  604  (in time) may be provided in configuration information for the first slot pattern  604  (e.g., as a ‘dl-UL-TransmissionPeriodicity’ parameter), and may be denoted herein as P. As illustrated, in the embodiment of  FIG.  6 A  and  FIG.  6 B , because the slot configuration  602  (and thus modified slot configuration  608 ) is coextensive with the first slot pattern  604 , the length of the slot configuration  602  (and the modified slot configuration  608 ) may also be understood by the UE to be P. 
       FIG.  6 B  illustrates a use of the slot configuration  602  to perform TDD communications  618  that use a UL gap, according to an embodiment. As illustrated, the TDD communications  618  proceed according to repetitions of the slot configuration  602  (which is made up of the first slot pattern  604 ). 
     The embodiment of  FIG.  6 A  and  FIG.  6 B  uses a slot configuration  602  that is coextensive with a single slot pattern (the first slot pattern  604 ). Accordingly, the embodiment of  FIG.  6 A  and  FIG.  6 B  may be analogous in many ways to the embodiment of  FIG.  1 A  and  FIG.  1 B , which shares the same characteristic. Accordingly, it should be understood, for example, that the repetitions of the slot configuration  602 /modified slot configuration  608  illustrated in the TDD communications  618  may be initialized such that the first symbol of every 20/P repetitions of the slot configuration  602 /modified slot configuration  608  is a first symbol in an even numbered radio frame, that the UE may determine a UL gap periodicity that is a multiple of the first slot pattern  604  (denoted as NP), and that the UE may be able to identify the location(s) of one (or more) of the periods  624   a ,  624   b , and/or  624   c  of the UL gap periodicity by using a received offset and the formula
 
(SFN×10+SubFN)mod(UL gap periodicity)=Offset
 
(where UL gap periodicity=NP).
 
     The UE may also determine a UL gap length (e.g., according to an indication of the UL gap length made by the base station to the UE). In the embodiment of  FIG.  6 B , the UE has determined the UL gap length to be equal to three. Accordingly, at during each period  624   a ,  624   b , and  624   c  of the UL gap periodicity, three semi-persistently configured UL slots are used for UE calibration purposes according to a UL gap. Note that these have been denoted ‘G’ (corresponding to the fact that the UE will use each such UL slot as a UL gap for UE calibration) instead of ‘U’ (which might correspond to use of the slot by the UE for regular UL transmission). For example, in  FIG.  6 B , the first semi-persistently configured UL slot  620   a , the second semi-persistently configured UL slot  620   b , and the third semi-persistently configured UL slot  620   c  (denoted ‘G’) may be used for UE calibration, while UL slots within the period  624   b  that are not used for UE calibration (such as the UL slot  626  and the UL slots  628 ), denoted ‘U’, remain available for regular UL transmissions. 
       FIG.  6 B  illustrates the use of a UL gap according to semi-persistently configured UL slots of a period (in part) in relation to the three initial semi-persistently configured UL slots  620   a ,  620   b , and  620   c  of the period  624   b  of the UL gap periodicity. It can be seen (with reference back to the SFI DCI  408  of  FIG.  4 A ) that no initial semi-persistently configured UL slot  620   a ,  620   b , and  620   c  of the period  624   b  corresponds to the UL slot indication from the dynamic DCI  606  that was used to generate the modified slot configuration  608  (e.g., semi-persistently configured UL slots  620   a ,  620   b , and  620   c  of the  624   b  do not include a UL slot corresponding to the UL slot indication from the dynamic DCI  606 ). Instead, each of the first semi-persistently configured UL slot  620   a , second semi-persistently configured UL slot  620   b , and third semi-persistently configured UL slot  620   c  corresponds to a UL slot provided according to the (original) slot configuration  602  (generated according to SP configuration methods). 
     Further, as can be seen, each of the first semi-persistently configured UL slot  620   a , the second semi-persistently configured UL slot  620   b , and the third semi-persistently configured UL slot  620   c  corresponds to the first slot pattern  604 , in that these slots are indicated for UL according to the use of the first slot pattern  604  within the repetitions of the slot configuration  602  in the TDD communications  618 . 
     By disregarding UL slot indications from dynamic DCI  606  in this manner, unfavorable network impacts that could otherwise occur may be minimized. For example, it may be that the base station sends the UE the dynamic DCI  606  having the illustrated UL slot indication  614  as a result of the base station requiring data from the UE that is latency sensitive. In such a case, interrupting the resulting UL slot  626  of the period  624   b  in order to perform UE calibration (instead of using that slot to send the regular, latency sensitive data) may cause the latency sensitive data to arrive late at the base station. 
     Note that due to the transitory nature of dynamic DCI configurations, previous and/or subsequent repetitions of a slot configuration within the period  624   b  may occur according to the original slot configuration  602 , and not according to the modified slot configuration  608 . This is illustrated, for example, in reference to the special slot  630  of the period  624   b  (which is not a UL slot as it would otherwise be if the corresponding repetition were to match the modified slot configuration  608 ). 
     Further, periods of the UL gap periodicity that are not affected by dynamic DCI changes, such as the period  624   a  and the period  624   c , may (also) use a UL gap corresponding to the (original) slot configuration  602 . This is illustrated by the special slot  634  and the UL slots  636  (which are UL slots for regular UL transmission, presuming that three semi-persistently configured UL slots for UE calibration occurred previously during the period  624   a ) of the period  624   a , and the special slot  632  and the fourth semi-persistently configured UL slot  622   a , the fifth semi-persistently configured UL slot  622   b , and the sixth semi-persistently configured UL slot  622   c  (which may be the three initial semi-persistently configured UL slots of the period  624   c  to be used for UE calibration instead of for regular UL transmission) of the period  624   c.    
     While the embodiment of  FIG.  6 B  assumes a use of a UL gap according to initial semi-persistently configured UL slots of a period, it is contemplated that the details described in relation to  FIG.  6 B  could also be applied in the case of a use of a UL gap according to initial semi-persistently configured UL slots of repetitions of the slot configuration in the period (as described in relation to  FIG.  5 A  through  FIG.  5 D ). 
     Persons of ordinary skill in the art, with the benefit of this disclosure, would understand that the use slot patterns configured according to a first hierarchical part, optionally a second hierarchical part, and a optionally third hierarchical part of an SP configuration, and as further modified according to a dynamic DCI (an example of which has been presented in relation to the embodiment of  FIG.  6 A  and  FIG.  6 B ) could be extended into embodiments involving more than one configured slot pattern (analogously to content presented in relation to the embodiments of  FIG.  2 A  and  FIG.  2 B  herein). For example, it may be that a slot configuration corresponds to first slot pattern of length P and second slot pattern of length P 2 , giving the slot configuration a length of P+P 2 , and that one (or both) of such slot patterns is configured according to a first hierarchical part, optionally a second hierarchical part, and a third hierarchical part of an SP configuration. In such a case, repetitions of such a slot configuration may be initialized such that the first symbol of every 20/(P+P 2 ) repetitions of the slot configuration is a first symbol in an even numbered radio frame, that the UE may determine a UL gap periodicity that is a multiple of the first slot pattern and the second slot pattern (denoted as N(P+P 2 )) and that accordingly comprises repetitions of the slot configuration, and that the UE may be able to identify the location(s) of one (or more) of those periods of the UL gap periodicity by using a received offset and the formula (SFN×10+SubFN)mod(UL gap periodicity)=Offset, 
     but with UL gap periodicity=N(P+P 2 ). 
     Then, as described herein, semi-persistently configured UL slots of such a period may be used for UE calibration. The number of the semi-persistently configured UL slots may be equal to the UL gap length. Further, the semi-persistently configured UL slots may correspond to slots indicated for UL in one or more of the first slot pattern and the second slot pattern. Each semi-persistently configured UL slot may correspond to one of a UL slot indication in a common configuration for the respective slot pattern, in a dedicated configuration for the respective slot pattern (if such was provided in relation to the slot pattern), or in an SFI DCI (if such was provided in relation to the slot pattern), in accordance with an SP configuration. Further, any (temporary) slots of the first or second pattern corresponding to UL slot indications from any subsequent dynamic DCI (temporarily) affecting the first or second slot pattern may then be excluded from use for UL gap/UE calibration purposes (e.g., are not considered semi-persistently configured UL slots). 
       FIG.  7    illustrates a method  700  of a UE, according to an embodiment. The method  700  includes determining  702 , using configuration information from a base station, a first slot pattern of a slot configuration used during TDD communication. The TDD communication may be with the base station. 
     The method  700  further includes determining  704  a UL gap periodicity, wherein a period of the UL gap periodicity comprises repetitions of the slot configuration during the TDD communication. 
     The method  700  further includes performing  706  UE calibration during one or more semi-persistently configured UL slots of the period, wherein a number of the one or more semi-persistently configured UL slots is equal to a UL gap length, and wherein a first UL slot of the one or more semi-persistently configured UL slots corresponds to the first slot pattern. 
     In some embodiments of the method  700 , the one or more semi-persistently configured UL slots are initial semi-persistently configured UL slots of the period. 
     In some embodiments of the method  700 , the one or more semi-persistently configured UL slots are initial semi-persistently configured UL slots of the repetitions of the slot configuration. 
     In some embodiments, the method  700  further includes determining, using the configuration information, a second slot pattern of the slot configuration, wherein a second UL slot of the one or more semi-persistently configured UL slots corresponds to the second slot pattern. 
     In some embodiments of the method  700 , the UL gap periodicity is a multiple of a length of the slot configuration. 
     In some embodiments, the method  700  further includes receiving, from the base station, a number of the repetitions of the slot configuration of the UL gap periodicity, wherein determining the UL gap periodicity comprises multiplying a length of the slot configuration by a number of the repetitions. In some of these embodiments, the length of the slot configuration equals a length of the first slot pattern. In some of these embodiments, the length of the slot configuration equals a sum of a length of the first slot pattern plus a length of a second slot pattern of the slot configuration. 
     In some embodiments of the method  700 , the configuration information includes a common configuration for all UE of a serving cell of the UE indicating the first slot pattern, and wherein the first UL slot corresponds to a first UL slot indication made in the common configuration. In some of these embodiments, the common configuration indicates a second slot pattern of the slot configuration, and a second UL slot of the one or more semi-persistently configured UL slots corresponds to a second UL slot indication made in the common configuration and to the second slot pattern. 
     In some embodiments of the method  700 , the configuration information includes a first dedicated configuration for the first slot pattern that is specific to the UE, and the first UL slot corresponds to a first UL slot indication made in the first dedicated configuration. In some of these embodiments, the configuration information includes a second dedicated configuration for a second slot pattern of the slot configuration, and a second UL slot of the one or more semi-persistently configured UL slots corresponds to a second UL slot indication made in the second dedicated configuration. 
     In some embodiments of the method  700 , the first slot pattern is further determined using first SFI DCI received from the base station, and the first UL slot corresponds to a first UL slot indication made in the first SFI DCI. In some of these embodiments, a second slot pattern of the slot configuration is determined using second SFI DCI received from the base station, and a second UL slot of the one or more semi-persistently configured UL slots corresponds to a second UL slot indication made in the second SFI DCI. 
     In some embodiments of the method  700 , the one or more semi-persistently configured UL slots does not include a UL slot corresponding to a UL slot indication made by dynamic DCI. 
     In some embodiments of the method  700 , the UL gap length is indicated to the UE by the base station. 
     Embodiments contemplated herein include an apparatus comprising means to perform one or more elements of the method  700 . This apparatus may be, for example, an apparatus of a UE (such as a wireless device  902  that is a UE, as described herein). 
     Embodiments contemplated herein include one or more non-transitory computer-readable media comprising instructions to cause an electronic device, upon execution of the instructions by one or more processors of the electronic device, to perform one or more elements of the method  700 . This non-transitory computer-readable media may be, for example, a memory of a UE (such as a memory  906  of a wireless device  902  that is a UE, as described herein). 
     Embodiments contemplated herein include an apparatus comprising logic, modules, or circuitry to perform one or more elements of the method  700 . This apparatus may be, for example, an apparatus of a UE (such as a wireless device  902  that is a UE, as described herein). 
     Embodiments contemplated herein include an apparatus comprising: one or more processors and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of the method  700 . This apparatus may be, for example, an apparatus of a UE (such as a wireless device  902  that is a UE, as described herein). 
     Embodiments contemplated herein include a signal as described in or related to one or more elements of the method  700 . 
     Embodiments contemplated herein include a computer program or computer program product comprising instructions, wherein execution of the program by a processor is to cause the processor to carry out one or more elements of the method  700 . The processor may be a processor of a UE (such as a processor(s)  904  of a wireless device  902  that is a UE, as described herein). These instructions may be, for example, located in the processor and/or on a memory of the UE (such as a memory  906  of a wireless device  902  that is a UE, as described herein). 
       FIG.  8    illustrates an example architecture of a wireless communication system  800 , according to embodiments disclosed herein. The following description is provided for an example wireless communication system  800  that operates in conjunction with the LTE system standards and/or 5G or NR system standards as provided by 3GPP technical specifications. 
     As shown by  FIG.  8   , the wireless communication system  800  includes UE  802  and UE  804  (although any number of UEs may be used). In this example, the UE  802  and the UE  804  are illustrated as smartphones (e.g., handheld touchscreen mobile computing devices connectable to one or more cellular networks), but may also comprise any mobile or non-mobile computing device configured for wireless communication. 
     The UE  802  and UE  804  may be configured to communicatively couple with a RAN  806 . In embodiments, the RAN  806  may be NG-RAN, E-UTRAN, etc. The UE  802  and UE  804  utilize connections (or channels) (shown as connection  808  and connection  810 , respectively) with the RAN  806 , each of which comprises a physical communications interface. The RAN  806  can include one or more base stations, such as base station  812  and base station  814 , that enable the connection  808  and connection  810 . 
     In this example, the connection  808  and connection  810  are air interfaces to enable such communicative coupling, and may be consistent with RAT(s) used by the RAN  806 , such as, for example, an LTE and/or NR. 
     In some embodiments, the UE  802  and UE  804  may also directly exchange communication data via a sidelink interface  816 . The UE  804  is shown to be configured to access an access point (shown as AP  818 ) via connection  820 . By way of example, the connection  820  can comprise a local wireless connection, such as a connection consistent with any IEEE 702.11 protocol, wherein the AP  818  may comprise a Wi-Fi® router. In this example, the AP  818  may be connected to another network (for example, the Internet) without going through a CN  824 . 
     In embodiments, the UE  802  and UE  804  can be configured to communicate using orthogonal frequency division multiplexing (OFDM) communication signals with each other or with the base station  812  and/or the base station  814  over a multicarrier communication channel in accordance with various communication techniques, such as, but not limited to, an orthogonal frequency division multiple access (OFDMA) communication technique (e.g., for downlink communications) or a single carrier frequency division multiple access (SC-FDMA) communication technique (e.g., for uplink and ProSe or sidelink communications), although the scope of the embodiments is not limited in this respect. The OFDM signals can comprise a plurality of orthogonal subcarriers. 
     In some embodiments, all or parts of the base station  812  or base station  814  may be implemented as one or more software entities running on server computers as part of a virtual network. In addition, or in other embodiments, the base station  812  or base station  814  may be configured to communicate with one another via interface  822 . In embodiments where the wireless communication system  800  is an LTE system (e.g., when the CN  824  is an EPC), the interface  822  may be an X2 interface. The X2 interface may be defined between two or more base stations (e.g., two or more eNBs and the like) that connect to an EPC, and/or between two eNBs connecting to the EPC. In embodiments where the wireless communication system  800  is an NR system (e.g., when CN  824  is a 5GC), the interface  822  may be an Xn interface. The Xn interface is defined between two or more base stations (e.g., two or more gNBs and the like) that connect to 5GC, between a base station  812  (e.g., a gNB) connecting to 5GC and an eNB, and/or between two eNBs connecting to 5GC (e.g., CN  824 ). 
     The RAN  806  is shown to be communicatively coupled to the CN  824 . The CN  824  may comprise one or more network elements  826 , which are configured to offer various data and telecommunications services to customers/subscribers (e.g., users of UE  802  and UE  804 ) who are connected to the CN  824  via the RAN  806 . The components of the CN  824  may be implemented in one physical device or separate physical devices including components to read and execute instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium). 
     In embodiments, the CN  824  may be an EPC, and the RAN  806  may be connected with the CN  824  via an S1 interface  828 . In embodiments, the S1 interface  828  may be split into two parts, an S1 user plane (S  1 -U) interface, which carries traffic data between the base station  812  or base station  814  and a serving gateway (S-GW), and the S1-MME interface, which is a signaling interface between the base station  812  or base station  814  and mobility management entities (MMEs). 
     In embodiments, the CN  824  may be a 5GC, and the RAN  806  may be connected with the CN  824  via an NG interface  828 . In embodiments, the NG interface  828  may be split into two parts, an NG user plane (NG-U) interface, which carries traffic data between the base station  812  or base station  814  and a user plane function (UPF), and the S1 control plane (NG-C) interface, which is a signaling interface between the base station  812  or base station  814  and access and mobility management functions (AMFs). 
     Generally, an application server  830  may be an element offering applications that use internet protocol (IP) bearer resources with the CN  824  (e.g., packet switched data services). The application server  830  can also be configured to support one or more communication services (e.g., VoIP sessions, group communication sessions, etc.) for the UE  802  and UE  804  via the CN  824 . The application server  830  may communicate with the CN  824  through an IP communications interface  832 . 
       FIG.  9    illustrates a system  900  for performing signaling  934  between a wireless device  902  and a network device  918 , according to embodiments disclosed herein. The system  900  may be a portion of a wireless communications system as herein described. The wireless device  902  may be, for example, a UE of a wireless communication system. The network device  918  may be, for example, a base station (e.g., an eNB or a gNB) of a wireless communication system. 
     The wireless device  902  may include one or more processor(s)  904 . The processor(s)  904  may execute instructions such that various operations of the wireless device  902  are performed, as described herein. The processor(s)  904  may include one or more baseband processors implemented using, for example, a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. 
     The wireless device  902  may include a memory  906 . The memory  906  may be a non-transitory computer-readable storage medium that stores instructions  908  (which may include, for example, the instructions being executed by the processor(s)  904 ). The instructions  908  may also be referred to as program code or a computer program. The memory  906  may also store data used by, and results computed by, the processor(s)  904 . 
     The wireless device  902  may include one or more transceiver(s)  910  that may include radio frequency (RF) transmitter and/or receiver circuitry that use the antenna(s)  912  of the wireless device  902  to facilitate signaling (e.g., the signaling  934 ) to and/or from the wireless device  902  with other devices (e.g., the network device  918 ) according to corresponding RATs. 
     The wireless device  902  may include one or more antenna(s)  912  (e.g., one, two, four, or more). For embodiments with multiple antenna(s)  912 , the wireless device  902  may leverage the spatial diversity of such multiple antenna(s)  912  to send and/or receive multiple different data streams on the same time and frequency resources. This behavior may be referred to as, for example, multiple input multiple output (MIMO) behavior (referring to the multiple antennas used at each of a transmitting device and a receiving device that enable this aspect). MIMO transmissions by the wireless device  902  may be accomplished according to precoding (or digital beamforming) that is applied at the wireless device  902  that multiplexes the data streams across the antenna(s)  912  according to known or assumed channel characteristics such that each data stream is received with an appropriate signal strength relative to other streams and at a desired location in the spatial domain (e.g., the location of a receiver associated with that data stream). Certain embodiments may use single user MIMO (SU-MIMO) methods (where the data streams are all directed to a single receiver) and/or multi user MIMO (MU-MIMO) methods (where individual data streams may be directed to individual (different) receivers in different locations in the spatial domain). 
     In certain embodiments having multiple antennas, the wireless device  902  may implement analog beamforming techniques, whereby phases of the signals sent by the antenna(s)  912  are relatively adjusted such that the (joint) transmission of the antenna(s)  912  can be directed (this is sometimes referred to as beam steering). 
     The wireless device  902  may include one or more interface(s)  914 . The interface(s)  914  may be used to provide input to or output from the wireless device  902 . For example, a wireless device  902  that is a UE may include interface(s)  914  such as microphones, speakers, a touchscreen, buttons, and the like in order to allow for input and/or output to the UE by a user of the UE. Other interfaces of such a UE may be made up of transmitters, receivers, and other circuitry (e.g., other than the transceiver(s)  910 /antenna(s)  912  already described) that allow for communication between the UE and other devices and may operate according to known protocols (e.g., Wi-Fi®, Bluetooth®, and the like). 
     The wireless device  902  may include a UL gap module  916 . The UL gap module  916  may be implemented via hardware, software, or combinations thereof. For example, the UL gap module  916  may be implemented as a processor, circuit, and/or instructions  908  stored in the memory  906  and executed by the processor(s)  904 . In some examples, the UL gap module  916  may be integrated within the processor(s)  904  and/or the transceiver(s)  910 . For example, the UL gap module  916  may be implemented by a combination of software components (e.g., executed by a DSP or a general processor) and hardware components (e.g., logic gates and circuitry) within the processor(s)  904  or the transceiver(s)  910 . 
     The UL gap module  916  may be used for various aspects of the present disclosure, for example, aspects of  FIG.  1 A  through  FIG.  6 B . For example, the UL gap module  916  may be configured to determine one or more slot patterns of a slot configuration used by the UE during TDD communications, determine a UL gap periodicity (e.g., as determined relative to the length(s) of the one or more slot patterns of the slot configuration), and instruct the UE to perform UE calibration during one or more semi-persistently configured UL slots of the period (e.g., that is equal in number to the gap length), where the semi-persistently configured UL slots each correspond to one of the slot pattern(s) (e.g., correspond to a UL slot indication of one of a common configuration, a dedicated configuration, or an SFI DCI for the corresponding slot pattern). 
     The network device  918  may include one or more processor(s)  920 . The processor(s)  920  may execute instructions such that various operations of the network device  918  are performed, as described herein. The processor(s)  904  may include one or more baseband processors implemented using, for example, a CPU, a DSP, an ASIC, a controller, an FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. 
     The network device  918  may include a memory  922 . The memory  922  may be a non-transitory computer-readable storage medium that stores instructions  924  (which may include, for example, the instructions being executed by the processor(s)  920 ). The instructions  924  may also be referred to as program code or a computer program. The memory  922  may also store data used by, and results computed by, the processor(s)  920 . 
     The network device  918  may include one or more transceiver(s)  926  that may include RF transmitter and/or receiver circuitry that use the antenna(s)  928  of the network device  918  to facilitate signaling (e.g., the signaling  934 ) to and/or from the network device  918  with other devices (e.g., the wireless device  902 ) according to corresponding RATs. 
     The network device  918  may include one or more antenna(s)  928  (e.g., one, two, four, or more). In embodiments having multiple antenna(s)  928 , the network device  918  may perform MIMO, digital beamforming, analog beamforming, beam steering, etc., as has been described. 
     The network device  918  may include one or more interface(s)  930 . The interface(s)  930  may be used to provide input to or output from the network device  918 . For example, a network device  918  that is a base station may include interface(s)  930  made up of transmitters, receivers, and other circuitry (e.g., other than the transceiver(s)  926 /antenna(s)  928  already described) that enables the base station to communicate with other equipment in a core network, and/or that enables the base station to communicate with external networks, computers, databases, and the like for purposes of operations, administration, and maintenance of the base station or other equipment operably connected thereto. 
     The network device  918  may include a UL gap module  932 . The UL gap module  932  may be implemented via hardware, software, or combinations thereof. For example, the UL gap module  932  may be implemented as a processor, circuit, and/or instructions  924  stored in the memory  922  and executed by the processor(s)  920 . In some examples, the UL gap module  932  may be integrated within the processor(s)  920  and/or the transceiver(s)  926 . For example, the UL gap module  932  may be implemented by a combination of software components (e.g., executed by a DSP or a general processor) and hardware components (e.g., logic gates and circuitry) within the processor(s)  920  or the transceiver(s)  926 . 
     The UL gap module  932  may be used for various aspects of the present disclosure, for example, aspects of  FIG.  1 A  through  FIG.  6 B . For example, the UL gap module  932  may be configured to cause the network device  918  to indicate to a UE whether to use UL gap length determinations in the manner described here, and/or whether the network device  918  expects the UE to use such determinations. The UL gap module  932  may also cause the network device  918  to provide a UL gap length to the UE in certain embodiments. The UL gap module  932  may also cause the network device  918  to provide an offset value (for determining the location of a period of a UL gap periodicity) to the UE in certain embodiments. The UL gap module  932  may also cause the network device  918  to provide a number m of initial semi-persistently configured UL slots of repetition(s) of the slot configuration of a period of the UL gap periodicity to the UE in certain embodiments. Further, the UL gap module  932  may cause the network device  918  to determine, for example, common configurations, dedicated configurations, and/or SFI DCI indications to the UE in light of the expectation that the UE is using UL gap length determinations as described herein. 
     For one or more embodiments, at least one of the components set forth in one or more of the preceding figures may be configured to perform one or more operations, techniques, processes, and/or methods as set forth herein. For example, a baseband processor as described herein in connection with one or more of the preceding figures may be configured to operate in accordance with one or more of the examples set forth herein. For another example, circuitry associated with a UE, base station, network element, etc. as described above in connection with one or more of the preceding figures may be configured to operate in accordance with one or more of the examples set forth herein. 
     Any of the above described embodiments may be combined with any other embodiment (or combination of embodiments), unless explicitly stated otherwise. The foregoing description of one or more implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of embodiments to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments. 
     Embodiments and implementations of the systems and methods described herein may include various operations, which may be embodied in machine-executable instructions to be executed by a computer system. A computer system may include one or more general-purpose or special-purpose computers (or other electronic devices). The computer system may include hardware components that include specific logic for performing the operations or may include a combination of hardware, software, and/or firmware. 
     It should be recognized that the systems described herein include descriptions of specific embodiments. These embodiments can be combined into single systems, partially combined into other systems, split into multiple systems or divided or combined in other ways. In addition, it is contemplated that parameters, attributes, aspects, etc. of one embodiment can be used in another embodiment. The parameters, attributes, aspects, etc. are merely described in one or more embodiments for clarity, and it is recognized that the parameters, attributes, aspects, etc. can be combined with or substituted for parameters, attributes, aspects, etc. of another embodiment unless specifically disclaimed herein. 
     It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users. 
     Although the foregoing has been described in some detail for purposes of clarity, it will be apparent that certain changes and modifications may be made without departing from the principles thereof. It should be noted that there are many alternative ways of implementing both the processes and apparatuses described herein. Accordingly, the present embodiments are to be considered illustrative and not restrictive, and the description is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.

Metadata:
Filing Date: 20210726
Publication Date: 20241126
Grant Date: 20241126
Priority Date: 20210726
Inventors: NIU, HUANING
ZHANG, DAWEI
CUI, JIE
RAGHAVAN, Manasa
LI, QIMING
SAMBHWANI, SHARAD
CHEN, XIANG
TANG, YANG
Assignee: APPLE INC
CPC Classifications: [{"code": "H04L5/1469", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/11", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/231", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/1268", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W72/0446", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W72/0446", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W72/11", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W72/231", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/11", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L5/1469", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/0446", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 85086073