CROSS-REFERENCE TO RELATED APPLICATIONS:

[0001] This application claims priority from U.S. provisional patent application no. 62/978,173 filed on February 18, 2020. The contents of this earlier filed application are hereby incorporated by reference in their entirety.

FIELD:

[0002] Some example embodiments may generally relate to mobile or wireless telecommunication systems, such as Long Term Evolution (LTE) or fifth generation (5G) radio access technology or new radio (NR) access technology, or other communications systems. For example, certain example embodiments may relate to apparatuses, systems, and/or methods for channel state information (CSI) triggering. BACKGROUND:

[0003] Examples of mobile or wireless telecommunication systems may include the Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN), Long Term Evolution (LTE) Evolved UTRAN (E-UTRAN), LTE-Advanced (LTE- A), MulteFire, LTE- A Pro, and/or fifth generation (5G) radio access technology or new radio (NR) access technology. Fifth generation (5G) wireless systems refer to the next generation (NG) of radio systems and network architecture. 5G is mostly built on a new radio (NR), but the 5G (or NG) network can also build on E-UTRAN radio. It is estimated that NR will provide bitrates on the order of 10-20 Gbit/s or higher, and will support at least enhanced mobile broadband (eMBB) and ultra-reliable low-latency- communication (URLLC) as well as massive machine type communication (mMTC). NR is expected to deliver extreme broadband and ultra-robust, low latency connectivity and massive networking to support the Internet of Things (IoT). With IoT and machine-to-machine (M2M) communication becoming more widespread, there will be a growing need for networks that meet the needs of lower power, low data rate, and long battery life. It is noted that, in 5G, the nodes that can provide radio access functionality to a user equipment (i.e., similar to Node B in UTRAN or eNB in LTE) are named gNB when built on NR radio and named NG-eNB when built on E-UTRAN radio.

SUMMARY:

[0004] Some example embodiments are directed to a method. The method may include receiving from a network element, a downlink scheduling downlink control information (DCI) that indicates a single or multiple transmission configuration indicator (TCI) states. The method may also include receiving from the network element, an uplink grant DCI comprising an indication of a trigger state for aperiodic or semi-persistent channel state information (CSI) reporting. The method may further include selecting a single or multiple CSI reporting configurations associated with the indicated trigger state based on a number of indicated TCI states in the downlink scheduling DCI. In addition, the method may include performing CSI measurements based on the selected CSI reporting configuration. The method may also include transmitting a single or multiple CSI reports to the network element according to the selected CSI reporting configuration.

[0005] Other example embodiments are directed to an apparatus that may include at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured, with the at least one processor to cause the apparatus at least to receive from a network element, a downlink scheduling downlink control information (DCI) that indicates a single or multiple transmission configuration indicator (TCI) states. The apparatus may also be caused to receive from the network element, an uplink grant DCI comprising an indication of a trigger state for aperiodic or semi-persistent channel state information (CSI) reporting. The apparatus may further be caused to select a single or multiple CSI reporting configurations associated with the indicated trigger state based on a number of indicated TCI states in the downlink scheduling DCI. In addition, the apparatus may be caused to perform CSI measurements based on the selected CSI reporting configuration. Further, the apparatus may be caused to transmit a single or multiple CSI reports to the network element according to the selected CSI reporting configuration. [0006] Other example embodiments are directed to an apparatus. The apparatus may include means for receiving from a network element, a downlink scheduling downlink control information (DCI) that indicates a single or multiple transmission configuration indicator (TCI) states. The apparatus may also include means for receiving from the network element, an uplink grant DCI comprising an indication of a trigger state for aperiodic or semi-persistent channel state information (CSI) reporting. The apparatus may further include means for selecting a single or multiple CSI reporting configurations associated with the indicated trigger state based on a number of indicated TCI states in the downlink scheduling DCI. In addition, the apparatus may include means for performing CSI measurements based on the selected CSI reporting configuration. Further, the apparatus may include means for transmitting a single or multiple CSI reports to the network element according to the selected CSI reporting configuration.

[0007] In accordance with other example embodiments, a non-transitory computer readable medium may be encoded with instructions that may, when executed in hardware, perform a method. The method may include receiving from a network element, a downlink scheduling downlink control information (DCI) that indicates a single or multiple transmission configuration indicator (TCI) states. The method may also include receiving from the network element, an uplink grant DCI comprising an indication of a trigger state for aperiodic or semi-persistent channel state information (CSI) reporting. The method may further include selecting a single or multiple CSI reporting configurations associated with the indicated trigger state based on a number of indicated TCI states in the downlink scheduling DCI. In addition, the method may include performing CSI measurements based on the selected CSI reporting configuration. The method may also include transmitting a single or multiple CSI reports to the network element according to the selected CSI reporting configuration. [0008] Other example embodiments may be directed to a computer program product that performs a method. The method may include receiving from a network element, a downlink scheduling downlink control information (DCI) that indicates a single or multiple transmission configuration indicator (TCI) states. The method may also include receiving from the network element, an uplink grant DCI comprising an indication of a trigger state for aperiodic or semi-persistent channel state information (CSI) reporting. The method may further include selecting a single or multiple CSI reporting configurations associated with the indicated trigger state based on a number of indicated TCI states in the downlink scheduling DCI. In addition, the method may include performing CSI measurements based on the selected CSI reporting configuration. The method may also include transmitting a single or multiple CSI reports to the network element according to the selected CSI reporting configuration.

[0009] Other example embodiments may be directed to an apparatus that may include circuitry configured to receive from a network element, a downlink scheduling downlink control information (DCI) that indicates a single or multiple transmission configuration indicator (TCI) states. The apparatus may also include circuitry configured to receive from the network element, an uplink grant DCI comprising an indication of a trigger state for aperiodic or semi-persistent channel state information (CSI) reporting. The apparatus may further include circuitry configured to select a single or multiple CSI reporting configurations associated with the indicated trigger state based on a number of indicated TCI states in the downlink scheduling DCI. In addition, the apparatus may include circuitry configured to perform CSI measurements based on the selected CSI reporting configuration. Further, the apparatus may include circuitry configured to transmit a single or multiple CSI reports to the network element according to the selected CSI reporting configuration. [0010] Certain example embodiments may be directed to a method. The method may include configuring a user equipment with trigger states and their associated channel state information (CSI) reporting configurations. The method may also include transmitting to the user equipment downlink scheduling downlink control information (DCI) that indicates a single or multiple transmission configuration indicator (TCI) states. The method may further include triggering CSI reporting from the user equipment by indicating a trigger state for aperiodic or semi-persistent CSI reporting in an uplink grant DCI. In addition, the method may include receiving a single or multiple CSI reports from the user equipment according to a selected CSI reporting configuration by the user equipment. [0011] Other example embodiments may be directed to an apparatus. The apparatus may include at least one processor and at least one memory including computer program code. The at least one memory and computer program code may be configured to, with the at least one processor, cause the apparatus at least to configure a user equipment with trigger states and their associated channel state information (CSI) reporting configurations. The apparatus may also be caused to transmit to the user equipment downlink scheduling downlink control information (DCI) that indicates a single or multiple transmission configuration indicator (TCI) states. The apparatus may further be caused to trigger CSI reporting from the user equipment by indicating a trigger state for aperiodic or semi- persistent CSI reporting in an uplink grant DCI. In addition, the apparatus may be caused to receive a single or multiple CSI reports from the user equipment according to a selected CSI reporting configuration by the user equipment.

[0012] Other example embodiments may be directed to an apparatus. The apparatus may include means for configuring a user equipment with trigger states and their associated channel state information (CSI) reporting configurations. The apparatus may also include means for transmitting to the user equipment downlink scheduling downlink control information (DCI) that indicates a single or multiple transmission configuration indicator (TCI) states. The apparatus may further include means for triggering CSI reporting from the user equipment by indicating a trigger state for aperiodic or semi-persistent CSI reporting in an uplink grant DCI. In addition, the apparatus may include means for receiving a single or multiple CSI reports from the user equipment according to a selected CSI reporting configuration by the user equipment.

[0013] In accordance with other example embodiments, a non-transitory computer readable medium may be encoded with instructions that may, when executed in hardware, perform a method. The method may include configuring a user equipment with trigger states and their associated channel state information (CSI) reporting configurations. The method may also include transmitting to the user equipment downlink scheduling downlink control information (DCI) that indicates a single or multiple transmission configuration indicator (TCI) states. The method may further include triggering CSI reporting from the user equipment by indicating a trigger state for aperiodic or semi- persistent CSI reporting in an uplink grant DCI. In addition, the method may include receiving a single or multiple CSI reports from the user equipment according to a selected CSI reporting configuration by the user equipment.

[0014] Other example embodiments may be directed to a computer program product that performs a method. The method may include configuring a user equipment with trigger states and their associated channel state information (CSI) reporting configurations. The method may also include transmitting to the user equipment downlink scheduling downlink control information (DCI) that indicates a single or multiple transmission configuration indicator (TCI) states. The method may further include triggering CSI reporting from the user equipment by indicating a trigger state for aperiodic or semi-persistent CSI reporting in an uplink grant DCI. In addition, the method may include receiving a single or multiple CSI reports from the user equipment according to a selected CSI reporting configuration by the user equipment. [0015] Other example embodiments may be directed to an apparatus that may include circuitry configured to configure configuring a user equipment with trigger states and their associated channel state information (CSI) reporting configurations. The apparatus may also include circuitry configured to transmit to the user equipment downlink scheduling downlink control information (DCI) that indicates a single or multiple transmission configuration indicator (TCI) states. The apparatus may further include circuitry configured to trigger CSI reporting from the user equipment by indicating a trigger state for aperiodic or semi -persistent CSI reporting in an uplink grant DCI. In addition, the apparatus may include circuitry configured to receive a single or multiple CSI reports from the user equipment according to a selected CSI reporting configuration by the user equipment.

BRIEF DESCRIPTION OF THE DRAWINGS:

[0016] For proper understanding of example embodiments, reference should be made to the accompanying drawings, wherein:

[0017] FIG. 1 illustrates a channel state information (CSI) triggering scheme, according to an example embodiment.

[0018] FIG. 2 illustrates trigger states and associated CSI reporting configuration, according to an example embodiment. [0019] FIG. 3 illustrates a flow diagram of a method, according to an example embodiment.

[0020] FIG. 4 illustrates a flow diagram of another method, according to an example embodiment. [0021] FIG. 5(a) illustrates an apparatus, according to an example embodiment.

[0022] FIG. 5(b) illustrates another apparatus, according to an example embodiment. DETAIFED DESCRIPTION:

[0023] It will be readily understood that the components of certain example embodiments, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. The following is a detailed description of some example embodiments of systems, methods, apparatuses, and computer program products for aperiodic and semi-persistent channel state information (CSI) triggering for single physical downlink control channel (PDCCH) based multiple transmission-reception point (multi-TRP) transmission.

[0024] The features, structures, or characteristics of example embodiments described throughout this specification may be combined in any suitable manner in one or more example embodiments. For example, the usage of the phrases “certain embodiments,” “an example embodiment,” “some embodiments,” or other similar language, throughout this specification refers to the fact that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment. Thus, appearances of the phrases “in certain embodiments,” “an example embodiment,” “in some embodiments,” “in other embodiments,” or other similar language, throughout this specification do not necessarily all refer to the same group of embodiments, and the described features, structures, or characteristics may be combined in any suitable manner in one or more example embodiments. [0025] Additionally, if desired, the different functions or steps discussed below may be performed in a different order and/or concurrently with each other. Furthermore, if desired, one or more of the described functions or steps may be optional or may be combined. As such, the following description should be considered as merely illustrative of the principles and teachings of certain example embodiments, and not in limitation thereof.

[0026] Multi-transmission and reception point (multi-TRP) design has been described for enhanced mobile broadband (eMBB) and ultra-reliable low latency communications (URLLC) based on non coherent joint transmission. The design may include, for example, single physical downlink control channel (PDCCH) based multi-TRP transmission, and multiple PDCCH based multi-TRP transmission. Furthermore, work on new radio (NR) multiple-input and multiple-output enhancements have been made. Improvements of the support for multi-TRP have also been in discussion in radio access network 1 (RANI), including channel state information (CSI) reporting aspects.

[0027] Multi-TRP communication may provide certain benefits. For example, multi-TRP may be beneficial in terms of improved reliability due to the spatial diversity that it provides. In addition, depending on the used multi-TRP transmission scheme (e.g., coherent joint transmission (CJT), non coherent joint transmission (NCJT), dynamic point selection (DPS), Coordinated beamforming (CB)/Coordinated scheduling (CS)), the superior macro-diversity that is inherent to multi-TRP scenarios may be exploited differently at the network side. Flowever, while there may be certain advantages, the performance of any multi-TRP transmission scheme may depend on the accuracy of beamforming and link adaptation.

[0028] To achieve the desired performance, the availability of accurate CSI at the TRPs/gNB may be important. This may be provided by advanced NR codebooks. In certain multi-TRP scenarios, it may be necessary for the user equipment (UE) to provide feedback of several CSI reports to the different cooperating TRPs/gNBs, including joint or independent precoding matrix indicators (PMIs) and jointly or independently computed channel quality indicator (CQI). Further two PMIs or a joint PMI may be provided for different cooperating TRPs/gNBs.

[0029] In certain scenarios, independent CSI reporting may be preferable as it may provide flexibility to dynamically control the uplink control information (UCI) payload. This may be implemented by enabling independent triggering PMI reporting for each of the TRPs. Additionally, independent CSI reporting for each TRP may have the benefit of being the natural extension of previous CSI reporting framework. Flowever, this option may introduce some ambiguity between TRPs and the UE, depending on the UE’s capabilities. For example, in the event of CSI omission due to insufficient physical uplink channel resources, the UE may provide an unequal number of coefficient groups from the CSI reports. Additionally, whether the CSI feedback is computed jointly or independently, the UE may be burdened with a non-negligible computational strain. Consequently, it may be desirable to carefully manage CSI reporting for multi-TRP in order to spare the network and the UE from superfluous measurements.

[0030] In certain multi-TRP operations, periodic CSI reporting may be extensively penalizing in terms of overhead. As such, aperiodic or semi-persistent CSI reporting may be preferable over periodic CSI reporting. Thus, it may be desirable to provide a highly dynamic CSI triggering framework for multi-TRP, enabling the network to efficiently manage CSI reporting overhead. In doing so, it may be possible to properly handle CSI triggering for multi-TRP in order to avoid high demand on trigger states. Further, in certain scenarios, the UE may not be triggered with a CSI report for a non-active BWP resulting in restriction and the demand of a large number of trigger states. [0031] The large number of trigger states may be due to CSI reports for different component carriers (CCs) or bandwidth parts (BWPs) being configured in different trigger states. As such, the UE may have to be configured with multiple trigger states to allow triggering CSI in different CCs/BWPs. However, for UEs with limited capabilities, it may not be possible to configure large numbers of trigger states for multiple CCs/BWPs. In addition, multi-TRP CSI triggering may further increase the demand for trigger states. Thus, certain example embodiments may provide an efficient and flexible aperiodic and semi-persistent CSI triggering framework, suitable for multi-TRP scenarios. [0032] Each CSI reporting configuration may be linked to one or multiple periodic, aperiodic or semi-persistent downlink reference signal (DL-RS) resource settings. If one DL RS resource setting is linked to the CSI reporting configuration, the DL-RS resource setting may be used for channel measurements. If more than one DL-RS resource settings are linked to the CSI report configuration, one of the resource settings may be used for channel measurements and the remaining may be used for interference measurements, performed on non-zero power channel state information reference signal (NZP CSI-RS) or channel state information-interference measurement (CSI-IM).

[0033] In certain example embodiments, a trigger state may be associated with different CSI reporting configurations. Each configuration may be linked to DL-RS resource settings, for channel measurement or interference measurement, containing DL-RS that are associated with more than one TRP. According to certain example embodiments, the UE may be configured to report CSIs based on the trigger state indicated by an uplink (UL) grant DCI (e.g., format 0_1 in 5G NR) indicating the trigger state. The UE may determine which subset of channel measurement or interference measurement resources to consider during CSI computations based on whether the UE receives a DL scheduling DCI (e.g., format 1_1 in 5G NR) indicating a single TCI state, or a DL scheduling DCI indicating more than one TCI state.

[0034] According to certain example embodiments, ah or a subset of channel measurement or interference measurement resources, linked to a CSI reporting configuration, may be selected when a specific TCI state is indicated by a downlink scheduling DCI, in a single TCI state TCI codepoint or in a multiple-TCI state TCI codepoint. [0035] In certain example embodiments, all or a subset of channel measurement or interference measurement resources, linked to a CSI reporting configuration, may be selected when a single TCI state is indicated by a downlink scheduling DCI, or when more than one TCI states are indicated by a downlink scheduling DCI, or regardless of the number of indicated TCI states by a downlink scheduling DCI.

[0036] Certain example embodiments may address at least the issues of aperiodic and semi- persistent CSI triggering for single downlink control information (DCI) based multi-TRP transmission. For instance, in certain example embodiments, this may be accomplished by enabling dynamic CSI triggering for single and multi-TRP while avoiding any increase in the number of trigger states for aperiodic and semi-persistent CSI reports when multiple TRPs are configured. [0037] In certain example embodiments, a trigger state may be associated with different sets of CSI reporting configurations. For instance, the trigger state may be associated with CSI reporting configurations that are activated, only when a single TCI state is indicated in downlink scheduling DCI, or only when more than one TCI state is indicated in downlink scheduling DCI, or regardless of the number of indicated TCI states. According to an example embodiment, the UE may be configured to report CSIs based on the trigger state indicated by an uplink (UL) grant DCI (e.g., format 0_1 in 5G NR) indicating the trigger state. The UE may determine which CSI reporting configuration set applies based on whether the UE receives a DL scheduling DCI (e.g., format 1_1 in 5G NR) indicating a single TCI state, or a DL scheduling DCI indicating more than one TCI state. [0038] According to certain example embodiments, a CSI reporting configuration, that is associated with the indicated trigger state, may be selected, only when a single TCI state is indicated by a downlink scheduling DCI, or only when more than one TCI state are indicated by a downlink scheduling DCI, or regardless of the number of indicated TCI states by a downlink scheduling DCI. Thus, certain example embodiments may provide dynamic triggering to enable the network to efficiently manage PUSCH resources without sacrificing CSI accuracy.

[0039] FIG. 1 illustrates a CSI triggering scheme, according to an example embodiment. In particular, according to certain example embodiments, a CSI triggering scheme for multi-TRP may be provided. For example, according to one example embodiment, the UE may be configured with a set of trigger states for aperiodic or semi-persistent CSI reporting. In one example embodiment, at least one of the trigger states may be associated with more than one CSI reporting configurations. According to an example embodiment, at least one of these configurations may be associated with DL-reference signal (RS) from more than one TRP.

[0040] In another example embodiment, when the UE receives an UL grant DCI (e.g., DCI format 0_1 in 5G NR), the UE may select an appropriate set of CSI reporting configurations based on the latest decoded DL scheduling DCI (e.g., format 1_1 in 5G NR). According to an example embodiment, if the received DL scheduling DCI indicates more than one TCI state, the UE may assume multi-TRP CSI reporting. The UE may also apply the CSI reporting configuration set that is associated with the received trigger state in UL grant DCI, and is configured to be activated when more than one TCI state is indicated, or to be used regardless of the number of indicated TCI states. [0041] According to an example embodiment, multi-TRP CSI reporting may include any combination of CSI quantities for cooperating TRPs. This may include, but not limited to, for example, PMIs, CQIs, strongest layer indicator (SLI), channel state information reference signal (CSI-RS) resource indicator (CRI), Ll-reference signal received power (RSRP), and rank indicator (RI). In an example embodiment, if the UE misses the DL scheduling DCI and is assuming an outdated TCI state, the gNBs/TRPs may still be capable of correctly predicting the payload of UL control information containing the CSI report based on an implicit or explicit indication in UCI part 1 (e.g., number of RIs). For example, if two RIs are transmitted in UCI part 1, the gNB receiving UCI may conclude that the UE applied CSI reporting configurations that specify, the feedback of two RIs, which may typically be the case when NCJT is scheduled or considered for scheduling. This means that the gNB can deduce if the UE reported based on the assumption of one TCI state or based on the assumption of multiple TCI states. [0042] In certain example embodiments, the UE may transmit a single UCI containing CSI reports for multi-TRP to a primary TRP. According to an example embodiment, the primary TRP may be identified as the TRP sending UL grant, or the TRP sending downlink control channel such as for example, physical downlink control channel, PDCCH, or the TRP sending DCI in specific CORESETs. Alternatively, in another example embodiment, the UE may transmit several UCIs, one for each TRP over multiple physical channels. According to a further example embodiment, DCI requesting CSI reporting for multi-TRP may trigger the transmission of multi-TRP CSI reports in the same or separate time instances, depending on the configuration. In another example embodiment, TRP may exchange reported CSI quantities over backhaul whether single UCI or multi- UCI is used. [0043] FIG. 2 illustrates trigger states and associated CSI reporting configurations, according to an example embodiment. Certain example embodiments may provide a CSI reporting configuration and triggering for multi-TRP. Certain example embodiments may also provide dynamic CSI triggering for multi-TRP without requiring excessive configuration of CSI triggering states for semi-persistent and aperiodic CSI reporting. In particular, according to one example embodiment, different interpretations of the same triggering states may be enabled depending on the indicated transmission configuration in DL scheduling DCI without introducing ambiguity. To do so, in one example embodiment, the CSI reporting configurations that are associated with CSI-triggering states for both semi-persistent and aperiodic in RRC may be configured to be activated dependent on the number of indicated TCI states. Moreover, at least one trigger state may be associated with more than one CSI-reporting configuration.

[0044] According to an example embodiment, one configuration may be associated with DL-RS (e.g., CSI-RS, synchronization signal block (SSB)) resources from a single TRP. Other configurations, however, may be associated with DL-RS (e.g., CSI-RS, SSB) resources from more than one TRPs. In an example embodiment, the mapping from the trigger state to the activated CSI reporting configurations may be accomplished based on the DL scheduling TCI. In one example embodiment, if the received downlink scheduling DCI indicates a single TCI state, UE performs CSI measurements and reporting according to CSI reporting configurations that are associated with the indicated trigger state, and that are activated when the received downlink scheduling DCI indicates a single TCI state, or that are activated regardless of the number of indicated TCI states. According to an example embodiment, if the downlink scheduling DCI indicates more than one TCI state, the UE may perform CSI measurements and reporting according to CSI reporting configurations that are associated with the indicated trigger state, and that are activated when the received downlink scheduling DCI indicates multiple TCI states, or that are activated regardless of the number of indicated TCI states.

[0045] In certain example embodiments, if the UE misses the DL scheduling DCI and is assuming an outdated TCI state, the gNBs/TRPs may still be capable of correctly predicting the payload of UL control information (UCI), containing the CSI reports, based on implicit or explicit indication in UCI part 1 (e.g., number of RIs).

[0046] In single and multiple UCIs carrying CSI report, the CSI triggering scheme in certain example embodiments may be applicable whether the UE transmits a single or multiple UCI. In one example embodiment, the UE may transmit different UCIs, one to each of the TRPs/gNBs. Alternatively, in another example embodiment, the UE may transmit a single UCI to a single TRP, referred to as primary TRP. In the latter case, the coordinating TRPs/gNBs may exchange CSI elements over the backhaul. In an example embodiment, single and multiple UCI cases may have different advantages. Depending on the backhaul quality, the network may prioritize one over the other. However, when multiple UCI transmission is considered, the UE may send CSI reports for several TRPs in the same or different time instances. In certain example embodiments, this behavior may be defined by the allocated physical uplink channel, such as for example, PUSCH/PUCCH resources.

[0047] FIG. 3 illustrates a flow diagram of a method, according to an example embodiment. In certain example embodiments, the flow diagram of FIG. 3 may be performed by a mobile station and/or UE, for instance similar to apparatus 10 illustrated in FIG. 5(a). According to one example embodiment, the method of FIG. 3 may include, at 300, receiving from a network element, a downlink scheduling downlink control information (DCI) that indicates a single or multiple TCI states. The method may also include, at 305, receiving from a network element, an uplink grant DCI including an indication of a trigger state for aperiodic or semi-persistent channel state information (CSI) reporting. The method may also include, at 310, selecting a single or multiple CSI reporting configurations associated with the indicated trigger state based on a number of indicated TCI states in the downlink scheduling DCI. Further, at 315, the method may include performing CSI measurements based on the selected CSI reporting configuration(s). At 320, the method may include transmitting a single or multiple CSI reports to the network element according to the selected CSI reporting configuration.

[0048] According to an example embodiment, the method may further include selecting all or a subset of channel measurement or interference measurement resources, in a selected channel state information reporting configuration. According to other example embodiments, the downlink scheduling DCI may correspond to a plurality of TCI states, or a single TCI state. According to another example embodiment, the method may include transmitting a single uplink control information (UCI) including CSI reports for multi-TRP to a primary TRP, or transmitting a plurality of UCIs, one for each TRP, over multi-physical uplink channel. In an example embodiment, the CSI report configurations may include reporting quantities for one or multiple of TRPs, and may be associated with measurement resources for one or multiple TRPs. According to an example embodiment, at least one trigger state may be associated with more than one CSI reporting configuration. According to another example embodiment, the CSI reporting configuration may include any combination of a rank indicator, strongest layer indicator, precoding matrix indicator, channel quality indicator, channel state information reference signal resource indicator, and Ll- reference signal received power for more than one TRP, as reporting quantities. According to a further example embodiment, a DCI may request CSI reporting for multi-TRP may trigger transmission of multi-TRP CSI reports in a same or separate time instance, depending on the CSI reporting configurations.

[0049] FIG. 4 illustrates a flow diagram of another method, according to an example embodiment. In an example embodiment, the method of FIG. 4 may be performed by a telecommunications network, network entity or network node in a 3GPP system, such as LTE or 5G-NR. For instance, in an example embodiment, the method of FIG. 4 may be performed by a base station, eNB, or gNB for instance similar to apparatus 20 illustrated in FIG. 5(b).

[0050] According to an example embodiment, the method of FIG. 4 may include, at 400, configuring a user equipment with trigger states and their associated channel state information (CSI) reporting configurations. The method may also include, at 405, transmitting to the user equipment downlink scheduling downlink control information (DCI) that indicates a single or multiple transmission configuration indicator (TCI) states. The method may also include, at 410, triggering CSI reporting from the user equipment by indicating a trigger state for aperiodic or semi-persistent CSI reporting in an uplink grant DCI. The method may also include, at 415, receiving a single or multiple CSI reports from the user equipment according to a selected CSI reporting configuration by the user equipment. [0051] According to an example embodiment, a new or existing field of a CSI reporting configuration that is associated with the indicated trigger state may include an explicit or implicit indication on whether it can be selected only when a single TCI state is indicated, or only when more than one TCI state are indicated, or regardless of the number of trigger states. In an example embodiment, the CSI reporting configuration may be configured by a higher layer. According to a further example embodiment, the CSI report may be a multi-transmission reception point (multi- TRP) report, or a single TRP report, or used for both single and multi-TRP, based on an indication in the downlink scheduling DCI. According to another example embodiment, the DCI may include aperiodic CSI trigger state or semi-persistent CSI trigger state information, and at least one trigger state may be associated with a plurality of CSI reporting configurations. According to a further example embodiment, the downlink scheduling DCI may correspond to a plurality of TCI states, or a single TCI state. In an example embodiment, at least one trigger state may be associated with more than one CSI reporting configuration. In another example embodiment, at least one CSI reporting may be associated with downlink reference signal (DL-RS) from more than one TRP. In a further example embodiment, the DCI may trigger transmission of multi-TRP CSI reports in a same or separate time instance, depending on the CSI reporting configuration. According to an example embodiment, the method may further include predicting a payload of uplink control information including the CSI report.

[0052] FIG. 5(a) illustrates an apparatus 10 according to an example embodiment. In an embodiment, apparatus 10 may be a node or element in a communications network or associated with such a network, such as a UE, mobile equipment (ME), mobile station, mobile device, stationary device, IoT device, or other device. As described herein, UE may alternatively be referred to as, for example, a mobile station, mobile equipment, mobile unit, mobile device, user device, subscriber station, wireless terminal, tablet, smart phone, IoT device, sensor or NB-IoT device, or the like. As one example, apparatus 10 may be implemented in, for instance, a wireless handheld device, a wireless plug-in accessory, or the like.

[0053] In some example embodiments, apparatus 10 may include one or more processors, one or more computer-readable storage medium (for example, memory, storage, or the like), one or more radio access components (for example, a modem, a transceiver, or the like), and/or a user interface. In some embodiments, apparatus 10 may be configured to operate using one or more radio access technologies, such as GSM, LTE, LTE-A, NR, 5G, WLAN, WiFi, NB-IoT, Bluetooth, NFC, MulteFire, and/or any other radio access technologies. It should be noted that one of ordinary skill in the art would understand that apparatus 10 may include components or features not shown in FIG. 5(a).

[0054] As illustrated in the example of FIG. 5(a), apparatus 10 may include or be coupled to a processor 12 for processing information and executing instructions or operations. Processor 12 may be any type of general or specific purpose processor. In fact, processor 12 may include one or more of general-purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), and processors based on a multi-core processor architecture, as examples. While a single processor 12 is shown in FIG. 5(a), multiple processors may be utilized according to other embodiments. For example, it should be understood that, in certain example embodiments, apparatus 10 may include two or more processors that may form a multiprocessor system (e.g., in this case processor 12 may represent a multiprocessor) that may support multiprocessing. According to certain example embodiments, the multiprocessor system may be tightly coupled or loosely coupled (e.g., to form a computer cluster).

[0055] Processor 12 may perform functions associated with the operation of apparatus 10 including, as some examples, precoding of antenna gain/phase parameters, encoding and decoding of individual bits forming a communication message, formatting of information, and overall control of the apparatus 10, including processes illustrated in FIGs. 1-3.

[0056] Apparatus 10 may further include or be coupled to a memory 14 (internal or external), which may be coupled to processor 12, for storing information and instructions that may be executed by processor 12. Memory 14 may be one or more memories and of any type suitable to the local application environment, and may be implemented using any suitable volatile or nonvolatile data storage technology such as a semiconductor-based memory device, a magnetic memory device and system, an optical memory device and system, fixed memory, and/or removable memory. For example, memory 14 can be comprised of any combination of random access memory (RAM), read only memory (ROM), static storage such as a magnetic or optical disk, hard disk drive (HDD), or any other type of non-transitory machine or computer readable media. The instructions stored in memory 14 may include program instructions or computer program code that, when executed by processor 12, enable the apparatus 10 to perform tasks as described herein.

[0057] In an embodiment, apparatus 10 may further include or be coupled to (internal or external) a drive or port that is configured to accept and read an external computer readable storage medium, such as an optical disc, USB drive, flash drive, or any other storage medium. For example, the external computer readable storage medium may store a computer program or software for execution by processor 12 and/or apparatus 10 to perform any of the methods illustrated in FIGs. 1-3.

[0058] In some embodiments, apparatus 10 may also include or be coupled to one or more antennas 15 for receiving a downlink signal and for transmitting via an uplink from apparatus 10. Apparatus 10 may further include a transceiver 18 configured to transmit and receive information. The transceiver 18 may also include a radio interface (e.g., a modem) coupled to the antenna 15. The radio interface may correspond to a plurality of radio access technologies including one or more of GSM, LTE, LTE-A, 5G, NR, WLAN, NB-IoT, Bluetooth, BT-LE, NFC, RFID, UWB, and the like. The radio interface may include other components, such as filters, converters (for example, digital- to-analog converters and the like), symbol demappers, signal shaping components, an Inverse Fast Fourier Transform (IFFT) module, and the like, to process symbols, such as OFDMA symbols, carried by a downlink or an uplink. [0059] For instance, transceiver 18 may be configured to modulate information on to a carrier waveform for transmission by the antenna(s) 15 and demodulate information received via the antenna(s) 15 for further processing by other elements of apparatus 10. In other embodiments, transceiver 18 may be capable of transmitting and receiving signals or data directly. Additionally or alternatively, in some embodiments, apparatus 10 may include an input and/or output device (I/O device). In certain embodiments, apparatus 10 may further include a user interface, such as a graphical user interface or touchscreen.

[0060] In an embodiment, memory 14 stores software modules that provide functionality when executed by processor 12. The modules may include, for example, an operating system that provides operating system functionality for apparatus 10. The memory may also store one or more functional modules, such as an application or program, to provide additional functionality for apparatus 10. The components of apparatus 10 may be implemented in hardware, or as any suitable combination of hardware and software. According to an example embodiment, apparatus 10 may optionally be configured to communicate with apparatus 20 via a wireless or wired communications link 70 according to any radio access technology, such as NR.

[0061] According to certain example embodiments, processor 12 and memory 14 may be included in or may form a part of processing circuitry or control circuitry. In addition, in some embodiments, transceiver 18 may be included in or may form a part of transceiving circuitry.

[0062] As discussed above, according to certain example embodiments, apparatus 10 may be a UE for example. According to certain embodiments, apparatus 10 may be controlled by memory 14 and processor 12 to perform the functions associated with example embodiments described herein. For instance, in one embodiment, apparatus 10 may be controlled by memory 14 and processor 12 to receive from a network element, a downlink scheduling downlink control information (DCI) that indicates a single or multiple TCI states. Apparatus 10 may also be controlled by memory 14 and processor 12 to receive from the network element, an uplink grant DCI including an indication of a trigger state for aperiodic or semi-persistent channel state information (CSI) reporting. Apparatus 10 may further be controlled by memory 14 and processor 12 to select a single or multiple CSI reporting configurations associated with the indicated trigger state based on a number of indicated TCI states in the downlink scheduling DCI. Further, apparatus 10 may be controlled by memory 14 and processor 12 to perform CSI measurements based on the selected CSI reporting configuration. In addition, apparatus 10 may be controlled by memory 14 and processor 12 to transmit a single or multiple CSI reports to the network element according to the selected CSI reporting configuration. [0063] FIG. 5(b) illustrates an apparatus 20 according to an example embodiment. In an example embodiment, the apparatus 20 may be a network element, node, host, or server in a communication network or serving such a network. For example, apparatus 20 may be a base station, a Node B, an evolved Node B (eNB), 5G Node B or access point, next generation Node B (NG-NB or gNB), and/or WLAN access point, associated with a radio access network (RAN), such as an LTE network, 5G or NR. It should be noted that one of ordinary skill in the art would understand that apparatus 20 may include components or features not shown in FIG. 5(b).

[0064] As illustrated in the example of FIG. 5(b), apparatus 20 may include a processor 22 for processing information and executing instructions or operations. Processor 22 may be any type of general or specific purpose processor. For example, processor 22 may include one or more of general-purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), and processors based on a multi-core processor architecture, as examples. While a single processor 22 is shown in FIG. 5(b), multiple processors may be utilized according to other embodiments. For example, it should be understood that, in certain embodiments, apparatus 20 may include two or more processors that may form a multiprocessor system (e.g., in this case processor 22 may represent a multiprocessor) that may support multiprocessing. In certain embodiments, the multiprocessor system may be tightly coupled or loosely coupled (e.g., to form a computer cluster.

[0065] According to certain example embodiments, processor 22 may perform functions associated with the operation of apparatus 20, which may include, for example, precoding of antenna gain/phase parameters, encoding and decoding of individual bits forming a communication message, formatting of information, and overall control of the apparatus 20, including processes illustrated in FIGS. 1, 2, and 4.

[0066] Apparatus 20 may further include or be coupled to a memory 24 (internal or external), which may be coupled to processor 22, for storing information and instructions that may be executed by processor 22. Memory 24 may be one or more memories and of any type suitable to the local application environment, and may be implemented using any suitable volatile or nonvolatile data storage technology such as a semiconductor-based memory device, a magnetic memory device and system, an optical memory device and system, fixed memory, and/or removable memory. For example, memory 24 can be comprised of any combination of random access memory (RAM), read only memory (ROM), static storage such as a magnetic or optical disk, hard disk drive (HDD), or any other type of non-transitory machine or computer readable media. The instructions stored in memory 24 may include program instructions or computer program code that, when executed by processor 22, enable the apparatus 20 to perform tasks as described herein. [0067] In an embodiment, apparatus 20 may further include or be coupled to (internal or external) a drive or port that is configured to accept and read an external computer readable storage medium, such as an optical disc, USB drive, flash drive, or any other storage medium. For example, the external computer readable storage medium may store a computer program or software for execution by processor 22 and/or apparatus 20 to perform the methods illustrated in FIGS. 1, 2, and 4. [0068] In certain example embodiments, apparatus 20 may also include or be coupled to one or more antennas 25 for transmitting and receiving signals and/or data to and from apparatus 20. Apparatus 20 may further include or be coupled to a transceiver 28 configured to transmit and receive information. The transceiver 28 may include, for example, a plurality of radio interfaces that may be coupled to the antenna(s) 25. The radio interfaces may correspond to a plurality of radio access technologies including one or more of GSM, NB-IoT, LTE, 5G, WLAN, Bluetooth, BT-LE, NFC, radio frequency identifier (RFID), ultra wideband (UWB), MulteFire, and the like. The radio interface may include components, such as filters, converters (for example, digital-to-analog converters and the like), mappers, a Fast Fourier Transform (FFT) module, and the like, to generate symbols for a transmission via one or more downlinks and to receive symbols (for example, via an uplink).

[0069] As such, transceiver 28 may be configured to modulate information on to a carrier waveform for transmission by the antenna(s) 25 and demodulate information received via the antenna(s) 25 for further processing by other elements of apparatus 20. In other embodiments, transceiver 18 may be capable of transmitting and receiving signals or data directly. Additionally or alternatively, in some embodiments, apparatus 20 may include an input and/or output device (I/O device).

[0070] In an embodiment, memory 24 may store software modules that provide functionality when executed by processor 22. The modules may include, for example, an operating system that provides operating system functionality for apparatus 20. The memory may also store one or more functional modules, such as an application or program, to provide additional functionality for apparatus 20. The components of apparatus 20 may be implemented in hardware, or as any suitable combination of hardware and software. [0071] According to some embodiments, processor 22 and memory 24 may be included in or may form a part of processing circuitry or control circuitry. In addition, in some embodiments, transceiver 28 may be included in or may form a part of transceiving circuitry.

[0072] As used herein, the term “circuitry” may refer to hardware-only circuitry implementations (e.g., analog and/or digital circuitry), combinations of hardware circuits and software, combinations of analog and/or digital hardware circuits with software/firmware, any portions of hardware processor(s) with software (including digital signal processors) that work together to cause an apparatus (e.g., apparatus 10 and 20) to perform various functions, and/or hardware circuit(s) and/or processor(s), or portions thereof, that use software for operation but where the software may not be present when it is not needed for operation. As a further example, as used herein, the term “circuitry” may also cover an implementation of merely a hardware circuit or processor (or multiple processors), or portion of a hardware circuit or processor, and its accompanying software and/or firmware. The term circuitry may also cover, for example, a baseband integrated circuit in a server, cellular network node or device, or other computing or network device.

[0073] As introduced above, in certain embodiments, apparatus 20 may be a network element, node, host, or server in a communication network or serving such a network. For example, apparatus 20 may be a satellite, base station, a Node B, an evolved Node B (eNB), 5G Node B or access point, next generation Node B (NG-NB or gNB), and/or WLAN access point, associated with a radio access network (RAN), such as an LTE network, 5G or NR. According to certain embodiments, apparatus 20 may be controlled by memory 24 and processor 22 to perform the functions associated with any of the embodiments described herein.

[0074] For instance, in one embodiment, apparatus 20 may be controlled by memory 24 and processor 22 to configure a user equipment with bigger states and their associated channel state information (CSI) reporting configurations. Apparatus 20 may also be controlled by memory 24 and processor 22 to transmit to the user equipment downlink scheduling downlink control information (DCI) that indicates a single or multiple bansmission configuration indicator (TCI) states. Apparatus 20 may further be conbolled by memory 24 and processor 22 to bigger CSI reporting from the user equipment by indicating a trigger state for aperiodic or semi-persistent CSI reporting in an uplink grant DCI. In addition, apparatus 20 may be conbolled by memory 24 and processor 22 to receive a single or multiple CSI reports from the user equipment according to a selected CSI reporting configuration by the user equipment.

[0075] Further example embodiments may provide means for performing any of the functions, steps, or procedures described herein. For example, one example embodiment may be dbected to an apparatus that includes means for receiving from a network element, a downlink scheduling downlink control information (DCI) that indicates a single or multiple TCI states. The apparatus may also include means for receiving from the network element, an uplink grant DCI including an indication of a bigger state for aperiodic or semi-persistent channel state information (CSI) reporting. The apparatus may further include means for selecting a single or multiple CSI reporting configurations associated with the indicated bigger state based on a number of indicated TCI states in the downlink scheduling DCI. In addition, the apparatus may include means for performing CSI measurements based on the selected CSI reporting configuration. Further, the apparatus may include means for transmitting a single or multiple CSI reports to the network element according to the selected CSI reporting configuration.

[0076] Another example embodiment may be directed to an apparatus that includes means for configuring a user equipment with trigger states and their associated channel state information (CSI) reporting configurations. The apparatus may also include means for transmitting to the user equipment downlink scheduling downlink conbol information (DCI) that indicates a single or multiple bansmission configuration indicator (TCI) states. The apparatus may further include means for biggering CSI reporting from the user equipment by indicating a trigger state for aperiodic or semi-persistent CSI reporting in an uplink grant DCI. In addition, the apparatus may include means for receiving a single or multiple CSI reports from the user equipment according to a selected CSI reporting configuration by the user equipment. [0077] Certain example embodiments described herein provide several technical improvements, enhancements, and /or advantages. In some example embodiments, it may be possible to provide CSI reporting for multi-TRP, and carefully manage CSI reporting for multi-TRP in order to spare the network and the UE from superfluous measurements. It may also be possible to properly handle CSI triggering for multi-TRP in order to avoid high demand on trigger states, and provide an efficient and flexible aperiodic and semi-persistent CSI triggering framework, suitable for multi-TRP scenarios. According to other example embodiments, it may be possible to provide dynamic CSI triggering for single and multi-TRP while avoiding a prohibitive increase in the number of trigger states for aperiodic and semi-persistent CSI reports when multiple TRPs are configured. According to further example embodiments, the gNBs/TRPs may dynamically control the total CSI reporting payload at a fine time granularity. It may also be possible to reduce the strain on CSI trigger states as each trigger may be interpreted differently depending on the indicated TCI states. [0078] A computer program product may include one or more computer-executable components which, when the program is run, are configured to carry out some example embodiments. The one or more computer-executable components may be at least one software code or portions of it. Modifications and configurations required for implementing functionality of an example embodiment may be performed as routine(s), which may be implemented as added or updated software routine(s). Software routine(s) may be downloaded into the apparatus.

[0079] As an example, software or a computer program code or portions of it may be in a source code form, object code form, or in some intermediate form, and it may be stored in some sort of carrier, distribution medium, or computer readable medium, which may be any entity or device capable of carrying the program. Such carriers may include a record medium, computer memory, read-only memory, photoelectrical and/or electrical carrier signal, telecommunications signal, and software distribution package, for example. Depending on the processing power needed, the computer program may be executed in a single electronic digital computer or it may be distributed amongst a number of computers. The computer readable medium or computer readable storage medium may be a non-transitory medium. [0080] In other example embodiments, the functionality may be performed by hardware or circuitry included in an apparatus (e.g., apparatus 10 or apparatus 20), for example through the use of an application specific integrated circuit (ASIC), a programmable gate array (PGA), a field programmable gate array (FPGA), or any other combination of hardware and software. In yet another example embodiment, the functionality may be implemented as a signal, a non-tangible means that can be carried by an electromagnetic signal downloaded from the Internet or other network.

[0081] According to an example embodiment, an apparatus, such as a node, device, or a corresponding component, may be configured as circuitry, a computer or a microprocessor, such as single-chip computer element, or as a chipset, including at least a memory for providing storage capacity used for arithmetic operation and an operation processor for executing the arithmetic operation.

[0082] One having ordinary skill in the art will readily understand that the invention as discussed above may be practiced with steps in a different order, and/or with hardware elements in configurations which are different than those which are disclosed. Therefore, although the invention has been described based upon these example embodiments, it would be apparent to those of skill in the art that certain modifications, variations, and alternative constructions would be apparent, while remaining within the spirit and scope of example embodiments. Although the above embodiments refer to 5G NR and LTE technology, the above embodiments may also apply to any other present or future 3GPP technology, such as LTE-advanced, and/or fourth generation (4G) technology.

[0083] Partial Glossary

[0084] CRI CSI-RS Resource Indicator [0085] CSI Channel State Information [0086] CSI-RS Channel State Information-Reference Signal [0087] DCI Downlink Control Information [0088] DL Downlink [0089] DPS Dynamic Point Selection [0090] eNB Enhanced Node B [0091] FR2 Frequency Range 2 [0092] gNB 5G or Next Generation NodeB [0093] IE Information Element [0094] IMR Interference Measurement Resource [0095] JT Joint Transmission [0096] LTE Long Term Evolution [0097] MAC CE MAC Control Element [0098] NR New Radio [0099] PDCCH Physical Downlink Control Channel [0100] PDSCH Physical Downlink Shared Channel [0101] PMI Precoding Matrix Indicator [0102] PSS Primary Synchronization Signal [0103] PUCCH Physical Uplink Control Channel [0104] PUSCH Physical Uplink Shared Channel [0105] RRC Radio Resource Control [0106] SSS Secondary Synchronization Signal [0107] TRP Transmission/Reception Point [0108] UCI Uplink Control Signaling [0109] UE User Equipment [0110] UL Uplink