CPU calculation for event based CSI reporting

Abstract

A user equipment (UE) determines an event and a time window for event-based reporting. The UE triggers, due to the event, an uplink (UL) signal to transmit a channel state information (CSI) report in

Description

TECHNICAL FIELD

[0001] The present invention is related to R19 MIMO / Mobility enhancements on event triggered reporting. BACKGROUND

[0002] The RANI (Radio Access Network (Working Group) 1) specification specifies an enhancement to facilitate UE-initiated (User Equipment) or event-driven beam management for reducing overhead and / or latency, assuming the unified TCI (Transmission Configuration Indication) while leveraging as much as possible legacy CSI (Channel State Information) measurement and reporting configuration frameworks, targeting FR2 (Frequency Range 2) and sTRP (single TRP, Transmission / Reception Point)) with intra- and inter-cell beam management. This comprises UL (uplink) signaling content(s) and procedure(s) as required for UE-initiated or event-driven beam reporting facilitating fast beam switching. Furthermore, this comprises UL signaling medium or container considering the UE-initiated or event-driven nature of the UL transmission, designed primarily for the purpose of beam reporting. Additionally, one of the objectives of 3 GPP NR release 19 mobility enhancements, is to specify necessary components to support event triggered layer 1 (LI) measurement reporting (such as CSI reporting but not limited to it) for L1 / L2 triggered mobility (LTM), which may be referred also as L1 / L2 centric mobility, lower layer triggered mobility or L2 mobility.

[0003] Currently 3GPP standard 38.214 defines a periodic / semi-persistent / aperiodic measurement and reporting of LI (Layer 1) measurement quantity.

[0004] 3GPP has defined LI reporting in 3GPP standard 38.214 as follows, at first considering reporting settings.

[0005] Each Reporting Setting CSI-ReportConfig is associated with a single downlink BWP (bandwidth part) (indicated by higher layer parameter BWP-Id) given in the associated CSI-ResourceConfig for channel measurement and CSI-ReportConfig contains the parameter(s) for one CSI reporting band: codebook configuration including codebook subset restriction, time-domain behavior, frequency granularity for CQI (channel quality indicator) and PMI (precoding matrix indicator), measurement restriction configurations, and the CSI-related quantities to be reported by the UE such as the layer indicator (LI), Ll-RSRP (reference signal received power for layer 1), Ll-SINR (signal to interference plus noise ratio for layer 1), CRI (channel state information reference signal resource indicator), SSBRI (Synchronization Signal Block Resource Indicator), Capabilityindex and TDCP (time-domain channel property).

[0006] The time-domain behavior of the CSI-ReportConfig is indicated by the higher layer parameter reportConfigType and the reportConfigType can be set to 'aperiodic', 'semiPersistentOnPUCCH' (Physical Uplink Control Channel), 'semiPersistentOnPUSCH' (Physical Uplink Shared Channel), or 'periodic'. For 'periodic' and 'semiPersistentOnPUCCH' / 'semiPersistentOnPUSCH' CSI reporting, the configured periodicity and slot offset applies in the numerology of the UL BWP in which the CSI report is configured to be transmitted on. A higher layer parameter reportQuantity indicates the CSI-related, Ll-RSRP-related, Ll-SINR-related, Capabilitylndex-related or TDCP-related quantities to report. The reportFreqConfiguration indicates the reporting granularity in the frequency domain, including the CSI reporting band and if PMI / CQI reporting is wideband or sub-band. The timeRestrictionForChannelMeasurements parameter in the CSI-ReportConfig may be configured to enable time domain restriction for channel measurements and timeRestrictionForlnterferenceMeasurements may be configured to enable time domain restriction for interference measurements.

[0007] Next into resource settings, each CSI Resource Setting CSI-ResourceConfig contains a configuration of a list of S>1 CSI Resource Sets (given by higher layer parameter csi-RS-ResourceSetLisf), where the list is comprised of references to either or both of NZP (non-zero-power) CSLRS (channel state information reference signal) resource set(s) and SS / PBCH (synchronization signal / physical broadcast channel) block set(s) or the list is comprised of references to CSLIM (channel state information for interference measurement) resource set(s). Each CSI Resource Setting is located in the DL BWP (downlink bandwidth part) identified by the higher layer parameter BWP- id, and all CSI Resource Settings linked to a CSI Report Setting have the same DL BWP.

[0008] The CPU (CSI processing unit) calculation in 3GPP Technical Specification (TS) 38.214 is defined as follows, covering the CSI processing criteria as in section 5.2.1.6 ofTS 38.214.

[0009] The UE indicates the number of supported simultaneous CSI calculations NCpu with parameter simultaneousCSI-ReportsPerCC in a component carrier, and simultaneousCSI-ReportsAUCC across all component carriers. If a UE supports NCPU simultaneous CSI calculations, it is said to have NCPU CSI processing units for processing CSI reports. If L CPUs are occupied for calculation of CSI reports in a given OFDM (orthogonal frequency division multiplexing) symbol, the UE has NCPU — L unoccupied CPUs. If N CSI reports start occupying their respective CPUs on the same OFDM symbol on which NCPU — L CPUs are unoccupied, where each CSI report n = 0,..., N — 1 corresponds to Ocp[J, the UE is not required to update the N — M requested CSI reports with lowest priority (according to Clause 5.2.5), where 0 <M <N is the largest value such that Xn=o ^cpu — ^cpu — holds.

[0010] A UE is not expected to be configured with an aperiodic CSI trigger state containing more than NCPU Reporting Settings. Processing of a CSI report occupies a number of CPUs for a number of symbols as follows (in the next two paragraphs). [0011 ] OCPU = 0 for a CSI report with CSI-ReportConfig with higher layer parameter reportQuantity set to 'none' and CSI-RS-ResourceSet with higher layer parameter trs-Info configured.

[0012] OCPU = 1 for a CSI report with CSI-ReportConfig with higher layer parameter reportQuantity set to 'cri-RSRP', 'ssb-Index-RSRP', 'cri-SINR', 'ssb-Index-SINR', 'cri-RSRP-Index', 'ssb-Index-RSRP-Index', 'cri-SINR-Index', 'ssb-Index-SINR-Index ' or 'none' (and CSI-RS-ResourceSet with higher layer parameter trs-Info not configured).

[0013] For a CSI report with CSI-ReportConfig with higher layer parameter reportQuantity not set to 'none', the CPU(s) are occupied for a number of OFDM symbols as follows (in the next three paragraphs).

[0014] A periodic or semi-persistent CSI report (excluding an initial semi-persistent CSI report on PUSCH after the PDCCH (physical downlink control channel) triggering the report) occupies CPU(s) from the first symbol of the earliest one of each CSI-RS / CSI-IM / SSB (channel state information reference signal / channel state information for interference measurement / synchronization signal block) resource for channel or interference measurement, respective latest CSI-RS / CSI-IM / SSB occasion no later than the corresponding CSI reference resource, until the last symbol of the configured PUSCH / PUCCH carrying the report.

[0015] An aperiodic CSI report occupies CPU(s) from the first symbol after the PDCCH triggering the CSI report until the last symbol of the scheduled PUSCH carrying the report. When the PDCCH reception includes two PDCCH candidates from two respective search space sets, as described in clause 10.1 of 3GPP Technical Specification 38.213, for the purpose of determining the CPU occupation duration, the PDCCH candidate that ends later in time is used.

[0016] An initial semi-persistent CSI report on PUSCH after the PDCCH trigger occupies CPU(s) from the first symbol after the PDCCH until the last symbol of the scheduled PUSCH carrying the report. When the PDCCH reception includes two PDCCH candidates from two respective search space sets, as described in clause 10.1 of 3GPP Technical Specification 38.213, for the purpose of determining the CPU occupation duration, the PDCCH candidate that ends later in time is used.

[0017] The technical problem to be solved can be determined as follows.

[0018] The event-based CSI reporting is being discussed currently in R19 (Release 19) MIMO (multiple-input and multiple-output). One of the aspects of CSI reporting is the CPU calculation. Each of the reporting and measurement configurations (that are active for the UE) consume processing units (Ncpu) based on one or more metrics associated with the configuration.

[0019] Currently, the CPU calculation is defined for periodic / semi-persistent and aperiodic CSI reporting.

[0020] As an example of current periodic reporting, the CPU occupancy is as depicted in a chart 10 shown in FIG. 1.

[0021] As shown in FIG. 1, there are synchronization signal blocks SSB1 101 (shown with intact arrows) and SSB2 102 (shown with dashed arrows) locating periodically as shown, in time domain. There is a Reference Resource 103 marked as a white rectangle. The CSI processing unit (CPU) occupancy 104 is set to start from a previous SSB1 101 right before the Reference Resource 103. Then there is a Reporting Slot 105, marked as a black rectangle. The Reporting Slot 105 can be marked as n’. Then the Reference Resource 103 can be marked as: Reference Resource = n’ - nCSIref (1)

[0022] The CPU occupancy 104 end time may be determined at the end of the Reporting Slot 105. Hence, the length of the CPU occupancy 104 along the time domain can be seen with the thick arrow on the top side of the illustration.

[0023] The technical problem is that CPU calculation for event-triggered CSI reporting is currently unclear. SUMMARY

[0024] The present invention presents new ways of determining starting and end times to CSI processing unit occupancy. Event-based CSI reporting is discussed in this connection. The UE has certain limitations regarding the CSI report sending, and also regarding the number of occupied CSI processing units. The present invention thus determines the CPU occupancy time interval in various different situations in a clearer fashion. In some embodiments, the end time of the CPU occupancy is discussed, and in some other embodiments, the start time of the CPU occupancy is discussed.

[0025] According to a first aspect of the present invention, there is provided an apparatus, comprising: means for determining an event for reporting; means for triggering, due to the event, an uplink signal indicating transmission of a Channel State Information, CSI, report, wherein the CSI report is scheduled to be transmitted in a reporting slot or an uplink signal indicating the event or an uplink signal requesting reporting resources; and means for determining an ending time for CSI processing unit, CPU, occupancy so that the CPU occupancy lasts until the reporting slot in case the uplink signal indicates the event.

[0026] In an embodiment, the apparatus further comprises: means for transmitting the CSI report in the reporting slot, wherein the CSI report is part of the transmitted uplink signal.

[0027] In an embodiment, the uplink signaling occasion is a symbol or a slot comprising uplink signaling.

[0028] In an embodiment, the event is a CSI reporting event in a configured or scheduled uplink resource.

[0029] In an embodiment, the uplink signal is a Physical Uplink Shared Channel, PUSCH, a Physical Uplink Control Channel, PUCCH, a Scheduling Request, SR, or a Physical Random Access Channel, PRACH.

[0030] In an embodiment, the CPU occupancy starts on an earliest downlink measurement reference signal before the determined event takes place.

[0031] In an embodiment, the CPU occupancy starts at a temporal location of the slot where the event for reporting is triggered.

[0032] In an embodiment, the CPU occupancy lasts until the last symbol or slot of the transmission of the event-triggered CSI report.

[0033] In an embodiment, a reference point specific for event-based CSI reporting is a first symbol of an earliest one of each channel measurement resource, wherein a respective latest channel measurement reference signal occasion locates no later than a corresponding CSI reference resource.

[0034] In an embodiment, a reference point specific for event-based CSI reporting is a first symbol or slot of a channel measurement resource, where the event has been triggered.

[0035] In an embodiment, the slot or symbol where for the event-based CSI reporting it is determined that the at least one condition or criterion for the event is not fulfilled, the CSI report does not occupy CPU resources from that slot onwards.

[0036] In an embodiment, the apparatus further comprises: means for determining a Downlink Control Information, DCI, scheduling the uplink resource for event-triggered CSI reporting; means for determining a start of CPU occupancy either on the symbol or slot of the uplink indication or the first symbol or slot after the uplink indication; and means for determining an end of CPU occupancy at the last symbol of the transmitted CSI report part of the transmitted uplink signal.

[0037] In an embodiment, the apparatus further comprises: means for determining a Downlink Control Information, DCI, scheduling the uplink resource for event-triggered CSI reporting; means for determining a start of CPU occupancy on the first symbol of the physical downlink control channel, PDCCH, or on the first symbol after the PDCCH triggering the CSI report; and means for determining an end of CPU occupancy at the last symbol of the transmitted CSI report part of the transmitted uplink signal.

[0038] In an embodiment, the scheduled uplink resource is either a PUCCH or a PUSCH.

[0039] In an embodiment, the CSI reference resource in the given slot representing the event is a valid downlink slot specific for event-based reporting.

[0040] In an embodiment, the transmitted CSI report has a reporting quantity set to either reference signal received power, RSRP, or signal to interference plus noise ratio for layer 1, Ll-SINR.

[0041] According to a second aspect of the present invention, there is provided an apparatus comprising at least one processor and at least one memory, said at least one memory stored with computer program code thereon, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: determining an event for reporting; triggering, due to the event, an uplink signal indicating transmission of a Channel State Information, CSI, report, wherein the CSI report is scheduled to be transmitted in a reporting slot or an uplink signal indicating the event or an uplink signal requesting reporting resources; and determining an ending time for CSI processing unit, CPU, occupancy so that the CPU occupancy lasts until the reporting slot in case the uplink signal indicates the event.

[0042] The above embodiments associated with the first aspect of the invention are also applicable in connection with the second aspect of the invention.

[0043] According to a third aspect of the present invention, there is a method, which comprises: determining, in a User Equipment, UE, an event for reporting; triggering, in the UE, due to the event, an uplink signal indicating transmission of a Channel State Information, CSI, report, wherein the CSI report is scheduled to be transmitted in a reporting slot or an uplink signal indicating the event or an uplink signal requesting reporting resources; and determining, in the UE, an ending time for CSI processing unit, CPU, occupancy so that the CPU occupancy lasts until the reporting slot in case the uplink signal indicates the event.

[0044] The above embodiments associated with the first aspect of the invention are also applicable in connection with the third aspect of the invention.

[0045] According to a fourth aspect of the present invention, there is a computer program comprising instructions which, when executed by an apparatus, cause the apparatus to perform at least the following: determining an event for reporting; triggering, due to the event, an uplink signal indicating transmission of a Channel State Information, CSI, report, wherein the CSI report is scheduled to be transmitted in a reporting slot or an uplink signal indicating the event or an uplink signal requesting reporting resources; and determining an ending time for CSI processing unit, CPU, occupancy so that the CPU occupancy lasts until the reporting slot in case the uplink signal indicates the event.

[0046] The above embodiments associated with the first aspect of the invention are also applicable in connection with the fourth aspect of the invention.

[0047] According to a fifth aspect of the present invention, there is a computer program product, stored on a non-transitory memory medium, comprising computer program code, which when executed by at least one processor, causes an apparatus at least to perform: determining an event for reporting; triggering, due to the event, an uplink signal indicating transmission of a Channel State Information, CSI, report, wherein the CSI report is scheduled to be transmitted in a reporting slot or an uplink signal indicating the event or an uplink signal requesting reporting resources; and determining an ending time for CSI processing unit, CPU, occupancy so that the CPU occupancy lasts until the reporting slot in case the uplink signal indicates the event.

[0048] The above embodiments associated with the first aspect of the invention are also applicable in connection with the fifth aspect of the invention.

[0049] According to a sixth aspect of the present invention, there is provided an apparatus, comprising: means for determining an event for reporting; means for triggering, due to the event, an uplink signal indicating transmission of a Channel State Information, CSI, report, wherein the CSI report is scheduled to be transmitted in a reporting slot or an uplink signal indicating the event or an uplink signal requesting reporting resources; and means for determining an ending time for CSI processing unit, CPU, occupancy so that the CPU occupancy lasts based on the uplink signaling occasion in case the uplink signal does not indicate the event.

[0050] In an embodiment, the apparatus further comprises: means for transmitting the CSI report in the reporting slot, wherein the CSI report is part of the transmitted uplink signal.

[0051] In an embodiment, the uplink signaling occasion is a symbol or a slot comprising uplink signaling.

[0052] In an embodiment, the event is a CSI reporting event in a configured or scheduled uplink resource.

[0053] In an embodiment, the uplink signal is a Physical Uplink Shared Channel, PUSCH, a Physical Uplink Control Channel, PUCCH, a Scheduling Request, SR, or a Physical Random Access Channel, PRACH.

[0054] In an embodiment, the CPU occupancy starts on an earliest downlink measurement reference signal before the determined event takes place.

[0055] In an embodiment, the CPU occupancy starts at a temporal location of the slot where the event for reporting is triggered.

[0056] In an embodiment, the CPU occupancy lasts until the last symbol or slot of the transmission of the event-triggered CSI report.

[0057] In an embodiment, a reference point specific for event-based CSI reporting is a first symbol of an earliest one of each channel measurement resource, wherein a respective latest channel measurement reference signal occasion locates no later than a corresponding CSI reference resource.

[0058] In an embodiment, a reference point specific for event-based CSI reporting is a first symbol or slot of a channel measurement resource, where the event has been triggered.

[0059] In an embodiment, the slot or symbol where for the event-based CSI reporting it is determined that the at least one condition or criterion for the event is not fulfilled, the CSI report does not occupy CPU resources from that slot onwards.

[0060] In an embodiment, the scheduled uplink resource is either a PUCCH or a PUSCH.

[0061] In an embodiment, the CSI reference resource in the given slot representing the event is a valid downlink slot specific for event-based reporting.

[0062] In an embodiment, the transmitted CSI report has a reporting quantity set to either reference signal received power, RSRP, or signal to interference plus noise ratio for layer 1, Ll-SINR.

[0063] According to a seventh aspect of the present invention, there is provided an apparatus comprising at least one processor and at least one memory, said at least one memory stored with computer program code thereon, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: determining an event for reporting; triggering, due to the event, an uplink signal indicating transmission of a Channel State Information, CSI, report, wherein the CSI report is scheduled to be transmitted in a reporting slot or an uplink signal indicating the event or an uplink signal requesting reporting resources; and determining an ending time for CSI processing unit, CPU, occupancy so that the CPU occupancy lasts based on the uplink signaling occasion in case the uplink signal does not indicate the event.

[0064] The above embodiments associated with the sixth aspect of the invention are also applicable in connection with the seventh aspect of the invention.

[0065] According to an eighth aspect of the present invention, there is a method, which comprises: determining, in a User Equipment, UE, an event for reporting; triggering, in the UE, due to the event, an uplink signal indicating transmission of a Channel State Information, CSI, report, wherein the CSI report is scheduled to be transmitted in a reporting slot or an uplink signal indicating the event or an uplink signal requesting reporting resources; and determining, in the UE, an ending time for CSI processing unit, CPU, occupancy so that the CPU occupancy lasts based on the uplink signaling occasion in case the uplink signal does not indicate the event.

[0066] The above embodiments associated with the sixth aspect of the invention are also applicable in connection with the eighth aspect of the invention.

[0067] According to a ninth aspect of the present invention, there is a computer program comprising instructions which, when executed by an apparatus, cause the apparatus to perform at least the following: determining an event for reporting; triggering, due to the event, an uplink signal indicating transmission of a Channel State Information, CSI, report, wherein the CSI report is scheduled to be transmitted in a reporting slot or an uplink signal indicating the event or an uplink signal requesting reporting resources; and determining an ending time for CSI processing unit, CPU, occupancy so that the CPU occupancy lasts based on the uplink signaling occasion in case the uplink signal does not indicate the event.

[0068] The above embodiments associated with the sixth aspect of the invention are also applicable in connection with the ninth aspect of the invention.

[0069] According to a tenth aspect of the present invention, there is a computer program product, stored on a non-transitory memory medium, comprising computer program code, which when executed by at least one processor, causes an apparatus at least to perform: determining an event for reporting; triggering, due to the event, an uplink signal indicating transmission of a Channel State Information, CSI, report, wherein the CSI report is scheduled to be transmitted in a reporting slot or an uplink signal indicating the event or an uplink signal requesting reporting resources; and determining an ending time for CSI processing unit, CPU, occupancy so that the CPU occupancy lasts based on the uplink signaling occasion in case the uplink signal does not indicate the event.

[0070] The above embodiments associated with the sixth aspect of the invention are also applicable in connection with the tenth aspect of the invention.

[0071] According to an eleventh aspect of the present invention, there is provided an apparatus, comprising: means for determining an event for reporting; means for determining a time window for the apparatus for the event-based reporting; means for triggering, due to the event, an uplink signal indicating transmission of a Channel State Information, CSI, report, wherein the CSI report is scheduled to be transmitted in a reporting slot or an uplink signal indicating the event or an uplink signal requesting reporting resources; means for determining an ending time for CSI processing unit, CPU, occupancy so that the CPU occupancy lasts until the reporting slot in case the uplink signal indicates the event; means for determining an ending time for CPU occupancy so that the CPU occupancy lasts based on the uplink signaling occasion in case the uplink signal does not indicate the event; means for using the determined time window for adjusting the total CPU load; and means for delaying the actual event-based reporting so that a transmission time instant of the CSI report remains within the determined time window.

[0072] In an embodiment, by adjusting the total CPU load, the apparatus is configured to be capable of maximizing up-to-date CSI reports sent to the network.

[0073] In an embodiment, the apparatus further comprises: means for transmitting the CSI report in the reporting slot, wherein the CSI report is part of the transmitted uplink signal.

[0074] In an embodiment, the uplink signaling occasion is a symbol or a slot comprising uplink signaling.

[0075] In an embodiment, the event is a CSI reporting event in a configured or scheduled uplink resource.

[0076] In an embodiment, the uplink signal is a Physical Uplink Shared Channel, PUSCH, a Physical Uplink Control Channel, PUCCH, a Scheduling Request, SR, or a Physical Random Access Channel, PRACH.

[0077] In an embodiment, the CPU occupancy starts on an earliest downlink measurement reference signal before the determined event takes place.

[0078] In an embodiment, the CPU occupancy starts at a temporal location of the slot where the event for reporting is triggered.

[0079] In an embodiment, the CPU occupancy lasts until the last symbol or slot of the transmission of the event-triggered CSI report.

[0080] In an embodiment, a reference point specific for event-based CSI reporting is a first symbol of an earliest one of each channel measurement resource, wherein a respective latest channel measurement reference signal occasion locates no later than a corresponding CSI reference resource.

[0081] In an embodiment, a reference point specific for event-based CSI reporting is a first symbol or slot of a channel measurement resource, where the event has been triggered.

[0082] In an embodiment, the slot or symbol where for the event-based CSI reporting it is determined that the at least one condition or criterion for the event is not fulfilled, the CSI report does not occupy CPU resources from that slot onwards.

[0083] In an embodiment, the apparatus further comprises: means for determining a Downlink Control Information, DCI, scheduling the uplink resource for event-triggered CSI reporting; means for determining a start of CPU occupancy either on the symbol or slot of the uplink indication or the first symbol or slot after the uplink indication; and means for determining an end of CPU occupancy at the last symbol of the transmitted CSI report part of the transmitted uplink signal.

[0084] In an embodiment, the apparatus further comprises: means for determining a Downlink Control Information, DCI, scheduling the uplink resource for event-triggered CSI reporting; means for determining a start of CPU occupancy on the first symbol of the physical downlink control channel, PDCCH, or on the first symbol after the PDCCH triggering the CSI report; and means for determining an end of CPU occupancy at the last symbol of the transmitted CSI report part of the transmitted uplink signal.

[0085] In an embodiment, the scheduled uplink resource is either a PUCCH or a PUSCH.

[0086] In an embodiment, the CSI reference resource in the given slot representing the event is a valid downlink slot specific for event-based reporting.

[0087] In an embodiment, the transmitted CSI report has a reporting quantity set to either reference signal received power, RSRP, or signal to interference plus noise ratio for layer 1, Ll-SINR.

[0088] In an embodiment, if the event is a reference signal received power, RSRP, event, and one measurement resource fulfils a RSRP level criterion, the CPU occupancy starts on the symbol or slot where the RSRP of the measurement resource was measured or on the symbol or slot when the measurement resources were measured.

[0089] According to a twelfth aspect of the present invention, there is provided an apparatus comprising at least one processor and at least one memory, said at least one memory stored with computer program code thereon, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: determining an event for reporting; determining a time window for the apparatus for the event-based reporting; triggering, due to the event, an uplink signal indicating transmission of a Channel State Information, CSI, report, wherein the CSI report is scheduled to be transmitted in a reporting slot or an uplink signal indicating the event or an uplink signal requesting reporting resources; determining an ending time for CSI processing unit, CPU, occupancy so that the CPU occupancy lasts until the reporting slot in case the uplink signal indicates the event; determining an ending time for CPU occupancy so that the CPU occupancy lasts based on the uplink signaling occasion in case the uplink signal does not indicate the event; using the determined time window for adjusting the total CPU load; and delaying the actual event-based reporting so that a transmission time instant of the CSI report remains within the determined time window.

[0090] The above embodiments associated with the eleventh aspect of the invention are also applicable in connection with the twelfth aspect of the invention.

[0091] According to a thirteenth aspect of the present invention, there is a method, which comprises: determining, in a User Equipment, UE, an event for reporting; determining, in the UE, a time window for the apparatus for the event-based reporting; triggering, in the UE, due to the event, an uplink signal indicating transmission of a Channel State Information, CSI, report, wherein the CSI report is scheduled to be transmitted in a reporting slot or an uplink signal indicating the event or an uplink signal requesting reporting resources; determining, in the UE, an ending time for CSI processing unit, CPU, occupancy so that the CPU occupancy lasts until the reporting slot in case the uplink signal indicates the event; determining, in the UE, an ending time for CPU occupancy so that the CPU occupancy lasts based on the uplink signaling occasion in case the uplink signal does not indicate the event; using, in the UE, the determined time window for adjusting the total CPU load; and delaying, in the UE, the actual event-based reporting so that a transmission time instant of the CSI report remains within the determined time window.

[0092] The above embodiments associated with the eleventh aspect of the invention are also applicable in connection with the thirteenth aspect of the invention.

[0093] According to a fourteenth aspect of the present invention, there is a computer program comprising instructions which, when executed by an apparatus, cause the apparatus to perform at least the following: determining an event for reporting; determining a time window for the apparatus for the event-based reporting; triggering, due to the event, an uplink signal indicating transmission of a Channel State Information, CSI, report, wherein the CSI report is scheduled to be transmitted in a reporting slot or an uplink signal indicating the event or an uplink signal requesting reporting resources; determining an ending time for CSI processing unit, CPU, occupancy so that the CPU occupancy lasts until the reporting slot in case the uplink signal indicates the event; determining an ending time for CPU occupancy so that the CPU occupancy lasts based on the uplink signaling occasion in case the uplink signal does not indicate the event; using the determined time window for adjusting the total CPU load; and delaying the actual event-based reporting so that a transmission time instant of the CSI report remains within the determined time window.

[0094] The above embodiments associated with the eleventh aspect of the invention are also applicable in connection with the fourteenth aspect of the invention.

[0095] According to a fifteenth aspect of the present invention, there is a computer program product, stored on a non-transitory memory medium, comprising computer program code, which when executed by at least one processor, causes an apparatus at least to perform: determining an event for reporting; determining a time window for the apparatus for the event-based reporting; triggering, due to the event, an uplink signal indicating transmission of a Channel State Information, CSI, report, wherein the CSI report is scheduled to be transmitted in a reporting slot or an uplink signal indicating the event or an uplink signal requesting reporting resources; determining an ending time for CSI processing unit, CPU, occupancy so that the CPU occupancy lasts until the reporting slot in case the uplink signal indicates the event; determining an ending time for CPU occupancy so that the CPU occupancy lasts based on the uplink signaling occasion in case the uplink signal does not indicate the event; using the determined time window for adjusting the total CPU load; and delaying the actual event-based reporting so that a transmission time instant of the CSI report remains within the determined time window.

[0096] The above embodiments associated with the eleventh aspect of the invention are also applicable in connection with the fifteenth aspect of the invention.

[0097] In various embodiments of the apparatus specified above, the apparatus may comprise at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the performance of the apparatus. In an embodiment, the apparatus is a UE. BRIEF DESCRIPTION OF THE DRAWINGS

[0098] FIG. 1 illustrates an example of a currently applied periodic reporting of the CPU occupancy;

[0099] FIG. 2 illustrates a first embodiment of a CSI processing unit occupancy calculation;

[0100] FIG. 3 illustrates a second embodiment of a CSI processing unit occupancy calculation;

[0101] FIG. 4 illustrates a third embodiment of a CSI processing unit occupancy calculation;

[0102] FIG. 5 illustrates a fourth embodiment of a CSI processing unit occupancy calculation;

[0103] FIG. 6a illustrates an exemplary radio network scenario in accordance with at least some embodiments of the present invention; and

[0104] FIG. 6b illustrates a simplified block diagram of a network node according to an embodiment of the present invention. DETAILED DESCRIPTION

[0105] The following describes in further detail suitable apparatus and possible mechanisms carrying out CPU occupancy determination for event-triggered CSI reporting. While the following focuses on 5G and / or 6G networks, the embodiments as described further below are by no means limited to be implemented in said networks only, but they are applicable in any network supporting the CPU occupancy determination procedures for event-triggered CSI reporting.

[0106] An embodiment comprises the following steps, considering the User Equipment side i.e. the apparatus.

[0107] At a first step, the apparatus comprises means for determining an event for reporting.

[0108] In some examples, the event for reporting may be one or more of the following (including but not limited to): Event-1: Quality (e.g. Ll-RSRP) of a reference signal is worse than a configured threshold. Event-2: Quality of at least one reference signal becomes a threshold value better than certain reference signal (such as reference signal corresponding to the PDCCH / PDSCH reception and / or PUCCH / PUSCH transmission). Event-3: Quality of a reference signal is better than a certain threshold.

[0109] In some example embodiments, the reporting triggered by an event may comprise of reporting downlink reference signal(s) and the measured quality of the reference signal(s).

[0110] At a second step, the apparatus comprises means for determining a time window for the apparatus for the event-based reporting.

[0111] At a third step, the apparatus comprises means for triggering, due to the event, an uplink signal indicating transmission of a Channel State Information, CSI, report, wherein the CSI report is scheduled to be transmitted in a reporting slot or an uplink signal indicating the event or an uplink signal requesting reporting resources.

[0112] At a fourth step, the apparatus comprises means for determining an ending time for CSI processing unit, CPU, occupancy so that the CPU occupancy lasts until the reporting slot in case the uplink signal indicates the event.

[0113] At a fifth step, the apparatus comprises means for determining an ending time for CPU occupancy so that the CPU occupancy lasts based on the uplink signaling occasion in case the uplink signal does not indicate the event.

[0114] At a sixth step, the apparatus comprises means for using the determined time window for adjusting the total CPU load.

[0115] At a seventh step, the apparatus comprises means for delaying the actual event-based reporting so that a transmission time instant of the CSI report remains within the determined time window.

[0116] In other words, there are three alternative parts in the above embodiment, namely: 1) means for triggering, due to the event, an uplink signal indicating transmission of a Channel State Information, CSI, report, wherein the CSI report is scheduled to be transmitted in a reporting slot. In other words, the 1st option is that the CSI report is indicated to be transmitted on the reporting slot associated with the uplink signal. 2) or means for triggering, due to the event, an uplink signal indicating the event. In other words, the 2nd option is that the uplink signal indicates the event but the reporting resource may be scheduled by the network. The uplink signal only indicates the event, so this is more general and could cover multiple ways to report, such as aperiodic reporting, for instance. 3) or means for triggering, due to the event, an uplink signal requesting reporting resources. In other words, the 3rd option is that the uplink signal indicates the event but the reporting resource may be scheduled by the network based on the uplink signal requesting the resource. The uplink signal indicates that the UE requests reporting resources.

[0117] In a further example embodiment, an apparatus comprises means for determining an event for reporting; means for triggering, due to the event, an uplink signal indicating transmission of a Channel State Information, CSI, report, wherein the CSI report is scheduled to be transmitted in a reporting slot or an uplink signal indicating the event or an uplink signal requesting reporting resources; means for determining an ending time for CSI processing unit, CPU, occupancy by following conditions: if the uplink signal indicates the event, the CPU occupancy lasts until the reporting slot, and if the uplink signal does not indicate the event, the CPU occupancy lasts based on the uplink signaling occasion.

[0118] The above steps form a respective embodiment involving the apparatus which in this case is a UE. Furthermore, the embodiments also relate to other aspects, for example a respective method, computer program, and computer program product. On the other hand, certain steps may be initiated by the base station, so an aspect is a telecommunication system (or connection) involving a base station and a UE. Embodiments may relate to various different telecommunication technologies, such as 5G and 6G, for instance.

[0119] Concerning CSI processing units (i.e. CPUs), the UE needs to determine the used CPUs per a CSI report when configured with CSI reporting. The UE may indicate the number of supported simultaneous CSI calculations (e.g. a number of CPUs) to the network. The (maximum) number of simultaneous CPUs may be carrier-specific (e.g. per one carrier / component carrier) and / or across multiple component carriers. There is a certain limit for a number of CSI reports, which the UE is capable to handle and the limitation is handled and monitored based on CPUs.

[0120] Specific boundaries may be set for the (number of) CPU occupancy in the time domain, so that there is a determined starting time for the CPUs (i.e. CPU occupancy) and a determined ending time for the CPUs in the UE. This time interval is the same as the CPU occupancy in the UE. The time occupancy may be calculated per each CSI report. Multiple CSI reports may occupy CPU units at the same time instance. Specific CSI report, depending on the type may have different start and end time for the report specific CPU occupancy.

[0121] In the present invention, the problem of determining occupancy of CSI processing units (i.e. CPUs) for event-based CSI reporting is considered, with various embodiment examples.

[0122] In other words, a new reporting mode is presented regarding CPUs in Layer 1 reporting for the UE.

[0123] More precisely, in the present invention, the CPU occupancy time is proposed for the event-based CSI report in which the CPU occupancy is based on the UL signal used to trigger the indication that an event has occurred and / or based on whether the UE has determined that the event-based reporting is to be performed (i.e. report is triggered or to be transmitted).

[0124] In an embodiment of the present invention, a chart 20 in FIG. 2 is referred to. In this illustration, there is a pre-determined event 203, which in this embodiment is CSI Reference Resource slot n. The event 203 is marked with a white rectangle with intact outer lines in the illustration. SSBls 201 and SSB2s 202 are illustrated with the arrows similarly as in FIG. 1, in a periodic style for both the SSBls 201 and the SSB2s 202. Alternatively, the arrows could represent CSI-RS or any DL RS configured for measurement (and reporting).

[0125] Then in this embodiment, the UE triggers an uplink signal 205 which indicates a reporting event on a configured uplink resource. The uplink signal 205 is marked as a grey rectangle in the illustration. This uplink signal 205 comprises the information that there was an event 203 (e.g. the UE indicates that a reporting event has occurred) on slot n, and that the CSI reporting should take place on reporting slot n’ 206. In the illustration, reporting slot n’ 206 is marked as a white rectangle limited by dashed, longer and thicker grey lines.

[0126] It is noted in this embodiment that the CPU occupancy 204 may start on a previous measurement RS (SSB1 201) right before the determined event 203 (= CSI Reference Resource slot n). Alternatively, the CPU occupancy 204 may start on some other earlier measurement RS (SSB1 201) before the event, i.e. on the 2nd, 3rd, 4th or so on measurement RS (SSB1) before the event 203 takes place. The illustration shows the option of selecting the starting time of the CPU occupancy 204 on the 2nd measurement RS (SSB1 201) before the event 203 takes place, as an example among many possible options.

[0127] In this embodiment shown in FIG. 2, the ending time of the CSI processing unit (= CPU) occupancy 204 is determined to happen at the end of the reporting slot n' 206. Two uppermost arrows show the temporal duration of the CPU occupancy 204, and also the ending time for the CPU occupancy 204. In practice, and in an embodiment, the CPU occupancy 204 will last until the last symbol of the actual eventbased reporting performed in the reporting slot n’ 206.

[0128] In an embodiment, the report in the reporting slot n’ 206 may be carried by a scheduled PUSCH or PUCCH. In other words, the PUSCH or PUCCH transmitted in a UL direction may comprise the CSI report. In that sense, the last symbol of that specific PUSCH or PUCCH then determines the ending time for the CSI processing unit occupancy 204.

[0129] In other words, summarizing the first main embodiment 20 as illustrated in FIG. 2, an event-triggered CSI report occupies CSI processing unit(s) on one or more symbols starting from a reference point specific for event-based reporting until the last symbol of the configured uplink resource for the event-based reporting (e.g. PUSCH or PUCCH) if the UE has triggered an uplink signal 205 (= the grey box) indicating the reporting event on the configured uplink resource. In this embodiment, an uplink channel carries the event-triggered CSI report.

[0130] In a further embodiment of the present invention, a chart 30 in FIG. 3 is referred to. In this illustration, there is a pre-determined event 303, which in this embodiment is CSI Reference Resource slot n. The event 303 is marked with a white rectangle with intact outer lines in the illustration. SSBls 301 and SSB2s 302 are illustrated with the arrows similarly as in FIG. 1 and in FIG. 2, in a periodic style for both the SSBls 301 and the SSB2s 302. The arrows could similarly illustrate CSI-RS or any DL-RS used for measurements for the reporting configuration.

[0131] Then in this embodiment, the UE transmits an uplink (UL) signal 305 but the UL signal does not indicate any reporting on a reporting slot n’ 306. The uplink signal 305 is marked as a white rectangle with shorter and thinner dashed outer lines in the illustration.

[0132] In the illustration, reporting slot n’ 306 is marked as a white rectangle limited by dashed, longer and thicker grey lines.

[0133] The starting time of the CPU occupancy 304 may be organized similarly as described above in connection with FIG. 2.

[0134] However, the ending time of the CPU occupancy 304 is defined differently.

[0135] In this embodiment 30 shown in FIG. 3, the ending time of the CSI processing unit (= CPU) occupancy 304 is determined to happen at the end of the uplink signal 305 transmitted by the UE. Two uppermost arrows show the temporal duration of the CPU occupancy 304, and also the ending time for the CPU occupancy 304. In practice, and in an embodiment, the CPU occupancy 304 will last until the last symbol of the configured uplink resource, i.e. until the last symbol of the UL signal 304 which is not indicating the reporting on the reporting slot n’ 306.

[0136] In one example, the UL signal 305 may refer to e.g. SR (scheduling request), PRACH (Physical Random Access Channel) preamble, SRS (Sounding Reference Signal), PUCCH (format) conveying indication associated with even based reporting or reporting event or any uplink signal that is configured in association with event-triggered reporting (i.e. to indicate event, indicate the use of UL resource for reporting of an event or request resource for reporting an event-triggered report).

[0137] In one example, the CSI reporting may be conveyed using a MAC CE.

[0138] It can be summarized for the embodiment 30 shown in FIG. 3 that the UE has nothing to report in this situation on the reporting slot n’ 306, regarding the CSI reports.

[0139] In other words, summarizing the second main embodiment 30 as illustrated in FIG. 3, an event-triggered CSI report occupies CSI processing unit(s) on one or more symbols starting from a reference point specific for event-based reporting until the last symbol of the configured uplink resource for the signal indicating the reporting event if the UE did not trigger an uplink signal indicating the reporting event. In this embodiment, an uplink channel triggers the event-triggered CSI report, but no actual CSI report is transmitted by the UE in this particular situation. Hence, in other words, the uplink channel does not carry the actual event-triggered CSI report.

[0140] This operational mode has a technical effect where the number of event-triggered CSI reports (and the CSI reports occupying CPUs) will be decreased. As there is a certain limit on the number of CSI reports which a UE is able to handle, this relieves the burden on the UE in this sense. This represents a clear advantage in the event-based channel state information reporting.

[0141] In one example embodiment, an event-triggered CSI report occupies CPU(s) on one or more symbols starting from a reference point specific for event-based reporting until N symbols or slots before the configured uplink resource for the eventbased reporting if it is determined that a reporting event has not been triggered, wherein N is a positive integer.

[0142] In one example embodiment, an event-triggered CSI report occupies CPU(s) on one or more symbols starting from a reference point specific for event-based reporting until a first symbol of the configured uplink resource for the event-based reporting if it is determined that a reporting event has not been triggered.

[0143] In one example embodiment, wherein a reference point specific for eventbased CSI reporting is a first symbol of an earliest one of each channel measurement resource, wherein a respective latest channel measurement reference signal occasion locates no later than a corresponding CSI reference resource.

[0144] In one example embodiment, wherein a reference point specific for eventbased CSI reporting is a first symbol or slot of the channel measurement resource, where the event has been triggered. In an embodiment, the event is triggered when the at least one condition or criterion for an event has been determined to be fulfilled. Furthermore, a following example is presented. If the event is an RSRP (reference signal received power) event, and one measurement resource fulfils a RSRP level criterion, the CPU occupancy starts on the symbol or slot where the RSRP of the measurement resource was measured OR on the symbol or slot when the measurement resources were measured.

[0145] In one example embodiment, the slot or symbol where for the event-based CSI reporting it is determined that the at least one condition or criterion for the event is not fulfilled, the CSI report does not occupy CPU resources from that slot (or symbol) onwards.

[0146] In a further embodiment 40 of the present invention, FIG. 4 is referred to.

[0147] In this example embodiment 40 according to FIG. 4, an event-based CSI report occupies CPU(s) from the first symbol after the uplink indication (or starting from the slot or symbol where the signal is transmitted) for the event-based reporting until the last symbol of the scheduled PUSCH or PUCCH carrying the CSI report. In other words, the start of the CPU occupancy 404 is, in a first option, on the symbol or slot of the uplink indication. Alternatively, the start of the CPU occupancy 404 is, in a second option, on the first slot or symbol after the uplink indication. Marking the start of the CPU occupancy 404 in the illustration, there is the UL signal 405 on slot n’ event to indicate event-triggered reporting (the rectangle with thin dashed outer lines). After the UL signal 405, there is a DCI 407 (downlink control information) scheduling the uplink resource for event-triggered reporting. This is marked as the rectangle with the text “DCI”. After the DCI407 block, there is a reporting slot n’ 406 marked with thicker grey dashed outer lines. In the reporting slot n’ 406, the actual reporting on scheduled resource takes place. Simultaneously, at the end of the reporting slot n’ 406, the end of CPU occupancy 404 is determined in this embodiment. Now the whole CPU occupancy 404 time interval can be seen as the topmost thicker horizontal arrow shows. As in the earlier embodiments, the left-hand most block in the time domain is the CSI reference resource slot n, representing the event 403.

[0148] In a further embodiment 50 of the present invention, FIG. 5 is referred to. FIG. 5 represents an alternative option to the embodiment already discussed above in connection with FIG. 4.

[0149] As illustrated in FIG. 5, in one example embodiment, an event-triggered (scheduled) CSI report occupies CPU(s) from the first symbol after the PDCCH triggering the CSI report until the last symbol of the scheduled UL resource carrying the CSI report on the reporting slot n’ 506. In other words, the CPU occupancy 504 starts at the starting point of the DCI 507 scheduling the uplink resource for the CSI report (i.e. for the event-triggered reporting). The CPU occupancy 504 ends at the end (= at the last symbol or slot) of the CSI reporting on scheduled resource on the reporting slot n’ 506, i.e. at the end of the reporting slot n’ 506. This CPU occupancy 504 time interval is shown in the top of the graph, too, with the thicker arrow. As in the previous embodiments and illustrations, the left-hand most block in the time domain is the CSI reference resource slot n, representing the event 503. After that, there is the UL signal 505 on slot n’ event to indicate the event-triggered reporting, shown as a rectangle with thinner dashed outer lines. In this embodiment, the CPU occupancy 504 is relatively short compared to the earlier embodiments. When comparing the alternative embodiments of FIG. 5 and FIG. 4 specifying the DCI, clearly the CPU occupancy 504 time interval of the FIG. 5 embodiment is shorter than the CPU occupancy 404 time interval of the FIG. 4 embodiment.

[0150] In a further embodiment in connection to the arrangement illustrated in FIG. 5, the scheduled UL resource is either a PUCCH or a PUSCH.

[0151] In one example embodiment, the CSI reference resource (at slot n representing an event) is a valid downlink slot specific for event-based reporting.

[0152] In one example embodiment, the reported CSI report has a reporting quantity set to either reference signal received power (RSRP) or signal to interference plus noise ratio for layer 1 (Ll-SINR).

[0153] Regarding the used notation, in an embodiment where the uplink signal does not indicate the event, this may mean at least two different possible scenarios. At a first possible option, it means that the uplink signal is not transmitted in the first place. At a second possible option, it means that the uplink signal is transmitted but the uplink signal does not indicate any event (or it indicates that no event has been triggered).

[0154] In one exemplary embodiment, there is determined a time window for the UE for the event-based reporting so that the UE uses the determined time window for adjusting the total CPU load so that the UE is able to maximize up-to-date CSI reports sent to the network. Hence, the UE may delay the actual event-based reporting as long as the transmission time instant of the CSI report would still be within the UE-defined time window. The time window is however defined so that the delay for the eventbased reporting is not significant. In other words, the delay for the event-based reporting may be set to be relatively small. In this exemplary embodiment, there is an advantage that the UE may have a better overall performance, when the UE is configured with both non-event-based and event-based CSI reporting.

[0155] In an embodiment of the present invention, the above discussed User Equipment 610 is a smartphone.

[0156] In a more general fashion, certain apparatus and network arrangements are disclosed next, and the present invention is applicable in these various telecommunication connection arrangements.

[0157] FIG:s 6a and 6b illustrate an example of a wireless telecommunication network implementation and an apparatus as part of the exemplary telecommunication network implementation.

[0158] FIG. 6a illustrates an exemplary radio network scenario in accordance with at least some embodiments of the present invention.

[0159] FIG. 6a illustrates an exemplary radio network scenario in accordance with at least some embodiments of the present invention. According to the example scenario of FIG. 6a, there may be a wireless communication network, which comprises User Equipment, UE 610, an access node, such as a Base Station, BS, 620, and core network element 630.

[0160] The present invention focuses on the UE 610 side of a wireless telecommunication connection, and FIG. 6a presents an example of an uplink and a downlink connection, i.e. the UE 610 transmits, and the base station 620 receives, or vice versa. In an example, some of the actions may be performed in the UE 610, and some other actions may be performed in the base station 620.

[0161] The configuration of FIG. 6a presents merely a single example of many possible apparatuses within many possible wireless communication systems. Thus, the present invention is not restricted solely to apparatus, connection type / direction and system examples of FIG: s 6a and 6b.

[0162] Back to FIG. 6a, UE 610 may comprise, for example, a smartphone, a cellular phone, a Machine-to-Machine (M2M) node, Machine-Type Communications (MTC) node, an Internet of Things (loT) node, a car, a car telemetry unit, a laptop computer, a tablet computer or another kind of suitable UE or mobile station. Generally, UE refers to any end device that may be capable of wireless communication. It can be either a mobile device or a stationary device. By way of example rather than limitation, a UE may also be referred to as a communication device, a terminal device, a Subscriber Station (SS), a Portable Subscriber Station, a Mobile Station (MS), or an Access Terminal (AT). In the example system of FIG. 6a, UE 610 may communicate wirelessly with BS 620, or with a cell of BS 620, via air interface 615. In some example embodiments, BS 620 may be considered as a serving BS, for UE 610. UE 610 may also communicate simultaneously with more than one BS 620 and / or more than one cell of BS 620.

[0163] BS 620 may be connected, directly or via at least one intermediate node, with core network 630 via interface 625. Core network 630 may be, in turn, coupled via interface 635 with another network (not shown in FIG. 6a), via whichever connectivity to further networks may be obtained, for example via a worldwide interconnection network. BS 620 may be connected with one or multiple other BS as well via an inter-base station interface (not shown in FIG. 6a).

[0164] UE 610 may be connected to BS 620 via air interface 615. Air interface 615 between UE 610 and BS 620 may be configured in accordance with a Radio Access Technology, RAT, which UE 610 and BS 620 are configured to support. Examples of cellular RATs include Long Term Evolution (LTE), New Radio (NR), which may also be known as fifth generation (5G) radio access technology. For example, in the context of LTE, BS 620 may be referred to as an eNB while in the context of NR, BS 620 may be referred to as a gNB. In any case, example embodiments are not restricted to any particular radio technology. Instead, example embodiments may be exploited in any wireless communication network (which may be a cellular or a non-cellular technology) operating in accordance to 3GPP standard, IEEE standard (such as for example IEEE 802.11 based local area networks), or it can be some other radio technology, wherein it is desirable to achieve an improved transmission and / or reception performance between an access node such as a BS, and a UE, and in particular, an improved MIMO performance.

[0165] Ever increasing data throughput requirements in wireless communication networks requires usage of wide frequency spectrum. Thus, for example, frequency bands for 5G (also referred to as NR) are currently separated into different frequency ranges. Frequency Range 1 (FR1) includes sub-6 GHz frequency bands, some of which are frequency bands traditionally used by previous standards, but the range has been extended to cover potential new spectrum offerings up to 7125 MHz. Another range is Frequency Range 2 (FR2) that at the moment includes frequency bands from 24.25 GHz to 52.6 GHz. Frequencies of this range and above are referred to as mmWave frequencies. MmWave frequency ranges are attractive because of higher available bandwidth than frequency bands in the FR1, which helps to offer data rates that satisfy 5G demands.

[0166] The described embodiments can be particularly beneficial for mmWave frequencies, including FR2 ranges, but can be applied equally to FR1 or any other frequencies. As said earlier, although applicable to any wireless networks, the 5G is mainly focused in the discussed examples, for the sake of simplicity. 5G has been envisaged to use more base stations or nodes than the current network deployments of LTE (a so-called small cell concept), including macro sites operating in co-operation with smaller local area access nodes and perhaps also employing a variety of radio technologies for better coverage and enhanced data rates. 5G will likely be comprised of more than one radio access technology / radio access network (RAT / RAN), each optimized for certain use cases and / or spectrum. 5G mobile communications may have a wider range of use cases and related applications including video streaming, augmented reality, different ways of data sharing and various forms of machine type applications, including vehicular safety, different sensors and real-time control.

[0167] MIMO is one of the key enabling techniques for 5G wireless technology. The underlying principle of MIMO is to use multiple transmit and receive antennas to increase throughput and / or reliability of data transmission. Increased throughput can be achieved by transmitting / receiving different data streams over multiple antennas, while increased reliability can be achieved by using multiple antennas for transmitting / receiving multiple versions of the same data.

[0168] Beamforming antenna arrays play an important role in 5G implementations. Although offering high bandwidth, mmWave frequencies have higher propagation losses that greatly vary depending on the environment. Smaller wavelength at higher carrier frequencies allows smaller antenna element sizes which gives an opportunity to place one or more (for example, two, three or more) relatively large antenna arrays at a UE. This in turn leads to various challenges to maintain the expected performance.

[0169] Considering as a non-limiting example 2x2 MIMO, downlink (DL) MIMO performance (for example, in mmWave frequency ranges, such as FR2) may be achieved by using polarization split (co-polar and cross-polar) of a dual feed antenna array at a base station (referred to also as a gNB) and / or at a UE, where each polarization corresponds to one MIMO branch. The reasoning behind this approach is to achieve high and similar antenna gain performance in both MIMO channels, while maintaining a compact spatial antenna design.

[0170] When designing dual-polarized antenna arrays, it is important to achieve high Cross Polarization Discrimination (XPD). XPD may be defined as a ratio of the co-polar component of the specified polarization and the orthogonal cross-polar component over a sector or beamwidth angle.

[0171] De-correlation at an antenna array may be obtained by ensuring that each antenna feed corresponds to a single polarization and that the resulting dual feed polarizations are designed to be orthogonal. This way, an antenna array with high XPD at the feed points may be designed. This approach will ensure full utilization of two MIMO channels for Line of Sight (LoS) and / or Non-Line of Sight (NLoS) operation provided that the maximum gain direction and the orientation of the orthogonal polarizations are aligned between antenna arrays at the UE and at the gNB.

[0172] In addition, high antenna gain requirements for mmWave (e.g. FR2) frequencies will reduce its radiation beam width, whereby beam steering at an antenna array (or arrays) is required to cover the needed angular space. The beam steering capabilities may be implemented using tunable phase shifters at each element in the antenna array, whereby the direction of the beam can be controlled electrically (phased array) instead of mechanical control.

[0173] The XPD of any antenna (or antenna array) depends on its radiation pattern and may change dynamically as a function of the Angle of Departure (AoD) and / or Angle of Arrival (AoA). This dependency increases as the variations in the radiation pattern change and as the radiation patterns change electrically. Higher antenna gain pattern leads to larger XPD variations over the angular space. Phase controlled arrays also have increased XPD variations over the angular space.

[0174] As such, the physical orientation of antennas at mmWave frequencies will affect MIMO throughput much more than what is seen at Sub-6 GHz frequencies, where the decorrelation at the UE is achieved by physical separation between two receiving antennas (each with random and different radiation pattern). Instead, the mmWave architecture may utilize dual orthogonally polarized antennas (or antenna arrays), designed for equal high gain radiation patterns.

[0175] FIG. 6b illustrates a simplified block diagram of a network node according to an embodiment of the present invention.

[0176] FIG. 6b illustrates an example of an apparatus 6000 for wireless communications which apparatus involves a transmitter and a receiver (i.e. a transceiver 6006). The apparatus 6000 may be a base station 620 in this example. In the following sections, the apparatus 6000 is also called as a network node. In another embodiment, the apparatus 6000 may be a UE 610 because the main structural parts are the same between the UE 610 and the base station 620. However, in the following, the functionalities in view of the base station 620 are mainly discussed.

[0177] Such apparatuses may comprise e.g. the functional units disclosed in FIG. 6b showing a simplified block diagram of a network node, i.e. the apparatus, according to the aspects and the related embodiments.

[0178] The network node 6000 of FIG. 6b may be a base station, an access point, an access node, a gNB, an evolved NodeB (eNB), a server, a host, or any other network entity that may communicate with the UE 610.

[0179] The apparatus 6000 may include at least one processor or control unit or module 6002 (marked as CPU). At least one memory 6004 may be provided in the apparatus. The memory 6004 may include computer program instructions or computer code contained therein. One or more transceivers 6006 may be provided, and the apparatus may also include an antenna 6008. Although only one antenna is shown, many antennas and multiple antenna elements may be provided in the apparatus. Other configurations of the apparatus, for example, may be provided. For example, in addition to wireless communication, the network node may be additionally configured for wired communication with the UE, and in such a case antenna 6008 may illustrate any form of communication hardware, without being limited to merely an antenna.

[0180] Transceiver 6006 may be a transmitter, a receiver, or both a transmitter and a receiver, or a unit or device that may be configured both for transmission and reception. The transmitter and / or receiver (as far as radio parts are concerned) may also be implemented as a remote radio head which is not located in the device itself, but in a mast, for example. The operations and functionalities may be performed in different entities, such as nodes, hosts or servers, in a flexible manner. In other words, division of labor may vary case by case. One possible use is to make a network node deliver local content. One or more functionalities may also be implemented as virtual application(s) in software that can run on a server.

[0181] In certain embodiments, the apparatus 6000 may comprise at least one processor 6002 and at least one memory 6004 including computer program code. The at least one memory 6004 including computer program code can be configured to, with the at least one processor 6002, cause the apparatus 6000 at least to perform any of the processes described herein.

[0182] Processors 6002 may be embodied by any computational or data processing device, such as a central processing unit (CPU), digital signal processor (DSP), application specific integrated circuit (ASIC), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), digitally enhanced circuits, or comparable device or a combination thereof. The processors 6002 may be implemented as a single controller, or a plurality of controllers or processors.

[0183] For firmware or software, the implementation may include modules or unit of at least one chip set (for example, procedures, functions, and so on). The at least one memory 6004 may independently be any suitable storage device, such as a non-transitory computer-readable medium. The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM). A hard disk drive (HDD), random access memory (RAM), flash memory, or other suitable memory may be used. The memory 6004 may be combined on a single integrated circuit as the processor 6002, or it may be separate therefrom. Furthermore, the computer program instructions may be stored in the memory 6004 and which may be processed by the processors 6002 can be any suitable form of computer program code, for example, a compiled or interpreted computer program written in any suitable programming language. The memory 6004 or data storage entity is typically internal but it may also be external or a combination thereof, such as in the case when additional memory capacity is obtained from a service provider. The memory 6004 may be fixed or removable.

[0184] The memory 6004 and the computer program instructions may be configured, with the processor 6002 for the particular device, to cause a hardware apparatus such as network node 6000, to perform any of the processes described above. Therefore, in certain embodiments, a non-transitory computer-readable medium may be encoded with instructions or one or more computer program (such as added or updated software routine, applet or macro) that, when executed in hardware, may perform a process such as one of the processes described herein. In other embodiments, a computer program product may encode instructions for performing any of the processes described above, or a computer program product embodied in a non-transitory computer-readable medium and encoding instructions that, when executed in hardware, perform any of the processes describes above. Computer programs may be coded by a programming language, which may be a high-level programming language, such as objective-C, C, C++, C#, Java, etc., or a low-level programming language, such as a machine language, or assembler. Alternatively, certain embodiments may be performed entirely in hardware.

[0185] Although the network element example in FIG. 6b discusses a base station 620, the respective main elements are also part of a UE 610, as a counterpart in a connection for the BS 620. Thus, the general structural elements above and the applicability of the above-mentioned process steps via a computer program are also present in the UE 610 side.

[0186] The technical effect and also the advantage of the present invention in view of the prior art is that the present invention defines the rules for CPU occupancy for event-based CSI reporting in a clear and concise manner. Hence, the limits which the UE may handle, regarding the CSI reports and the number of these reports, are better managed and fulfilled and causing UE not to drop CSI report due to excessive CPU utilization. This makes the operations around CSI reports by the UE smoother, thus ensuring better operability of the UEs in both the UL and DL transmission directions. In general, the present invention defines the CPU occupancy for event-triggered reporting and some of the examples provide means to determine CPU occupancy that may limit the number of occupied CPUs for event-triggered reporting thus causing the UE not to drop CSI reports (e.g. due to priority issues and exceeding CPU limits). The reduction of dropped CSI reports may increase throughput since the reports provide the network with information on the UE channel conditions and enable more flexible scheduling.

[0187] The foregoing description has provided by way of exemplary and nonlimiting examples a full and informative description of the exemplary embodiments of the present invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended examples. However, all such and similar modifications of the teachings of the present invention will still fall within the scope of the present invention, where the scope is defined by the claims.

Claims

1. An apparatus (610), comprising:means for determining an event (203, 303) for reporting;means for determining a time window for the apparatus for the event-based reporting;means for triggering, due to the event (203, 303), an uplink signal (205, 305) indicating transmission of a Channel State Information, CSI, report, wherein the CSI report is scheduled to be transmitted in a reporting slot (206, 306) or an uplink signal (205, 305) indicating the event (203, 303) or an uplink signal (205, 305) requesting reporting resources;means for determining an ending time for CSI processing unit, CPU, occupancy (204, 304) so that the CPU occupancy (204, 304) lasts until the reporting slot (206, 306) in case the uplink signal (205, 305) indicates the event (203, 303);means for determining an ending time for CPU occupancy (204, 304) so that the CPU occupancy (204, 304) lasts based on the uplink signaling occasion in case the uplink signal (205, 305) does not indicate the event;means for using the determined time window for adjusting the total CPU load; andmeans for delaying the actual event-based reporting so that a transmission time instant of the CSI report remains within the determined time window.

2. The apparatus (610) according to claim 1, wherein by adjusting the total CPU load, the apparatus is configured to be capable of maximizing up-to-date CSI reports sent to the network.

3. The apparatus (610) according to claim 1, wherein the apparatus further comprises:means for transmitting the CSI report in the reporting slot (206, 306), wherein the CSI report is part of the transmitted uplink signal (205, 305).

4. The apparatus (610) according to claim 1, wherein the uplink signaling occasion is a symbol or a slot comprising uplink signaling.

5. The apparatus (610) according to claim 1, wherein the event (203, 303) is a CSI reporting event in a configured or scheduled uplink resource.

6. The apparatus (610) according to claim 1, wherein the uplink signal (205, 305) is a Physical Uplink Shared Channel, PUSCH, a Physical Uplink Control Channel, PUCCH, a Scheduling Request, SR, or a Physical Random Access Channel, PRACH.

7. The apparatus (610) according to claim 1, wherein the CPU occupancy (204, 304) starts on an earliest downlink measurement reference signal before the determined event (203, 303) takes place.

8. The apparatus (610) according to claim 1, wherein the CPU occupancy (204, 304) starts at a temporal location of the slot where the event (203, 303) for reporting is triggered.

9. The apparatus (610) according to claim 1, wherein the CPU occupancy (204, 304) lasts until the last symbol or slot of the transmission of the event-triggered CSI report.

10. The apparatus (610) according to claim 1, wherein a reference point specific for event-based CSI reporting is a first symbol of an earliest one of each channel measurement resource, wherein a respective latest channel measurement reference signal occasion locates no later than a corresponding CSI reference resource.

11. The apparatus (610) according to claim 1, wherein a reference point specific for event-based CSI reporting is a first symbol or slot of a channel measurement resource, where the event (203, 303) has been triggered.

12. The apparatus (610) according to claim 1, wherein the slot or symbol where for the event-based CSI reporting it is determined that the at least one condition or criterion for the event (203, 303) is not fulfilled, the CSI report does not occupy CPU resources from that slot onwards.

13. The apparatus (610) according to claim 1, wherein the apparatus further comprises:means for determining a Downlink Control Information, DCI, (407) scheduling the uplink resource for event-triggered CSI reporting;means for determining a start of CPU occupancy (404) either on the symbol or slot of the uplink indication or the first symbol or slot after the uplink indication; andmeans for determining an end of CPU occupancy (404) at the last symbol of the transmitted CSI report part of the transmitted uplink signal.

14. The apparatus (610) according to claim 1, wherein the apparatus further comprises:means for determining a Downlink Control Information, DCI, (507) scheduling the uplink resource for event-triggered CSI reporting;means for determining a start of CPU occupancy (504) on the first symbol of the physical downlink control channel, PDCCH, or on the first symbol after the PDCCH triggering the CSI report; andmeans for determining an end of CPU occupancy (504) at the last symbol of the transmitted CSI report part of the transmitted uplink signal.

15. The apparatus (610) according to claim 13 or 14, wherein the scheduled uplink resource is either a PUCCH or a PUSCH.

16. The apparatus (610) according to claim 10, wherein the CSI reference resource in the given slot representing the event (203, 303) is a valid downlink slot specific for event-based reporting.

17. The apparatus (610) according to claim 1, wherein the transmitted CSI report has a reporting quantity set to either reference signal received power, RSRP, or signal to interference plus noise ratio for layer 1, Ll-SINR.

18. The apparatus (610) according to claim 1, wherein if the event (203, 303) is a reference signal received power, RSRP, event, and one measurement resource fulfils a RSRP level criterion, the CPU occupancy (204, 304) starts on the symbol or slot where the RSRP of the measurement resource was measured or on the symbol or slot when the measurement resources were measured.

19. A method, comprising:determining, in a User Equipment, UE, an event (203, 303) for reporting;determining, in the UE, a time window for the apparatus for the event-based reporting;triggering, in the UE, due to the event (203, 303), an uplink signal (205, 305) indicating transmission of a Channel State Information, CSI, report, wherein the CSI report is scheduled to be transmitted in a reporting slot (206, 306) or an uplinksignal (205, 305) indicating the event (203, 303) or an uplink signal (205, 305) requesting reporting resources;determining, in the UE, an ending time for CSI processing unit, CPU, occupancy (204, 304) so that the CPU occupancy (204, 304) lasts until the reporting slot (206, 306) in case the uplink signal (205, 305) indicates the event (203, 303);determining, in the UE, an ending time for CPU occupancy (204, 304) so that the CPU occupancy (204, 304) lasts based on the uplink signaling occasion in case the uplink signal (205, 305) does not indicate the event;using, in the UE, the determined time window for adjusting the total CPU load; anddelaying, in the UE, the actual event-based reporting so that a transmission time instant of the CSI report remains within the determined time window.

20. A computer program comprising instructions which, when executed by an apparatus, cause the apparatus to perform at least the following:determining an event (203, 303) for reporting;determining a time window for the apparatus for the event-based reporting;triggering, due to the event (203, 303), an uplink signal (205, 305) indicating transmission of a Channel State Information, CSI, report, wherein the CSI report is scheduled to be transmitted in a reporting slot (206, 306) or an uplink signal (205, 305) indicating the event (203, 303) or an uplink signal (205, 305) requesting reporting resources;determining an ending time for CSI processing unit, CPU, occupancy (204, 304) so that the CPU occupancy (204, 304) lasts until the reporting slot (206, 306) in case the uplink signal (205, 305) indicates the event (203, 303);determining an ending time for CPU occupancy (204, 304) so that the CPU occupancy (204, 304) lasts based on the uplink signaling occasion in case the uplink signal (205, 305) does not indicate the event;using the determined time window for adjusting the total CPU load; anddelaying the actual event-based reporting so that a transmission time instant of the CSI report remains within the determined time window.

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