Adaptation of channel state information reference signal related processing in wireless networks, and related devices, methods and computer programs

Abstract

Devices, methods and computer programs for adaptation of channel state information reference signal related processing in wireless networks are disclosed. At least some example embodiments may allow defining rules for a channel state information (CSI) processing unit CPU (CPU) occupancy for CSI reporting with a high number of antenna ports.

Description

[0001]ADAPTATION OF CHANNEL STATE INFORMATION REFERENCE SIGNAL RELATEDPROCESSING IN WIRELESS NETWORKS, AND RELATED DEVICES, METHODS AND COMPUTER PROGRAMS TECHNICAL FIELD The disclosure relates generally to communications and, more particularly but not exclusively, to adaptation of channelstate information reference signal related processing in wire-less networks, as well as related devices, methods and computerprograms. BACKGROUND To enhance coverage and spectral efficiency of downlink data transmission, e.g., upcoming sixth generation (6G) wireless networks aim to significantly increase the number of antennaports for, e.g., for downlink (DL) channel state information(CSI) acquisition.That is, to address a coverage issue for new 6G fre-quency bands (e.g., 6.425-7.125 GHz), the use of larger antennaarrays with an increased number of antennas elements and ports has been proposed. The use of large antenna arrays can enable the needed enhanced coverage and spectrum efficiency in down- link. However, at least in some situations, from a user equipment (UE) point of view, increasing the number of antenna ports may result in increased processing load and / or processingtime associated with CSI reference signal (CSI-RS) related pro-cessing. Accordingly, at least in some situations, it may bebeneficial to be able to adapt the channel state informationreference signal related processing in wireless networks asneeded. BRIEF SUMMARY The scope of protection sought for various example em- bodiments of the invention is set out by the independent claims. The example embodiments and features, if any, described in this specification that do not fall under the scope of the independent claims are to be interpreted as examples useful for understand- ing various example embodiments of the invention. An example embodiment of a user device comprises atleast one processor, and at least one memory storing instruc-tions that, when executed by the at least one processor, causethe user device at least to determine a number of channel stateinformation, CSI, processing units, CPUs, associated with aninitial number of antenna ports. The instructions, when executed by the at least one processor, cause the user device at leastto determine a first scaling factor associated with channelstate information computation for a subsequent number of theantenna ports. The instructions, when executed by the at leastone processor, cause the user device at least to determine asecond scaling factor associated with the channel state infor-mation computation for the subsequent number of antenna ports.The instructions, when executed by the at least one processor,cause the user device at least to calculate the number of CPUsfor the subsequent number of antenna ports based on the deter-mined initial number of the antenna ports, the first scalingfactor and the second scaling factor. The subsequent number ofantenna ports is higher than the initial number of antenna ports. In an example embodiment, alternatively or in additionto the above-described example embodiments, the first scalingfactor is determined based on a capability indication obtainedfor the user device. In an example embodiment, alternatively or in additionto the above-described example embodiments, the first scalingfactor is determined via inclusion in the at least one memory. In an example embodiment, alternatively or in additionto the above-described example embodiments, the first scalingfactor is associated with one of: a CSI related computation with 48 antenna ports with respect to a CSI related computation with32-antenna ports, a CSI related computation with 64 antennaports with respect to a CSI related computation with 32-antennaports, a CSI related computation with 128 antenna ports withrespect to a CSI related computation with 32-antenna ports, ora CSI related computation with 256 antenna ports with respectto a CSI related computation with 32-antenna ports. In an example embodiment, alternatively or in additionto the above-described example embodiments, the second scalingfactor is determined based on a set of numbers obtained via acapability indication for the user device.In an example embodiment, alternatively or in additionto the above-described example embodiments, the second scalingfactor is determined from the set of numbers in a descending order. In an example embodiment, alternatively or in additionto the above-described example embodiments, the set of numberscomprises at least 1, 0.5, 0.25, and 0.125. In an example embodiment, alternatively or in additionto the above-described example embodiments, the user device isconfigured with one or more resources with more than 32 CSIreference signal, CSI-RS, antenna ports. An example embodiment of a method comprises determin-ing, by a user device, a number of channel state information,CSI, processing units, CPUs, associated with an initial numberof antenna ports. The method further comprises determining, bythe user device, a first scaling factor associated with channelstate information computation for a subsequent number of theantenna ports. The method further comprises determining, by theuser device, a second scaling factor associated with the channelstate information computation for the subsequent number of an-tenna ports. The method further comprises calculating, by the user device, the number of CPUs for the subsequent number of antenna ports based on the determined initial number of theantenna ports, the first scaling factor and the second scalingfactor. The subsequent number of antenna ports is higher thanthe initial number of antenna ports. An example embodiment of an apparatus comprises means for carrying out a method according to any of the above-described example embodiments. An example embodiment of a computer program comprisesinstructions for causing a user device to perform at least thefollowing: determining a number of channel state information,CSI, processing units, CPUs, associated with an initial numberof antenna ports; determining a first scaling factor associatedwith channel state information computation for a subsequent num-ber of the antenna ports; determining a second scaling factorassociated with the channel state information computation forthe subsequent number of antenna ports; and calculating thenumber of CPUs for the subsequent number of antenna ports basedon the determined initial number of the antenna ports, the firstscaling factor and the second scaling factor, wherein the sub-sequent number of antenna ports is higher than the initial number of antenna ports. DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to pro- vide a further understanding of the embodiments and constitute a part of this specification, illustrate embodiments and to- gether with the description help to explain the principles of the embodiments. In the drawings: FIG. 1 shows an example embodiment of the subject mat-ter described herein illustrating an example system, where var-ious embodiments of the present disclosure may be implemented; FIG. 2 shows an example embodiment of the subject mat-ter described herein illustrating a user device;FIG. 3 shows an example embodiment of the subject mat-ter described herein illustrating a method for a user device;FIG. 4 shows an example embodiment of the subject mat-ter described herein illustrating channel state information pro-cessing unit occupancy for downlink channel state informationmeasurement and reporting. Like reference numerals are used to designate like parts in the accompanying drawings. DETAILED DESCRIPTION Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. The detailed description provided below in connection with the appended drawings is intended as a description of the present examples and is not intended to represent the only forms in which the present example may be constructed or utilized. The description sets forth the functions of the example and the sequence of steps for constructing and operating the example.However, the same or equivalent functions and sequences may beaccomplished by different examples. Fig. 1 illustrates example system 100, where various embodiments of the present disclosure may be implemented. System 100 may comprise radio access network cell 110 of, e.g., a fifth generation (5G) or sixth generation (6G) network or of a network beyond 6G wireless networks. An example representation of system 100 is shown depicting user device 200 and network node device 210. At least in some embodiments, the network of radio accessnetwork cell 110 may be comprised in a massive machine-to-ma-chine (M2M) network, massive machine type communications (mMTC) network, internet of things (IoT) network, industrial internet- of-things (IIoT) network, enhanced mobile broadband (eMBB) net- work, ultra-reliable low-latency communication (URLLC) network, and / or the like. In other words, the network of radio accessnetwork cell 110 may be configured to serve diverse servicetypes and / or use cases, and it may logically be seen as compris- ing one or more networks. User device 200 may include, e.g., a mobile phone, asmartphone, a tablet computer, a smart watch, or any hand-held,portable and / or wearable device. User device 200 may also bereferred to as a user equipment (UE). Network node device 210may comprise, e.g., a base station or a transmission and recep-tion point (TRP). The base station or TRP may include, e.g., anydevice suitable for providing an air interface for user devices to connect to a wireless network via wireless transmissions. In the following, various concepts and terms that maybe relevant to at least some example embodiments will be dis-cussed. At least in some situations, periodic / semi-persis-tent / aperiodic measurement and reporting of layer 1 (L1) meas-urement quantities may currently be implemented at least partly as follows.A reporting setting CSI-ReportConfig may be associatedwith a single downlink bandwidth part (BWP) (indicated by higherlayer parameter BWP-Id) given in an associated CSI-ResourceConfig for channel measurement, and it may comprise pa-rameter(s) for one CSI reporting band, such as a codebook con-figuration including a codebook subset restriction, a time-do- main behaviour, a frequency granularity for a channel qualityindicator (CQI) and a precoding matrix indicator (PMI), meas-urement restriction configurations, and / or CSI-related quanti-ties to be reported by a UE, such as a layer indicator (LI), anL1 reference signal received power (L1-RSRP), an L1 signal-to- interference-plus-noise ratio (L1-SINR), a CSI resource index (CRI), a synchronization signal block (SSB) resource indicator(SSBRI), a CapabilityIndex, and / or a time-domain channel prop-erty (TDCP). Time domain behaviour of the CSI-ReportConfig may beindicated by a higher layer parameter reportConfigType, and maybe set to 'aperiodic', 'semiPersistentOnPUCCH', 'semiPersisten- tOnPUSCH', or 'periodic'. For 'periodic' and 'semiPersistentOn-PUCCH' / 'semiPersistentOnPUSCH' CSI reporting, the configuredperiodicity and slot offset may apply in a numerology of theuplink (UL) BWP in which the CSI report is configured to betransmitted on. The higher layer parameter reportQuantity may indicate CSI-related, L1-RSRP-related, L1-SINR-related, Capa- bilityIndex-related or TDCP-related quantities to report. ThereportFreqConfiguration may indicate a reporting granularity inthe frequency domain, including a CSI reporting band and ifPMI / CQI reporting is wideband or sub-band. The timeRestriction-ForChannelMeasurements parameter in CSI-ReportConfig may be con-figured to enable a time domain restriction for channel meas-urements, and timeRestrictionForInterferenceMeasurements may beconfigured to enable a time domain restriction for interference measurements. ACSI Resource Setting CSI-ResourceConfig may comprisea configuration of a list of S≥1 CSI resource sets (given by higher layer parameter csi-RS-ResourceSetList), where the listmay include references to either or both of non-zero-power (NZP)CSI-RS resource set(s) and synchronization signal (SS) / physi-cal broadcast channel (PBCH) block set(s), or the list may in-clude references to CSI-IM resource set(s). A CSI resource set-ting may be located in a downlink (DL) BWP identified by a higherlayer parameter BWP-id, and all CSI resource settings linked to a CSI report setting may have the same DL BWP. AUE may indicate a number of supported simultaneousCSI calculations N^^^with a parameter simultaneousCSI-Reports- PerCC in a component carrier, and simultaneousCSI-ReportsAllCC across all component carriers. If a UE supports N^^^simultane-ous CSI calculations, it is said to have N^^^ CSI processingunits for processing CSI reports. If L CPUs are occupied for calculation of CSI reports in a given orthogonal frequency di-vision multiplexing (OFDM) symbol, the UE may have N^^^ − L un-occupied CPUs. If N CSI reports start occupying their respectiveCPUs on the same OFDM symbol on which N^^^ − L CPUs are unoccu-pied, where each CSI report n = 0, … , − 1 corresponds theUE may not be required to update the N − M requested CSI reportswith lowest priority, where 0 ≤ M ≤ N is the largest value suchthat N^^^ − L holds.A UE may not be expected to be configured with anaperiodic CSI trigger state containing more than N^^^reportingsettings. Processing of a CSI report may occupy a number of CPUsfor a number of symbols as follows: -O^^^ = 0 for a CSI report with CSI-ReportConfig withhigher layer parameter reportQuantity set to 'none' and CSI-RS- ResourceSet with higher layer parameter trs-Info configured; -O^^^ = 1 for a CSI report with CSI-ReportConfig withhigher 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). For a CSI report with CSI-ReportConfig with higher layer parameter reportQuantity not set to 'none', the CPU(s) maybe occupied for a number of OFDM symbols as follows:- a periodic or semi-persistent CSI report (excludingan initial semi-persistent CSI report on PUSCH after the PDCCHtriggering the report) may occupy CPU(s) from the first symbolof the earliest one of each CSI-RS / CSI-IM / SSB resource for chan-nel or interference measurement, respective latest CSI-RS / CSI-IM / SSB occasion no later than the corresponding CSI referenceresource, until the last symbol of the configured PUSCH / PUCCH carrying the report; -an aperiodic CSI report may occupy CPU(s) from thefirst 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 respec- tive search space sets, for the purpose of determining the CPU occupation duration, the PDCCH candidate that ends later in timemay be used;- an initial semi-persistent CSI report on a physicaluplink shared channel (PUSCH) after a physical downlink controlchannel (PDCCH) trigger occupies CPU(s) from the first symbolafter the PDCCH until the last symbol of the scheduled PUSCHcarrying the report. When the PDCCH reception includes two PDCCHcandidates from two respective search space sets, for the pur- pose of determining the CPU occupation duration, the PDCCH can-didate that ends later in time may be used.In general, when a UE receives one or more NZP-CSI-RS resource associated with some antenna ports for a DL CSI acqui- sition, the UE may require a certain amount of time for perform-ing measurements (e.g., reception and channel estimation) andfor computing a CSI report (e.g., PMI, RI, CQI). The measurementand reporting configurations (that are active for the UE) may consume processing units (Ncpu) based on one or more metrics associated with the configuration. Currently, the CPU calculation is defined for peri- odic / semi-persistent and aperiodic CSI reporting by assuming themaximum of antenna ports to be 32. Diagram 400 of Fig. 4 showsan example of current periodic reporting of the CPU occupancy for DL CSI measurement and reporting. Currently, it is assumed that a maximum number of an-tenna ports associated with an NZP-CSI-RS resource is 32. As aresult of this, problems may arise for determining the occupancy of CSI units for CSI reporting with channel measurement re-sources (e.g., NZP-CSI-RS) with a higher number (e.g., more than32) of antenna ports. In the following, various example embodiments will bediscussed. At least some of these example embodiments describedherein may allow adaptation of channel state information refer-ence signal related processing in wireless networks.Furthermore, at least some of the example embodimentsdescribed herein may allow defining rules for CPU occupancy forCSI reporting with a high number of antenna ports. Furthermore, at least some of the example embodimentsdescribed herein may allow a user device to adapt its CSI-RSmeasurement and processing load in the dimension of a CSI hy-pothesis, wherein the CSI hypothesis may comprise at least oneof a precoder matrix or a rank estimation. The functionality maybe subject to a certain antenna port number, e.g., when the userdevice is configured for more than 32 antenna ports for the CSI-RS based CSI calculation comprising at least one of the precodermatrix or the rank estimation.Fig. 2 is a block diagram of user device 200, in ac-cordance with an example embodiment. User device 200 comprises one or more processors 202 and one or more memories 204 that comprise computer program code. User device 200 may also include other elements, such as transceiver 206 configured to enable user device 200 to transmit and / or receive information to / from other devices, as well as other elements not shown in Fig. 2. In one example, user device 200 may use transceiver 206 to transmit or receive signalling information and data in accordance with at least one cellular communication protocol. Transceiver 206 may be configured to provide at least one wireless radio connection, such as for example a 3GPP mobile broadband connection (e.g., 5G or 6G). Transceiver 206 may comprise, or be configured to be coupled to, at least one antenna to transmit and / or receive radio frequency signals. Although user device 200 is depicted to include only one processor 202, user device 200 may include more processors. In an embodiment, memory 204 is capable of storing instructions, such as an operating system and / or various applications. Fur- thermore, memory 204 may include a storage that may be used to store, e.g., at least some of the information and data used in the disclosed embodiments. Furthermore, processor 202 is capable of executing the stored instructions. In an embodiment, processor 202 may be embodied as a multi-core processor, a single core processor, or a combination of one or more multi-core processors and one or more single core processors. For example, processor 202 may be embodied as one or more of various processing devices, such as a coprocessor, a microprocessor, a controller, a digital signal processor (DSP), a processing circuitry with or without an ac- companying DSP, or various other processing devices including integrated circuits such as, for example, an application spe- cific integrated circuit (ASIC), a field programmable gate array (FPGA), a microcontroller unit (MCU), a hardware accelerator, a special-purpose computer chip, a neural network (NN) chip, anartificial intelligence (AI) accelerator, a tensor processingunit (TPU), a neural processing unit (NPU), or the like. In an embodiment, processor 202 may be configured to execute hard- coded functionality. In an embodiment, processor 202 is embodied as an executor of software instructions, wherein the instruc- tions may specifically configure processor 202 to perform the algorithms and / or operations described herein when the instruc- tions are executed. Memory 204 may be embodied as one or more volatile memory devices, one or more non-volatile memory devices, and / or a combination of one or more volatile memory devices and non- volatile memory devices. For example, memory 204 may be embodied as semiconductor memories (such as mask ROM, PROM (programmable ROM), EPROM (erasable PROM), flash ROM, RAM (random access memory), etc. User device 200 may comprise any of various types of devices used directly by an end user entity and capable of communication in a wireless network, such as a user equipment (UE). Such devices include but are not limited to smartphones, tablet computers, smart watches, lap top computers, internet- of-things (IoT) devices, massive machine-to-machine (M2M) de- vices, massive machine type communications (mMTC) devices, in- dustrial internet-of-things (IIoT) devices, enhanced mobile broadband (eMBB) devices, ultra-reliable low-latency communica-tion (URLLC) devices, relay nodes (such as integrated access andbackhaul nodes) configured to facilitate backhaul connections,and / or devices mounted in vehicles, etc. When executed by at least one processor 202, instructions stored in at least one memory 204 cause user device200 at least to determine a number of channel state information(CSI) processing units (CPUs) associated with an initial numberof antenna ports. User device 200 may be configured with one or moreresources with more than 32 CSI reference signal (CSI-RS) an-tenna ports. The instructions, when executed by at least one pro-cessor 202, cause user device 200 at least to determine a firstscaling factor associated with channel state information compu-tation for a subsequent number of the antenna ports. At least in some embodiments, the first scaling factormay be determined based on a capability indication obtained foruser device 200. Alternatively and / or additionally, the first scaling factor may be determined via inclusion in (and retrieval from) at least one memory 204. At least in some embodiments, the first scaling factormay be associated with one of the following: a CSI related computation with 48 antenna ports with respect to a CSI related computation with 32-antenna ports, a CSI related computationwith 64 antenna ports with respect to a CSI related computationwith 32-antenna ports, a CSI related computation with 128 an-tenna ports with respect to a CSI related computation with 32-antenna ports, or a CSI related computation with 256 antennaports with respect to a CSI related computation with 32-antenna ports. The instructions, when executed by at least one pro-cessor 202, cause user device 200 at least to determine a secondscaling factor associated with the channel state information computation for the subsequent number of antenna ports.At least in some embodiments, the second scaling factormay be determined based on a set of numbers obtained via acapability indication for user device 200. At least in someembodiments, the second scaling factor may be determined fromthe set of numbers in a descending order. For example, the set of numbers may comprise at least 1, 0.5, 0.25, and 0.125. The instructions, when executed by at least one pro-cessor 202, cause user device 200 at least to calculate thenumber of CPUs for the subsequent number of antenna ports basedon the determined initial number of the antenna ports, the firstscaling factor and the second scaling factor. The subsequentnumber of antenna ports is higher than the initial number of antenna ports. In other words, the processing of a CSI report with a high number of antenna ports may occupy a number of CPUs for anumber of symbols, e.g., as follows:- for a CSI report with CSI-ReportConfig with a higherlayer parameter reportQuantity set to 'cri-RI-PMI-CQI-portExt- 6G', 'cri-RI-i1-portExt-6G', 'cri-RI-i1-CQI-portExt-6G, 'cri- RI-CQI-portExt-6G', or 'cri-RI-LI-PMI-CQI-portExt-6G': -O^^^^^^^^ ^^^ = Q, which may be reported by userdevice 200 capability indication or defined in a suitable stand-ard / specification. - P48-portis a scaling factor associated with the CSI com- putation with 48 antenna ports with respect to CSI computationwith 32 antenna ports. This value may be defined in a suitablestandard / specification, or it may be based, e.g., on user device200 capability reporting. L48-portis a set of numbers in a descending order whichmay be reported, e.g., by user device 200 capability indication.For example, user device 200 may have reported L whichmay be the following set: L48-port ∈ {1,0.5,0.25,0.125}. Then,user device 200 may apply different values of L48-port in the CPUcalculation, such that the CPU calculation starts with the larg-est value, e.g., 1, and continues with the CSI hypothesis re-duction by applying a next value in the set. -O^^^^^^^^ == P64-port 64-port^^^ *Q*L , where: P64-portis a scaling factor associated with the CSI com- putation with 64 antenna ports with respect to the CSI computa-tion with 32 antenna ports. This value may be defined in asuitable standard / specification, or it may be based on, e.g.,user device 200 capability reporting. L64-portis a set of numbers in a descending order whichmay be reported, e.g., by user device 200 capability indication.For example, user device 200 may have reported L whichmay be the following set: L64-port ∈ {1,0.5,0.25,0.125}. Then,user device 200 may apply different values of L64-port in CPUcalculation such that the CPU calculation starts with the larg- est value, e.g. 1, and continues with the CSI hypothesis reduc- tion by applying a next value in the set. ^^^^^^^^^ P128-portis a scaling factor associated with the CSI computation with 128 antenna ports with respect to the CSI com-putation with 32 antenna ports. This value may be defined in asuitable standard / specification, or it may be based on, e.g.,user device 200 capability reporting. L128-portis a set of numbers in a descending order whichmay be reported by, e.g., user device 200 capability indication.For example, user device 200 may have reported L whichmay be the following set: L128-port ∈ {1,0.5,0.25,0.125}. Then,user device 200 may apply different values of L128-portin the CPU calculation such that the CPU calculation starts with the larg-est value, e.g., 1, and continues with the CSI hypothesis re-duction by applying a next value in set.- O^^^^^^^^^ ^^^= = P256-port*Q*L256-port, where: 256-po Prtis a factor associated with the CSI computation with 256 antenna ports with respect to the CSI com-putation with 32 antenna ports. This value may be defined in asuitable standard / specification, or it may be based on. E.g.,user device 200 capability reporting.L256-portis a set of numbers in a descending order whichmay be reported by, e.g., user device 200 capability indication.For example, user device may have reported L whichmay be the following set: L256-port ∈ {1,0.5,0.25,0.125}. Then,user device 200 may apply different values of L256-port in the CPUcalculation, such that the CPU calculation starts with the larg-est value, e.g. 1, and continues with the CSI hypothesis reduc-tion by applying a next value in set. At least in some embodiments, the above number of theCPUs may be extended to any resource and / or antenna port con-figuration by extending antenna port specific values of L and P. At least in some embodiments, the instructions, whenexecuted by at least one processor 202, may further cause userdevice 200 to receive, from network node device 210, channelstate information (CSI) resource configuration information atleast specifying resources to be used for transmitting CSI ref-erence signals (CSI-RSs) by network node device 210. A resource setting in the CSI resource configuration information may, e.g., define N different CSI measurement re- source settings and M different CSI reporting settings for CSI measurements and reporting. A CSI measurement resource setting may define, e.g., resources for channel measurement(s) (e.g., non-zero power channel state information reference signal (NZP- CSI-RS)) and / or for interference measurements (e.g., NZP-CSI-RS or CSI interference measurement (CSI-IM) resources), a resource allocation (e.g., in time and frequency), and / or a time type (e.g., periodic, semi-persistent, or aperiodic). NZP CSI-RS is a reference signal which enables userdevice 200 to estimate the channel of the antenna port overwhich the CSI-RS is transmitted, and the configuration of a CSI- RS resource may indicate which resource elements (RE)s the ref-erence signal (RS) is transmitted on, as well as an RS sequenceused. A CSI-IM resource on the other hand may define a numberof REs where user device 200 is supposed to perform a measurementof a received interference power.A CSI reporting setting may define, e.g., resources for reporting (e.g., PUSCH, PUCCH), a time type, a content of the report (e.g., a reporting quantity), a precoder matric indicator (PMI), a rank indicator (RI), and / or a CQI. The CSI reporting setting may also be associated with a certain carrier, and thus multiple CSI reporting settings may be configured, e.g., to enable multi-carrier CSI reporting for carrier aggregation (CA).The CSI resource configuration information may includeat least one CSI hypothesis comprising information on one ormore transmission parameters used by network node device 210.The at least one CSI hypothesis may further comprise informationon a precoder matrix and / or a rank estimation.Furthermore, a CSI hypothesis may further comprise acomputation of one or more channel quality indicator values (CQIs), where a CQI may take into account a possible modulationchannel coding (MCS), such as a modulation order and a channelencoding rate. Furthermore, a CSI hypothesis may further com-prise a computation of interference estimates based on, e.g.,interference measurement resource(s) configured in the CSI re-source configuration information.The one or more transmission parameters may be relatedto, e.g., downlink transmission of a non-zero-power (NZP) CSI- RS resource. For example, a CSI hypothesis may include assump- tions that can be made by user device 200 about particular transmission parameter settings used by network node device 210 or a set of network node devices 210 when transmitting a physicaldownlink shared channel (PDSCH). Parameters defined in a CSIhypothesis may include, e.g., a CSI resource index (CRI), a rank indicator (e.g., a number of layers for a transmit signal), a precoder matrix indicator, a channel quality indicator (CQI), and / or a number of network node devices 210. At least in some embodiments, the instructions, whenexecuted by at least one processor 202, may further cause userdevice 200 to adapt processing of the received at least one CSIhypothesis. At least in some embodiments, the instructions, whenexecuted by at least one processor 202, may further cause userdevice 200 to perform one or more measurements on at least oneCSI-RS received in accordance with the received CSI resourceconfiguration information. At least in some embodiments, the instructions, whenexecuted by at least one processor 202, may further cause userdevice 200 to generate at least one CSI feedback report basedon the performed one or more measurements and the processing adapted at least one CSI hypothesis.At least in some embodiments, the instructions, whenexecuted by at least one processor 202, may further cause userdevice 200 to transmit the generated at least one CSI feedbackreport to network node device 210. At least in some embodiments, the instructions, when executed by at least one processor 202, may further cause userdevice 200 to perform the adapting of the processing of thereceived at least one CSI hypothesis by reducing a processingload of the received at least one CSI hypothesis without skippingany resources specified for use in at least one of the performing of the one or more measurements or the generating of the at least one CSI feedback report, thereby reducing a first pro- cessing load associated with the performing of the one or more measurements, and / or reducing a second processing load associ- ated with the generating of the at least one CSI feedback report. At least in some embodiments, the adapting of the pro- cessing of the received at least one CSI hypothesis may beperformed via resource specific reduction of the at least onereceived CSI hypothesis, thereby reducing computational pro- cessing complexity. In other words, user device 200 may adapt its CSI-RSmeasurement and processing load in the dimension of the CSIhypothesis, wherein the CSI hypothesis comprises at least oneof the precoder matrix or the rank estimation, without skippingresources used in CPU computation. This may be achieved, e.g.,by reducing the computational processing complexity with a re-source specific CSI hypothesis reduction. This functionality maybe subject to a certain antenna port number, e.g. when user device 200 is configured for more than 32 antenna ports for the CSI-RS based CSI calculation comprising at least one of theprecoder matrix or the rank estimation.At least in some embodiments, at least one CSI hypoth-esis of the at least one received CSI hypothesis may be associ-ated with a high number (e.g., more than 32) of antenna port resources. The instructions, when executed by at least one pro-cessor 202, may further cause user device 200 to perform theadapting of the processing of the received at least one CSIhypothesis via reducing a number of the at least one CSI hypoth-esis associated with the high number of the antenna port re-sources by a first factor associated with a first CSI processingunit (CPU) value. For example, the first CPU value may be re-source specific and / or antenna port specific. At least in some embodiments, the instructions, when executed by at least one processor 202, may further cause userdevice 200 to perform the reducing of the number of the at leastone CSI hypothesis for a resource by a second factor associatedwith a second CPU value. For example, the second CPU value maybe resource specific and / or antenna port specific.At least in some embodiments, the instructions, when executed by at least one processor 202, may further cause userdevice 200 to perform the reducing of the number of the at leastone CSI hypothesis based on a reduction condition.In other words, when, e.g., N CSI reports start occu-pying their respective CPUs on the same OFDM symbol on which NCPU−^ CPUs are unoccupied, where L defines the number of occupiedCPUS, and where each CSI report ^=0,…,^−1 corresponds to O(^)^^^, and at least one of CSI report is associated with high numberof antenna (>32) where 0≤^≤^ is the largest value suchthat condition(^) ^^^ ≤ N^^^ − L does not hold, the followingmay be applied: -step 0: user device 200 may reduce the number of CSIhypotheses associated with a high number of antenna port re-sources (e.g., NZP-CSI) by a scaling / reduction factor which maybe associated with a resource and / or antenna port specific CPUvalue; -step 1: user device 200 may check whether a condition (^) ^^^ ≤ N^^^ − L is fulfilled or not. If the condition is not^^^ fulfilled, user device 200 may further reduce the number of CSI hypotheses for a resource by another scaling / reduction factorwhich may be associated with a resource and / or antenna portspecific CPU value. User device 200 may continue steps 0 and 1 until the above condition is fulfilled. If the condition is fulfilled, user device 200 may update the CSI for the requested report with the reduced number of CSI hypotheses. At least in some embodiments, the maximum reduction factor may be configurable (e.g., via radio resource control (RRC)). At least in some embodiments, the reduction factor maycomprise a set of values which may be configurable or specifiedin a suitable specification.At least in some embodiments, whether the reductionfactor may be applied or may be applied for specific CSI report,may be configurable. At least in some embodiments, whether the reductionfactor may be applied or may be applied for a specific CSIreport, may be dependent on the number of ports per resource.For example, the reduction factor may be applied for resourceswith a specific number of ports (e.g., N ports).At least in some embodiments, the reduction factor maybe configurable, and may have N candidate values, i.e., valuesthat are applied in order so that the factor resulting in the lowest reduction of the CSI hypothesis is applied first. At least in some embodiments, if the maximum reduction of the CSI hypothesis is reached and it does not result in anamount of CPUs which user device 200 is capable of processing,then user device 200 may apply CSI priority rules for determiningfor which CSI requests / reports it is not required to update the CSI. At least in some embodiments, network node device 210may be configured to transmit, to user device 200, the CSIresource configuration information at least specifying the re-sources to be used for transmitting the CSI-RSs by network nodedevice 210. As described above in more detail, the CSI resourceconfiguration information may include the at least one CSI hy-pothesis comprising the information on the one or more trans-mission parameters used by network node device 210. The at leastone CSI hypothesis may further comprise the information on theprecoder matrix and / or the rank estimation.At least in some embodiments, network node device 210may be further configured to receive, from user device 200, theat least one CSI feedback report generated based on the one or more measurements performed on the at least one CSI-RS trans-mitted in accordance with the transmitted CSI resource configu-ration information and further based on the transmitted at leastone CSI hypothesis processing adapted by user device 200.At least in some embodiments, network node device 210may be further configured to provide user device 200 with thefirst factor associated with the first CPU value and / or thesecond factor associated with the second CPU value.Fig. 3 illustrates an example flow chart of method 300for user device 200, in accordance with an example embodiment. At operation 301, user device 200 determines the numberof the CPUs associated with the initial number of the antennaports. At operation 302, user device 200 determines the firstscaling factor associated with the channel state informationcomputation for the subsequent number of the antenna ports.At operation 303, user device 200 determines the secondscaling factor associated with the channel state information computation for the subsequent number of the antenna ports. At operation 304, user device 200 calculates the numberof the CPUs for the subsequent number of antenna ports based onthe determined initial number of the antenna ports, the firstscaling factor and the second scaling factor. The subsequentnumber of antenna ports is higher than the initial number of antenna ports. Embodiments and examples with regard to Fig. 3 may becarried out by user device 200 of Fig. 2. Operations 301-304 may, for example, be carried out by at least one processor 202 and at least one memory 204. Further features of method 300 directly resulting from the functionalities and parameters ofuser device 200 are not repeated here. Method 300 can be carriedout by computer program(s) or portions thereof. Another example of an apparatus suitable for carryingout the embodiments and examples with regard to Fig. 3 comprisesmeans for: determining, at operation 301, a number of channelstate information, CSI, processing units, CPUs, associated withan initial number of antenna ports; determining, at operation 302, a first scaling factorassociated with channel state information computation for a sub-sequent number of the antenna ports; determining, at operation 303, a second scaling factorassociated with the channel state information computation forthe subsequent number of antenna ports; and calculating, at operation 304, the number of CPUs forthe subsequent number of antenna ports based on the determinedinitial number of the antenna ports, the first scaling factorand the second scaling factor, wherein the subsequent number of antenna ports is higher than the initial number of antenna ports. The functionality described herein can be performed, at least in part, by one or more computer program product com- ponents such as software components. According to an embodiment,user device 200 may comprise a processor or processor circuitry,such as for example a microcontroller, configured by the program code when executed to execute the embodiments of the operations and functionality described. Alternatively, or in addition, the functionality described herein can be performed, at least in part, by one or more hardware logic components. For example, and without limitation, illustrative types of hardware logic compo- nents that can be used include Field-programmable Gate Arrays (FPGAs), Application-specific Integrated Circuits (ASICs), Ap- plication-specific Standard Products (ASSPs), System-on-a-chipsystems (SOCs), Complex Programmable Logic Devices (CPLDs), Ten-sor Processing Units (TPUs), and Graphics Processing Units(GPUs). Any range or device value given herein may be extendedor altered without losing the effect sought. Also, any embodi-ment may be combined with another embodiment unless explicitly disallowed. Although the subject matter has been described in lan- guage specific to structural features and / or acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as examples of implementing the claims and other equivalent features and acts are intended to be within the scope of the claims. It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. The embodiments are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages. It will furtherbe understood that reference to 'an' item may refer to one ormore of those items. The steps of the methods described herein may be car- ried out in any suitable order, or simultaneously where appro- priate. Additionally, individual blocks may be deleted from any of the methods without departing from the spirit and scope of the subject matter described herein. Aspects of any of the em- bodiments described above may be combined with aspects of any of the other embodiments described to form further embodiments without losing the effect sought. The term 'comprising' is used herein to mean including the method, blocks or elements identified, but that such blocks or elements do not comprise an exclusive list and a method or apparatus may contain additional blocks or elements. It will be understood that the above description is given by way of example only and that various modifications may be made by those skilled in the art. The above specification, examples and data provide a complete description of the struc- ture and use of exemplary embodiments. Although various embodi- ments have been described above with a certain degree of par-ticularity, or with reference to one or more individual embodi-ments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of this specification.

Claims

CLAIMS:

1. A user device (200), comprising: at least one processor (202); and at least one memory (204) storing instructions that, when executed by the at least one processor (202), cause the user device (200) at least to: determine a number of channel state information, CSI,processing units, CPUs, associated with an initial number ofantenna ports; determine a first scaling factor associated with chan-nel state information computation for a subsequent number of theantenna ports; determine a second scaling factor associated with thechannel state information computation for the subsequent numberof antenna ports; and calculate the number of CPUs for the subsequent number of antenna ports based on the determined initial number of theantenna ports, the first scaling factor and the second scalingfactor, wherein the subsequent number of antenna ports is higher than the initial number of antenna ports.

2. The user device (200) according to claim 1, wherein the first scaling factor is determined based on a capabilityindication obtained for the user device (200).

3. The user device (200) according to claim 1, wherein the first scaling factor is determined via inclusion in the at least one memory (204).

4. The user device (200) according to any of claims 1to 3, wherein the first scaling factor is associated with oneof: a CSI related computation with 48 antenna ports with respect to a CSI related computation with 32-antenna ports, a CSI relatedcomputation with 64 antenna ports with respect to a CSI relatedcomputation with 32-antenna ports, a CSI related computationwith 128 antenna ports with respect to a CSI related computationwith 32-antenna ports, or a CSI related computation with 256antenna ports with respect to a CSI related computation with 32- antenna ports.

5. The user device (200) according to any of claims 1to 4, wherein the second scaling factor is determined based ona set of numbers obtained via a capability indication for theuser device (200).

6. The user device (200) according to claim 5, wherein the second scaling factor is determined from the set of numbers in a descending order.

7. The user device (200) according to claim 5 or 6, wherein the set of numbers comprises at least 1, 0.5, 0.25, and 0.

125.

8. The user device (200) according to any of claims 1to 7, wherein the user device (200) is configured with one ormore resources with more than 32 CSI reference signal, CSI-RS,antenna ports.

9. A method (300), comprising: determining (301), by a user device (200), a number ofchannel state information, CSI, processing units, CPUs, associ-ated with an initial number of antenna ports; determining (302), by the user device (200), a firstscaling factor associated with channel state information compu-tation for a subsequent number of the antenna ports; determining (303), by the user device (200), a second scaling factor associated with the channel state information computation for the subsequent number of antenna ports; and calculating (304), by the user device (200), the number of CPUs for the subsequent number of antenna ports based on thedetermined initial number of the antenna ports, the first scal-ing factor and the second scaling factor, wherein the subsequentnumber of antenna ports is higher than the initial number of antenna ports.

10. An apparatus, comprising means for carrying out the method (300) according to claim 9.

11. A computer program comprising instructions for causing a user device to perform at least the following: determining a number of channel state information, CSI,processing units, CPUs, associated with an initial number ofantenna ports; determining a first scaling factor associated withchannel state information computation for a subsequent numberof the antenna ports; determining a second scaling factor associated with thechannel state information computation for the subsequent numberof antenna ports; and calculating the number of CPUs for the subsequent num-ber of antenna ports based on the determined initial number ofthe antenna ports, the first scaling factor and the second scal-ing factor, wherein the subsequent number of antenna ports is higher than the initial number of antenna ports.

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