Conditional ordered channel state information (CSI) reporting

Abstract

A method, system and apparatus are disclosed for generating ordered-based channel state information (CSI) reports. In some embodiments, a method of CSI reporting implemented in a user equipment (UE) (22) that is configured to communicate with a network node (16), is provided. The method includes generating an order-based CSI report that indicates an ordering of the one or more CSI instances, the ordering being based on an ordering criterion, and transmitting the order-based CSI report.

Description

[0001] CONDITIONAL ORDERED CHANNEL STATE INFORMATION (CSI) REPORTING TECHNICAL FIELD

[0002] The present disclosure relates to wireless communications, and in particular, to ordered-based channel state information (CSI) reporting.

[0003] BACKGROUND

[0004] The Third Generation Partnership Project (3GPP) has developed and is developing standards for Fourth Generation (4G) (also referred to as Long Term Evolution (LTE)) and Fifth Generation (5G) (also referred to as New Radio (NR)) wireless communication systems. Such systems provide, among other features, broadband communication between network nodes, such as base stations, and mobile user equipments (UE), as well as communication between network nodes and between UEs. The 3GPP is also developing standards for Sixth Generation (6G) wireless communication networks.

[0005] General overviews to codebook-based precoding as well as CSI reference signals (CSI-RS) as discussed below, as well as more specific background information.

[0006] Multi-antenna techniques can significantly increase the data rates and reliability of a wireless communication system. The performance is in particular improved if both the transmitter and the receiver are equipped with multiple antennas, which results in a multiple-input multiple-output (MIMO) communication channel. Such systems and / or related techniques are commonly referred to as MIMO.

[0007] A component of the fifth Generation (5G) wireless network or New Radio (NR) is the support of MIMO antenna deployments and MIMO related techniques such as spatial multiplexing. Spatial multiplexing can be used to increase data rates in favorable channel conditions. FIG. 1 shows an example of spatial multiplexing. An information carrying symbol vector s is multiplied by an NTX r precoding matrix or precoder W, which serves to distribute the transmit energy in a subspace of the NTdimensional vector space. The precoding matrix is typically selected from a codebook of possible precoding matrices, and typically indicated by means of a precoding matrix indicator (PMI), which specifies a unique precoding matrix in the codebook for a given number of symbol streams. The r symbols in s each correspond to a MIMO layer and r is referred to as the transmission rank, which equals to the number of columns of the precoder W. In this way, spatial multiplexing is achieved since multiple symbols can be transmitted simultaneously overthe same time / frequency resource element (RE). The number of symbols r is typically adapted to suit the current channel properties.

[0008] NR uses Orthogonal Frequency Division Multiplexing (OFDM) in downlink. The received NRx 1 vector ynat a user equipment (UE) on a certain RE can be expressed as yn= HnWsn+ en

[0009] where enis a receiver noise / interference vector. The precoder W can be constant over frequency (i.e., wideband), frequency selective (i.e., per subband), or the combination of both.

[0010] The precoder W is chosen to match the characteristics of the NRX NTMIMO channel matrix Hn, resulting in so-called channel dependent precoding. This is also commonly referred to as closed-loop precoding.

[0011] In closed-loop precoding, the UE feeds back recommendations on a suitable precoder to the gNB (e.g., network node) in the form of a PMI based on downlink channel measurements. For that purpose, the UE is configured with a channel state information (CSI) report configuration including CSI reference signals (CSI-RS) for channel measurements and a codebook of candidate precoders. In addition to precoders, the feedback may also include a rank indicator (RI) and one or two channel quality indicators (CQIs). RI, PMI and CQI are part of a CSI feedback. In NR, CSI feedback can be either wideband, where one CSI is reported for the entire channel bandwidth, or frequency-selective, where one CSI is reported for each subband, which is defined as a number of contiguous physical resource blocks (PRBs) ranging between 4-32 PRBs depending on the band width part (BWP) size.

[0012] Given the CSI feedback from the UE, the network node determines the transmission parameters it wishes to use to transmit to the UE, including the precoding matrix, transmission rank, and modulation and coding scheme (MCS).

[0013] Channel State Information Reference Signals (CSI-RS)

[0014] For CSI measurement and feedback, CSI-RS are defined. A CSI-RS is transmitted on an antenna port at the network node and is used by a UE to measure the downlink channel between the antenna port and each of the UE’s receive antenna ports. The transmit antenna ports are also referred to as CSI-RS ports. The supported number of CSI-RS ports in NR are {1,2,4,8,12,16,24,32}. By measuring the received CSI-RS, aUE can estimate the channel that the CSI-RS is traversing, including the radio propagation channel and antenna gains. The CSI-RS for the above purpose is also referred to as Non-Zero Power (NZP) CSI-RS.CSI-RS can be configured to be transmitted in certain REs in a slot or certain slots. FIG. 2 shows an example of CSI-RS REs for 12 antenna ports, where IRE per RB per port is shown.

[0015] In addition, the interference measurement resource (IMR) is also defined in NR for a UE to measure interference. An IMR resource contains 4 REs, either 4 adjacent RE in frequency in the same OFDM symbol or 2 by 2 adjacent REs in both time and frequency in a slot. By measuring both the channel based on NZP CSI-RS and the interference based on an IMR, a UE can estimate the effective channel and noise plus interference to determine the CSI. Furthermore, a UE in NR may be configured to measure interference based on one or multiple NZP CSI-RS resource.

[0016] NZP CSI-RS configuration details are given in clause 7.4.1.5 of 3GPP TS 38.211 V17.3.0.

[0017] In general,

[0018] ■ A UE can be configured to measure K?> 1 NZP CSI-RS resources with equal number of ports, with up to 32 ports per NZP CSI-RS resource and a total of 128 ports.

[0019] ■ A UE reports M quadruplets ‘cri-RI-PMI-CQI ‘ in a single report.

[0020] o ‘cri-RI-LI-PMI-CQF is also supported for Type-I

[0021] ■ Network can also configure MR< M of K resources to be always reported by aUE as part of the M quadruplets.

[0022] ■ Moreover, CSI reporting for multiple resources have been agreed for the following codebooks: Rel-15 Type-I Single Panel and Rel-16 eType-II. ■ With respect to ordering of CSI reports it has been agreed that resources are sorted according to their CSI-RS Resource Indicator (CRI) index.

[0023] The utilization of centimeter-wave frequencies, particularly within the 7-15GHz range, has gained significant traction and has been identified as one main topic for some of the early 6G releases. This is because many bands within 7-15GHz will become available during the 6G time frame; these bands have potential to provide high data rates, low latency, and enhanced network capacity due to the larger bandwidths in comparison with sub-6GHz bands.

[0024] When operating in the centimeter-wave spectrum, Massive Multiple-Input Multiple-Output (MIMO) systems are expected to continue being a pivotal beamforming technology. It is expected that even large antenna arrays are deployed (compared to sub-6GHz massive MIMO arrays), which will enable leveraging the spatial domain of thechannel even further. One may want to keep the physical aperture of the antenna array fixed regardless of the wavelength used. Thus, when compared to sub-6GHz massive MIMO arrays, uniform-planar arrays (UP As) will have an increase in antenna elements from two factors: from 1) being able to pack more antennas in the horizontal domain of the array, and 2) being able to pack more antennas in the vertical domain of the array.

[0025] As previously mentioned, the number of antenna elements in 7-15GHz massive MIMO network node arrays are expected to grow, thus different types of hybrid beamforming architectures to implement massive MIMO systems in these bands are being considered for a cost-efficient beamforming solution. Compared to standard hybrid beamforming solutions in millimeter wave bands (where only 2 layers are typically possible to be transmitted for antenna arrays with thousands of antenna elements), however, the requirements on the port reduction / expansion are eased thanks to relatively affordable RF components at 7-15GHz frequency. Therefore, research on this topic has gained attention to investigate whether the same types of hybrid beamforming solutions as in millimeter wave systems is reasonable, or if there are other cost-efficient solutions to these specific bands in terms of the trade-off between the performance and hardware complex! ty / costs.

[0026] When it comes to time domain precoding calculation, there are two approaches: downlink feedback (CSI reports using CSI-RS as channel measurement resource) based approaches and uplink reference signal (SRS) based approaches. Complete reliance on SRS, i.e., performing channel sounding with uplink signals only, is conceptually attractive since frequency-domain precoding weights with the singular value decomposition (SVD) on channel estimates is the optimal solution compared to codebook-based approaches (e.g., PMI). However, it has some practical disadvantages like coverage limitations, increased inter-cell interference, etc. Moreover, the use of SRS is UE specific and in a large array context (with a fixed TD beamformer) a complete reliance on SRS is resource inefficient - the RS transmission bandwidth may need to be constrained. This makes it practical to use a CSI-RS based beam selection (where CSI-RS can be common to multiple UEs) method for large arrays.

[0027] In light of the above, one of the commonly used (and still promising) solutions that enables estimation / computation of frequency-independent beamforming weights is beam sweeping, where a network node or a UE or both sequentially test various beam directions from a predefined beam set. In comparison with mmwave bands, where such beam sweeping approaches significantly increase the corresponding time overhead due to theaggressive port reduction / expansion (which naturally increases the number of possible angle directions to be covered by frequency-independent beamforming), performing beam sweeping (to figure out frequency independent beamforming weights) could still be a promising solution for cmWave massive MIMO arrays, since the port expansion / reduction of cmWave bands is expected to be less aggressive compared to the mmWave bands.

[0028] With the larger arrays - and resulting narrower beam widths and a larger number of precoder options for both the frequency-dependent beamforming and frequencyindependent (i.e., wideband) beamforming components - the overhead associated with beam sweeping for evaluating these options grows. This may imply costs in terms of network resources (more RS transmitted), UE processing (evaluation of more precoding options), and robustness and performance (a longer evaluation process makes it more difficult to follow channel variations).

[0029] One problem that occurs more often in cmWave operation is that, after completing a beam sweeping procedure, similar channel qualities may be reported for two or more candidate beams corresponding to two or more CRIs. For example, the same CQI values may be reported for two or more beams. One reason for this is that richer scattering channel environments (i.e., larger number of paths from different angles) as well as wider angle spreads especially in nonline-of-sight NLoS (i.e., larger range of angle) are found in cmWave bands, compared to mmWave bands, which more likely leads to multiple beam candidates resulting in closely-good channel conditions. Since the CSI reports quantizes / uses a finite set of values to describe the channel quality of beams experienced by the UE (e.g. either because of CQI saturation due to the limited dynamic range, or because of CQI quantization steps) the beams’ true qualities may still differ even though the associated CQIs are reported as the same. As a result, there is ambiguity in the beam selection: the network may not know which beam is best since it has the same reported information for two or more beams.

[0030] Note that in mmwave systems, where there is likely one strong path (e.g., line of sight (LoS)) and low angle spreads, thus this ambiguity happens less often. And in FR1 (i.e., sub-6GHz), there is no need of beam sweeping to configure frequency-independent beamforming for port expansion / reduction, since sub-6GHz massive MIMO is typically fully-digital and thus can see the full channel via uplink channel estimation process, implying that such ambiguity is not a common issue in FR1. However, upcoming cmWave bands, where richer channels are expected, potentially have multipaths with wider spreads that are equally good in channel qualities.There is currently no guidance on how to select among beam candidates with similar reported qualities.

[0031] There is thus a need for a solution that helps to select the best beam from multiple beam candidate options that report similar channel qualities so that the effective link quality for the UE is maximized.

[0032] SUMMARY

[0033] Some embodiments advantageously provide methods, systems, and apparatuses for ordered-based CSI reporting.

[0034] In some embodiments, when UEs generate CSI reports, there are some intermediate parameters that are computed by the UE but are not visible to the network node based on the current structure of CSI reporting (and these parameters could aid the network node to solve the beam ambiguity problem).

[0035] After DL beam sweep, a UE reports one or more CSIs corresponding to one or more CSI-RS resource indicators (i.e. CRIs) so that they are ordered based on intermediate parameter(s) computed at the UE, which is not reported as part of legacy CSI report contents if the UE identifies CSI ambiguity in one or more CSI instances. For example, SINR estimates used in the UE internal SINR-CQI mapping table can be used to order the CSIs even if the resulting CQI values are equal / similar. In some embodiments, the network node may interpret this order to infer the intermediate parameter(s) that were not explicitly reported by the UE.

[0036] In accordance with one aspect of the present disclosure, a method of channel state information (CSI) reporting implemented in a user equipment (UE) that is configured to communicate with a network node, is provided. The method includes generating an orderbased CSI report that indicates an ordering of one or more CSI instances, the ordering being based on an ordering criterion, and transmitting the order-based CSI report.

[0037] In accordance with another aspect of the present disclosure, a UE configured to communicate with a network node, is provided. The UE is configured to generate an order-based channel state information (CSI) report that indicates an ordering of the one or more CSI instances, the ordering being based on an ordering criterion, and transmit the order-based CSI report.

[0038] In accordance with another aspect of the present disclosure, a method implemented in a network node that is configured to communicate with a user equipment (UE), is provided. The method includes receiving, from the UE, an order-based channel stateinformation (CSI) report that indicates an ordering of one or more CSI instances, the ordering being based on an ordering criterion for ordering one or more CSI instances corresponding to one or more CRIs.

[0039] In accordance with another aspect of the present disclosure, a network node configured to communicate with a user equipment (UE), is provided. The network node is configured to receive, from the UE, an order-based channel state information (CSI) report that indicates an ordering of one or more CSI instances, the ordering being based on an ordering criterion for ordering one or more CSI instances corresponding to one or more CRIs.

[0040] BRIEF DESCRIPTION OF THE DRAWINGS

[0041] A more complete understanding of the present embodiments, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:

[0042] FIG. l is a block diagram of the transmission structure of spatial multiplexing in NR;

[0043] FIG. 2 is an example of RE allocation for a 12-port CSI-RS in NR;

[0044] FIG. 3 is a schematic diagram of an example network architecture illustrating a communication system according to principles disclosed herein;

[0045] FIG. 4 is a block diagram of a network node in communication with a user equipment over a wireless connection according to some embodiments of the present disclosure;

[0046] FIG. 5 is a schematic diagram of another example network architecture illustrating a communication system according to principles disclosed herein;

[0047] FIG. 6 is a flowchart of an example process in a user equipment according to some embodiments of the present disclosure;

[0048] FIG. 7 is a flowchart of an example process in a network node according to some embodiments of the present disclosure;

[0049] FIG. 8 is a flowchart of another example process in a network node according to some embodiments of the present disclosure;

[0050] FIG. 9 is a flowchart of another example process in a user equipment according to another embodiment of the present disclosure;FIG. 10 is a graph illustrating the impact of zenith of departure (ZoD) spread on the occurrence of beam ambiguity during the beam sweeping process in a UE; and FIG. 11 is a graph illustrating the actual gain, measured as the beam gain difference in dB between the minimum and maximum beam gains among beams identified ambiguous, when ambiguity is resolved.

[0051] DETAILED DESCRIPTION

[0052] Before describing in detail exemplary embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to ordered-based CSI reporting for indicating intermediate parameters, such as, when there is ambiguity in the CSI reports.

[0053] Accordingly, components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

[0054] As used herein, relational terms, such as “first” and “second,” “top” and “bottom,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and / or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0055] In embodiments described herein, the joining term, “in communication with” and the like, may be used to indicate electrical or data communication, which may be accomplished by physical contact, induction, electromagnetic radiation, radio signaling, infrared signaling or optical signaling, for example. One having ordinary skill in the art will appreciate that multiple components may interoperate and modifications and variations are possible of achieving the electrical and data communication.In some embodiments described herein, the term “coupled,” “connected,” and the like, may be used herein to indicate a connection, although not necessarily directly, and may include wired and / or wireless connections.

[0056] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and / or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0057] The term “network node” used herein can be any kind of network node comprised in a radio network which may further comprise any of base station (BS), radio base station, base transceiver station (BTS), base station controller (BSC), radio network controller (RNC), g Node B (gNB), evolved Node B (eNB or eNodeB), Node B, multistandard radio (MSR) radio node such as MSR BS, multi -cell / multicast coordination entity (MCE), relay node, donor node controlling relay, radio access point (AP), transmission points, transmission nodes, Remote Radio Unit (RRU) Remote Radio Head (RRH), a core network node (e.g., mobile management entity (MME), self-organizing network (SON) node, a coordinating node, positioning node, MDT node, etc.), an external node (e.g., 3rd party node, a node external to the current network), nodes in distributed antenna system (DAS), a spectrum access system (SAS) node, an element management system (EMS), etc. The network node may also comprise test equipment. The term “radio node” used herein may be used to also denote a user equipment (UE) such as a wireless device (WD) or a radio network node.

[0058] In some embodiments, the non-limiting terms wireless device (WD) or a user equipment (UE) are used interchangeably. The UE herein can be any type of user equipment capable of communicating with a network node or another UE over radio signals, such as a wireless device (WD). The UE may also be a radio communication device, target device, device to device (D2D) UE, machine type UE or UE capable of machine to machine communication (M2M), low-cost and / or low-complexity UE, a sensor equipped with UE, Tablet, mobile terminals, smart phone, laptop embedded equipped (LEE), laptop mounted equipment (LME), USB dongles, Customer Premises Equipment (CPE), an Internet of Things (loT) device, or a Narrowband loT (NB-IOT) device etc.Also, in some embodiments the generic term “radio network node” is used. It can be any kind of a radio network node which may comprise any of base station, radio base station, base transceiver station, base station controller, network controller, RNC, evolved Node B (eNB), Node B, gNB, Multi-cell / multicast Coordination Entity (MCE), relay node, access point, radio access point, Remote Radio Unit (RRU) Remote Radio Head (RRH).

[0059] In the context of this disclosure the term “hybrid beamforming” is used to refer to any combination of frequency-dependent beamforming and frequency-independent (i.e., wideband) beamforming, thus it can include traditional analog phase shifter based approaches, advanced digital-time domain beamforming approaches, hybrids of the previous two, etc.

[0060] Note that although terminology from one particular wireless system, such as, for example, 3GPP LTE and / or New Radio (NR) and / or 6G, may be used in this disclosure, this should not be seen as limiting the scope of the disclosure to only the aforementioned system. It is contemplated that other 3GPP systems may make use of the concepts and arrangements disclosed herein. For example, a disclosure relating to NR may also be implementable in a 6G system and / or an LTE system, a disclosure relating to 6G may also be implementable in a NR and / or LTE system, and a disclosure relating to LTE may also be implementable in a NR and / or 6G system. Other wireless systems, including without limitation Wide Band Code Division Multiple Access (WCDMA), Worldwide Interoperability for Microwave Access (WiMax), Ultra Mobile Broadband (UMB) and Global System for Mobile Communications (GSM), may also benefit from exploiting the ideas covered within this disclosure.

[0061] Note further, that functions described herein as being performed by a user equipment or a network node may be distributed over a plurality of user equipments and / or network nodes. In other words, it is contemplated that the functions of the network node and user equipment described herein are not limited to performance by a single physical device and, in fact, can be distributed among several physical devices.

[0062] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.Some embodiments are directed to ordered-based CSI reporting.

[0063] Referring to the drawing figures, in which like elements are referred to by like reference numerals, there is shown in FIG. 3 a schematic diagram of a communication system 10, according to an embodiment, such as a 3 GPP -type cellular network that may support standards such as LTE and / or NR (5G) and / or 6G, which comprises an access network 12, such as a radio access network, and a core network 14. The core network 14 includes one or more core network nodes 15. The access network 12 comprises a plurality of network nodes 16a, 16b, 16c (referred to collectively as network nodes 16), such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 18a, 18b, 18c (referred to collectively as coverage areas 18). Each network node 16a, 16b, 16c is connectable to the core network 14 over a wired or wireless connection 20. A first user equipment (UE) 22a located in coverage area 18a is configured to wirelessly connect to, or be paged by, the corresponding network node 16a. A second UE 22b in coverage area 18b is wirelessly connectable to the corresponding network node 16b. While a plurality of UEs 22a, 22b (collectively referred to as user equipments 22) are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding network node 16. Note that although only two UEs 22 and three network nodes 16 are shown for convenience, the communication system may include many more UEs 22 and network nodes 16.

[0064] As one example, in certain embodiments, access network 12 may contain some access network nodes 16 that support 3 GPP radio access technologies (RAT), such as LTE or NR, while other access network nodes 16 support (or the same access network nodes 16 additionally support) non-3GPP RATs, such as Wi-Fi or a proprietary RAT. As another example, communication system 10 may support multiple generations of related communication standards (e.g., 4G, 5G and 6G 3 GPP communication standards) and, as a result, may include an access network 12 and / or a core network 14 that supports multiple different standard generations or may include multiple access networks 12 and / or multiple core networks 14 with individual networks supporting different standards generations.

[0065] Also, it is contemplated that a UE 22 can be in simultaneous communication and / or configured to separately communicate with more than one network node 16 and more than one type of network node 16. For example, a UE 22 can have dual connectivity with a network node 16 that supports LTE and the same or a different network node 16 that supports NR. As an example, UE 22 can be in communication withan eNB for LTEZE-UTRAN, a gNB for NR / NG-RAN (i.e. being configured for multiradio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC) and / or Wi-Fi.

[0066] A network node 16 (eNB or gNB) is configured to include a criterion unit 24 which is configured to perform one or more network node 16 functions as described herein such as with respect to the ordering criterion for ordering CSI instance(s). A user equipment 22 is configured to include a report unit 26 which is configured to perform one or more UE 22 functions as described herein such as with respect to an order-based CSI report.

[0067] Example implementations, in accordance with an embodiment, of the UE 22 and network node 16 discussed in the preceding paragraphs will now be described with reference to FIG. 4.

[0068] The communication system 10 includes a network node 16 provided in a communication system 10 and including hardware 28 enabling it to communicate with the UE 22. The hardware 28 may include a communication interface 29 comprising a radio interface 30 for setting up and maintaining at least a wireless connection 32 with a UE 22 located in a coverage area 18 served by the network node 16. The radio interface 30 may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and / or one or more RF transceivers. The radio interface 30 includes an array of antennas 34 to radiate and receive signal(s) carrying electromagnetic waves.

[0069] In the embodiment shown, the hardware 28 of the network node 16 further includes processing circuitry 36. The processing circuitry 36 may include a processor 38 and a memory 40. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 36 may comprise integrated circuitry for processing and / or control, e.g., one or more processors and / or processor cores and / or FPGAs (Field Programmable Gate Array) and / or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 38 may be configured to access (e.g., write to and / or read from) the memory 40, which may comprise any kind of volatile and / or nonvolatile memory, e.g., cache and / or buffer memory and / or RAM (Random Access Memory) and / or ROM (Read-Only Memory) and / or optical memory and / or EPROM (Erasable Programmable Read-Only Memory).

[0070] Thus, the network node 16 further has software 42 stored internally in, for example, memory 40, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the network node 16 via an external connection. Thesoftware 42 may be executable by the processing circuitry 36. The processing circuitry 36 may be configured to control any of the methods and / or processes described herein and / or to cause such methods, and / or processes to be performed, e.g., by network node 16.

[0071] Processor 38 corresponds to one or more processors 38 for performing network node 16 functions described herein. The memory 40 is configured to store data, programmatic software code and / or other information described herein. In some embodiments, the software 42 may include instructions that, when executed by the processor 38 and / or processing circuitry 36, causes the processor 38 and / or processing circuitry 36 to perform the processes described herein with respect to network node 16. For example, processing circuitry 36 of the network node 16 may include criterion unit 24 which is configured to perform one or more network node 16 functions as described herein such as with respect to ordering criterion for ordering one or more channel state information (CSI) instances corresponding to one or more CSI-reference signal (RS) resource indicators (CRIs).

[0072] The network node 16 may be composed of multiple distinct network entities (e.g., a NodeB entity and a RNC entity, or a BTS entity and a BSC entity, etc.), which may each have or utilize their own respective physical components. In certain scenarios in which the network node 16 comprises multiple such entities (e.g., BTS and BSC), one or more of the separate entities may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, the network node 16 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memories 40 or portions of memory 40 for different RATs) and some components may be reused (e.g., a same antenna may be shared by different RATs). The network node 16 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 16, for example GSM, WCDMA, LTE, NR, Wi-Fi (e.g., according to an IEEE 802.11 family standard), Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 16.

[0073] In certain alternative embodiments, network node 16 may be capable of wireless communication but does not include separate radio front-end circuitry, instead, the processing circuitry 36 includes radio front-end circuitry and is connected to the antenna 34. Similarly, in some embodiments, all or some of the RF receivers, transmitters and / ortransceivers are part of the radio interface 30. In still other embodiments, the communication interface 29 includes one or more ports or terminals, the radio interface 30, and the RF receiver, transmitter and / or transceiver, and the communication interface 31 communicates with baseband processing circuitry, which is part of a digital unit (not shown).

[0074] The antenna 34 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 34 may be coupled to the radio front-end circuitry in radio interface 30 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 34 is separate from the network node 16 and connectable to the network node 16 through one or more interfaces or ports.

[0075] Core network node 15 can include one or more components described above with respect to network node 16, e.g., communication interface 29, radio interface 30, antenna 34, ports, processing circuitry 36, processor 38, memory 40 and software 42. These elements of core network node 15 can be arranged such that core network node 15 can perform various core network functions. Core network node 15 can communicate wirelessly or via a wired connection with network nodes 16 via communication link 59.

[0076] The communication system 10 further includes the UE 22 already referred to. The UE 22 may have hardware 44 that may include a radio interface 46 configured to set up and maintain a wireless connection 32 with a network node 16 serving a coverage area 18 in which the UE 22 is currently located. The radio interface 46 may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and / or one or more RF transceivers. The radio interface 46 includes an array of antennas 48 to radiate and receive signal(s) carrying electromagnetic waves.

[0077] Communication functions of the radio interface 46 may include cellular communication, Wi-Fi communication (e.g., according to an IEEE 802.11 family standard), LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented according to one or more communication protocols and / or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission controlprotocol / internet protocol (TCP / IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0078] The hardware 44 of the UE 22 further includes processing circuitry 50. The processing circuitry 50 may include a processor 52 and memory 54. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 50 may comprise integrated circuitry for processing and / or control, e.g., one or more processors and / or processor cores and / or FPGAs (Field Programmable Gate Array) and / or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 52 may be configured to access (e.g., write to and / or read from) memory 54, which may comprise any kind of volatile and / or nonvolatile memory, e.g., cache and / or buffer memory and / or RAM (Random Access Memory) and / or ROM (Read-Only Memory) and / or optical memory and / or EPROM (Erasable Programmable Read-Only Memory).

[0079] Thus, the UE 22 may further comprise software 56, which is stored in, for example, memory 54 at the UE 22, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the UE 22. The software 56 may be executable by the processing circuitry 50. The software 56 may include a client application 58. The client application 58 may be operable to provide a service to a human or non-human user via the UE 22.

[0080] The processing circuitry 50 may be configured to control any of the methods and / or processes described herein and / or to cause such methods, and / or processes to be performed, e.g., by UE 22. The processor 52 corresponds to one or more processors 52 for performing UE 22 functions described herein. The UE 22 includes memory 54 that is configured to store data, programmatic software code and / or other information described herein. In some embodiments, the software 56 and / or the client application 58 may include instructions that, when executed by the processor 52 and / or processing circuitry 50, causes the processor 52 and / or processing circuitry 50 to perform the processes described herein with respect to UE 22. For example, the processing circuitry 50 of the user equipment 22 may include report unit 26 which is configured to perform one or more user equipment 22 functions described herein.

[0081] In some embodiments, the inner workings of the network node 16 and UE 22 may be as shown in FIG. 4 and independently, the surrounding network topology may be that of FIG. 3.The wireless connection 32 between the UE 22 and the network node 16 is in accordance with the teachings of the embodiments described throughout this disclosure. More precisely, the teachings of some of these embodiments may improve the data rate, latency, and / or power consumption and thereby provide benefits such as reduced user waiting time, relaxed restriction on file size, better responsiveness, extended battery lifetime, etc. In some embodiments, a measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve.

[0082] Although FIGS. 3 and 4 show various “units” such as criterion unit 24 and report unit 26 as being within a respective processor, it is contemplated that these units may be implemented such that a portion of the unit is stored in a corresponding memory within the processing circuitry. In other words, the units may be implemented in hardware or in a combination of hardware and software within the processing circuitry.

[0083] FIG. 5 is another example of a communication system 10 according to some embodiments. As used herein, the communication system 10 of FIG. 5 includes multiple access points (APs) 60 (with four example APs 60a, 60b, 60c, and 60d being depicted) and multiple wireless devices, referred to in the context of communication system 10 of FIG. 5 as stations (STAs) 62 (referred to individually as STA 62a, STA 62b, STA 62c, STA 62d, and STA 62e). STA 62a is served by AP 60a in a first basic service set (BSS) 64a. STA 62b and STA 62c are served by AP 60b in a second BSS, BSS 64b. STA 62d is served by AP 60c in a third BSS, BSS 64c. STA 62e is served by AP 60d in a fourth BSS, BSS 64d. Stations 62 may be non-AP STAs and correspond to various kinds of wireless devices, for example, user terminals, such as mobile or stationary computing devices like smartphones, laptop computers, desktop computers, tablet computers, gaming devices, head-mounted displays (HMDs) for Augmented Reality (AR) or Virtual Reality (VR), or the like, including UEs 22 that are shown and described with respect to FIGS. 3 and 4. In other words, in some embodiment, STA 62 is a UE 22. Further, stations 62 could, for example, correspond to other kinds of equipment like smart home devices, printers, multimedia devices, data storage devices, or the like.

[0084] Each of STAs 62 may connect through a radio link to one of APs 60. For example, depending on location or channel conditions experienced by a given STA 62, the STA may select an appropriate AP and BSS for establishing the radio link. The radio link may be based on one or more orthogonal frequency-division multiplexing (OFDM) carriers from a frequency spectrum that is shared on the basis of a contention-based mechanism,e.g., an unlicensed or license exempt band like 2.4 GHz Industrial, Scientific, and Medical (ISM) band, the 5 GHz band, the 6 GHz band, or the 60 GHz band.

[0085] Each AP 60 may provide data connectivity to STAs 62 connected to a particular AP 60. As illustrated, APs 60 may be connected to a data network 66. In this way, APs 60 may also provide data connectivity between STAs 62 and other entities, e.g., to one or more servers, service providers, data sources, data sinks, user terminals, or the like.

[0086] Accordingly, the radio link established between a given STA 62 and its serving AP 60 may be used for providing various kinds of services to STA 62, e.g., a voice service, a multimedia service, or other data service. Such services may be based on applications that are executed on STA 62 and / or on a device linked to STA 62. By way of example, FIG. 5 illustrates an application service platform 68 provided in data network 66. The application(s) executed on STA 62 and / or on one or more other devices linked to STA 62 may use the radio link for data communication with one or more other STA 62 and / or the application service platform 68, thereby enabling utilization of the corresponding service(s) at STA 62.

[0087] FIG. 6 is a flowchart of an example process in a UE 22 according to some embodiments of the present disclosure. One or more blocks described herein may be performed by one or more elements of UE 22 such as by one or more of processing circuitry 50 (including the report unit 26), processor 52, and / or radio interface 46. UE 22 is configured to generate (Block S90) an order-based CSI report that indicates an ordering of one or more CSI instances, the ordering based on an ordering criterion. UE 22 is further configured and transmit (Block S92) the order-based CSI report, as described herein.

[0088] According to one or more embodiments, UE 22 is further configured to identify CSI ambiguity in one or more CSI instances, and performing the generating based on the CSI ambiguity being identified.

[0089] According to one or more embodiments, UE 22 is further configured to obtain an ordering criterion for ordering the one or more CSI instances, the one or more CSI instances corresponding to one or more CRIs, wherein the ordering criterion for ordering the one or more CSI instances corresponding to one or more CRIs is received as part of a CSI reporting configuration from the network node 16.

[0090] According to one or more embodiments, the ordering criterion is chosen from a predefined set of parameters.According to one or more embodiments, identifying the CSI ambiguity comprises determining whether there are two or more CSI instances with same CQI values or CQI values that are within a predefined range.

[0091] According to one or more embodiments, the predefined range may be at least one of a same reported CQI, plus or minus one CQI step, and plus or minus two CQI steps.

[0092] According to one or more embodiments, the ordering of one or more CSI instances corresponding to one or more CRIs based on the ordering criterion is applied when the CSI ambiguity is identified.

[0093] According to one or more embodiments, the ordering criterion is based on an estimate of a first parameter, and wherein the first parameter is internal to the UE 22.

[0094] According to one or more embodiments, if the first parameter is equal to or within a predetermined margin, the ordering is determined based on a second parameter or a function of the first parameter and the second parameter.

[0095] According to one or more embodiments, the first parameter and the second parameter are either Reference Signal Received Power (RSRP) or Signal-to-Noise-Ratio (SINR).

[0096] According to one or more embodiments, if the CSI ambiguity is determined or if the first parameter is equal to or within a predetermined margin, UE 22 is further configured to provide at least one of additional information and signaling to the network node 16, the signaling comprising a sounding reference signal (SRS).

[0097] According to one or more embodiments, the order-based CSI report comprises additional quality indications for multiple reported CSI instances corresponding to the one or more CRIs, the additional quality indications are based on the first parameter.

[0098] According to one or more embodiments, the additional quality indications are reported as differential values in relation to a highest-quality CSI instance.

[0099] According to one or more embodiments, UE 22 is further configured to signal capability related to CSI report ordering.

[0100] According to one or more embodiments, UE 22 is further configured to receive from the network node a radio resource control (RRC) reconfiguration message, the RRC reconfiguration message including a configuration parameter to selectively enable or disable the ordering of the one or more CSI instances corresponding to one or more CRIs according to the ordering criterion.According to one or more embodiments, the configuration parameter to selectively enable or disable the ordering of the one or more CSI instances is a one-bit field that may be set to one of two values.

[0101] FIG. 7 is a flowchart of an example process in a network node 16 according to some embodiments of the present disclosure. One or more blocks described herein may be performed by one or more elements of network node 16 such as by one or more of processing circuitry 36 (including the criterion unit 24), processor 38, and / or radio interface 30. Network node 16 is configured to send (Block S94), to UE 22, an ordering criterion for ordering one or more CSI instances corresponding to one or more CRIs, as described herein. Network node 16 is further configured to receive (Block S96), from UE 22, an order-based CSI report that indicates an ordering of the one or more CSI instances based on the ordering criterion, as described herein.

[0102] FIG. 8 is a flowchart of another example process in a network node 16 according to some embodiments of the present disclosure. One or more blocks described herein may be performed by one or more elements of network node 16 such as by one or more of processing circuitry 36 (including the criterion unit 24), processor 38, and / or radio interface 30. Network node 16 is configured to receive (Block S98) from the UE 22, an order-based CSI report that indicates an ordering of one or more CSI instances, the ordering being based on an ordering criterion for ordering one or more CSI instances corresponding to one or more CRIs.

[0103] According to some embodiments, the ordering criterion is chosen from a predefined set of parameters.

[0104] According to some embodiments, network node 16 is further configured to send, to the UE 22, the ordering criterion for ordering the one or more CSI instances corresponding to the one or more CRIs.

[0105] According to some embodiments, the ordering criterion is based on an estimate of a first parameter and wherein the first parameter is internal to the UE 2).

[0106] According to some embodiments, the first parameter is at least one of reference signal received power (RSRP) and signal -to-noise-ratio (SINR).

[0107] Having described the general process flow of arrangements of the disclosure and having provided examples of hardware and software arrangements for implementing the processes and functions of the disclosure, the sections below provide details and examples of arrangements for providing order-based CSI reporting in a communication network.One or more network node 16 function described below may be performed by one or more of processing circuitry 36, criterion unit 24, radio interface 30, processor 38, etc. One or more UE 22 functions described below may be performed by one or more of processing circuitry 50, processor 52, report unit 26, radio interface 46, etc.

[0108] FIG. 9 is a flowchart for providing order-based CSI reporting in accordance with embodiments of the present disclosure. In some embodiments, UE 22 is configured to obtain (Block 101) a criterion (i.e., ordering criterion) for ordering one or more CSI instances corresponding to one or more CRIs (note that each CRI corresponds to one beam candidate which is transmitted over a CSI-RS resource). In some embodiments, the ordering criterion is pre-specified in 3GPP specifications. In some embodiments, the ordering criterion is received from network node 16 by UE 22 via a control channel (e.g., via a reporting configuration). In some embodiments, network node 16 transmits a Radio Resource Control (RRC) Reconfiguration message to UE 22, where the message includes CSI-RS configuration parameters, including one or more of resource set identifiers, periodicity, subcarrier spacing, and time / frequency domain allocation and a configuration parameter to selectively enable or disable ordering of one or more CSI instances corresponding to one or more CRIs according to the ordering criterion.

[0109] In some embodiments, the configuration parameter to selectively enable or disable ordering of one or more CSI instances corresponding to one or more CRIs is a one-bit field that may be set to one of two values. A first value of the parameter instructs UE 22 to enable ordering of one or more CSI instances corresponding to one or more CRIs, while a second value of the switching parameter instructs UE 22 to disable the ordering of the one or more CSI instances corresponding to the one or more CRIs. Upon receiving this message, UE 22 updates its measurement and reporting procedures so that subsequent CSI reports conform to the newly obtained information regarding enabling or disabling of ordering.

[0110] In some embodiments, UE 22 is configured to receive (Block 102) two or more (precoded) CSI-RS resources, each indicating a different beam candidate, and calculates the corresponding CSI instances per resource.

[0111] In some embodiments, UE 22 is configured to check (or determine) (Block 103) whether two or more CSI instances result in CSI ambiguity by applying an ambiguity criterion. If ambiguity is declared, then UE 22 is configured to make a decision (Block 104) to compute the ordering according to the ordering criterion based on first (UE-intemal) parameter estimates (e.g., RSRPs, SINRs) used to generate CQIs correspondingto two or more CSI instances corresponding to two or more CRIs. If no ambiguity is detected, then ordering computation may be omitted, e.g., UE 22 is configured to signal (Block 106) to network node 16 a CSI report comprising one or more CSI instances based on a default configuration.

[0112] There are numerous possible criteria to declare ambiguity. In some embodiments, ambiguity is defined (e.g., by the ambiguity criterion) when two or more CSI instances corresponding to two or more CRIs result in the same CQI. In other embodiments, UE 22 may determine ambiguity by assessing whether the two or more CSI instances corresponding to two or more CRIs have CQI values that are within X CQI levels, i.e., the difference between the computed CQI values is below a threshold, e.g., less than X=2 levels. In other embodiments, UE 22 may declare ambiguity if the difference between internal metrics, e.g., SINR, for two CSI instances corresponding to two CRIs is below a threshold, e.g., below 2 dB. And in other embodiments, UE 22 may declare ambiguity if certainty / reliability of a CSI estimation-related measurement, e.g., signal power or interference component, is below a threshold. Hence, the ambiguity criterion may be an ambiguity criteria that may include one or more rules for determining whether an ambiguity exists.

[0113] In some embodiments, UE 22 is configured to (Block 104) the ordering of the multiple CSI instances corresponding to the multiple CRIs based on a UE -internal first parameter estimate and the obtained ordering criterion. In some embodiments, the first parameter used for ordering is one or more of RSRP, SNR and SINR. In other embodiments, in case the first parameter used to determine the ordering of CSI instances (e.g., RSRP) is equal or within a margin, a second parameter (e.g., SINR) is used for ordering. In still other embodiments, if the first parameter (e.g., RSRP) is equal / within a margin, UE 22 alternatively provides additional information / signaling to network node 16 (by transmitting a UL reference signal, e.g., SRS), so that network node 16 can determine which of the multiple reported CSI instances was best.

[0114] Besides computing the ordering in Block 104, UE 22 is also configured to compute additional quality indications for the multiple reported CSI instances corresponding to multiple CRIs and adds these additional quality indications to the order-based CSI report. In some embodiments, the first parameter used for computing the additional quality indication is based on the first parameter and is reported as an absolute value. In other embodiments, the additional quality indications are reported as differential values in relation to a highest-quality CSI instance. In still other embodiments, when the qualityindicator of multiple reported CSI instances is the same or within a margin, UE 22 reports a common quality indicator, e.g., a legacy CQI, and provides additional information to the network via an UL reference signal.

[0115] In some embodiments, UE 22 is configured to signal (Block 105) to network node 16 an ordered CSI report (i.e., order-based CSI report) comprising one or more CSI instances based on the computed ordering. The terms “ordered CSI report” and “orderbased CSI report” are used interchangeably throughout this disclosure and refer to the same report.

[0116] If UE 22 identifies no ambiguity within received CSI instances (e.g., based on the ambiguity criterion), UE 22 is configured to signal (Block 106) to network node 16 a nonordered CSI report based on a default CSI report configuration.

[0117] As shown in the flowchart of FIG. 9, there is no additional computational burden at UE 22 for ordering, as internal UE parameters are generally computed for existing CSI reports already (i.e., for the UE 22 to determine CQI / PMI).

[0118] To validate the effectiveness of one or more embodiments described herein, shown below are possible performance gains via link-level simulation. Consider a single user MIMO scenario, where network node 16 conducts beam sweeping over a predefined set of beams through multiple CSI-RS resources, receiving the corresponding CSI reports from UE 22. In one example, a case where each beam pattern in the predefined set is used by a distinct CSI-RS resource is considered. The major simulation parameters are listed in Table 1 below.

[0119] Table 1: Simulation parameters

[0120]

[0121]

[0122] First, to demonstrate the frequency of the beam ambiguity problem in centimeter wave bands, FIG. 10 highlights the impact of zenith of departure (ZoD) spread on the occurrence of beam ambiguity during the beam sweeping process in a UE 22.

[0123] Understanding this relationship is used for optimizing beam management strategies in these bands, as beam ambiguity can lead to suboptimal beam selection and degrade communication quality. Beam ambiguity is defined as a situation where two or more beam candidates corresponding to two or more CRIs are identified as having the same channel quality indicator (CQI). By visualizing the probability of beam ambiguity as a function of ZoD spread, FIG. 10 provides insights into how angular dispersion affects the UE's ability (with the current reporting framework) to distinguish between multiple beam candidates with similar channel quality.

[0124] The x-axis represents the ZoD spread, while the y-axis shows the probability of beam ambiguity. Except for ZoD = 2 degrees, FIG. 10 reveals that narrower ZoD spreads are generally associated with lower probabilities of beam ambiguity. This is because narrower ZoD spreads likely result in one beam direction being distinguishably different from other candidates. However, when ZoD spreads become extremely narrow, all beam candidates within the spread are identified as equally strong, leading to a high probability of occurrence. In such cases, although the probability of occurrence is high, the actual gain from resolving the ambiguity is minor, as shown later in FIG. 10. Conversely, wider ZoD spreads correlate with higher ambiguity probabilities, likely due to the increased probability of multiple strong paths existing within the spread. These insights underscorethe importance of managing beam ambiguity in richer channel environments, such as those in centimeter wave bands, thereby enhancing the reliability and efficiency of the beamforming process in these frequency ranges.

[0125] Building on the insights from FIG. 10, which illustrated the probability of beam ambiguity occurrence as a function of zenith of departure (ZoD) spread, another point of consideration are the potential gains achievable by resolving this ambiguity when it arises. FIG. 11 presents the actual gain, measured as the beam gain difference in dB between the minimum and maximum beam gains among beams identified ambiguous, when ambiguity is effectively resolved. The x-axis represents the ZoD spread, while the y-axis indicates the gain in dB obtained by selecting the optimal beam.

[0126] FIG. 11 illustrates practical benefits of mitigating beam ambiguity in centimeter wave bands, where precise beam management is advantageous.

[0127] As mentioned above, there is currently no guidance on how to select among beam candidates with similar reported qualities. One solution to this is to randomly select one from those beam candidates having similar channel qualities; however, this will result in, e.g., suboptimal performance or unnecessary energy consumption. For example, the simulated results associated with FIG. 11 show that the actual resulting channel quality for the user may differ significantly (up to 1-2 dB) between the beam candidates that return the same CQI report. A non-informed frequency-independent beam selection among those beams reported with close channel qualities could therefore lead to performance loss in data transmission (e.g., Physical Data Shared Channel, “PDSCH”). One important reason that explains why the actual PDSCH throughput may differ across beams with same reported CQI values is because a different MCS may be determined by the network node 16 for each beam. This is because MCS computation may be performed based on multiple criteria - e.g., UL signals, present CQI, PMI, RI, outer loop corrections based on past ACK / NACK reports, etc. And even if MCSs are selected for several beams using the same CQI value, and therefore projected throughputs are the same, using the best beam will result in lower block-error rates.

[0128] The results in FIG. 11 show that for narrower ZoD spreads, the gain from resolving beam ambiguity is generally modest, particularly in situations where all beam candidates are very close to each other in the angle domain. This suggests that even if the probability of occurrence is high, the actual performance impact remains limited due to the nearly equivalent quality of the competing beams. However, as the ZoD spread increases, the potential gain from resolving ambiguities becomes more significant. This is likely becausethe differentiation between beam candidates becomes more pronounced, allowing UE 22 to select a beam that offers a substantial improvement in signal strength, as reflected in the increased dB gain. These findings underscore the importance of adopting context-sensitive beam management strategies when / if a UE 22 identifies the beam ambiguity in CQI.

[0129] In some embodiments of the present disclosure, a method in a UE 22 for CSI reporting comprises obtaining an ordering criterion for ordering one or more CSI instances corresponding to one or more CRIs; and signaling to a network node 16 an order-based CSI report comprising one or more CSI instances corresponding to one or more CRIs based on the ordering criterion when the UE 22 identifies CSI ambiguity in the one or more CSI instances.

[0130] In some embodiments, the ordering criterion for ordering the one or more CSI instances corresponding to one or more CRIs is received as part of CSI reporting configuration from the network node 16.

[0131] In some embodiments, the ordering criterion is predefined in standard specifications.

[0132] In some embodiments, identifying CSI ambiguity comprises determining whether there are two or more CSI instances with the same CQI values or CQI values that are within X CQI levels. In some embodiments, the range of X levels may be the same reported CQI, ±1 CQI step, ±2 CQI steps, etc. In one or more embodiments, X is a positive integer.

[0133] In some embodiments, the ordering of one or more CSI instances corresponding to one or more CRIs based on the ordering criterion is applied when X is below a threshold / margin.

[0134] In some embodiments, the ordering criterion is based on intermediate parameters such as a first (UE-internal) parameter estimate such as, for example, Reference Signal Received Power (RSRP), Signal-to-Noise-Ratio (SINR) used to generate the CQI via an internal mapping table, sum MI, etc. In some embodiments, if the first parameter (e.g., RSRP) is equal / within an X margin, the ordering is based on a second parameter (e.g., SINR). In some embodiments, if the first parameter (e.g. RSRP) is equal / within an X margin, the ordering is determined based on a function of a first parameter estimate (e.g., RSRP) and a second parameter (e.g., one or more of SINR, sum MI, ...). In some embodiments, if the first parameter (e.g., RSRP) is equal / within a X margin, the UE 22 provides additional information / signaling to the network node 16 (e.g., transmit SRS).In some embodiments, the order-based CSI report comprises additional quality indications for the multiple reported CSI-RS resource indicators (CRIs). In some embodiments, the additional quality indication is based on the first parameter. In some embodiments, the additional quality indications are reported as differential values in relation to a highest-quality CSI instance.

[0135] In some embodiments, the order-based CSI report is signaled as part of wide-band CSI.

[0136] In some embodiments, signaling UE 22 capability is related to CSI report ordering. In some embodiments, an order-based CSI report includes indicator bit(s) indicating whether the ordering has been applied.

[0137] Some embodiments of the present disclosure may advantageously allow the network node 16 to obtain more complete / accurate information about the candidate beams corresponding to one or more CRIs from CSI reports, leading to better spectral efficiency.

[0138] Some embodiments of the present disclosure may advantageously allow CSI report ordering-related computations and report handling to be performed only when needed due to a need to resolve CSI ambiguity.

[0139] Some additional examples include:

[0140] Example Al . A network node 16 configured to communicate with a user equipment (UE) 22 the network node 16 configured to, and / or comprising a radio interface and / or comprising processing circuitry configured to:

[0141] send, to the UE 22, an ordering criterion for ordering one or more channel state information (CSI) instances corresponding to one or more CSI-reference signal (RS) resources CRIs; and

[0142] receive, from the UE 22, an order-based CSI report that indicates an ordering of the one or more CSI instances, the ordering being based on the ordering criterion.

[0143] Example A2. The network node 16 of Example Al, wherein the ordering criterion for ordering the one or more CSI instances corresponding to one or more CRIs is part of a CSI reporting configuration.

[0144] Example A3. The network node 16 of any of Examples A1-A2,

[0145] wherein the ordering criterion is sent to the UE 22 via a control channel.

[0146] Example A4. The network node 16 of any of Examples A1-A3, wherein the ordering criterion is based on an estimate of a first parameter.Example A5. The network node 16 of Example A4, wherein the first parameter is internal to the UE 22.

[0147] Example A6. The network node 16 of Example A4, wherein the first parameter is at least one of reference signal received power (RSNP), signal-to-noise-ratio, and SINR, used to generate a channel quality indicator (CQI) via an internal mapping table.

[0148] Example A7. The network node 16 of Example A4, wherein if the first parameter is equal to or within a predetermined margin, the ordering of the one or more CSI instances being based on a second parameter different from the first parameter.

[0149] Example A8. The network node 16 of Example A4, wherein if the first parameter is equal to or within a predetermined margin, the ordering is determined based on a function of the first parameter and a second parameter that is different from the first parameter.

[0150] Example A9. The network node 16 of Example A4, wherein if the first parameter is equal to or within a predetermined margin,

[0151] the network node 16 is further configured to receive from the UE 22 at least one of additional information and signaling comprising a sounding reference signal (SRS).

[0152] Example A10. The network node 16 of any of Examples A1-A9, wherein the order-based CSI report comprises additional quality indications for multiple reported CSI instances corresponding to the one or more CRIs, the additional quality indications are based on a first parameter.

[0153] Example All. The network node 16 of Example A10, wherein the additional quality indications are reported as differential values in relation to a highest-quality CSI instance.

[0154] Example A12. The network node 16 of any of Examples Al-All, wherein the network node is further configured to transmit a radio resource control (RRC) reconfiguration message to the UE 22, the RRC reconfiguration message including C SIRS configuration parameters comprising at least one or more of resource set identifiers, periodicity, subcarrier spacing, time / frequency domain allocation and a configuration parameter to selectively enable or disable the ordering of the one or more CSI instances corresponding to one or more CRIs according to the ordering criterion.

[0155] Example A13. The network node 16 of Example A12, wherein the configuration parameter to selectively enable or disable the ordering of the one or more CSI instances is a one-bit field that may be set to one of two values.Example A14. The network node 16 of Example A13, wherein the first value of the configuration parameter instructs the UE 22 to enable the ordering of the one or more CSI instances corresponding to the one or more CRIs and a second value of the configuration parameter instructs the UE 22 to disable the ordering of the one or more CSI instances corresponding to the one or more CRIs.

[0156] Example Bl. A method implemented in a network node 16 that is configured to communicate with a user equipment (UE) 22, the method comprising:

[0157] sending, to the UE 22, an ordering criterion for ordering one or more channel state information (CSI) instances corresponding to one or more CSI-reference signal (RS) resources CRIs; and

[0158] receiving, from the UE 22, an order-based CSI report that indicates an ordering of the one or more CSI instances, the ordering being based on the ordering criterion.

[0159] Example B2. The method of Example Bl, wherein the ordering criterion for ordering the one or more CSI instances corresponding to one or more CRIs is part of a CSI reporting configuration.

[0160] Example B3. The method of any of Examples Bl -B2, wherein the ordering criterion is sent to the UE 22 via a control channel.

[0161] Example B4. The method of any of Examples Bl -B3, wherein the ordering criterion is based on an estimate of a first parameter.

[0162] Example B5. The method of Example B4, wherein the first parameter is internal to the UE 22.

[0163] Example B6. The method of Example B4, wherein the first parameter is at least one of reference signal received power (RSNP), and signal-to-noise-ratio (SINR) used to generate a channel quality indicator (CQI) via an internal mapping table.

[0164] Example B7. The method of Example B4, wherein if the first parameter is equal to or within a predetermined margin, the ordering of the one or more CSI instances being based on a second parameter different from the first parameter.

[0165] Example B8. The method of Example B4, wherein if the first parameter is equal to or within a predetermined margin, the ordering is determined based on a function of the first parameter and a second parameter that is different from the first parameter.

[0166] Example B9. The method of Example B4, wherein if the first parameter is equal to or within a predetermined margin, further comprising receiving from the UE 22 at least one of additional information and signaling comprising a sounding reference signal (SRS).Example BIO. The method of any of Examples Bl -B9, wherein the order-based CSI report comprises additional quality indications for multiple reported CSI instances corresponding to the one or more CRIs, the additional quality indications are based on a first parameter.

[0167] Example Bl 1. The method of Example BIO, wherein the additional quality indications are reported as differential values in relation to a highest-quality CSI instance.

[0168] Example B12. The method of any of Examples Bl-Bl 1, further comprising transmitting a radio resource control (RRC) reconfiguration message to the UE 22, the RRC reconfiguration message including CSI-RS configuration parameters comprising at least one or more of resource set identifiers, periodicity, subcarrier spacing, time / frequency domain allocation and a configuration parameter to selectively enable or disable the ordering of the one or more CSI instances corresponding to one or more CRIs according to the ordering criterion.

[0169] Example B13. The method of Example Bl 2, wherein the configuration parameter to selectively enable or disable the ordering of the one or more CSI instances is a one-bit field that may be set to one of two values.

[0170] Example B14. The method of Example B13, wherein the first value of the configuration parameter instructs the UE 22 to enable the ordering of the one or more CSI instances corresponding to the one or more CRIs and a second value of the configuration parameter instructs the UE to disable the ordering of the one or more CSI instances corresponding to the one or more CRIs.

[0171] Example Cl . A user equipment (UE) 22 configured to communicate with a network node 16, the UE 22 configured to, and / or comprising a radio interface and / or processing circuitry configured to:

[0172] generate an order-based channel state information (CSI) report that indicates an ordering of the one or more CSI instances, the ordering being based on an ordering criterion; and

[0173] transmit the order-based CSI report.

[0174] Example C2. The UE 22 of Example Cl, wherein the UE 22 is further configured to identify CSI ambiguity in one or more CSI instances.

[0175] Example C3. The UE 2 of any of Examples C1-C2, wherein the UE 22 is further configured to:obtain an ordering criterion for ordering the one or more CSI instances, the one or more CSI instances corresponding to one or more CSI-reference signal (RS) resources, CRIs,.

[0176] Example C4. The UE 22 of Example C3, wherein the ordering criterion for ordering the one or more CSI instances corresponding to one or more CRIs is received as part of a CSI reporting configuration from the network node 16.

[0177] Example C5. The UE 22 of any of Examples C2-C4, wherein identifying the CSI ambiguity comprises determining whether there are two or more CSI instances with same channel quality indicator (CQI) values or CQI values that are within a predetermined CQI level

[0178] Example C6. The UE 22 of any of Examples C1-C5, wherein a range of predetermined CQI levels may be at least one of a same reported CQI, plus or minus one CQI step, and plus or minus two CQI steps.

[0179] Example C7. The UE 22 of any of Examples C3-C6, wherein the ordering of one or more CSI instances corresponding to one or more CRIs based on the ordering criterion is applied when the predetermined CQI level is below a threshold / margin.

[0180] Example C8. The UE 22 of any of Examples C3-C7, wherein the ordering criterion is based on an estimate of a first parameter.

[0181] Example C9. The UE 22 of Example C8, wherein the first parameter is internal to the UE.

[0182] Example CIO. The UE 22 of any of Examples C8-C9, wherein if the first parameter is equal to or within a predetermined margin, the ordering is based on a second parameter.

[0183] Example Cl 1. The UE 22 of any of Examples C8-C10, wherein if the first parameter is equal to or within a predetermined margin, the ordering is determined based on a function of the first parameter estimate and a second parameter.

[0184] Example C12. The UE 22 of any of Examples C8-C11, wherein the first parameter is Reference Signal Received Power (RSNP) and the second parameter is Signal-to-Noise-Ratio (SINR).

[0185] Example C13. The UE 22 of any of Examples C8-C12, wherein if the first parameter is equal to or within a predetermined margin, the UE 22 is further configured to provide at least one of additional information and signaling to the network node, the signaling comprising a sounding reference signal (SRS).Example C14. The UE 22 of any of Examples C1-C13, wherein the order-based CSI report comprises additional quality indications for multiple reported CSI instances corresponding to the one or more CRIs, the additional quality indications are based on the first parameter.

[0186] Example Cl 5. The UE 22 of Example Cl 4, wherein the additional quality indications are reported as differential values in relation to a highest-quality CSI instance.

[0187] Example Cl 6. The UE 22 of any of Examples Cl -Cl 5, wherein signaling UE capability is related to CSI report ordering.

[0188] Example DI . A method of channel state information (CSI) reporting implemented in a user equipment (UE) 22 that is configured to communicate with a network node 16, the method comprising:

[0189] generating an order-based channel state information (CSI) report that indicates an ordering of the one or more CSI instances, the ordering being based on an ordering criterion; and

[0190] transmitting the order-based CSI report.

[0191] Example D2. The method of Example DI, further comprising identifying CSI ambiguity in one or more CSI instances.

[0192] Example D3. The method of any of Examples D1-D2, further comprising obtaining an ordering criterion for ordering the one or more CSI instances, the one or more CSI instances corresponding to one or more CSI-reference signal (RS) resources (CRIs).

[0193] Example D4. The method of Example D3, wherein the ordering criterion for ordering the one or more CSI instances corresponding to one or more CRIs is received as part of a CSI reporting configuration from the network node.

[0194] Example D5. The method of any of Examples D2-D4, wherein identifying the CSI ambiguity comprises determining whether there are two or more CSI instances with same channel quality indicator (CQI) values or CQI values that are within a predetermined CQI level.

[0195] Example D6. The method of any of Examples D1-D5, wherein a range of predetermined CQI levels may be at least one of a same reported CQI, plus or minus one CQI step, and plus or minus two CQI steps.

[0196] Example D7. The method of any of Examples D3-D6, wherein the ordering of one or more CSI instances corresponding to one or more CRIs based on the ordering criterion is applied when the predetermined CQI level is below a threshold / margin.Example D8. The method of any of Examples D3-D7, wherein the ordering criterion is based on an estimate of a first parameter.

[0197] Example D9. The method of Example D8, wherein the first parameter is internal to the UE 22.

[0198] Example DIO. The method of any of Examples D8-D9, wherein if the first parameter is equal to or within a predetermined margin, the ordering is based on a second parameter.

[0199] Example Dll. The method of any of Examples D8-D10, wherein if the first parameter is equal to or within a predetermined margin, the ordering is determined based on a function of the first parameter estimate and a second parameter.

[0200] Example D12. The method of any of Examples D8-D11, wherein the first parameter is Reference Signal Received Power, RSNP, and the second parameter is Signal-to-Noise-Ratio (SINR).

[0201] Example D13. The method of any of Examples D8-D12, wherein if the first parameter is equal to or within a predetermined margin, further comprising providing at least one of additional information and signaling to the network node 16, the signaling comprising a sounding reference signal, SRS.

[0202] Example D14. The method of any of Examples D1-D13, wherein the order-based CSI report comprises additional quality indications for multiple reported CSI instances corresponding to the one or more CRIs, the additional quality indications are based on the first parameter.

[0203] Example DI 5. The method of Example DI 4, wherein the additional quality indications are reported as differential values in relation to a highest-quality CSI instance.

[0204] Example DI 6. The method of any of Examples DI -DI 5, wherein signaling UE 22 capability is related to CSI report ordering.

[0205] As will be appreciated by one of skill in the art, the concepts described herein may be embodied as a method, data processing system, computer program product and / or computer storage media storing an executable computer program. Accordingly, the concepts described herein may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects all generally referred to herein as a “circuit” or “module.” Any process, step, action and / or functionality described herein may be performed by, and / or associated to, a corresponding module, which may be implemented in software and / or firmware and / or hardware. Furthermore, the disclosure may take the form of a computer program producton a tangible computer usable storage medium having computer program code embodied in the medium that can be executed by a computer. Any suitable tangible computer readable medium may be utilized including hard disks, CD-ROMs, electronic storage devices, optical storage devices, or magnetic storage devices.

[0206] Some embodiments are described herein with reference to flowchart illustrations and / or block diagrams of methods, systems and computer program products. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer (to thereby create a special purpose computer), special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0207] These computer program instructions may also be stored in a computer readable memory or storage medium that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instruction means which implement the function / act specified in the flowchart and / or block diagram block or blocks.

[0208] The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0209] It is to be understood that the functions / acts noted in the blocks may occur out of the order noted in the operational illustrations. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality / acts involved. Although some of the diagrams include arrows on communication paths to show a primary direction of communication, it is to be understood that communication may occur in the opposite direction to the depicted arrows.Computer program code for carrying out operations of the concepts described herein may be written in an object oriented programming language such as Python, Java® or C++. However, the computer program code for carrying out operations of the disclosure may also be written in conventional procedural programming languages, such as the "C" programming language. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer. In the latter scenario, the remote computer may be connected to the user's computer through a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).

[0210] Many different embodiments have been disclosed herein, in connection with the above description and the drawings. It will be understood that it would be unduly repetitious and obfuscating to literally describe and illustrate every combination and subcombination of these embodiments. Accordingly, all embodiments can be combined in any way and / or combination, and the present specification, including the drawings, shall be construed to constitute a complete written description of all combinations and subcombinations of the embodiments described herein, and of the manner and process of making and using them, and shall support claims to any such combination or subcombination.

[0211] It will be appreciated by persons skilled in the art that the embodiments described herein are not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope of the following claims.

Claims

CLAIMS1. A method of channel state information, CSI, reporting implemented in a user equipment, UE (22), that is configured to communicate with a network node (16), the method comprising:generating an order-based CSI report that indicates an ordering of one or more CSI instances, the ordering being based on an ordering criterion (S90); andtransmitting the order-based CSI report (S92).

2. The method of Claim 1, further comprising:identifying CSI ambiguity in one or more CSI instances; andperforming the generating based on the CSI ambiguity being identified.

3. The method of any one of Claims 1 and 2, further comprising obtaining an ordering criterion for ordering the one or more CSI instances, the one or more CSI instances corresponding to one or more CSI-reference signal, RS, resource indicators, CRIs, wherein the ordering criterion for ordering the one or more CSI instances corresponding to one or more CRIs is received as part of a CSI reporting configuration from the network node (16).

4. The method of Claim 3, wherein the ordering criterion is chosen from a predefined set of parameters.

5. The method of any one of Claims 2-4, wherein identifying the CSI ambiguity comprises determining whether there are two or more CSI instances with same channel quality indicator, CQI, values or CQI values that are within a predefined range.

6. The method of Claim 5, wherein the predefined range may be at least one of a same reported CQI, plus or minus one CQI step, and plus or minus two CQI steps.

7. The method of any one of Claims 3-6, wherein the ordering of one or more CSI instances corresponding to one or more CRIs based on the ordering criterion is applied when the CSI ambiguity is identified.

8. The method of any one of Claims 3-7, wherein the ordering criterion is based on an estimate of a first parameter; andthe first parameter is internal to the UE (22).

9. The method of Claim 8, wherein if the first parameter is equal to or within a predetermined margin, the ordering is determined based on a second parameter or a function of the first parameter and the second parameter.

10. The method of any one of Claims 8 and 9, wherein the first parameter and the second parameter are either Reference Signal Received Power, RSRP, or Signal -to-Noise-Ratio, SINR.

11. The method of any one of Claims 8-10, wherein if the CSI ambiguity is determined or if the first parameter is equal to or within a predetermined margin, further comprising providing at least one of additional information and signaling to the network node (16), the signaling comprising a sounding reference signal, SRS.

12. The method of any one of Claims 8-11, wherein the order-based CSI report comprises additional quality indications for multiple reported CSI instances corresponding to the one or more CRIs, the additional quality indications are based on the first parameter.

13. The method of Claim 12, wherein the additional quality indications are reported as differential values in relation to a highest-quality CSI instance.

14. The method of any one of Claims 1-13, further comprising signaling capability related to CSI report ordering.

15. The method of any one of Claims 1-14, further comprising receiving from the network node a radio resource control, RRC, reconfiguration message, the RRC reconfiguration message including a configuration parameter to selectively enable or disable the ordering of the one or more CSI instances corresponding to one or more CRIs according to the ordering criterion.

16. The method of Claim 15, wherein the configuration parameter to selectively enable or disable the ordering of the one or more CSI instances is a one-bit field that may be set to one of two values.

17. A user equipment, UE (22), configured to communicate with a network node (16), the UE (22) configured to:generate an order-based channel state information, CSI, report that indicates an ordering of one or more CSI instances, the ordering being based on an ordering criterion; andtransmit the order-based CSI report.

18. The UE (22) of Claim 17, wherein the UE (22) is further configured to: identify CSI ambiguity in one or more CSI instances; andperform the generating based on the CSI ambiguity being identified.

19. The UE (22) of any one of Claims 17 and 18, wherein the UE (22) is further configured to obtain an ordering criterion for ordering the one or more CSI instances, the one or more CSI instances corresponding to one or more CSI-reference signal, RS, resource indicators, CRIs, wherein the ordering criterion for ordering the one or more CSI instances corresponding to one or more CRIs is received as part of a CSI reporting configuration from the network node (16).

20. The UE (22) of Claim 19, wherein the ordering criterion is chosen from a predefined set of parameters.

21. The UE (22) of any one of Claims 18-20, wherein identifying the CSI ambiguity comprises determining whether there are two or more CSI instances with same channel quality indicator, CQI, values or CQI values that are within a predefined range.

22. The UE (22) of Claim 21, wherein the predefined range may be at least one of a same reported CQI, plus or minus one CQI step, and plus or minus two CQI steps.

23. The UE (22) of any one of Claims 19-22, wherein the ordering of one or more CSI instances corresponding to one or more CRIs based on the ordering criterion is applied when the CSI ambiguity is identified.

24. The UE (22) of any one of Claims 18-23, wherein the ordering criterion is based on an estimate of a first parameter and wherein the first parameter is internal to the UE (22).

25. The UE (22) of Claim 24, wherein if the first parameter is equal to or within a predetermined margin, the ordering is determined based on a second parameter or a function of the first parameter and the second parameter.

26. The UE (22) of any one of Claims 24 and 25, wherein the first parameter and the second parameter are either Reference Signal Received Power, RSRP, or Signal-to-Noise-Ratio, SINR.

27. The UE (22) of any one of Claims 24-26, wherein if the CSI ambiguity is determined or if the first parameter is equal to or within a predetermined margin, the UE is further configured to provide at least one of additional information and signaling to the network node (16), the signaling comprising a sounding reference signal, SRS.

28. The UE (22) of any one of Claims 24-27, wherein the order-based CSI report comprises additional quality indications for multiple reported CSI instances corresponding to the one or more CRIs, the additional quality indications are based on the first parameter.

29. The UE (22) of Claim 28, wherein the additional quality indications are reported as differential values in relation to a highest-quality CSI instance.

30. The UE (22) of any one of Claims 17-29, wherein the UE (22) is further configured to signal capability related to CSI report ordering.

31. The UE (22) of any one of Claims 17-30, wherein the UE (22) is further configured to receive from the network node (16) a radio resource control, RRC, reconfiguration message, the RRC reconfiguration message including a configuration parameter to selectively enable or disable the ordering of the one or more CSI instances corresponding to one or more CRIs according to the ordering criterion.

32. The UE (22) of Claim 31, wherein the configuration parameter to selectively enable or disable the ordering of the one or more CSI instances is a one-bit field that may be set to one of two values.

33. A method implemented in a network node (16) that is configured to communicate with a user equipment, UE, (22) the method comprising:receiving, from the UE (22), an order-based channel state information, CSI, report that indicates an ordering of one or more CSI instances, the ordering being based on an ordering criterion for ordering one or more CSI instances corresponding to one or more CSI-reference signal, RS, resource indicators, CRIs (S98).

34. The method of Claim 33, wherein the ordering criterion is chosen from a predefined set of parameters.

35. The method of any one of Claims 33 and 34, further comprising sending, to the UE (22), the ordering criterion for ordering the one or more CSI instances corresponding to the one or more CRIs.

36. The method of any one of Claims 33-35, wherein the ordering criterion is based on an estimate of a first parameter and wherein the first parameter is internal to the UE (22).

37. The method of Claim 36, wherein the first parameter is at least one of reference signal received power, RSRP, and signal-to-noise-ratio, SINR.

38. A network node (16) configured to communicate with a user equipment, UE (22), the network node (16) configured to:receive, from the UE (22), an order-based channel state information, CSI, report that indicates an ordering of one or more CSI instances, the ordering being based on an ordering criterion for ordering one or more CSI instances corresponding to one or more CSI-reference signal, RS, resource indicators, CRIs.

39. The network node (16) of Claim 38, wherein the ordering criterion is chosen from a predefined set of parameters.

40. The network node (16) of any one of Claims 38 and 39, wherein the network node (16) is further configured to send, to the UE (22), the ordering criterion for ordering the one or more CSI instances corresponding to the one or more CRIs.

41. The network node (16) of any one of Claims 38-40, wherein the ordering criterion is based on an estimate of a first parameter and wherein the first parameter is internal to the UE (22).

42. The network node (16) of Claim 41, wherein the first parameter is at least one of reference signal received power, RSRP, and signal-to-noise-ratio, SINR.

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