Port and resource index mapping for larger array sizes

Abstract

A method includes receiving, by a user equipment (UE), a configuration for mapping a first port associated with a channel state information reference signal (CSI-RS) resource in a resource set to a second port from a first apparatus The UE performs a first mapping of the first port to a first group of indices based upon the received configuration, and performs a second mapping of the first group of indices to the second port based upon the received configuration.

Description

PORT AND RESOURCE INDEX MAPPING FOR LARGER ARRAY SIZES FIELD

[0001] Various example embodiments relate generally to wireless networks and, moreparticularly, for port and resource index mapping for larger array sizes. BACKGROUND

[0002] Current legacy user equipments (UEs) are configured with a limited number of channelstart information reference signal (CSI-RS) ports. Larger transmission arrays are being implemented that may exceed that number of ports.

[0003] Accordingly, an issue in deploying larger arrays with larger number of configured CSI-RS ports is that the gNodeB (gNB) may be able to support legacy UEs (e.g., pre Release(Rel)-19UEs) which do not have capabilities to measure CSI for more than one resource with additionalports (e.g., up to 32 ports). Using different CSI-RS resources for Rel-19 UEs and pre-Rel-19 UEsmay create issues with RS overhead, scheduling of resources to accommodate two differentresource sets and switching between two different sets of beamforming weights. SUMMARY

[0004] In an aspect of the present disclosure, a method includes receiving, by a user equipment(UE), a configuration for mapping a first port associated with a channel state information reference signal (CSI-RS) resource in a resource set to a second port from a first apparatus. The UE performs a first mapping of the first port to a first group of indices based upon the received configuration, and performs a second mapping of the first group of indices to the second port based upon the received configuration.

[0005] In an aspect of the method, the configuration for mapping the first port to the secondport comprises a first pair of values indicating an azimuth dimension and an elevation dimension for multiple resources in the resource set and a second pair of values indicating an azimuth dimension and an elevation dimension for a single resource in the resource set.

[0006] In an aspect of the method, the azimuth dimension or the elevation dimension of thefirst pair of values is a multiple, respectively, of the azimuth or elevation dimension of the second pair of values.

[0007] In an aspect of the method, the first group of indices comprises one or more of anazimuth index, an elevation index, a polarization index or a resource index.

[0008] In an aspect of the method, the UE is configured to report CSI across more than oneCSI-RS resource in the resource set.

[0009] In an aspect of the method, the method further includes calculating, by the UE, a CSI.

[0010] In an aspect of the method, the method further includes transmitting, by the UE, a CSIreport to the first apparatus.

[0011] In an aspect of the method, the second port is associated with an element of a vectorobtained by the Kronecker product of two vectors.

[0012] In an aspect of the method, an order of the two vectors in the Kronecker productdepends on the configuration and wherein the order of the two vectors determines the mapping between the first port and the second port.

[0013] In an aspect of the method, the second port indicates one of the elements of a precodingvector corresponding to a reported precoding matrix indicator (PMI).

[0014] In an aspect of the method, the reported PMI is applicable to a physical data sharedchannel (PDSCH) symbol ^(^)(^) of a layer ^ = 1, … ,to form a corresponding PDSCH signal.

[0015] In an aspect of the method, the first apparatus is a gNB.

[0016] In an aspect of the present disclosure, a UE includes at least one processor, and at leastone memory storing instructions which, when executed by the at least one processor, cause the apparatus at least to perform any of the foregoing methods.

[0017] In an aspect of the present disclosure, a processor-readable medium storing instructionswhich, when executed by at least one processor of an apparatus, cause the apparatus at least to perform any of the foregoing methods.

[0018] According to some aspects, there is provided the subject matter of the independentclaims. Some further aspects are defined in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Some example embodiments will now be described with reference to the accompanyingdrawings.

[0020] FIG. 1 is a diagram of an example embodiment of wireless networking between anetwork system and a user equipment (UE), according to one illustrated aspect of the disclosure;

[0021] FIG. 2 is a diagram of example components of a network system, according to oneillustrated aspect of the disclosure;

[0022] FIG. 3 is a diagram of an example beam structure, according to one illustrated aspectof the disclosure;

[0023] FIG. 4A is an example diagram of a mapping of a CSI-RS port for a resource to anintermediate index, according to one illustrated aspect of the disclosure;

[0024] FIG. 4B is an example diagram of a mapping of a CSI-RS port for a resource to anintermediate index, according to another illustrated aspect of the disclosure;

[0025] FIG. 5 is an example diagram of a vertical aggregation mapping of an intermediateindex for a resource to a precoding matrix indicator (PMI) port, according to one illustrated aspect of the disclosure;

[0026] FIG. 6 is an example diagram of an aggregation mapping of an intermediate index fora resource to a PMI port, according to another illustrated aspect of the disclosure;

[0027] FIG. 7 is an example diagram of a horizontal aggregation mapping of an intermediateindex for a resource to a PMI port, according to one illustrated aspect of the disclosure;

[0028] FIG. 8 is an example diagram of a horizontal aggregation mapping of an intermediateindex for a resource to a PMI port, according to another illustrated aspect of the disclosure;

[0029] FIG. 9 is a diagram of an example embodiment of signals and operations among a gNBand a UE, according to one illustrated aspect of the disclosure;

[0030] FIG. 10 is a flow diagram of an example method of mapping a CSI-RS port to a PMIport, according to one illustrated aspect of the disclosure;

[0031] FIG. 11 is a flow diagram of an example method of mapping a CSI-RS port to a PMIport, according to another illustrated aspect of the disclosure; and

[0032] FIG.12 is a diagram of an example embodiment of components of a UE or of a networkapparatus, according to one illustrated aspect of the present disclosure. DETAILED DESCRIPTION

[0033] In the following description, certain specific details are set forth in order to provide athorough understanding of disclosed aspects. However, one skilled in the relevant art will recognize that aspects may be practiced without one or more of these specific details or with other methods, components, materials, etc. In other instances, well-known structures associated withtransmitters, receivers, or transceivers have not been shown or described in detail to avoid unnecessarily obscuring descriptions of the aspects.

[0034] Reference throughout this specification to “one aspect” or “an aspect” means that aparticular feature, structure, or characteristic described in connection with the aspect is included in at least one aspect. Thus, the appearances of the phrases “in one aspect” or “in an aspect” in various places throughout this specification are not necessarily all referring to the same aspect. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more aspects.

[0035] Embodiments described in the present disclosure may be implemented in wirelessnetworking apparatuses, such as, without limitation, apparatuses utilizing Worldwide Interoperability for Microwave Access (WiMAX), Global System for Mobile communications (GSM, 2G), GSM EDGE radio access Network (GERAN), General Packet Radio Service (GRPS), Universal Mobile Telecommunication System (UMTS, 3G) based on basic wideband-code division multiple access (W-CDMA), high-speed packet access (HSPA), Long Term Evolution (LTE), LTE-Advanced, enhanced LTE (eLTE), 5G New Radio (5G NR), 5G Advance, 6G (and beyond) and 802.11ax (Wi-Fi 6), among other wireless networking systems. The term ‘eLTE’ here denotes the LTE evolution that connects to a 5G core. LTE is also known as evolved UMTS terrestrial radio access (EUTRA) or as evolved UMTS terrestrial radio access network (EUTRAN).

[0036] The present disclosure may use the term “serving network device” to refer to a networknode or network device (or a portion thereof) that services a UE. As used herein, the terms “transmit to,” “receive from,” and “cooperate with,” (and their variations) include communications that may or may not involve communications through one or more intermediate devices or nodes. The term “acquire” (and its variations) includes acquiring in the first instance or reacquiring after the first instance. The term “connection” may mean a physical connection or a logical connection.

[0037] The present disclosure uses 5G NR as an example of a wireless network and may usesmartphones and / or extended reality headsets as an example of UEs. It is intended and shall be understood that such examples are merely illustrative, and the present disclosure is applicable to other wireless networks and user equipment.

[0038] FIG. 1 is a diagram depicting an example of wireless networking between a networksystem 100 and a user equipment (UE) 150. The network system 100 may include one or more network nodes 120, one or more servers 110, and / or one or more network equipment 130 (e.g.,test equipment). The network nodes 120 will be described in more detail below. As used herein, the term “network apparatus” may refer to any component of the network system 100, such as the server 110, the network node 120, the network equipment 130, any component(s) of the foregoing, and / or any other component(s) of the network system 100. Examples of network apparatuses include, without limitation, apparatuses implementing aspects of 5G NR, among others. The present disclosure describes embodiments related to 5G NR and embodiments that involve aspects defined by 3rd Generation Partnership Project (3GPP). However, it is contemplated that embodiments relating to other wireless networking technologies are encompassed within the scope of the present disclosure.

[0039] The following description provides further details of examples of network nodes. In a5G NR network, a gNodeB (also known as gNB) may include, e.g., a node that provides new radio(NR) user plane and control plane protocol terminations towards the UE and that is connected viaa NG interface to the 5G core (5GC), e.g., according to 3GPP TS 38.300 V16.6.0 (2021-06) section 3.2, which is hereby incorporated by reference herein.

[0040] A gNB supports various protocol layers, e.g., Layer 1 (L1) – physical layer, Layer 2(L2), and Layer 3 (L3).

[0041] The layer 2 (L2) of NR is split into the following sublayers: Medium Access Control(MAC), Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP) and Service Data Adaptation Protocol (SDAP), where, e.g.: oThe physical layer offers to the MAC sublayer transport channels;o The MAC sublayer offers to the RLC sublayer logical channels;o The RLC sublayer offers to the PDCP sublayer RLC channels;o The PDCP sublayer offers to the SDAP sublayer radio bearers;o The SDAP sublayer offers to 5GC quality of service (QoS) flows;o Control channels include broadcast control channel (BCCH) and physical controlchannel (PCCH).

[0042] Layer 3 (L3) includes, e.g., radio resource control (RRC), e.g., according to 3GPP TS38.300 V16.6.0 (2021-06) section 6, which is hereby incorporated by reference herein.

[0043] A gNB central unit (gNB-CU) includes, e.g., a logical node hosting, e.g., radio resourcecontrol (RRC), service data adaptation protocol (SDAP), and packet data convergence protocol (PDCP) protocols of the gNB or RRC and PDCP protocols of the en-gNB, that controls theoperation of one or more gNB distributed units (gNB-DUs). The gNB-CU terminates the F1 interface connected with the gNB-DU. A gNB-CU may also be referred to herein as a CU, a central unit, a centralized unit, or a control unit.

[0044] A gNB Distributed Unit (gNB-DU) includes, e.g., a logical node hosting, e.g., radiolink control (RLC), media access control (MAC), and physical (PHY) layers of the gNB or en- gNB, and its operation is partly controlled by the gNB-CU. One gNB-DU supports one or multiple cells. One cell is supported by only one gNB-DU. The gNB-DU terminates the F1 interface connected with the gNB-CU. A gNB-DU may also be referred to herein as DU or a distributed unit.

[0045] As used herein, the term “network node” may refer to any of a gNB, a gNB-CU, or agNB-DU, or any combination of them. A RAN (radio access network) node or network node suchas, e.g., a gNB, gNB-CU, or gNB-DU, or parts thereof, may be implemented using, e.g., anapparatus with at least one processor and / or at least one memory with processor-readable instructions (“program”) configured to support and / or provision and / or process CU and / or DU related functionality and / or features, and / or at least one protocol (sub-)layer of a RAN (radioaccess network), e.g., layer 2 and / or layer 3. Different functional splits between the central anddistributed unit are possible. An example of such an apparatus and components will be describedin connection with FIG. 12 below.

[0046] The gNB-CU and gNB-DU parts may, e.g., be co-located or physically separated. ThegNB-DU may even be split further, e.g., into two parts, e.g., one including processing equipment and one including an antenna. A central unit (CU) may also be called baseband unit / radio equipment controller / cloud-RAN / virtual-RAN (BBU / REC / C-RAN / V-RAN), open-RAN (O- RAN), or part thereof. A distributed unit (DU) may also be called remote radio head / remote radio unit / radio equipment / radio unit (RRH / RRU / RE / RU), or part thereof. Hereinafter, in various example embodiments of the present disclosure, a network node, which supports at least one of central unit functionality or a layer 3 protocol of a radio access network, may be, e.g., a gNB-CU. Similarly, a network node, which supports at least one of distributed unit functionality or a layer 2 protocol of the radio access network, may be, e.g., a gNB-DU.

[0047] A gNB-CU may support one or multiple gNB-DUs. A gNB-DU may support one ormultiple cells and, thus, could support a serving cell for a user equipment (UE) or support a candidate cell for handover, dual connectivity, and / or carrier aggregation, among other procedures.

[0048] The user equipment (UE) 150 may be or include a wireless or mobile device, anapparatus with a radio interface to interact with a RAN (radio access network), a smartphone, an in-vehicle apparatus, an IoT device, or a M2M device, among other types of user equipment. Such UE 150 may include: at least one processor; and at least one memory including program code; where the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to perform certain operations, such as, e.g., RRC connection to the RAN. An example of components of a UE will be described in connection with FIG. 12. In embodiments, the UE 150 may be configured to generate a message (e.g., including a cell ID) to be transmitted via radio towards a RAN (e.g., to reach and communicate with a serving cell). In embodiments, the UE 150 may generate and transmit and receive RRC messages containing one or more RRC PDUs (packet data units). Persons skilled in the art will understand RRC protocol as well as other procedures a UE may perform.

[0049] With continuing reference to FIG. 1, in the example of a 5G NR network, the networksystem 100 provides one or more cells, which define a coverage area of the network system 100.As described above, the network system 100 may include a gNB of a 5G NR network or may include any other apparatus configured to control radio communication and manage radio resources within a cell. As used herein, the term “resource” may refer to radio resources, such asa resource block (RB), a physical resource block (PRB), a radio frame, a subframe, a time slot, asub-band, a frequency region, a sub-carrier, a beam, etc. In embodiments, the network node 120 may be called a base station.

[0050] FIG. 1 provides an example and is merely illustrative of a network system 100 and aUE 150. Persons skilled in the art will understand that the network system 100 includes components not illustrated in FIG. 1 and will understand that other user equipment may be in communication with the network system 100.

[0051] FIG. 2 is a block diagram of example components of the network system 100 of FIG.1. A 5G NR network may be described as an example of the network system 100, and it is intendedthat aspects of the following description shall be applicable to other types of network systems, aswell. The network system may operate in accordance with the signals and connections shown inFIG. 1 such that the UE 150 is in communication with the network system 100 through the radioaccess network 225. Additionally, the network system may be divided into user plane componentsand functions and control plane components and functions, as shown and described herein. Unlessindicated otherwise, the terms “component”, “function”, and “service” may be usedinterchangeably herein, and they may refer to and be implemented by instructions executed by one or more processors.

[0052] Example functions of the components are described below. The example functions aremerely illustrative, and it shall be understood that additional operations and functions may be performed by the components described herein. Additionally, the connections between components may be virtual connections over service-based interfaces such that any component may communicate with any other component. In this manner, any component may act as a service“producer,” for any other component that is a service “consumer,” to provide services for networkfunctions.

[0053] For example, a core network 210 is described in the control plane of the networksystem. The core network 210 may include an authentication server function (AUSF) 211, anaccess and mobility function (AMF) 212, and a session management function (SMF) 213. Thecore network 210 may also include a network slice selection function (NSSF) 214, a networkexposure function (NEF) 215, a network repository function (NRF) 216, and a unified datamanagement function (UDM) 217, which may include a uniform data repository (UDR) 224.

[0054] Additional components and functions of the core network 210 may include anapplication function 218, policy control function (PCF) 219, network data analytics function (NWDAF) 220, analytics data repository function (ADRF) 221, management data analyticsfunction (MDAF) 222, and operations and management function (OAM) 223.

[0055] The user plane includes the UE 150, a radio access network (RAN) 225, a user planefunction (UPF) 226, and a data network (DN) 227. The RAN 225 may include one or morecomponents described in connection with FIG. 1, such as one or more network nodes. However,the RAN 225 may not be limited to such components. The UPF 226 provides connection for data being transmitted over the RAN 225. The DN 226 identifies services from service providers,Internet access, and third party services, for example.

[0056] The AMF 212 processes connection and mobility tasks. The AUSF 211 receivesauthentication requests from the AMF 212 and interacts with UDM 217 to authenticate and validate network responses for determination of successful authentication. The SMF 213 conducts packet data unit (PDU) session management, as well as manages session context with the UPF 226.

[0057] The NSSF 214 may select a network slicing instance (NSI) and determine the allowednetwork slice selection assistance information (NSSAI). This selection and determination isutilized to set the AMF 212 to provide service to the UE 150. The NEF 215 secures access tonetwork services for third parties to create specialized network services. The NRF 216 acts as a repository to store network functions to allow the functions to register with and discover each other.

[0058] The UDM 217 generates authentication vectors for use by the AUSF 211 and ADM212 and provides user identification handling. The UDM 217 may be connected to the UDR 224 which stores data associated with authentication, applications, or the like. The AF 218 provides application services to a user (e.g., streaming services, etc.). The PCF 219 provides policy control functionality. For example, the PCF 219 may assist in network slicing and mobility management, as well as provide quality of service (QoS) and charging functionality.

[0059] The NWDAF 220 collects data (e.g., from the UE 150 and the network system) toperform network analytics and provide insight to functions that utilize the analytics in theproviding of services. The ADRF 221 allows the storage, retrieval, and removal of data andanalytics by consumers. The MDAF 222 provides additional data analytics services for networkfunctions. The OAM 223 provides provisioning and management processing functions to manageelements in or connected to the network (e.g., UE 150, network nodes, etc.).

[0060] FIG. 2 is merely an example of components of a network system, and variations arecontemplated to be within the scope of the present disclosure. In embodiments, the network system may include other components not illustrated in FIG.2. In embodiments, the network system may not include every component illustrated in FIG. 2. In embodiments, the components and connections may be implemented with different connections than those illustrated in FIG.2. Such and other embodiments are contemplated to be within the scope of the present disclosure.

[0061] Although further detail will be provided below, a method is described herein, which invarious embodiments provides for a mapping between channel state information reference signal(CSI-RS) ports and precoding matrix indicator (PMI) ports. In Release 19 of the third generationpartnership (3GPP) standards, CSI reporting is extended for larger number of CSI-RS ports (e.g.,up to 128) without introducing enhancements to the CSI-RS resource structure or parameters.Because legacy CSI-RS resources support up to 32 ports, with 16 ports per polarization, it is necessary to aggregate K=2,3,4 resources with up to 32 ports per resource.

[0062] As mentioned above, an issue in deploying larger arrays with larger number ofconfigured CSI-RS ports is that the gNB supports legacy UEs which do not have capabilities tomeasure CSI for more than one resource with up to 32 ports.

[0063] For example, legacy UEs supporting measurement on a single CSI-RS resource with^ = 2^^^^ ports are configured for CSI reporting with port layout (^^, ^^) per polarization. Invarious embodiments, UEs supporting measurement across ^ CSI-RS resources with a total of^^ = 2^^^^ ports are configured for CSI reporting with port layout (^^, ^^) per polarization. Invarious embodiments, the order in which the CSI-RS ports are mapped to PMI ports depends onthe specified beam structure. In various embodiments, the term PMI port is used to indicate theelements of a precoding vector corresponding to the reported PMI, which are applicable to aPDSCH symbol ^(^)(^) of a layer ^ = 1, … ,to form a corresponding PDSCH signal. For CQI(channel quality indication) calculation, a UE assumes that the PDSCH signal is transmitted onthe ^ (or ^′) antenna ports of a CSI-RS resource (or across ^ CSI-RS resources). In variousembodiments, supported are two-dimensional beams obtained by the Kronecker product, ^^ ⊗ ^^,between a horizontal / Azimuth beam, ^^ , comprising ^^ elements and a vertical / elevation beam,^^, comprising ^^ elements. In various embodiments, to be able to serve all UEs, the mapping of2^^^^ CSI-RS ports across the ^ resources to the 2^^^^ PMI ports is such that the 2^^^^ portsof a single resource can be mapped to a horizontal beam with ^^ elements and a vertical beam with^^, for each polarization.

[0064] Accordingly, in various embodiments a two-stage mapping approach may be utilizedbetween the aggregated ports across ^ resources and the PMI ports for Rel-19 UEs supporting >32ports. The resulting mapping is compatible with pre-Rel-19 UEs because any of the CSI-RSresources can be reused for CSI reporting with legacy parameters (^^, ^^). The proposed mappingis dependent on the configuration of at least two pairs of parameters, a first one,describing the 2D beam structure of a beam of size 2^^^^, and a second one (^^, ^^) describingthe 2D beam structure of a beam of legacy size 2^^^^.

[0065] In various embodiments, (e.g., ^′ = 2^^^^) the total number of CSI-RS ports across^ resources, and ^ = 2^^^^ the number of ports per CSI-RS resource, such that ^′ = ^^ =2^^^^^. The table below shows possible combinations of (^^, ^^) for the new supported valuesof (^^, ^^).Total number of CSI-Extended CSI-RS port Number of Type of RS ports across CSI-RS layout per CSI-RS CSI-RS aggregated resources port resource resources resource (^) layout(^^, ^^)for aggregati (^^, ^^) legacy newchannelonmeasurem ent (^) 48 (8,3) (4,3) 2 horizontal(8,1) 3 vertical(6,4) (6,2) 2 vertical(2,4) 3 horizontal(6,1) 4 vertical64 (16,2) (16,1) 2 vertical(8,2) 2 horizontal(4,2) 4 horizontal(8,4) (8,2) 2 vertical(4,4) 2 horizontal(8,1) 4 vertical(2,4) 4 horizontal128 (16,4) (4,4) 4 horizontal(16,1) 4 vertical(8,8) (8,2) 4 vertical(2,8) 4 horizontal

[0066] As used herein, a communication with a radio access network (RAN) may refer to andmean a communication with a portion of a RAN, such as with a network node (e.g., a DU and / or a CU), or another portion of a RAN. As used herein, a communication with a core network may refer to and mean a communication with one or more services / applications of the core network, such as AMF or another service of a core network.

[0067] As used herein, the terms “first” and “second”, or the like, may refer to a first or secondinstance of a message being transmitted / received by a component (e.g., UE, apparatus, etc.), or a first or second component in a sequence of described components. As such, the terms are used in a non-limiting manner, and can refer to any message, operation, device, component, or the like.

[0068] FIG. 3 is a diagram of an example beam structure 300, according to one illustratedaspect of the disclosure. As shown in FIG. 3, elevation beams include n2 elements each andazimuth beams include n1elements each (e.g., 4), with oversampling factors O1, O2. In variousembodiments, for a given value of (^^, ^^), the mapping of CSI-RS ports to PMI ports for each ofthe ^ resources is compatible with the ordering implied by the 2D DFT beam structure formed bya Kronecker product of azimuth and elevation beams, as shown in FIG. 3 for an example with(^^, ^^) = (4,2) and oversampling factors (^^, ^^) = (4,4). In various embodiments, thefollowing equations describe the Kronecker product of azimuth and elevation beams.

[0069] In various embodiments, compatibility between UEs (e.g., Rel-19 and Pre-Rel-19) maybe achieved via a first mapping between the port of index ^, with ^ = 0, … , ^^ − 1, of CSI-RSresource ^, with ^ = 0, … , ^ − 1, and intermediate indices− 1is the index of elements in a vector representing a beam of lengthin the horizontal / Azimuthdirection, ^^ = 0, … , ^^ − 1, is the index of elements in a vector representing a beam in thevertical / Elevation direction, and ^ = 0,1 is the polarization index. In various embodiments, thefirst mapping is applicable to any port layout parameters (^^, ^^) for ports contained in a singleCSI-RS resource. In various embodiments, the map is obtained by mapping a 3-dimensional arrayof indices ^^, ^) and size (^^, ^^, 2), to a linear sequence (i.e., one-dimensional array) of index^, following the order:→ ^, in accordance with the following equation:^ = ^^^^^ + ^^^^ + ^^.

[0070] In accordance with the brief description, FIG. 4A is an example diagram 400A of amapping of a CSI-RS port for a resource to an intermediate index, according to one illustratedaspect of the disclosure, and FIG. 4B is an example diagram 400B of a mapping of a CSI-RS portfor a resource to an intermediate index, according to another illustrated aspect of the disclosure.

[0071] In various embodiments shown below (e.g., FIGS. 4A-8), the mapping of ports followsthe solid arrows shown in the Figures show the mapping order and the dashed arrows show thedirection for the next port in the mapping order. In various embodiments, FIGS. 4A and 4B showa mapping of CSI-RS port ^ of resource ^ = 0, … , ^ − 1 to intermediate indices^^, ^, ^) for aport layout (^^, ^^) – one polarization, ^ = 0,1, of a resource ^. For example, two layout examplesare shownvarious embodiments, the mapping order is ^^ → ^, such that ^ = ^^^^^ + ^^^^ + ^^. Themapping shown in FIGS. 4A and 4B may be referred to as a first mapping below in various embodiments.

[0072] In accordance with the brief description, FIG. 5 is an example diagram of a verticalaggregation mapping 500 of an intermediate index for a resource to a PMI port, according to oneillustrated aspect of the disclosure. In various embodiments, the mapping 500 shown in FIG. 5may be referred to as a second mapping of intermediate port indices to the PMI port ^′, with ^′ =0, … , − 1 across the ^ resources. If ^^ is a multiple of ^^, i.e., ^^ = ^^^, the aggregation isvertical and (^^, ^^) = (^^, ^^^). In this case, the second mapping follows the index order: ^^ →^ → ^ in accordance with the following equation:

[0073] In various embodiments, FIG. 5 shows a mapping of CSI-RS port intermediate indices(^^, ^^, ^, ^) to PMI port ^ by vertical aggregation, for CSI report with parameters^^, ^^, ^^)if ^^ is multiple of ^^– one polarisation, ^ = 0,1, of ^ resources. In various embodiments, thethat ^′ = ^^^^^^ + ^^^^^ + ^^^ + ^^ = ^^^^^ +

[0074] In various embodiments, the beam structure (^^^ →→ ^) may be in accordance withthe following equation:

[0075] In accordance with the brief description, FIG. 6 is an example diagram of anaggregation mapping 600 of an intermediate index for a resource to a PMI port, according toanother illustrated aspect of the disclosure. In various embodiments, the mapping 600 may be forthe case when ^^ is a multiple of ^^, i.e., ^^ = ^^^, where the splitting of vertical beams acrossthe CSI-RS resources is avoided by changing the order of horizontal and vertical beams in the beam structure.

[0076] In various embodiments, FIG. 6 shows a mapping of CSI-RS port intermediate indices(^^, ^^, ^, ^) to PMI port ^ by vertical aggregation, for CSI report with parameters^^, ^^, ^^)if ^^ is multiple of ^^– one polarization, ^ = 0,1, of ^ resources. In various embodiments, thethat ^′ = ^^^^^^ + ^^^^^ + ^^^^ + ^^ = ^^^^^ +

[0077] In various embodiments, the beam structure (^^ ^^ → ^^ → ^) for FIG. 6 may be inaccordance with the following equation:

[0078] In accordance with the brief description, FIG. 7 is an example diagram of a horizontalaggregation mapping 700 of an intermediate index for a resource to a PMI port, according to one illustrated aspect of the disclosure. In various embodiments, if ^^is a multiple of ^^, i.e.,=^^^, the CSI-RS resource aggregation is horizontal and (^^, ^^) = (^^^, ^^). In variousembodiments, the second mapping may follow the index order:→ ^ → ^ such that ^′ =

[0079] In various embodiments, FIG. 7 shows a mapping of CSI-RS port intermediate indices(^^, ^^, ^, ^) to PMI port ^ by horizontal aggregation, for CSI report with parameters(^^, ^^, ^^, ^^)is multiple of ^^– one polarization, ^ = 0,1, of ^ resources. In variousembodiments, the mapping order is ^^→ ^ → ^ such that ^′ =

[0080] In various embodiments, the beam structure (^^^ →→ ^) may be in accordance withthe following equation:

[0081] In accordance with the brief description, FIG. 8 is an example diagram of a horizontalaggregation mapping 800 of an intermediate index for a resource to a PMI port, according to another illustrated aspect of the disclosure. In various embodiments, such as the case whenis amultiple of ^^, = ^^^, the mapping 800 may be employed.

[0082] Accordingly, in various embodiments, the mapping of CSI-RS port intermediateindices (^^, ^^, ^, ^) to PMI port ^ by horizontal aggregation may be, for CSI report with parameters(^^, ^^, ^^, ^^) if ^^ is multiple of ^^– one polarization, ^ = 0,1, of ^ resources. IN variousembodiments, the mapping order→ ^ → ^^ → ^ may be such that ^′ = ^^^^^^ +

[0083] In various embodiments, the beam structure (^^^ → ^^^ → ^) may be in accordance withthe following equation:

[0084] In various embodiments, for vertical and horizontal resource aggregation, respectively,the second mapping can be parametrized for the two cases of vertical and horizontal aggregation,by using the same mapping formula that depends on a parameter ^, defined as follows: when ^^is a multiple of ^^, i.e., ^^ = ^^^, set ^ = 1; whenis a multiple of ^^, i.e.,= ^^^, set ^ =^^.

[0085] Accordingly, in various embodiments, the second mapping can be calculated as followsfor any set of parameters (^^, ^^, ^^ , ^^) in accordance with the following equation:^′ = ^^^^^^^^ + ^^^^ + ^^ +^ ^.

[0086] A mapping method and signaling is described below in more detail with reference toFIGS. 9-11. For example, in accordance with the brief description, FIG. 9 is a diagram of anexample embodiment of signals and operations among a gNB and a UE, according to oneillustrated aspect of the disclosure. In various embodiments, the components depicted in FIG. 9may correspond to similar components described above in FIGS. 1 and 2. It will be understood that a described signal may have associated operations and a described operation may have associated signals.

[0087] At operation 901, the gNB transmits a configuration message to the UE to configure ^CSI-RS resources and CSI report with parameters (^^^^, ^^, ^^), and the UE receives theconfiguration message.

[0088] In various embodiments, the configuration parameters (^^, ^^) determine the two-dimensional structure of the spatial beams applied to the ^′ = 2^^^^ ports across the ^ CSI-RSresources, is the number of elements of the DFT vector, ^^, in the horizontal / Azimuth dimension and ^^is the number of elements of the DFT vector, ^^, in the vertical / elevationdimension, such that a length-^′ beam of an oversampled 2D-DFT codebook with oversamplingfactors (^^, ^^) = (4,4) is described in accordance with the following equation:

[0089] In various embodiments, the configuration parameters (^^, ^^) determine the two-dimensional structure of the spatial beams applied to the ^ = 2^^^^ ports of any single one of the^ CSI-RS resources, where ^^ is the number of elements of the DFT vector, ^′^, in thehorizontal / Azimuth dimension and ^^is the number of elements of the DFT vector, ^′^, in thevertical / elevation dimension, such that a length-^ beam of an oversampled 2D-DFT codebookwith oversampling factors (^^, ^^) = (4,4) is described in accordance with the followingequation:

[0090] At operation 902, the gNB transmits a trigger / activate report if not periodic message tothe UE and the UE receives the trigger / activate report if not periodic message. In variousembodiments, the UE may activate a report procedure based upon receiving the trigger / activate report if not periodic message.

[0091] At operation 903, the UE applies a first mapping of port index of a resource k tointermediate ports indices. In various embodiments, the first mapping may be in accordance withthe mapping described above and below in FIG. 10.

[0092] At operation 904, the UE applies a second mapping of intermediate port indices to PMIport index, which depends on whether N2 is a multiple of n2 or N1 is a multiple of n1. In variousembodiments, the second mapping may be in accordance with the mapping described above and below in FIG.10.

[0093] At operation 905, the UE calculates the CSI.

[0094] Based on the calculated CSI, at operation 906, the UE transmits a CSI report (e.g.,report CSI) to the gNB and the gNB receives the CSI report.

[0095] At operation 907, the gNB reconstructs the precoding weights based upon the CSIreport received at operation 906.

[0096] The operations of FIG. 9 are merely illustrative, and variations are contemplated to bewithin the scope of the present disclosure. In embodiments, the operations may include other operations not illustrated in FIG. 9. In embodiments, the operations may not include every operation illustrated in FIG. 9. In embodiments, the operations may be implemented in a different order than that illustrated in FIG. 9. Such and other embodiments are contemplated to be within the scope of the present disclosure. Persons of skill in the art will appreciate that, although various example components are described as perform various functions, other components may perform those functions described in FIG. 9.

[0097] FIG. 10 is a flow diagram of an example method 1000 of mapping a CSI-RS port to aPMI port, according to one illustrated aspect of the disclosure. At block 1010, a CSI report isconfigured with parameters (^^, ^^, ^^, ^^) associated to ^ CSI-RS resources. In variousembodiments, the configuration may be provided at operation 901 described above.

[0098] At block 1020, a first mapping is performed of port ^ of CSI-RS resource ^ tointermediate indices (^^, ^^ , ^, ^), such that ^ = ^^^^^ + ^^^^ + ^^. In various embodiments, thefirst mapping may be performed at operation 903 described above.

[0099] At block 1030, a setting for variable α is performed. For example, If ^^ = ^^^, set^ = 1, otherwise if ^^ = ^^^, set ^ =The variable α may be applied for the second mappingdescribed below.

[0100] At block 1040, a second mapping is performed of intermediate indices (^^, ^^ , ^, ^) toPMI port ^′ = ^^^ ^^^^ + ^^^^ + ^^ + ^^ ^. In various embodiments, this operation may be performed at operation 904 described above.

[0101] It should be noted that although an order is shown in the method 1000, other ordersmay be implemented and certain blocks may or may not be included in the method 1000 in various embodiments.

[0102] FIG. 11 is a flow diagram of an example method 1100 of a mapping a CSI-RS port toa PMI port, according to another illustrated aspect of the disclosure. In various embodiments,method 1100 may be performed for vertical and horizontal resource aggregation, respectively,where the CSI-RS port and resource mapping to PMI ports can be implicitly defined by the twobeam structures: ^ =⊗ ^^ for horizontal aggregation and ^^,^ = ^^ ⊗foraggregation.

[0103] At block 1110, the CSI report is configured with parameters (^^, ^^, ^^, ^^) associatedto ^ CSI-RS resources. Similarly to above, in various embodiments, block 1110 may be performedat operation 901 as described above.

[0104] At block 1120, it is determined if ^ = ^^^, in which case beam structure:^^ ⊗ ^^ is used, and if ^^ = ^^^, beam structure: v^,^ = ^^ ⊗ ^^ is used. In variousembodiments, block 1120 may be performed at operation 904 described above.

[0105] It should be noted that although an order is shown in the method 1100, other ordersmay be implemented and certain blocks may or may not be included in the method 1100 in various embodiments.

[0106] The following describes operations from the perspective of a UE. From such aperspective, a method may include receiving, by the UE, a configuration for mapping a firstport associated with a channel state information reference signal (CSI-RS) resource in a resource set to a second port from a first apparatus, performing a first mapping, by the UE, of the first port to a first group of indices based upon the received configuration, and performing a second mapping, by the UE, of the first group of indices to the second port based upon the received configuration.

[0107] Referring now to FIG. 12, there is shown a block diagram of example components of aUE or a network apparatus (e.g., of a RAN or a core network). The apparatus includes an electronicstorage 1210, a processor 1220, a network interface 1240, and a memory 1250. The variouscomponents may be communicatively coupled with each other. The processor 1220 may be andmay include any type of processor, such as a single-core central processing unit (CPU), a multi- core CPU, a microprocessor, a digital signal processor (DSP), a System-on-Chip (SoC), or anyother type of processor. The memory 1250 may be a volatile type of memory, e.g., RAM, or a non-volatile type of memory, e.g., NAND flash memory. The memory 1250 includes processor-readable instructions that are executable by the processor 1220 to cause the apparatus to performvarious operations, including those mentioned herein, such as the operations described in FIGS 3-11.

[0108] The electronic storage 1210 may be and include any type of electronic storage used forstoring data, such as hard disk drive, solid state drive, optical disc, and / or other non-transitory computer-readable mediums, among other types of electronic storage. The electronic storage 1210 stores processor-readable instructions for causing or configured for causing the apparatus to perform its operations and also stores data associated with such operations, such as storing datarelating to 5G NR standards, among other data. The network interface 1240 may implementwireless networking technologies such as 5G NR and / or other wireless networking technologies.

[0109] The components shown in FIG. 12 are merely examples, and persons skilled in the artwill understand that an apparatus includes other components not illustrated and may include multiples of any of the illustrated components. Such and other embodiments are contemplated tobe within the scope of the present disclosure. For example, a transmitter and a receiver may beincluded as components for transmitting and receiving signals.

[0110] Further embodiments of the present disclosure include the following examples.

[0111] Example 1.1. A user equipment (UE), comprising:means for receiving, by the UE, a configuration for mapping a first port associated witha channel state information reference signal (CSI-RS) resource in a resource set to a second port from a first apparatus; means for performing a first mapping, by the UE, of the first port to a first group of indices based upon the received configuration; andmeans for performing a second mapping, by the UE, of the first group of indices to the second port based upon the received configuration.

[0112] Example 1.2. The UE of example 1.1, wherein the configuration for mapping thefirst port to the second port comprises a first pair of values indicating an azimuth dimension and an elevation dimension for multiple resources in the resource set and a second pair of values indicating an azimuth dimension and an elevation dimension for a single resource in the resource set.

[0113] Example 1.3. The UE of example 1.2, wherein the azimuth dimension or theelevation dimension of the first pair of values is a multiple, respectively, of the azimuth or elevation dimension of the second pair of values.

[0114] Example 1.4. The UE of example 1.1, wherein the first group of indices comprisesone or more of an azimuth index, an elevation index, a polarization index or a resource index.

[0115] Example 1.5. The UE of example 1.1, wherein the UE is configured to report CSIacross more than one CSI-RS resource in the resource set.

[0116] Example 1.6. The UE of example 1.5, further comprising means for calculating,by the UE, a CSI.

[0117] Example 1.7. The UE of example 1.6, further comprising means for transmitting,by the UE, a CSI report to the first apparatus.

[0118] Example 1.8. The UE as in any one of examples 1.1 to 1.7, wherein the secondport is associated with an element of a vector obtained by the Kronecker product of two vectors.

[0119] Example 1.9. The UE of example 1.8, wherein an order of the two vectors in theKronecker product depends on the configuration and wherein the order of the two vectors determines the mapping between the first port and the second port.

[0120] Example 1.10. The UE as in any one of examples 1.1 to 1.9, wherein the secondport indicates one of the elements of a precoding vector corresponding to a reported precoding matrix indicator (PMI).

[0121] Example 1.11. The UE of example 1.10, wherein the reported PMI is applicable toa physical data shared channel (PDSCH) symbol x^((l) ) (i) of a layer l=1,…,υ, to form a corresponding PDSCH signal.

[0122] Example 1.12. The UE as in any one of examples 1.1 to 1.11, wherein the firstapparatus is a gNB.

[0123] The embodiments and aspects disclosed herein are examples of the present disclosureand may be embodied in various forms. For instance, although certain embodiments herein are described as separate embodiments, each of the embodiments herein may be combined with one or more of the other embodiments herein. Specific structural and functional details disclosed herein are not to be interpreted as limiting, but as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure. Like reference numerals may refer to similar or identical elements throughout the description of the figures.

[0124] The phrases “in an aspect,” “in aspects,” “in various aspects,” “in some aspects,” or “inother aspects” may each refer to one or more of the same or different aspects in accordance with this present disclosure. The phrase “a plurality of” may refer to two or more.

[0125] In various embodiments, the terms “first message” and “second message”, as well asany subsequent messages may refer to any messages that are transmitted or received in an order and are not necessarily limited to any particular message.

[0126] The phrases “in an embodiment,” “in embodiments,” “in various embodiments,” “insome embodiments,” or “in other embodiments” may each refer to one or more of the same or different embodiments in accordance with the present disclosure. A phrase in the form “A or B” means “(A), (B), or (A and B).” A phrase in the form “at least one of A, B, or C” means “(A); (B); (C); (A and B); (A and C); (B and C); or (A, B, and C).”

[0127] Any of the herein described methods, programs, algorithms or codes may be convertedto, or expressed in, a programming language or computer program. The terms “programming language” and “computer program,” as used herein, each include any language used to specify instructions to a computer, and include (but is not limited to) the following languages and their derivatives: Assembler, Basic, Batch files, BCPL, C, C+, C++, Delphi, Fortran, Java, JavaScript, machine code, operating system command languages, Pascal, Perl, PL1, Python, scripting languages, Visual Basic, metalanguages which themselves specify programs, and all first, second, third, fourth, fifth, or further generation computer languages. Also included are database and otherdata schemas, and any other meta-languages. No distinction is made between languages which areinterpreted, compiled, or use both compiled and interpreted approaches. No distinction is made between compiled and source versions of a program. Thus, reference to a program, where the programming language could exist in more than one state (such as source, compiled, object, orlinked) is a reference to any and all such states. Reference to a program may encompass the actual instructions and / or the intent of those instructions.

[0128] While aspects of the present disclosure have been shown in the drawings, it is notintended that the present disclosure be limited thereto, as it is intended that the present disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular aspects. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

Claims

WHAT IS CLAIMED IS:

1. A method, comprising:receiving, by a user equipment (UE), a configuration for mapping a first port associatedwith a channel state information reference signal (CSI-RS) resource in a resource set to a secondport from a first apparatus;performing a first mapping, by the UE, of the first port to a first group of indices based upon the received configuration; and performing a second mapping, by the UE, of the first group of indices to the second port based upon the received configuration.

2. The method of claim 1, wherein the configuration for mapping the first port to thesecond port comprises a first pair of values indicating an azimuth dimension and an elevationdimension for multiple resources in the resource set and a second pair of values indicating an azimuth dimension and an elevation dimension for a single resource in the resource set.

3. The method of claim 2, wherein the azimuth dimension or the elevation dimensionof the first pair of values is a multiple, respectively, of the azimuth or elevation dimension of the second pair of values.

4. The method of claim 1, wherein the first group of indices comprises one or moreof an azimuth index, an elevation index, a polarization index or a resource index.

5. The method of claim 1, wherein the UE is configured to report CSI across morethan one CSI-RS resource in the resource set.

6. The method of claim 5, further comprising calculating, by the UE, a CSI.

7. The method of claim 6, further comprising transmitting, by the UE, a CSI report tothe first apparatus.

8. The method as in any one of claims 1 to 7, wherein the second port is associatedwith an element of a vector obtained by the Kronecker product of two vectors.

9. The method of claim 8, wherein an order of the two vectors in the Kroneckerproduct depends on the configuration and wherein the order of the two vectors determines themapping between the first port and the second port.

10. The method as in any one of claims 1 to 9, wherein the second port indicates oneof the elements of a precoding vector corresponding to a reported precoding matrix indicator(PMI).

11. The method of claim 10, wherein the reported PMI is applicable to a physical datashared channel (PDSCH) symbol ^(^)(^) of a layer ^ = 1, … ,to form a corresponding PDSCHsignal.

12. The method as in any one of claims 1 to 11, wherein the first apparatus is a gNB.

13. A user equipment, comprising:at least one processor; and at least one memory storing instructions which, when executed by the at least oneprocessor, causes the UE at least to perform:receiving, by the UE, a configuration for mapping a first port associated with a channel state information reference signal (CSI-RS) resource in a resource set to a second port from a first apparatus; performing a first mapping, by the UE, of the first port to a first group of indices based upon the received configuration; and performing a second mapping, by the UE, of the first group of indices to the second port based upon the received configuration.

14. A user equipment (UE), comprising:at least one processor; andat least one memory storing instructions which, when executed by the at least oneprocessor, cause the apparatus at least to perform a method as in any one of claims 1 to 12.

15. A processor-readable medium storing instructions which, when executed by at leastone processor of an apparatus, cause the apparatus at least to perform a method as in any one ofclaims 1 to 12.

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