WO2024100551A1 - Priority rules for csi reports with type ii codebook for high/medium velocities - Google Patents

Abstract

Systems and methods are disclosed for Channel State Information (CSI) reporting. In one embodiment, a method performed by a User Equipment (UE) comprises determining CSI comprising at least a Rank Indicator (RI) indicating a number of Multiple Input Multiple Output (MIMO) transmission layers, and PMI. The PMI comprises information for determining a set of Non-Zero Coefficients (NZCs), wherein each NZC is associated to one MIMO transmission layer, one spatial beam, one Frequency Domain (ED) basis vector for the one MIMO transmission layer, and one Doppler Domain (DD) basis vector for the one MIMO transmission layer. The method further comprises reporting the CSI, wherein the NZCs are each indexed by a MIMO layer related index, a spatial beam related index, a ED basis related index, and a DD related index, and each of the NZCs is assigned a priority in accordance with a priority order based on the indices.

Description

PRIORITY RULES FOR CSI REPORTS WITH TYPE II CODEBOOK FOR HIGH/MEDIUM VELOCITIES

Related Applications

[0001] This application claims the benefit of provisional patent application serial number 63/423,198, filed November 7, 2022, the disclosure of which is hereby incorporated herein by reference in its entirety.

Technical Field

[0002] The present disclosure relates to Channel State Information (CSI) reporting in a cellular communications network.

Background

Codebook-Based Precoding

[0003] Multi-antenna techniques can significantly increase the data rates and reliability of a wireless communication system. In particular, the performance is 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.

[0004] A core component of the Fourth and Fifth Generation (4G/5G) wireless network or New Radio (NR) specified in 3^rd Generation Partnership Project (3GPP) 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. Figure 1 shows an example of spatial multiplexing in NR, where an information carrying symbol vector s is multiplied by an N_T X r (rows X columns) precoding matrix or precoder W, which serves to distribute the transmit energy on the N_T transmit antenna ports in r “virtual” spatial directions such that they can be distinguished at the UE. The precoding matrix is typically selected from a codebook of possible precoding matrices, and typically reported by a UE in the form of a Precoding Matrix Indicator (PMI). A PMI indicates a desired precoding matrix in the codebook for a given number of symbol streams. Vector s contains r symbols each corresponding to a MIMO layer and r is referred to as the transmission rank. In this way, spatial multiplexing is achieved since multiple symbols can be transmitted simultaneously over the same time/frequency Resource Element (RE). The transmission rank, r, is selected to suit the channel.

[0005] NR uses Orthogonal Division Multiplexing (OFDM) in the downlink. The received AR x 1 vector y at a UE on a certain RE can be expressed as y = HWx + e where e is a receiver noise/interference vector.

[0006] The precoder W is chosen to match the characteristics of the NRXNT MIMO channel matrix H. This is also commonly referred to as closed-loop precoding. In closed-loop precoding, the UE feeds back recommendations on a suitable precoder to the NR base station (gNB) 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 a Channel Quality Indicator (CQI). RI, PMI, and CQI are part of a CSI feedback. In NR, PMI feedback can be either wideband, where one PMI is reported for the entire channel bandwidth, or frequency-selective, where one PMI 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 bandwidth part (BWP) size.

[0007] Given the CSI feedback from the UE, the gNB 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).

2D Antenna Arrays [0008] Two-dimensional antenna arrays are widely used and can be described by a number of antenna ports, N^, in a first dimension (e.g., the horizontal dimension), a number of antenna ports, N₂, in a second dimension perpendicular to the first dimension (e.g., the vertical dimension), and a number of polarizations N_p. The total number of antenna ports is thus N = N₁N₂N_p. The concept of an antenna port is non-limiting in the sense that it can refer to any virtualization (e.g., linear mapping) to the physical antenna elements. For example, pairs of physical antenna elements could be fed the same signal, and hence share the same virtualized antenna port.

[0009] An example of a two-dimensional 4x4 (i.e., N₁ X N_2l) antenna array with dualpolarized antenna elements (i.e., N_p = 2) with Ni=4 horizontal antenna elements and N2=4 vertical antenna elements is illustrated in Figure 2A.

[0010] Precoding may also be interpreted as beamforming where the signal to be transmitted on the antenna ports are multiplied by a set of beamforming weights prior to transmission. The beamforming weights are specified by the precoding matrix. Each MIMO layer is transmitted on an antenna beam. Channel State Information Reference Signals

[0011] A CSI-RS is transmitted on an antenna port at the gNB 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 values of the number of CSI-RS ports in NR are { 1,2,4,8,12,16,24,32}. By measuring the received CSI- RS, a UE 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.

[0012] CSI-RS can be transmitted in certain REs in a slot and certain slots. Figure 2B shows an example of CSI-RS REs for 12 antenna ports in one Resource Block (RB), where each CSI- RS port is transmitted in one RE per RB. The REs for CSI-RS is referred to as CSI-RS resource. [0013] In addition, Interference Measurement Resource (IMR) is also defined in NR for a UE to measure interference. An IMR resource contains 4 REs, either four adjacent REs in frequency in the same OFDM symbol or a 2 by 2 grid of adjacent REs in both time and frequency in a slot. By measuring both the channel and the interference, a UE can estimate the effective channel and noise plus interference and determine the CSI.

CSI Framework in NR

[0014] In NR, a UE can be configured with multiple CSI reporting settings and multiple CSI resource settings. Each CSI-RS resource setting can contain multiple CSI-RS resource sets, and each CSI-RS resource set can contain up to 8 CSI-RS resources. For each CSI reporting setting, a UE feeds back a CSI report. Each CSI reporting setting contains at least the following information:

• a CSI resource setting for channel measurement;

• a CSI resource setting for interference measurement;

• time-domain behavior, i.e. periodic, semi-persistent, or aperiodic reporting;

• frequency granularity, i.e. wideband or subband;

• CSI parameters to be reported such as RI, PMI, CQI, and CSI-RS Resource Indicator (CRI) in case of multiple CSI-RS resources configured in a resource set;

• Codebook types, i.e., type I or II, and codebook subset restriction;

• Measurement restriction; • Subband size. One out of two possible subband sizes is indicated, where the value range depends on the bandwidth of the bandwidth part (BWP). One CQI/PMI (if configured for subband reporting) is fed back per subband).

DFT -Based Pre coders

[0015] A common type of precoder is a Discrete Fourier Transform (DFT) based precoder, where the precoding vector used to precode each MIMO layer is a DFT vector. For a singlepolarized Uniform Linear Array (ULA) with N antennas, a DFT based precoder is defined as:

where k = 0,1, ... ON — 1 is the precoder index and 0 is an integer oversampling factor. u_k is also referred to as a one dimensional (1-D) DFT beam with beam index k. If the ULA is along the horizontal dimension, each DFT beam points to an azimuth direction. If the ULA is along the vertical dimension, each DFT beam points to an elevation direction. Each precoder corresponds to a DFT beam.

[0016] For a two-dimensional Uniform Planar Array (UPA) with N₁ antenna ports in one dimension and N₂ antenna ports in another dimension, a DFT based procoder can be created by taking the Kronecker product of two DFT precoder vectors, one in each dimension, as: where:

the two dimensions, and O₁ and O₂ are the over sampling factors in the two dimensions associated with N₁ and N₂ , respectively. v_{k l} is also referred to a two dimensional (2-D) DFT beam characterized by two beam indices (k, l), one in each dimension. Each precoder corresponds to a 2D DFT beam.

[0017] Extending the DFT precoder for a dual-polarized UPA can then be done as:

where

is a co-phasing factor that may be selected from M-PSK alphabet such as QPK with The above assumes that the same DFT beam is used for both polarizations.

[0018] A precoding matrix W_{2D DP} for multi-layer transmission may be created by appending columns of DFT precoder vectors as:

where r is the number of transmission layers. Such DFT-based precoders are used for instance in NR Type I CSI feedback, where each layer is associated with one 2D DFT beam.

MU-MIMO

[0019] With Multi-User MIMO (MU-MIMO), two or more users in the same cell are coscheduled on a same time-frequency resource. That is, multiple data streams are transmitted to different User Equipments (UEs) at the same time-frequency resource, and each UE may be allocated with one or more layers. By transmitting several streams simultaneously, the capacity of the system can be increased.

[0020] To avoid across UE or layer interference, Zero-Forcing (ZF) type of precoders may be used in which the feedback precoders associated with all co-scheduled UEs in a same time frequency resource are used together to generate a set of new orthogonal precoders. This requires each of the feedback precoders to be a good representation of the underlying channel.

[0021] However, a single DFT beam is generally not a good representation of a MIMO layer under multipath channel as each layer may be transmitted over multiple paths each corresponding to a DFT beam.

[0022] To improve the above single DFT beam based precoder, type II codebook based CSI feedback was introduced in NR Rel-15 and further enhanced in NR Rel-16 and Rel-17. The basic concept is that, due to multipath propagation, each layer may contain more than one DFT beam. Hence a better precoder may be created by combining multiple DFT beams for each layer, and the UE feeds back both the multiple DFT beams and the combining coefficients.

NR Rel-15 Type II Codebook

[0023] In NR Rel-15, a type II codebook was introduced in which a precoder is a combination of multiple DFT beams. For each precoder, the UE feeds back the corresponding selected multiple DFT beams and the combination coefficients. A precoder may be reported for each layer and each subband. A common set of DFT beams is selected for all subbands and all layers. The number of DFT beams to be selected is Radio Resource Control (RRC) configured. [0024] For a given 2D cross-polarized antenna array with N₁ antenna ports in one dimension and N₂ antenna ports in another dimension at each polarization, a precoding vector for each layer l ∈ {1,2} in NR Rel-15 type codebook can be expressed as

where and

y y y y selected 2-D DFT beams,

and are the beam

indices in each dimension for the ith selected DFT beam. l ∈ {2,3,4} is configured by

RRC. Wi is common to all layers.

•

the combining coefficient associated with the ith beam, and \ and are the wideband

amplitude, subband amplitude, and phase of w_{2 l j}, respectively.

[0025] wl is expressed in section 5.2.2.2.3 of 3GPP Technical Specification (TS) 38.214

V15.16.0 as:

NR Rel-16 Enhanced Type II Codebook

[0026] The Rel-15 type II codebook is enhanced in NR rel-16 in which, instead of reporting separate precoders for different subbands, the precoders for all subbands are reported together by using a so called Frequency Domain (FD) basis. It takes advantage of frequency domain channel correlations by representing the precoder changes in frequency domain with a set of frequency domain DFT basis vectors (which will be simply referred to as frequency domain basis vectors). Due to channel correlation in frequency, only a few DFT basis vectors may be used to represent the precoder changes over all the subbands. By doing so, the feedback overhead can be reduced or performance can be improved for the same feedback overhead. [0027] For a given CSI-RS resource with N₁ CSI-RS antenna ports in one dimension and N₂ CSI-RS antenna ports in another dimension, and with two polarizations, the Rel-16 type II precoding vectors for each layer I (1 = 1, ... , v) and across all subbands can be expressed as:

where:

• precoding vector at a PMI subband with subband index

for layer I, where is the number of CSI-RS ports in a

configured NZP CSI-RS resource;

•

is the number of subbands for PMI, where N_SB is the number of CQI subbands and R ∈ {1,2} is a scaling factor. Both N_SB and R are RRC configured

• W_i is the same as in Rel-15 type II codebook

• is a size N₃ X M_v frequency domain (FD) compression

matrix for layer I comprising M_v selected FD basis vectors and

^ = and and

is the number of selected FD basis vectors, which

depends on the RRC configured parameter p_v and can be different for different rank. Supported values of p_v can be found in Table 1. Note that y[°^ always corresponds to

o For

a one-step free selection is used.

■ For each layer, the selected FD basis vectors are indicated with a bit combinatorial indicator. In TS 38.214, the

combinatorial indicator is given by the index which is reported by

UE to the gNB. o For a two-step selection with layer-common intermediary subset (IntS)

is used.

■ In the first step, a window-based layer-common IntS selection is used, which is parameterized by The IntS consists of FD basis vectors In TS 38.214, the

selected IntS is reported by the UE to the gNB via the parameter i_{i 5}, which is reported per layer as part of the PMI reported. ■ In the second step, the selected FD basis vectors are indicated with an

-bit combinatorial indicator for each layer. In TS

38.214, the combinatorial indicator is given by the index t_{1 6 l}, which is reported by UE to the gNB.

• is a size 2L X M_v coefficient

matrix. For layer I, only a subset of

coefficients are non-zero and reported by the UE. The remaining non-reported coefficients are considered zero.

o is the maximum number of non-zero coefficients per layer,

where p is a RRC configured parameter. Supported P values are shown in Table 1. o For v G {2, 3, 4}, the total number of non-zero coefficients summed across all layers,

shall satisfy

o Selected coefficient subset for each layer is indicated with Ki ^Z Is in a size 2LM_V bitmap, i_{17 I} . o The strongest coefficient of layer I (whose amplitude and phase are not reported) is identified by

o The amplitude coefficients in are indicated by (wideband) and and

the phase coefficients in are indicated by

[0028] The above is described in 3GPP TS 38.214, section 5.2.2.2.5, where is

expressed as follows:

quantities reported by a UE and

• ^arc reported via the parameter while are reported via the parameter

• are the indices of the M_v FD basis

vectors and are reported via parameter i_{1 6 t} and i_{1 5} if N₃ >19

• are wideband amplitudes (also referred to as reference amplitudes

in this disclosure) of the coefficients at two polarizations, reported by ,and

the subband amplitude of the coefficient , where is part of

and is reported

• is phase of the coefficient , where is part of

Table 1: Codebook parameter configurations for L, 0 and p_v for Rel-16 enhanced type II codebook

NR Rel-16 Enhanced Type II Port Selection Codebook

[0029] The enhanced Type II (eType II) port selection (PS) codebook was also introduced in Rel-16, which is intended to be used for beamformed CSI-RS, i.e., each CSI-RS port corresponds to a 2D spatial beam. Based on the measurement, the UE selects the best CSI-RS ports and recommends a rank, a precoding matrix, and a CQI conditioned on the rank and the precoding matrix to the gNB.

[0030] The precoding matrix comprises linear combinations of the selected CSI-RS ports. For a given transmission layer I, with and v being the rank indicated by the rank

indicator (RI), the precoder matrix has the same form as Rell6 enhanced Type II codebook, i.e.

and are the same as in Rel-16 enhanced Type II codebook. The main difference is on

which is a size

port selection matrix given by

0,1, ..., L — 1 is a

and contains one element with value of one at location

indicating the selected CSI-RS port while all the other elements

are with values of zeros, e.g., e₀ = [1,0, ... ,0]^T and L is the number

of selected CSI-RS ports from each polarization and the same ports are selected for both polarizations. Supported L values can be found in Table 2. The value of d is configured with the higher layer parameter portSelectionSamplingSize, where and d <

min

[0031] Selected CSI-RS ports are indicated by i_{l t} G which is

reported by the UE to gNB. i₁₂ is irrelevant and thus is not reported.

Table 2: Reproduction of Table 5.2.2.2.6-1 of 3GPP TS 38.214 (Codebook parameter configurations for L, β and p_v for Rel-16 enhanced port selection type II codebook)

[0032] For Rel-16 Enhanced Type II CSI feedback, a CSI report comprises of two parts. Part 1 has a fixed payload size and is used to identify the number of information bits in Part 2. Part 1 contains RI, CQI, and an indication of the overall number of non-zero amplitude coefficients across layers, i.e., K^_t G {1, 2, ... , 2/f₀}. Part 2 contains the PMI. Part 1 and 2 are separately encoded. NR Rel-17 Further Enhanced Type II Port Selection Codebook

[0033] The Rel-16 port selection codebook is further enhanced in Rel-17, in which it is assumed that some channel delay associated to each CSI-RS port have been pre-compensated before being transmitted and, thus, only one or two frequency domain basis vectors may be selected by a UE, i.e., M_v G {1,2}. The one or two FD basis vectors are the same for all layers; therefore, M is used instead of M_v.

[0034] The number, L, of CSI-RS ports or beams at each polarization to be selected is indirectly configured as , where parameter a is configured by RRC as shown in

Table 3. The 2L total CSI-RS ports are selected from PCSI-RS ports based on L port selection vectors, , which are identified by

which are indicated by the index i₁₂ , where

[0035] The M selected FD basis vectors, are

identified by n₃ , and where

with the indices assigned such that increases with f . The parameter

{2,4} is configured with the higher-layer parameter valueOfN, when is indicated by

the index

[0036] For Rel-16 Enhanced Type II CSI feedback, a CSI report comprises two parts. Part 1 has a fixed payload size and is used to identify the number of information bits in Part 2. Part 1 contains RI, CQI, and an indication of the overall number of non-zero amplitude coefficients across layers, i.e., Part 2 contains the PMI. Part 1 and 2 are separately

encoded.

Table 3: Codebook parameter configurations for α, M and for Rel-17 further enhanced type II port selection codebook

Priority Rules for Type II CSI Report

[0037] For Type II CSI report on PUSCH, a CSI report comprises of two parts. Part 1 has a fixed payload size and is used to identify the number of information bits in Part 2. Part 1 shall be transmitted in its entirety before Part 2.

• For Rel-16 Enhanced Type II CSI feedback (see Clause 5.2.2.2.5 of 3GPP TS 38.214 V17.2.0) and Rel-17 Further Enhanced Type II Port Selection CSI feedback (see Clause 5.2.2.2.7 of 3GPP 38.214 V17.2.0), Part 1 contains RI (if reported),

• CQI, and

• an indication of the overall number of non-zero amplitude coefficients across layers. [0038] The fields of Part 1 - RI (if reported), CQI, and the indication of the overall number of non-zero amplitude coefficients across layers - are separately encoded. Part 2 contains the PMI of the Rel-16 Enhanced Type II or Rel-17 Further Enhanced Type II Port Selection CSI. Part 1 and 2 are separately encoded.

[0039] When the Uplink Control Information (UCI) code rate on Physical Uplink Shared Channel (PUSCH) is too high due to, for example, small PUSCH resource allocation and large CSI payload size, the UE may omit a portion of the Part 2 to reduce the code rate to below a threshold (whereby the CSI payload will “fit” on the PUSCH allocation). Omission of Part 2 CSI is according to the priority order shown in Table 5.2.3-1 (reproduced below as Table 4) of 3GPP TS 38.214 V17.2.0, where is the number of CSI reports configured to be carried on the

PUSCH. Priority 0 is the highest priority and priority is the lowest priority, and the CSI

report n corresponds to the CSI report with the nth smallest value among the

CSI reports as defined in Clause 5.2.5 of 3GPP TS 38.214 V17.2.0. The subbands for a given CSI report n are numbered continuously in increasing order with the lowest subband as subband 0.

[0040] When omitting Part 2 CSI information for a particular priority level, the UE shall omit all of the information at that priority level. [0041] For Rel-16 Enhanced Type II reports, for a given CSI report n, each reported element of indices and indexed by and is associated with a priority value

Pri(

and is the index of the f

^th selected FD basis vector. The element with the highest priority has the lowest associated value Pri(l, i,f). Omission of Part 2 CSI is according to the priority order shown in Table 5.2.3-1, where:

• Group 0 includes indices (if reported), (if reported) and , i.e.,

and the index of the beam and polarization associated to the strongest

coefficient.

• Group 1 includes indices (if reported), (if reported), the

highest priority elements of the max highest priority elements

of i_{2 4}1 and the max highest priority elements of . In

other words, Group 1 includes . wideband amplitudes, part of the higher priority NZC

bitmap, and part of the higher priority amplitude and phase coefficients of

• Group 2 includes the lowest priority elements of the min

lowest priority elements of i_{24 J} and the min lowest priority elements of

In other words, Group 2 includes the remaining low priority part of

the NZC bitmap, the amplitude and phase coefficients of

[0042] Similarly, for Rel-17 Further Enhanced Type II Port Selection reports, for a given CSI report n, each reported element of and indexed by I, i and /, is associated with a

priority value

0, ... , M — 1. The element with the highest priority has the lowest associated value Pri (l, i, f).

Omission of Part 2 CSI is according to the priority order shown in Table 5.2.3-1, where:

• Group 0 includes i_{1 2} (if reported), i_{1 8 l}

(if reported), i.e., the indices of the selected CSI-RS ports, the port and polarization associated to the strongest

coefficient, and the index of the second FD basis vector if configured

• Group 1 includes the highest priority elements of (if reported),

the max highest priority elements of and the

highest priority elements of In other words, Group 1 includes

wideband amplitudes, part of the higher priority NZC bitmap, and part of the higher priority amplitude and phase coefficients of

• Group 2 includes the lowest priority elements of _{7 £} (if reported), the

min lowest priority elements of t_{24 l} and the min

lowest priority elements of In other words, Group 2 includes the

remaining low priority part of the NZC bitmap, the amplitude and phase coefficients of

Table 4: Reproduction of Table 5.2.3-1 (Priority reporting levels for Part 2 CSI) from TS 38.214 V17.2.0

Enhanced Type II Codebook for High/Medium UE Velocities

[0043] It has been observed in measurements in real deployments that downlink MU-MIMO precoding performance degrades when one or more of the co-scheduled UEs start to move faster than a few kilometers per hour (km/h) relative to the base station. One of the main reasons is that the information of the channels, used to compute the MIMO precoding at the base station, becomes outdated rather soon when this occurs. Thereby, the precoder loses its effectiveness to protect co-scheduled users from interference when transmitting to an intended user. Hence, downlink MU-MIMO precoding needs to be made robust to higher UE speeds. [0044] One solution to mitigate this problem and to cope with such rapid channel variations is to configure faster CSI reporting (i.e., more frequent CSI reporting and measurement). A problem with this approach is that this incurs a large signaling and reporting overhead.

Furthermore, even if the CSI-RS periodicity is increased, there is still a CSI reporting and scheduling delay that may cause the reported CSI to become outdated. Hence, with the current CSI framework in NR, it is difficult to obtain accurate CSI for medium-to-high-speed UEs with a reasonable amount of overhead. [0045] It has been agreed in the 3GPP Rel-18 work item on MIMO Evolution for Downlink and Uplink to specify CSI reporting enhancement for high/medium UE velocities by exploiting time-domain correlation/Doppler-domain information to assist downlink (DL) precoding. In particular, Rel- 16/17 Type-II codebook refinement, without modification to the spatial and frequency domain basis should be investigated.

[0046] In the Rel- 16 Type II codebook, the coefficients in represent the relative

amplitude and phase of channel clusters in angle-delay domain. Figure 3 illustrates a schematic example with three dominating propagation paths between a gNB and a UE which is conveyed through three different channel clusters. Since the different clusters have different angle-of- departures (AODs) and the different paths have different propagation delays, the three clusters can be distinguished in a joint angle-delay domain. The coefficients in give information on

how to combine these clusters in the best way for each transmission layer. In Figure 3, the UE is moving in a direction indicated by the arrow. The different paths will then also have different Doppler shifts since the relative angle between the velocity vector and the arrival path of the cluster is different for different clusters. With the Rel-18 Type II codebook it can be possible to distinguish different Doppler components by introducing a Doppler-domain (DD) basis, W_d, in addition to and The linear combining coefficients for the Rel-18 Type II codebook is

denoted as and they tell how the channel clusters should be combined in angle-delay-

Doppler domain (in a relative sense) for the different layers.

[0047] In Rel-18 discussions, the following codebook structure was agreed in RANl#110bis- e.

Agreement

For the Rel-18 Type-II codebook refinement for high/medium velocities, support the following codebook structure where N4 is gNB-configured via higher-layer signaling:

• For N4=l, Doppler-domain basis is the identity (no Doppler-domain compression) reusing the legacy

, and W_f , e.g.

• For N₄>1 , Doppler-domain orthogonal DFT basis commonly selected for all SD/FD bases reusing the legacy

o Only Q (denoting the number of selected DD basis vectors) >1 is allowed o TBD (by RAN 1#110bis): whether rotation is used or not o FFS: identical or different rotation factors for different SD components o FFS: Whether Q is RRC-configured or reported by the UE

Note: Detailed designs for SD/FD bases including the associated UCI parameters follow the legacy specification FFS: Whether one CSI reporting instance includes multiple W₂ and a single W₁ and W_f report.

Agreement For the Rel-18 Type- II codebook refinement for high/medium velocities, when N₄>1, if multiple candidates of Q value are supported, the value of Q is gNB- configured via higher-layer (RRC) signalling.

[0048] According to the above agreement, N4 represents the total number of DD basis vectors, and Q denotes the number of selected DD basis vectors. The DD basis matrix W_d includes the Q selected DD basis vectors.

[0049] By only selecting Q DD basis vectors, compression can be achieved in doppler domain when N4 is large (e.g., N4>3). For example, when N4=3, Q=2 DD basis vectors may be selected in which case the combining coefficients corresponding to only two of the three DD basis vectors need to be fed back as part of , thus achieving compression in the Doppler-

domain.

[0050] When N4=l, there is no DD compression as the Doppler-domain basis matrix has a scalar value of 1. However, N4=l still allows for the UE to predict a CSI corresponding to a future slot as opposed to the Rel-16 type II codebook in which case the reported CSI is calculated based on the CSI reference resource as defined in 3GPP TS 38.214 V17.2.0.

[0051] Due to the condition ‘Only Q (denoting the number of selected DD basis vectors) >1 is allowed’ in the agreement above, when N4=2, there will be two DD basis vectors and both of the two DD basis vectors have to be selected. Hence, only limited or no Doppler-domain compression is possible when N4=2.

Summary

[0052] Systems and methods are disclosed for Channel State Information (CSI) reporting with a Type II codebook in a manner that is particularly well-suited for high or medium velocities. In one embodiment, a method performed by a User Equipment (UE) comprises receiving a CSI report configuration for predicted Precoder Matrix Indication (PMI), wherein the configuration comprises an indication of one or more Non-Zero Power CSI Reference Signals (NZP CSI-RS) resources for channel measurement. The method further comprises determining CSI to be reported, wherein the CSI comprises at least a Rank Indicator (RI) indicating a number of Multiple Input Multiple Output (MIMO) transmission layers, and a PMI. The PMI comprises information about one or more spatial beams or spatial domain basis vectors, information about one or more Frequency Domain (FD) basis vectors for each of the number of MIMO transmission layers, and information about one or more Doppler Domain (DD) basis vectors for each of the number of MIMO transmission layers. The PMI further comprises information for determining a set of Non-Zero Coefficients (NZCs), wherein each of the NZCs is associated to one of the number of MIMO transmission layers, one of the one or more spatial beams, one of the one or more FD basis vectors for the one of the number of MIMO transmission layers, and one of the one or more DD basis vectors for the one of the number of MIMO transmission layers. The method further comprises reporting the CSI, wherein coefficients comprised in the set of NZCs are each indexed by a MIMO layer related index, a spatial beam related index, a FD basis related index, and a DD related index and each of the coefficients is assigned a priority in accordance with a priority order, from high to low, given in increasing order of first the MIMO layer related index over the number of MIMO layers, second the spatial beam related index, third the FD basis related index, and fourth the DD basis related index. In this manner, improved performance can be achieved in the case of omission when a UE is moving with high or medium velocities.

[0053] In one embodiment, the one or more spatial beams, the one or more FD basis vectors, and the one or more DD basis vectors are determined based on channel measurements based on the one or more NZP CSI-RS resources for channel measurement.

[0054] In one embodiment, the PMI further comprises a bitmap for each of the number of MIMO layers, wherein bits in the bitmap are each indexed by the MIMO layer related index, the spatial beam related index, the FD basis related index, and the DD related index, and each bit in the bitmap is associated to a coefficient with the same indices and is used to indicate whether the coefficient is a zero or non-zero coefficient. In one embodiment, each of the bits in the bitmap is assigned a priority in accordance with a priority order, from high to low, given in increasing order of first the MIMO layer related index over the number of MIMO layers, second the spatial beam related index, third the FD basis related index, and fourth the DD basis related index. [0055] In one embodiment, each of the NZCs comprises an amplitude and phase factor.

[0056] In one embodiment, the one or more FD basis vectors are common for the number of

MIMO layers.

[0057] In one embodiment, the coefficients comprised in the set of NZCs that are comprised in the PMI for the one or more MIMO layers are arranged according to their assigned priorities into different priority groups. In one embodiment, if needed, the coefficients in the different priority groups are omitted (506-B) from the reported CSI, starting with the priority group having a lowest priority first. In one embodiment, the method further comprises omitting the coefficients in one or more of the different priority groups in order of priorities assigned to the different priority groups starting with one of the different priority groups having a lowest priority first.

[0058] In one embodiment, the CSI further comprises a channel quality indicator, and an indication of an overall number of NZCs across the one or more MIMO layers. In one embodiment, the CSI is divided into a first part and a second part, wherein: the first part comprises the rank indicator, the channel quality indicator, and the indication of an overall number of NZCs across the one or more MIMO layers, and the second part comprises multiple priority groups, wherein the coefficients in the set of NZCs that are comprised in the PMI are arranged into the multiple priority groups based on the priorities assigned to the coefficients. In one embodiment, if needed, the coefficients in at least one of the multiple priority groups of the second part of the CSI are omitted (506-B) from the reported CSI, starting with the priority group having a lowest priority first. In one embodiment, the method further comprises omitting at least one of the multiple priority groups in the second part of the CSI in order of priorities assigned to the multiple priority groups starting with one of the multiple priority groups having a lowest priority first. In one embodiment, a first priority group from among the multiple priority groups having a highest priority comprises spatial beam related indices that indicate the one or more spatial beams and, for each MIMO layer, an indication of a strongest coefficient; a second priority group from among the multiple priority groups having a second highest priority comprises information that indicates, for each MIMO layer, the one or more FD basis vectors and the one or more DD basis vectors; the second priority group further comprises, for each MIMO layer, a first subset of the set of NZCs comprised in the precoding matrix indicator; and a third priority group from among the multiple priority groups having a third highest priority comprises, a second subset of the set of NZCs comprised in the precoding matrix indicator, wherein the coefficients in the second subset of the set of NZCs have lower priority than the coefficients in the first subset of the set of NZCs.

[0059] In one embodiment, the method further comprises receiving, from a network node, a configuration of: (a) a total number of DD basis vectors to be used for the CSI; (b) a set of parameters comprising: (i) a number of spatial beams, (ii) number of FD basis vectors, (iii) a number of DD basis vectors, or (iv) any one or more of (i)-(iii), to be used for the CSI; or (c) both (a) and (b).

[0060] In one embodiment, the precoding matrix indicator further comprises a single NZC bitmap of size 2LM_V Q for each of the number of MIMO layers, where L is the number of spatial beams, M_v is the number of FD basis vectors, and Q is the number of DD basis vectors.

[0061] In one embodiment, the precoding matrix indicator further comprises, for each of the number of MIMO layers, a separate NZC bitmap corresponding to each of the one or more DD basis vectors, wherein each NZC bitmap is of size 2LM_V, where L is the number of spatial beams and M_v is the number of FD basis vectors. [0062] Corresponding embodiments of a UE are also disclosed. In one embodiment, a UE is adapted to receive a CSI report configuration for predicted PMI, wherein the configuration comprises an indication of one or more NZP CSI-RS resources for channel measurement. The UE is further adapted to determine CSI to be reported, wherein the CSI comprises at least a RI indicating a number of MIMO transmission layers, and a PMI. The PMI comprises information about one or more spatial beams or spatial domain basis vectors, information about one or more FD basis vectors for each of the number of MIMO transmission layers, and information about one or more DD basis vectors for each of the number of MIMO transmission layers. The PMI further comprises information for determining a set of NZCs, wherein each of the NZCs is associated to one of the number of MIMO transmission layers, one of the one or more spatial beams, one of the one or more FD basis vectors for the one of the number of MIMO transmission layers, and one of the one or more DD basis vectors for the one of the number of MIMO transmission layers. The UE is further adapted to report the CSI, wherein coefficients comprised in the set of NZCs are each indexed by a MIMO layer related index, a spatial beam related index, a FD basis related index, and a DD related index, and each of the coefficients is assigned a priority in accordance with a priority order, from high to low, given in increasing order of first the MIMO layer related index over the number of MIMO layers, second the spatial beam related index, third the FD basis related index, and fourth the DD basis related index.

[0063] In one embodiment, a UE comprises a communication interface comprising a transmitter and a receiver, and processing circuitry associated with the communication interface. The processing circuitry is configured to cause the UE to receive a CSI report configuration for predicted PMI, wherein the configuration comprises an indication of one or more NZP CSI-RS resources for channel measurement. The processing circuitry is further configured to cause the UE to determine CSI to be reported, wherein the CSI comprises at least a RI indicating a number of MIMO transmission layers, and a PMI. The PMI comprises information about one or more spatial beams or spatial domain basis vectors, information about one or more FD basis vectors for each of the number of MIMO transmission layers, and information about one or more DD basis vectors for each of the number of MIMO transmission layers. The PMI further comprises information for determining a set of NZCs, wherein each of the NZCs is associated to one of the number of MIMO transmission layers, one of the one or more spatial beams, one of the one or more FD basis vectors for the one of the number of MIMO transmission layers, and one of the one or more DD basis vectors for the one of the number of MIMO transmission layers. The processing circuitry is further configured to cause the UE to report the CSI, wherein coefficients comprised in the set of NZCs are each indexed by a MIMO layer related index, a spatial beam related index, a FD basis related index, and a DD related index, and each of the coefficients is assigned a priority in accordance with a priority order, from high to low, given in increasing order of first the MIMO layer related index over the number of MIMO layers, second the spatial beam related index, third the FD basis related index, and fourth the DD basis related index. [0064] Embodiments of a method performed by a network node are also disclosed. In one embodiment, a method performed by a network node comprises transmitting a CSI report configuration for predicted PMI to a UE, wherein the configuration comprises an indication of one or more NZP CSI-RS resources for channel measurement. The method further comprises receiving a report of CSI from the UE, wherein the CSI comprises at least a RI indicating a number of MIMO transmission layers, and a PMI. The PMI comprises information about one or more spatial beams or spatial domain basis vectors, information about one or more FD basis vectors for each of the number of MIMO transmission layers, and information about one or more DD basis vectors for each of the number of MIMO transmission layers. The PMI further comprises information for determining a set of non- NZCs, wherein each of the NZCs is associated to one of the number of MIMO transmission layers, one of the one or more spatial beams, one of the one or more FD basis vectors for the one of the number of MIMO transmission layers, and one of the one or more DD basis vectors for the one of the number of MIMO transmission layers. Coefficients comprised in the set of NZCs are each indexed by a MIMO layer related index, a spatial beam related index, a FD basis related index, and a DD related index, and each of the coefficients is assigned a priority in accordance with a priority order, from high to low, given in increasing order of first the MIMO layer related index over the number of MIMO layers, second the spatial beam related index, third the FD basis related index, and fourth the DD basis related index.

[0065] Corresponding embodiments of a network node are also disclosed. In one embodiment, a network node is adapted to transmit a CSI report configuration for predicted PMI to a UE, wherein the configuration comprises an indication of one or more NZP CSI-RS resources for channel measurement. The network node is further adapted to receive a report of CSI from the UE, wherein the CSI comprises at least a RI indicating a number of MIMO transmission layers, and a PMI. The PMI comprises information about one or more spatial beams or spatial domain basis vectors, information about one or more FD basis vectors for each of the number of MIMO transmission layers, and information about one or more DD basis vectors for each of the number of MIMO transmission layers. The PMI further comprises information for determining a set of non- NZCs, wherein each of the NZCs is associated to one of the number of MIMO transmission layers, one of the one or more spatial beams, one of the one or more FD basis vectors for the one of the number of MIMO transmission layers, and one of the one or more DD basis vectors for the one of the number of MIMO transmission layers. Coefficients comprised in the set of NZCs are each indexed by a MIMO layer related index, a spatial beam related index, a FD basis related index, and a DD related index, and each of the coefficients is assigned a priority in accordance with a priority order, from high to low, given in increasing order of first the MIMO layer related index over the number of MIMO layers, second the spatial beam related index, third the FD basis related index, and fourth the DD basis related index.

[0066] In one embodiment, a network node comprises processing circuitry configured to cause the network node to transmit a CSI report configuration for predicted PMI to a UE, wherein the configuration comprises an indication of one or more NZP CSI-RS resources for channel measurement. The processing circuitry is further configured to cause the network node to receive a report of CSI from the UE, wherein the CSI comprises at least a RI indicating a number of MIMO transmission layers, and a PMI. The PMI comprises information about one or more spatial beams or spatial domain basis vectors, information about one or more FD basis vectors for each of the number of MIMO transmission layers, and information about one or more DD basis vectors for each of the number of MIMO transmission layers. The PMI further comprises information for determining a set of non- NZCs, wherein each of the NZCs is associated to one of the number of MIMO transmission layers, one of the one or more spatial beams, one of the one or more FD basis vectors for the one of the number of MIMO transmission layers, and one of the one or more DD basis vectors for the one of the number of MIMO transmission layers. Coefficients comprised in the set of NZCs are each indexed by a MIMO layer related index, a spatial beam related index, a FD basis related index, and a DD related index, and each of the coefficients is assigned a priority in accordance with a priority order, from high to low, given in increasing order of first the MIMO layer related index over the number of MIMO layers, second the spatial beam related index, third the FD basis related index, and fourth the DD basis related index.

Brief Description of the Drawings

[0067] The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.

[0068] Figure 1 illustrates an example of spatial multiplexing in New Radio (NR); [0069] Figure 2A illustrates an example of a two-dimensional 4x4 (i.e.,

,) antenna array with dual-polarized antenna elements (i.e., N_p = 2) with Ni=4 horizontal antenna elements and N2=4 vertical antenna elements;

[0070] Figure 2B illustrates an example of Channel State Information Reference Signal (CSI- RS) Resource Elements (REs) for twelve antenna ports in one Resource Block (RB), where each CSI-RS port is transmitted in one RE per RB ;

[0071] Figure 3 illustrates an example with three dominating propagation paths between a NR base station (gNB) and a User Equipment (UE) which is conveyed through three different channel clusters;

[0072] Figure 4A illustrates an example of priority allocation based on for two

selected Doppler Domain (DD) basis vectors with rank 4, M_v=2, and L=2, according to an embodiment of the disclosure;

[0073] Figure 4B illustrates another example of priority allocation where the priority order is switched between Frequency Domain (FD) basis and DD basis, in accordance with another embodiment of the present disclosure;

[0074] Figure 5A is a flowchart of a method in a communication system according to an embodiment of the disclosure;

[0075] Figure 5B illustrates a method performed by a UE according to some embodiments of the disclosure;

[0076] Figure 5C illustrates a method performed by a network node according to some embodiments of the disclosure;

[0077] Figure 6 shows an example of a communication system in accordance with some embodiments;

[0078] Figure 7 shows a UE in accordance with some embodiments;

[0079] Figure 8 shows a network node in accordance with some embodiments;

[0080] Figure 9 is a block diagram of a host, which may be an embodiment of the host of

Figure 6, in accordance with various aspects described herein;

[0081] Figure 10 is a block diagram illustrating a virtualization environment in which functions implemented by some embodiments may be virtualized; and

[0082] Figure 11 shows a communication diagram of a host communicating via a network node with a UE over a partially wireless connection in accordance with some embodiments. Detailed Description

[0083] The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure.

[0084] Certain challenges exist. In the above agreed codebook structure for the 3^rd Generation Partnership Project (3GPP) Rel-18 enhanced Type II codebook for high/medium User Equipment (UE) velocities, new components such as selected Doppler Domain (DD) basis vectors are newly introduced. How to allocate Precoding Matrix Indicator (PMI) parameters for the newly agreed Rel-18 codebook structure in different groups in Part 2 of the Channel State Information (CSI) is an open problem that needs to be solved.

[0085] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges. Some embodiments of the current disclosure provide a method in a communication system for CSI report for type II CSI feedback with DD compression. The method includes one or more of the following:

• Configuring a UE, with a total number of DD basis vectors, and a set of parameters including a number of spatial beams, number of Frequency Domain (FD) basis vectors, and a number of DD basis vectors to be selected for Enhanced type II CSI report

• Measuring by the UE channels based on the Channel State Information Reference Signal (CSI-RS) resources

• Determining by the UE a number of spatial beams, a number of FD basis vectors, and a number of DD basis vectors to be selected

• Computing by the UE a precoding matrix for each Multiple Input Multiple Output (MIMO) layer, comprising a set of Non-Zero Coefficients (NZCs), based on the determined spatial beams, FD basis vectors, and DD basis vectors

• Assigning a priority level to the coefficients according to a priority order, from high to low in the order given by layer index 1

SD basis index i

FD basis index f

DD basis index q

• The coefficients are ordered according to their priority levels into different groups and, optionally, a group with lower priority level is dropped first if needed.

[0086] Some embodiments of the current disclosure provide a method of determining priority order with a priority function indexed by layer index 1 SD basis index i FD basis index f DD basis index q. In a method according to another embodiment, a priority order is determined with a priority function indexed by layer index 1 SD basis index i DD basis index q FD basis index f.

[0087] Some embodiments of the current disclosure provide a method including allocating NZC coefficients to Group 1 and Group 2 of Part 2 of the CSI according to the priority assignment.

[0088] Some embodiments of the current disclosure provide a method including reporting the selected DD basis vectors as part of Group 1.

[0089] Communication systems and devices adapted to perform one or a combination of these steps are also provided, according to some embodiments of the current disclosure.

[0090] Certain embodiments may provide one or more of the following technical advantage(s). Certain embodiments may provide better Multi-User MIMO (MU-MIMO) performance in case of omission when a user equipment is moving with high or medium velocities.

[0091] Reported Components of Rel-18 Enhanced Type II CSI for High/Medium

Velocities

[0092] In one embodiment, for a Rel-18 enhanced Type II CSI report n. the UE receives configuration of N4 (which represents the total number of DD basis vectors). Optionally, the UE may receive a configuration of Q (which represents the number of selected DD basis vectors). [0093] In one embodiment, for a Rel-18 enhanced Type II CSI report n, one or more of the following are reported:

• L selected spatial Discrete Fourier Transform (DFT) vectors (or spatial beams) wherein the corresponding to the L spatial DFT vectors are reported via the parameter

while {n_1; n₂} corresponding to the L spatial DFT vectors are reported via the parameter

• selected FD basis vectors corresponding to the I^th layer which

are given by indices wherein denotes

the index corresponding to the ) selected FD basis vector and the

layer; the selected FD basis vectors are reported via parameter and

• Q selected DD basis vectors denoted b corresponding to the I

^th layer which are given by indices wherein

denotes the index corresponding to the q^ttl (q = 0,1, Q — 1) selected DD basis vector and the l^ttl layer; the q^ttl selected DD basis vector is defined as:

the Q selected DD basis vectors are reported via parameter

• the amplitudes of linear combination coefficients

(

are reported via the following:

o reference amplitudes of the coefficients reported by

parameter

o differential amplitude of coefficient the is given by , where is part

differential amplitudes are reported via

• is phase of the coefficient where is part of

[0094] In one embodiment, there is one non-zero coefficient bitmap corresponding to each selected DD basis vector. The non-zero coefficient bitmap corresponding to the q^th selected DD basis vector and the I^th layer is reported via parameter Each such bitmap is of size 2LM_V,

and there are vQ bitmaps in total.

[0095] In an alternative embodiment, there is a single bitmap for each layer of size 2LM_VQ. In this case, non-zero coefficient bitmap corresponding to the l^ttl layer is reported via parameter

[0096] Then the precoder matrix corresponding to PMI subband t (t = 0,1, ..., N₃ — 1), and

CSI instance is given by:

[0097] Enhanced Priority Function

[0098] In one embodiment, for a Rel-18 enhanced Type II CSI report, the linear combining coefficients reported in (differential amplitudes),

(phase of linear combination

coefficients), and bitmaps

(or alternatively single bitmap are indexed by I, i, f and q

and prioritized according to a function of the following form:

where

• is a function that determines the priority value/level associated with a DD basis, o an example of co(q) could be

o another example could be

• layer index I = 1,2, ... , v, wherein v is the RI

[0099] According to the above prioritization function, the element with the highest priority has the lowest value associated with Pri(Z, i, f, q). In this embodiment, the priority order, from high to low is given by layer index I -> SD basis index i -> FD basis index f -> DD basis index q.

[0100] An example of priority allocation based on P is shown in Figure 4A.

Figure 4A illustrates an example of priority allocation based on

for two selected DD basis vectors with rank 4, M_v=2 and L=2, according to an embodiment of the disclosure. The element with the highest priority has the lowest associated value In this example,

the highest priority is assigned to the coefficients associated with n

, and the lowest priority ( is assigned to

the coefficients associated with

where and

[0101] In another embodiment, for a Rel-18 enhanced Type II CSI report, the linear combining coefficients reported in (differential amplitudes), (phase of linear

combination coefficients), and bitmaps (or alternatively single bitmap ) are indexed by

and q and prioritized according to a function of the following form:

[0102] An example is shown in Figure 4B, where the priority order is switched between FD basis and DD basis, i.e., the priority order from high to low is given by layer index I -> SD basis index i -> DD basis index q -> FD basis index f. Figure 4B illustrates an example of an alternative priority allocation based on Pri(l,i,f,q) for two selected DD basis vectors with rank 4 (i.e., v=4), M_v=2, Q=2, and L=2, according to an embodiment of the disclosure.

[0103] Grouping of CSI Part 2

[0104] In case of a bitmap

per selected DD basis vector is reported and total number of non-zero coefficients, K^NZ , is configured, the parameters in Part 2 would be arranged in Groups 0 to 2 as follows:

• Group 0 includes the spatial domain basis indices (if reported), (if reported) and

the index for the strongest coefficient indication.

• Group 1 includes indices (if reported), (if reported), (if reported), the

highest priority elements of (or for single bitmap per

layer), the max highest priority elements of and the

highest priority elements of . In

other words, Group 1 includes reference amplitudes, part of the higher priority NZC

bitmap per selected DD basis vector, and part of the higher priority differential amplitude and phase coefficients of

• Group 2 includes the lowest priority elements of ( or for single

bitmap per layer), the min lowest priority elements of and the

min lowest priority elements of In other words,

Group 2 includes the remaining low priority part of the NZC bitmaps, the differential amplitude and phase coefficients of

[0105] In an alternative embodiment, a subset of the bitmaps is

included in Group 1 and the other subset of bitmaps is included in Group 2. Let us assume that there are Q selected DD basis vectors and hence Q bitmaps Hence, the first strongest

bitmaps corresponding to the DD basis vectors associated with the strongest NZC

coefficients (e.g., in terms of sum of the power of the corresponding coefficients) and the coefficients associated to the first strongest bitmaps are included in Group 1. The remaining

bitmaps corresponding to the DD basis vectors associated with the weaker NZC

coefficients and the coefficients associated to the remaining Q — |^j bitmaps are included in Group 2. The first |^j strongest bitmaps G, 7,;, <7 may be indicated (e.g., by a bitmap) in Group 0. [0106] In another embodiment, a bitmap

(q = 0, Q — 1) with all zeros is not reported in the CSI. The reported bitmaps in Part 2 may be indicated, e.g., with another bitmap in Part 1. In an alternative embodiment, the total number of reported bitmaps in Part 2 is indicated in Part 1. The indices (e.g., I, q) of the reported bitmaps are indicated in Group 0 or 1 of Part 2.

[0107] In a further embodiment, the total number of non-zero coefficients associated to each bitmap (q = 0, ... , Q — 1) is reported. A bitmap is not reported if its associated coefficients are all zero.

[0108] In case that some part of Part 2 needs to be dropped (see step 508-A of Figure 5A), Group 2 parameters are dropped first, then parameters in Group 1. Group 0 parameters are dropped last.

[0109] A flowchart of a method in a communication system according to an embodiment of the disclosure is shown in Figure 5A. The method includes one or more of the following steps, that can be performed in any combination: (Step 500-A): The network configures a UE with a type -II CB based CSI report for high or medium speeds, the configuration comprising N4 total number of DD basis vectors and Q number of DD basis vectors to be selected. Note that the CSI report configuration is for predicted PMI, wherein the configuration further comprises an indication of one or more NZP CSI-RS resources for channel measurement. (Step 502- A): The network requests the UE to report a type-II CB based CSI according to the configuration. (Step 504- A): The UE measures the channel based on the CSI-RS(s) and calculates a CSI comprising a RI, a CQI, and a PMI, where the PMI comprises N4 PMI instances with possibly DD compression depending on the value of N4. The PMI has L selected spatial beams, M(_V,_S) selected FD basis vectors, and Q selected FD basis vectors and the corresponding linear combining coefficients. (Step 506-A): The UE reports the CSI in two parts, Part 1 and Part 2. Part 1 comprises the RI, CQI, and an indication of the overall number of non-zero amplitude coefficients across layers. Part 2 comprises three groups, i.e., groups 0,1,2, which are arranged according to the priority order, wherein the priority indexing follows the order where layers have the highest priority, the spatial beam related index has the second highest priority, the FD basis related index has the third or lowest priority, and the DD basis related index has the lowest or third priority. (Step 508-A): In case that some part of Part 2 needs to be dropped, Group 2 parameters are dropped first, then Group 1. Group 0 parameters are dropped last. The steps can be performed in any combination and in any order. [0110] Introducing more than 3 groups of CSI part 2

[0111] Another alternative that facilitates CSI omission with Doppler domain CSI compression is to introduce more groups in the CSI part 2, so that the CSI associated with different DD basis are reported in different pairs of groups in CSI part 2. In this case, the legacy priority function

with

with and for Re116

enhanced Type II CSI and

1 and f = 0, ... , M — 1 for Rel-17 further enhanced Type II CSI, is reused for each DD basis. [0112] In one embodiment, for each CSI report, 2 Q + 1 groups are used for reporting the enhanced Type II CSI for high/medium velocities, where

• Group 0 includes the spatial domain basis indices i_{1 1} (if reported), i₁₂ (if reported) and the index for the strongest coefficient indication;

• Group 1 includes indices (if reported), (if reported), (if reported), the

highest priority elements of (if reported), the

max highest priority elements of and the highest

priority elements of , which are associated with the first selected DD

basis (e.g., denoted as

• Group 2 includes the lowest priority elements of (if reported), the

min lowest priority elements of and the min

lowest priority elements of , which are associated with the first selected DD basis (e.g., denoted as

• Group 3 includes the highest priority elements of (if reported),

the max highest priority elements of and the max

highest priority elements of , which are associated with the first

second DD basis (e.g., denoted as .

• Group 4 includes the lowest priority elements of (if reported), the

min lowest priority elements of and the min

lowest priority elements of

, which are associated with the second selected DD basis (e.g., denoted as • Group 2 Q — 1 includes the

highest priority elements of (if

reported), the max highest priority elements of and the

— v \ highest priority elements of which are associated

with the Q-th selected DD basis (e.g., denoted as

• Group 2 Q includes the lowest priority elements of (if reported), the

min lowest priority elements of and the min

lowest priority elements of which are associated with the Q-th

selected DD basis (e.g., denoted as

[0113] When CSI omission happens, CSI group with larger index has lower priority and will be dropped first, e.g., Group 2Q has lower priority than Group 2Q — 1, so Group 2Q will be dropped first.

[0114] Figure 5B illustrates a method performed by a UE according to some embodiments of the disclosure. The method includes one or more of:

• determining (500-B), e.g. by receiving A configuration for, a total number of DD basis vectors and/or a set of parameters including one or more of a number of spatial beams, number of FD basis vectors, and a number of DD basis vectors to be selected for Enhanced type II CSI report;

• determining (502-B) a precoding matrix for each MIMO layer, comprising a set of nonzero coefficients (NZCs), based on one or more of determined spatial beams, FD basis vectors, and dd basis vectors;

• reporting (504-B) the CSI, wherein coefficients are ordered into priority groups, e.g., groups 0,1,2, which are arranged according to a priority order wherein the priority indexing follows the order where layers have the highest priority, the spatial beam related index has the second highest priority, the FD basis related index has the third or lowest priority, and the DD basis related index has the lowest or third priority;

• At step (506-B), in case that some part of Part 2 components needs to be dropped, Group 2 parameters are dropped first, then Group 1 and group 0 parameters are dropped last.

The steps can be performed in any combination and in any order.

[0115] Figure 5C illustrates a method performed by a network node according to some embodiments of the disclosure. The method includes one or more of: • transmitting (500-C) a configuration for a total number of DD basis vectors and/or a set of parameters including one or more of a number of spatial beams, number of FD basis vectors, and a number of DD basis vectors to be selected for Enhanced type II CSI report;

• receiving (502-C) a CSI including a precoding matrix indicator for a precoding matrix for each MIMO layer, comprising a set of non-zero coefficients (NZCs), based on one or more of determined spatial beams, FD basis vectors, and DD basis vectors;

• receiving (504-C) a CSI wherein coefficients are ordered into priority groups, e.g., groups 0,1,2, which are arranged according to a priority order wherein the priority indexing follows the order where layers have the highest priority, the spatial beam related index has the second highest priority, the FD basis related index has the third or lowest priority, and the DD basis related index has the lowest or third priority;

• (506-C) in case that some part of Part 2 component needs to be dropped, Group 2 parameters are dropped first, then Group 1 , and group 0 parameters are dropped last. The steps can be performed in any combination and in any order.

[0116] Figure 6 shows an example of a communication system 600 in accordance with some embodiments.

[0117] In the example, the communication system 600 includes a telecommunication network 602 that includes an access network 604, such as a Radio Access Network (RAN), and a core network 606, which includes one or more core network nodes 608. The access network 604 includes one or more access network nodes, such as network nodes 610A and 610B (one or more of which may be generally referred to as network nodes 610), or any other similar Third Generation Partnership Project (3GPP) access node or non-3GPP Access Point (AP). The network nodes 610 facilitate direct or indirect connection of User Equipment (UE), such as by connecting UEs 612A, 612B, 612C, and 612D (one or more of which may be generally referred to as UEs 612) to the core network 606 over one or more wireless connections.

[0118] Example wireless communications over a wireless connection include transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 600 may include any number of wired or wireless networks, network nodes, UEs, and/or any other components or systems that may facilitate or participate in the communication of data and/or signals whether via wired or wireless connections. The communication system 600 may include and/or interface with any type of communication, telecommunication, data, cellular, radio network, and/or other similar type of system. [0119] The UEs 612 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and/or operable to communicate wirelessly with the network nodes 610 and other communication devices. Similarly, the network nodes 610 are arranged, capable, configured, and/or operable to communicate directly or indirectly with the UEs 612 and/or with other network nodes or equipment in the telecommunication network 602 to enable and/or provide network access, such as wireless network access, and/or to perform other functions, such as administration in the telecommunication network 602.

[0120] In the depicted example, the core network 606 connects the network nodes 610 to one or more hosts, such as host 616. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 606 includes one more core network nodes (e.g., core network node 608) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and/or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 608. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-Concealing Function (SIDE), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and/or a User Plane Function (UPF).

[0121] The host 616 may be under the ownership or control of a service provider other than an operator or provider of the access network 604 and/or the telecommunication network 602 and may be operated by the service provider or on behalf of the service provider. The host 616 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio/video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

[0122] As a whole, the communication system 600 of Figure 6 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system 600 may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and/or other suitable Second, Third, Fourth, or Fifth Generation (2G, 3G, 4G, or 5G) standards, or any applicable future generation standard (e.g., Sixth Generation (6G)); Wireless Local Area Network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and/or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and/or any Low Power Wide Area Network (LPWAN) standards such as LoRa and Sigfox.

[0123] In some examples, the telecommunication network 602 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunication network 602 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 602. For example, the telecommunication network 602 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing enhanced Mobile Broadband (eMBB) services to other UEs, and/or massive Machine Type Communication (mMTC)/massive Internet of Things (loT) services to yet further UEs.

[0124] In some examples, the UEs 612 are configured to transmit and/or receive information without direct human interaction. For instance, a UE may be designed to transmit information to the access network 604 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 604. Additionally, a UE may be configured for operating in single- or multi-Radio Access Technology (RAT) or multi-standard mode. For example, a UE may operate with any one or combination of WiFi, New Radio (NR), and LTE, i.e., be configured for Multi-Radio Dual Connectivity (MR-DC), such as Evolved UMTS Terrestrial RAN (E-UTRAN) NR - Dual Connectivity (EN-DC).

[0125] In the example, a hub 614 communicates with the access network 604 to facilitate indirect communication between one or more UEs (e.g., UE 612C and/or 612D) and network nodes (e.g., network node 610B). In some examples, the hub 614 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 614 may be a broadband router enabling access to the core network 606 for the UEs. As another example, the hub 614 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 610, or by executable code, script, process, or other instructions in the hub 614. As another example, the hub 614 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 614 may be a content source. For example, for a UE that is a Virtual Reality (VR) headset, display, loudspeaker or other media delivery device, the hub 614 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 614 then provides to the UE either directly, after performing local processing, and/or after adding additional local content. In still another example, the hub 614 acts as a proxy server or orchestrator for the UEs, in particular in if one or more of the UEs are low energy loT devices.

[0126] The hub 614 may have a constant/persistent or intermittent connection to the network node 61 OB. The hub 614 may also allow for a different communication scheme and/or schedule between the hub 614 and UEs (e.g., UE 612C and/or 612D), and between the hub 614 and the core network 606. In other examples, the hub 614 is connected to the core network 606 and/or one or more UEs via a wired connection. Moreover, the hub 614 may be configured to connect to a Machine-to-Machine (M2M) service provider over the access network 604 and/or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 610 while still connected via the hub 614 via a wired or wireless connection. In some embodiments, the hub 614 may be a dedicated hub - that is, a hub whose primary function is to route communications to/from the UEs from/to the network node 610B. In other embodiments, the hub 614 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and the network node 610B, but which is additionally capable of operating as a communication start and/or end point for certain data channels.

[0127] Figure 7 shows a UE 700 in accordance with some embodiments. As used herein, a UE refers to a device capable, configured, arranged, and/or operable to communicate wirelessly with network nodes and/or other UEs. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, Voice over Internet Protocol (VoIP) phone, wireless local loop phone, desktop computer, Personal Digital Assistant (PDA), wireless camera, gaming console or device, music storage device, playback appliance, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, Laptop Embedded Equipment (LEE), Laptop Mounted Equipment (LME), smart device, wireless Customer Premise Equipment (CPE), vehicle-mounted or vehicle embedded/integrated wireless device, etc. Other examples include any UE identified by the 3GPP, including a Narrowband Internet of Things (NB-IoT) UE, a Machine Type Communication (MTC) UE, and/or an enhanced MTC (eMTC) UE.

[0128] A UE may support Device-to-Device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), Vehicle-to- Vehicle (V2V), Vehicle-to-Infrastructure (V2I), or Vehicle- to-Everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user who owns and/or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller).

Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

[0129] The UE 700 includes processing circuitry 702 that is operatively coupled via a bus 704 to an input/output interface 706, a power source 708, memory 710, a communication interface 712, and/or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in Figure 7. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0130] The processing circuitry 702 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in the memory 710. The processing circuitry 702 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, Field Programmable Gate Arrays (FPGAs), Application Specific Integrated Circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general purpose processors, such as a microprocessor or Digital Signal Processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 702 may include multiple Central Processing Units (CPUs).

[0131] In the example, the input/output interface 706 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and/or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into the UE 700. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device. [0132] In some embodiments, the power source 708 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. The power source 708 may further include power circuitry for delivering power from the power source 708 itself, and/or an external power source, to the various parts of the UE 700 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging the power source 708. Power circuitry may perform any formatting, converting, or other modification to the power from the power source 708 to make the power suitable for the respective components of the UE 700 to which power is supplied.

[0133] The memory 710 may be or be configured to include memory such as Random Access Memory (RAM), Read Only Memory (ROM), Programmable ROM (PROM), Erasable PROM (EPROM), Electrically EPROM (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, the memory 710 includes one or more application programs 714, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 716. The memory 710 may store, for use by the UE 700, any of a variety of various operating systems or combinations of operating systems.

[0134] The memory 710 may be configured to include a number of physical drive units, such as Redundant Array of Independent Disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, High Density Digital Versatile Disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, Holographic Digital Data Storage (HDDS) optical disc drive, external mini Dual In-line Memory Module (DIMM), Synchronous Dynamic RAM (SDRAM), external micro-DIMM SDRAM, smartcard memory such as a tamper resistant module in the form of a Universal Integrated Circuit Card (UICC) including one or more Subscriber Identity Modules (SIMs), such as a Universal SIM (USIM) and/or Internet Protocol Multimedia Services Identity Module (ISIM), other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as a ‘SIM card.’ The memory 710 may allow the UE 700 to access instructions, application programs, and the like stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system, may be tangibly embodied as or in the memory 710, which may be or comprise a device-readable storage medium. [0135] The processing circuitry 702 may be configured to communicate with an access network or other network using the communication interface 712. The communication interface 712 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 722. The communication interface 712 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include a transmitter 718 and/or a receiver 720 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 718 and receiver 720 may be coupled to one or more antennas (e.g., the antenna 722) and may share circuit components, software, or firmware, or alternatively be implemented separately.

[0136] In the illustrated embodiment, communication functions of the communication interface 712 may include cellular communication, WiFi communication, LPWAN communication, data communication, voice communication, multimedia communication, short- range communications such as Bluetooth, NFC, 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 CDMA (WCDMA), GSM, LTE, NR, UMTS, WiMax, Ethernet, Transmission Control Protocol/Internet Protocol (TCP/IP), Synchronous Optical Networking (SONET), Asynchronous Transfer Mode (ATM), Quick User Datagram Protocol Internet Connection (QUIC), Hypertext Transfer Protocol (HTTP), and so forth.

[0137] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 712, or via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

[0138] As another example, a UE comprises an actuator, a motor, or a switch related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, the UE may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

[0139] A UE, when in the form of an loT device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application, and healthcare. Non-limiting examples of such an loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a television, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door/window sensor, a flood/moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a head-mounted display for Augmented Reality (AR) or VR, a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or itemtracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an loT device comprises circuitry and/or software in dependence of the intended application of the loT device in addition to other components as described in relation to the UE 700 shown in Figure 7.

[0140] As yet another specific example, in an loT scenario, a UE may represent a machine or other device that performs monitoring and/or measurements and transmits the results of such monitoring and/or measurements to another UE and/or a network node. The UE may in this case be an M2M device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3GPP NB-IoT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship, an airplane, or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation.

[0141] In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g., by controlling an actuator) to increase or decrease the drone’s speed. The first and/or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator and handle communication of data for both the speed sensor and the actuators. [0142] Figure 8 shows a network node 800 in accordance with some embodiments. As used herein, network node refers to equipment capable, configured, arranged, and/or operable to communicate directly or indirectly with a UE and/or with other network nodes or equipment in a telecommunication network. Examples of network nodes include, but are not limited to, APs (e.g., radio APs), Base Stations (BSs) (e.g., radio BSs, Node Bs, evolved Node Bs (eNBs), and NR Node Bs (gNBs)).

[0143] BSs may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto BSs, pico BSs, micro BSs, or macro BSs. A BS may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio BS such as centralized digital units and/or Remote Radio Units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such RRUs may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio BS may also be referred to as nodes in a Distributed Antenna System (DAS).

[0144] Other examples of network nodes include multiple Transmission Point (multi-TRP) 5G access nodes, Multi-Standard Radio (MSR) equipment such as MSR BSs, network controllers such as Radio Network Controllers (RNCs) or BS Controllers (BSCs), Base Transceiver Stations (BTSs), transmission points, transmission nodes, Multi-Cell/Multicast Coordination Entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and/or Minimization of Drive Tests (MDTs).

[0145] The network node 800 includes processing circuitry 802, memory 804, a communication interface 806, and a power source 808. The network node 800 may be composed of multiple physically separate components (e.g., a Node B component and an RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which the network node 800 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple Node Bs. In such a scenario, each unique Node B and RNC pair may in some instances be considered a single separate network node. In some embodiments, the network node 800 may be configured to support multiple RATs. In such embodiments, some components may be duplicated (e.g., separate memory 804 for different RATs) and some components may be reused (e.g., an antenna 810 may be shared by different RATs). The network node 800 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 800, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, Long Range Wide Area Network (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 the network node 800.

[0146] The processing circuitry 802 may comprise a combination of one or more of a microprocessor, controller, microcontroller, CPU, DSP, ASIC, FPGA, or any other suitable computing device, resource, or combination of hardware, software, and/or encoded logic operable to provide, either alone or in conjunction with other network node 800 components, such as the memory 804, to provide network node 800 functionality.

[0147] In some embodiments, the processing circuitry 802 includes a System on a Chip (SOC). In some embodiments, the processing circuitry 802 includes one or more of Radio Frequency (RF) transceiver circuitry 812 and baseband processing circuitry 814. In some embodiments, the RF transceiver circuitry 812 and the baseband processing circuitry 814 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of the RF transceiver circuitry 812 and the baseband processing circuitry 814 may be on the same chip or set of chips, boards, or units.

[0148] The memory 804 may comprise any form of volatile or non-volatile computer- readable memory including, without limitation, persistent storage, solid state memory, remotely mounted memory, magnetic media, optical media, RAM, ROM, mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD), or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non-transitory device-readable, and/or computer-executable memory devices that store information, data, and/or instructions that may be used by the processing circuitry 802. The memory 804 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and/or other instructions capable of being executed by the processing circuitry 802 and utilized by the network node 800. The memory 804 may be used to store any calculations made by the processing circuitry 802 and/or any data received via the communication interface 806. In some embodiments, the processing circuitry 802 and the memory 804 are integrated.

[0149] The communication interface 806 is used in wired or wireless communication of signaling and/or data between a network node, access network, and/or UE. As illustrated, the communication interface 806 comprises port(s)/terminal(s) 816 to send and receive data, for example to and from a network over a wired connection. The communication interface 806 also includes radio front-end circuitry 818 that may be coupled to, or in certain embodiments a part of, the antenna 810. The radio front-end circuitry 818 comprises filters 820 and amplifiers 822. The radio front-end circuitry 818 may be connected to the antenna 810 and the processing circuitry 802. The radio front-end circuitry 818 may be configured to condition signals communicated between the antenna 810 and the processing circuitry 802. The radio front-end circuitry 818 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. The radio front-end circuitry 818 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of the filters 820 and/or the amplifiers 822. The radio signal may then be transmitted via the antenna 810. Similarly, when receiving data, the antenna 810 may collect radio signals which are then converted into digital data by the radio front-end circuitry 818. The digital data may be passed to the processing circuitry 802. In other embodiments, the communication interface 806 may comprise different components and/or different combinations of components.

[0150] In certain alternative embodiments, the network node 800 does not include separate radio front-end circuitry 818; instead, the processing circuitry 802 includes radio front-end circuitry and is connected to the antenna 810. Similarly, in some embodiments, all or some of the RF transceiver circuitry 812 is part of the communication interface 806. In still other embodiments, the communication interface 806 includes the one or more ports or terminals 816, the radio front-end circuitry 818, and the RF transceiver circuitry 812 as part of a radio unit (not shown), and the communication interface 806 communicates with the baseband processing circuitry 814, which is part of a digital unit (not shown).

[0151] The antenna 810 may include one or more antennas, or antenna arrays, configured to send and/or receive wireless signals. The antenna 810 may be coupled to the radio front-end circuitry 818 and may be any type of antenna capable of transmitting and receiving data and/or signals wirelessly. In certain embodiments, the antenna 810 is separate from the network node 800 and connectable to the network node 800 through an interface or port.

[0152] The antenna 810, the communication interface 806, and/or the processing circuitry 802 may be configured to perform any receiving operations and/or certain obtaining operations described herein as being performed by the network node 800. Any information, data, and/or signals may be received from a UE, another network node, and/or any other network equipment. Similarly, the antenna 810, the communication interface 806, and/or the processing circuitry 802 may be configured to perform any transmitting operations described herein as being performed by the network node 800. Any information, data, and/or signals may be transmitted to a UE, another network node, and/or any other network equipment. [0153] The power source 808 provides power to the various components of the network node 800 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 808 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 800 with power for performing the functionality described herein. For example, the network node 800 may be connectable to an external power source (e.g., the power grid or an electricity outlet) via input circuitry or an interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 808. As a further example, the power source 808 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

[0154] Embodiments of the network node 800 may include additional components beyond those shown in Figure 8 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and/or any functionality necessary to support the subject matter described herein. For example, the network node 800 may include user interface equipment to allow input of information into the network node 800 and to allow output of information from the network node 800. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 800.

[0155] Figure 9 is a block diagram of a host 900, which may be an embodiment of the host 616 of Figure 6, in accordance with various aspects described herein. As used herein, the host 900 may be or comprise various combinations of hardware and/or software including a standalone server, a blade server, a cloud-implemented server, a distributed server, a virtual machine, container, or processing resources in a server farm. The host 900 may provide one or more services to one or more UEs.

[0156] The host 900 includes processing circuitry 902 that is operatively coupled via a bus 904 to an input/output interface 906, a network interface 908, a power source 910, and memory 912. Other components may be included in other embodiments. Features of these components may be substantially similar to those described with respect to the devices of previous figures, such as Figures 7 and 8, such that the descriptions thereof are generally applicable to the corresponding components of the host 900.

[0157] The memory 912 may include one or more computer programs including one or more host application programs 914 and data 916, which may include user data, e.g., data generated by a UE for the host 900 or data generated by the host 900 for a UE. Embodiments of the host 900 may utilize only a subset or all of the components shown. The host application programs 914 may be implemented in a container-based architecture and may provide support for video codecs (e.g., Versatile Video Coding (VVC), High Efficiency Video Coding (HEVC), Advanced Video Coding (AVC), Moving Picture Experts Group (MPEG), VP9) and audio codecs (e.g., Free Lossless Audio Codec (FLAC), Advanced Audio Coding (AAC), MPEG, G.711), including transcoding for multiple different classes, types, or implementations of UEs (e.g., handsets, desktop computers, wearable display systems, and heads-up display systems). The host application programs 914 may also provide for user authentication and licensing checks and may periodically report health, routes, and content availability to a central node, such as a device in or on the edge of a core network. Accordingly, the host 900 may select and/or indicate a different host for Over-The-Top (OTT) services for a UE. The host application programs 914 may support various protocols, such as the HTTP Live Streaming (HLS) protocol, Real-Time Messaging Protocol (RTMP), Real-Time Streaming Protocol (RTSP), Dynamic Adaptive Streaming over HTTP (DASH or MPEG-DASH), etc.

[0158] Figure 10 is a block diagram illustrating a virtualization environment 1000 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices, and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more Virtual Machines (VMs) implemented in one or more virtual environments 1000 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, UE, core network node, or host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized.

[0159] Applications 1002 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment 900 to implement some of the features, functions, and/or benefits of some of the embodiments disclosed herein.

[0160] Hardware 1004 includes processing circuitry, memory that stores software and/or instructions executable by hardware processing circuitry, and/or other hardware devices as described herein, such as a network interface, input/output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 1006 (also referred to as hypervisors or VM Monitors (VMMs)), provide VMs 1008A and 1008B (one or more of which may be generally referred to as VMs 1008), and/or perform any of the functions, features, and/or benefits described in relation with some embodiments described herein. The virtualization layer 1006 may present a virtual operating platform that appears like networking hardware to the VMs 1008.

[0161] The VMs 1008 comprise virtual processing, virtual memory, virtual networking, or interface and virtual storage, and may be run by a corresponding virtualization layer 1006. Different embodiments of the instance of a virtual appliance 1002 may be implemented on one or more of the VMs 1008, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as Network Function Virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers and customer premise equipment.

[0162] In the context of NFV, a VM 1008 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non- virtualized machine. Each of the VMs 1008, and that part of the hardware 1004 that executes that VM, be it hardware dedicated to that VM and/or hardware shared by that VM with others of the VMs 1008, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 1008 on top of the hardware 1004 and corresponds to the application 1002.

[0163] The hardware 1004 may be implemented in a standalone network node with generic or specific components. The hardware 1004 may implement some functions via virtualization. Alternatively, the hardware 1004 may be part of a larger cluster of hardware (e.g., such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration 1010, which, among others, oversees lifecycle management of the applications 1002. In some embodiments, the hardware 1004 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a RAN or a BS. In some embodiments, some signaling can be provided with the use of a control system 1012 which may alternatively be used for communication between hardware nodes and radio units.

[0164] Figure 11 shows a communication diagram of a host 1102 communicating via a network node 1104 with a UE 1106 over a partially wireless connection in accordance with some embodiments. Example implementations, in accordance with various embodiments, of the UE (such as the UE 612A of Figure 6 and/or the UE 700 of Figure 7), the network node (such as the network node 610A of Figure 6 and/or the network node 800 of Figure 8), and the host (such as the host 616 of Figure 6 and/or the host 900 of Figure 9) discussed in the preceding paragraphs will now be described with reference to Figure 11.

[0165] Eike the host 900, embodiments of the host 1102 include hardware, such as a communication interface, processing circuitry, and memory. The host 1102 also includes software, which is stored in or is accessible by the host 1102 and executable by the processing circuitry. The software includes a host application that may be operable to provide a service to a remote user, such as the UE 1106 connecting via an OTT connection 1150 extending between the UE 1106 and the host 1102. In providing the service to the remote user, a host application may provide user data which is transmitted using the OTT connection 1150.

[0166] The network node 1104 includes hardware enabling it to communicate with the host 1102 and the UE 1106 via a connection 1160. The connection 1160 may be direct or pass through a core network (like the core network 606 of Figure 6) and/or one or more other intermediate networks, such as one or more public, private, or hosted networks. For example, an intermediate network may be a backbone network or the Internet.

[0167] The UE 1106 includes hardware and software, which is stored in or accessible by the UE 1106 and executable by the UE’s processing circuitry. The software includes a client application, such as a web browser or operator-specific “app” that may be operable to provide a service to a human or non-human user via the UE 1106 with the support of the host 1102. In the host 1102, an executing host application may communicate with the executing client application via the OTT connection 1150 terminating at the UE 1106 and the host 1102. In providing the service to the user, the UE’s client application may receive request data from the host's host application and provide user data in response to the request data. The OTT connection 1150 may transfer both the request data and the user data. The UE’s client application may interact with the user to generate the user data that it provides to the host application through the OTT connection 1150.

[0168] The OTT connection 1150 may extend via the connection 1160 between the host 1102 and the network node 1104 and via a wireless connection 1170 between the network node 1104 and the UE 1106 to provide the connection between the host 1102 and the UE 1106. The connection 1160 and the wireless connection 1170, over which the OTT connection 1150 may be provided, have been drawn abstractly to illustrate the communication between the host 1102 and the UE 1106 via the network node 1104, without explicit reference to any intermediary devices and the precise routing of messages via these devices. [0169] As an example of transmitting data via the OTT connection 1150, in step 1108, the host 1102 provides user data, which may be performed by executing a host application. In some embodiments, the user data is associated with a particular human user interacting with the UE 1106. In other embodiments, the user data is associated with a UE 1106 that shares data with the host 1102 without explicit human interaction. In step 1110, the host 1102 initiates a transmission carrying the user data towards the UE 1106. The host 1102 may initiate the transmission responsive to a request transmitted by the UE 1106. The request may be caused by human interaction with the UE 1106 or by operation of the client application executing on the UE 1106. The transmission may pass via the network node 1104 in accordance with the teachings of the embodiments described throughout this disclosure. Accordingly, in step 1112, the network node 1104 transmits to the UE 1106 the user data that was carried in the transmission that the host 1102 initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step 1114, the UE 1106 receives the user data carried in the transmission, which may be performed by a client application executed on the UE 1106 associated with the host application executed by the host 1102.

[0170] In some examples, the UE 1106 executes a client application which provides user data to the host 1102. The user data may be provided in reaction or response to the data received from the host 1102. Accordingly, in step 1116, the UE 1106 may provide user data, which may be performed by executing the client application. In providing the user data, the client application may further consider user input received from the user via an input/output interface of the UE 1106. Regardless of the specific manner in which the user data was provided, the UE 1106 initiates, in step 1118, transmission of the user data towards the host 1102 via the network node 1104. In step 1120, in accordance with the teachings of the embodiments described throughout this disclosure, the network node 1104 receives user data from the UE 1106 and initiates transmission of the received user data towards the host 1102. In step 1122, the host 1102 receives the user data carried in the transmission initiated by the UE 1106.

[0171] One or more of the various embodiments improve the performance of OTT services provided to the UE 1106 using the OTT connection 1150, in which the wireless connection 1170 forms the last segment. More precisely, the teachings of these embodiments may improve the e.g., data rate, latency, power consumption, etc. and thereby provide benefits such as e.g., reduced user waiting time, relaxed restriction on file size, improved content resolution, better responsiveness, extended battery lifetime, etc.

[0172] In an example scenario, factory status information may be collected and analyzed by the host 1102. As another example, the host 1102 may process audio and video data which may have been retrieved from a UE for use in creating maps. As another example, the host 1102 may collect and analyze real-time data to assist in controlling vehicle congestion (e.g., controlling traffic lights). As another example, the host 1102 may store surveillance video uploaded by a UE. As another example, the host 1102 may store or control access to media content such as video, audio, VR, or AR which it can broadcast, multicast, or unicast to UEs. As other examples, the host 1102 may be used for energy pricing, remote control of non-time critical electrical load to balance power generation needs, location services, presentation services (such as compiling diagrams etc. from data collected from remote devices), or any other function of collecting, retrieving, storing, analyzing, and/or transmitting data.

[0173] In some examples, 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. There may further be an optional network functionality for reconfiguring the OTT connection 1150 between the host 1102 and the UE 1106 in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection 1150 may be implemented in software and hardware of the host 1102 and/or the UE 1106. In some embodiments, sensors (not shown) may be deployed in or in association with other devices through which the OTT connection 1150 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or by supplying values of other physical quantities from which software may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 1150 may include message format, retransmission settings, preferred routing, etc. ; the reconfiguring need not directly alter the operation of the network node 1104. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling that facilitates measurements of throughput, propagation times, latency, and the like by the host 1102. The measurements may be implemented in that software causes messages to be transmitted, in particular empty or ‘dummy’ messages, using the OTT connection 1150 while monitoring propagation times, errors, etc.

[0174] Although the computing devices described herein (e.g., UEs, network nodes, hosts) may include the illustrated combination of hardware components, other embodiments may comprise computing devices with different combinations of components. It is to be understood that these computing devices may comprise any suitable combination of hardware and/or software needed to perform the tasks, features, functions, and methods disclosed herein. Determining, calculating, obtaining, or similar operations described herein may be performed by processing circuitry, which may process information by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination. Moreover, while components are depicted as single boxes located within a larger box or nested within multiple boxes, in practice computing devices may comprise multiple different physical components that make up a single illustrated component, and functionality may be partitioned between separate components. For example, a communication interface may be configured to include any of the components described herein, and/or the functionality of the components may be partitioned between the processing circuitry and the communication interface. In another example, non-computationally intensive functions of any of such components may be implemented in software or firmware and computationally intensive functions may be implemented in hardware.

[0175] In certain embodiments, some or all of the functionality described herein may be provided by processing circuitry executing instructions stored in memory, which in certain embodiments may be a computer program product in the form of a non-transitory computer- readable storage medium. In alternative embodiments, some or all of the functionality may be provided by the processing circuitry without executing instructions stored on a separate or discrete device-readable storage medium, such as in a hardwired manner. In any of those particular embodiments, whether executing instructions stored on a non-transitory computer- readable storage medium or not, the processing circuitry can be configured to perform the described functionality. The benefits provided by such functionality are not limited to the processing circuitry alone or to other components of the computing device but are enjoyed by the computing device as a whole and/or by end users and a wireless network generally.

[0176] Some example embodiments of the present disclosure are as follows:

Group A Embodiments

[0177] Embodiment 1 : A method performed by a user equipment, UE, the method comprising one or more of:

• determining (500-B), e.g. by receiving a configuration for, a total number of DD basis vectors and/or a set of parameters including one or more of a number of spatial beams, number of FD basis vectors, and a number of DD basis vectors to be selected for Enhanced type II CSI report; • determining (502-B) a precoding matrix for each MIMO layer, comprising a set of nonzero coefficients (NZCs), based on one or more of determined spatial beams, FD basis vectors, and DD basis vectors;

• reporting (504-B) the CSI, wherein coefficients are ordered into priority groups, e.g., groups 0,1,2, which are arranged according to a priority order wherein the priority indexing follows the order where layers have the highest priority, the spatial beam related index has the second highest priority, the FD basis related index has the third or lowest priority, and the DD basis related index has the lowest or third priority; and/or

• in case that some part of Part 2 components needs to be dropped, Group 2 parameters are dropped first, then Group 1 and group 0 parameters are dropped last(506-B).

[0178] Embodiment 2: The method of the previous embodiment wherein there is one nonzero coefficient bitmap corresponding to each selected DD basis vector, of size 2LM_V, where L is the number selected spatial DFT vectors (or spatial beams), M_v is the number of selected FD basis vectors.

[0179] Embodiment 3: The method of any of the previous embodiments wherein there is a single bitmap for each layer, of size 2LM_V Q, where L is the number selected spatial DFT vectors (or spatial beams), M_v is the number of selected FD basis vectors, Q is he number of selected DD basis vectors.

Group B Embodiments

[0180] Embodiment 4: A method performed by a network node (e.g., a TRP), the method comprising one or more of:

• transmitting (500-C) a configuration for a total number of DD basis vectors and/or a set of parameters including one or more of a number of spatial beams, number of FD basis vectors, and a number of DD basis vectors to be selected for Enhanced type II CSI report;

• receiving (502-C) a CSI including a precoding matrix indicator corresponding to precoding matrices for each MIMO layer, comprising a set of non-zero coefficients (NZCs), based on one or more of determined spatial beams, FD basis vectors, and DD basis vectors;

• receiving (504-B) a CSI wherein coefficients are ordered into priority groups, e.g., groups 0,1,2, which are arranged according to a priority order wherein the priority indexing follows the order where layers have the highest priority, the spatial beam related index has the second highest priority, the FD basis related index has the third or lowest priority, and the DD basis related index has the lowest or third priority; and/or • in case that some part of Part 2 component needs to be dropped, Group 2 parameters are dropped first, then Group 1, and group 0 parameters are dropped last (506-C).

[0181] Embodiment 5: The method of the previous embodiment including any of the features of Group A Embodiments.

[0182] Embodiment 6: The method of any of the previous embodiments, further comprising: obtaining user data; and forwarding the user data to a host or a user equipment.

Group C Embodiments

[0183] Embodiment 7: A user equipment, comprising: processing circuitry configured to perform any of the steps of any of the Group A embodiments; and power supply circuitry configured to supply power to the processing circuitry.

[0184] Embodiment 8: A network node, the network node comprising: processing circuitry configured to perform any of the steps of any of the Group B embodiments; and power supply circuitry configured to supply power to the processing circuitry.

[0185] Embodiment 9: A user equipment (UE), the UE comprising: an antenna configured to send and receive wireless signals; radio front-end circuitry connected to the antenna and to processing circuitry, and configured to condition signals communicated between the antenna and the processing circuitry; the processing circuitry being configured to perform any of the steps of any of the Group A embodiments; an input interface connected to the processing circuitry and configured to allow input of information into the UE to be processed by the processing circuitry; an output interface connected to the processing circuitry and configured to output information from the UE that has been processed by the processing circuitry; and a battery connected to the processing circuitry and configured to supply power to the UE.

[0186] Embodiment 10: A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising: processing circuitry configured to provide user data; and a network interface configured to initiate transmission of the user data to a cellular network for transmission to a user equipment (UE), wherein the UE comprises a communication interface and processing circuitry, the communication interface and processing circuitry of the UE being configured to perform any of the steps of any of the Group A embodiments to receive the user data from the host.

[0187] Embodiment 11 : The host of the previous embodiment, wherein the cellular network further includes a network node configured to communicate with the UE to transmit the user data to the UE from the host. [0188] Embodiment 12: The host of the previous 2 embodiments, wherein: the processing circuitry of the host is configured to execute a host application, thereby providing the user data; and the host application is configured to interact with a client application executing on the UE, the client application being associated with the host application.

[0189] Embodiment 13: A method implemented by a host operating in a communication system that further includes a network node and a user equipment (UE), the method comprising: providing user data for the UE; and initiating a transmission carrying the user data to the UE via a cellular network comprising the network node, wherein the UE performs any of the operations of any of the Group A embodiments to receive the user data from the host.

[0190] Embodiment 14: The method of the previous embodiment, further comprising: at the host, executing a host application associated with a client application executing on the UE to receive the user data from the UE.

[0191] Embodiment 15: The method of the previous embodiment, further comprising: at the host, transmitting input data to the client application executing on the UE, the input data being provided by executing the host application, wherein the user data is provided by the client application in response to the input data from the host application.

[0192] Embodiment 16: A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising: processing circuitry configured to provide user data; and a network interface configured to initiate transmission of the user data to a cellular network for transmission to a user equipment (UE), wherein the UE comprises a communication interface and processing circuitry, the communication interface and processing circuitry of the UE being configured to perform any of the steps of any of the Group A embodiments to transmit the user data to the host.

[0193] Embodiment 17: The host of the previous embodiment, wherein the cellular network further includes a network node configured to communicate with the UE to transmit the user data from the UE to the host.

[0194] Embodiment 18: The host of the previous 2 embodiments, wherein: the processing circuitry of the host is configured to execute a host application, thereby providing the user data; and the host application is configured to interact with a client application executing on the UE, the client application being associated with the host application.

[0195] Embodiment 19: A method implemented by a host configured to operate in a communication system that further includes a network node and a user equipment (UE), the method comprising: at the host, receiving user data transmitted to the host via the network node by the UE, wherein the UE performs any of the steps of any of the Group A embodiments to transmit the user data to the host.

[0196] Embodiment 20: The method of the previous embodiment, further comprising: at the host, executing a host application associated with a client application executing on the UE to receive the user data from the UE.

[0197] Embodiment 21: The method of the previous embodiment, further comprising: at the host, transmitting input data to the client application executing on the UE, the input data being provided by executing the host application, wherein the user data is provided by the client application in response to the input data from the host application.

[0198] Embodiment 22: A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising: processing circuitry configured to provide user data; and a network interface configured to initiate transmission of the user data to a network node in a cellular network for transmission to a user equipment (UE), the network node having a communication interface and processing circuitry, the processing circuitry of the network node configured to perform any of the operations of any of the Group B embodiments to transmit the user data from the host to the UE.

[0199] Embodiment 23: The host of the previous embodiment, wherein: the processing circuitry of the host is configured to execute a host application that provides the user data; and the UE comprises processing circuitry configured to execute a client application associated with the host application to receive the transmission of user data from the host.

[0200] Embodiment 24: A method implemented in a host configured to operate in a communication system that further includes a network node and a user equipment (UE), the method comprising: providing user data for the UE; and initiating a transmission carrying the user data to the UE via a cellular network comprising the network node, wherein the network node performs any of the operations of any of the Group B embodiments to transmit the user data from the host to the UE.

[0201] Embodiment 25: The method of the previous embodiment, further comprising, at the network node, transmitting the user data provided by the host for the UE.

[0202] Embodiment 26: The method of any of the previous 2 embodiments, wherein the user data is provided at the host by executing a host application that interacts with a client application executing on the UE, the client application being associated with the host application.

[0203] Embodiment 27: A communication system configured to provide an over-the-top service, the communication system comprising a host comprising: processing circuitry configured to provide user data for a user equipment (UE), the user data being associated with the over-the-top service; and a network interface configured to initiate transmission of the user data toward a cellular network node for transmission to the UE, the network node having a communication interface and processing circuitry, the processing circuitry of the network node configured to perform any of the operations of any of the Group B embodiments to transmit the user data from the host to the UE.

[0204] Embodiment 28: The communication system of the previous embodiment, further comprising: the network node; and/or the user equipment.

[0205] Embodiment 29: A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising: processing circuitry configured to initiate receipt of user data; and a network interface configured to receive the user data from a network node in a cellular network, the network node having a communication interface and processing circuitry, the processing circuitry of the network node configured to perform any of the operations of any of the Group B embodiments to receive the user data from a user equipment (UE) for the host.

[0206] Embodiment 30: The host of the previous 2 embodiments, wherein: the processing circuitry of the host is configured to execute a host application, thereby providing the user data; and the host application is configured to interact with a client application executing on the UE, the client application being associated with the host application.

[0207] Embodiment 31: The host of the any of the previous 2 embodiments, wherein the initiating receipt of the user data comprises requesting the user data.

[0208] Embodiment 32: A method implemented by a host configured to operate in a communication system that further includes a network node and a user equipment (UE), the method comprising: at the host, initiating receipt of user data from the UE, the user data originating from a transmission which the network node has received from the UE, wherein the network node performs any of the steps of any of the Group B embodiments to receive the user data from the UE for the host.

[0209] Embodiment 33: The method of the previous embodiment, further comprising at the network node, transmitting the received user data to the host.

[0210] Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.

Claims

Claims

1. A method performed by a user equipment, UE, the method comprising: receiving (5000-A; 500-B) a Channel State Information, CSI, report configuration for predicted precoder matrix indication, PMI, wherein the configuration comprises an indication of one or more non-zero power CSI reference signals, NZP CSI-RS, resources for channel measurement; determining (504-A; 502-B) Channel State Information, CSI, to be reported, wherein the CSI comprises at least a rank indicator, RI, indicating a number of Multiple Input Multiple Output, MIMO, transmission layers, and a PMI, wherein the PMI comprises information about one or more spatial beams or spatial domain basis vectors, information about one or more Frequency Domain, FD, basis vectors for each of the number of MIMO transmission layers, and information about one or more Doppler Domain, DD, basis vectors for each of the number of MIMO transmission layers, wherein the PMI further comprises information for determining a set of non-zero coefficients, NZCs, wherein each of the NZCs is associated to one of the number of MIMO transmission layers, one of the one or more spatial beams, one of the one or more FD basis vectors for the one of the number of MIMO transmission layers, and one of the one or more DD basis vectors for the one of the number of MIMO transmission layers; reporting (504-B) the CSI, wherein: coefficients comprised in the set of NZCs are each indexed by a MIMO layer related index, a spatial beam related index, a FD basis related index, and a DD related index; and each of the coefficients is assigned a priority in accordance with a priority order, from high to low, given in increasing order of first the MIMO layer related index over the number of MIMO layers, second the spatial beam related index, third the FD basis related index, and fourth the DD basis related index.

2. The method of claim 1, wherein the one or more spatial beams, the one or more FD basis vectors, and the one or more DD basis vectors are determined based on channel measurements based on the one or more NZP CSI-RS resources for channel measurement.

3. The method of claim 1 or 2, wherein the PMI further comprises a bitmap for each of the number of MIMO layers, wherein bits in the bitmap are each indexed by the MIMO layer related index, the spatial beam related index, the FD basis related index, and the DD related index, and each bit in the bitmap is associated to a coefficient with the same indices and is used to indicate whether the coefficient is a zero or non-zero coefficient.

4. The method of claim 3, wherein each of the bits in the bitmap is assigned a priority in accordance with a priority order, from high to low, given in increasing order of first the MIMO layer related index over the number of MIMO layers, second the spatial beam related index, third the FD basis related index, and fourth the DD basis related index.

5. The method of any of claims 1 to 4, wherein each of the NZCs comprises an amplitude and phase factor.

6. The method of any of claims 1 to 5, wherein the one or more Frequency Domain, FD, basis vectors are common for the number of MIMO layers.

7. The method of any of claims 1 to 6, wherein the coefficients comprised in the set of NZCs that are comprised in the PMI for the one or more MIMO layers are arranged according to their assigned priorities into different priority groups.

8. The method of claim 7, wherein, if needed, the coefficients in the different priority groups are omitted (506-B) from the reported CSI, starting with the priority group having a lowest priority first.

9. The method of claim 7, further comprising omitting (506-B) the coefficients in one or more of the different priority groups in order of priorities assigned to the different priority groups starting with one of the different priority groups having a lowest priority first.

10. The method of claim 1, wherein the CSI further comprises a channel quality indicator, and an indication of an overall number of NZCs across the one or more MIMO layers.

11. The method of claim 10, wherein the CSI is divided into a first part and a second part, wherein: the first part comprises the rank indicator, the channel quality indicator, and the indication of an overall number of NZCs across the one or more MIMO layers; and the second part comprises multiple priority groups, wherein the coefficients in the set of NZCs that are comprised in the PMI are arranged into the multiple priority groups based on the priorities assigned to the coefficients.

12. The method of claim 11, wherein, if needed, the coefficients in at least one of the multiple priority groups of the second part of the CSI are omitted (506-B) from the reported CSI, starting with the priority group having a lowest priority first.

13. The method of claim 11, further comprising omitting (506-B) at least one of the multiple priority groups in the second part of the CSI in order of priorities assigned to the multiple priority groups starting with one of the multiple priority groups having a lowest priority first.

14. The method of any of claims 11 to 13, wherein: a first priority group from among the multiple priority groups having a highest priority comprises spatial beam related indices that indicate the one or more spatial beams and, for each MIMO layer, an indication of a strongest coefficient; a second priority group from among the multiple priority groups having a second highest priority comprises information that indicates, for each MIMO layer, the one or more FD basis vectors and the one or more DD basis vectors; the second priority group further comprises, for each MIMO layer, a first subset of the set of NZCs comprised in the precoding matrix indicator; and a third priority group from among the multiple priority groups having a third highest priority comprises, a second subset of the set of NZCs comprised in the precoding matrix indicator, wherein the coefficients in the second subset of the set of NZCs have lower priority than the coefficients in the first subset of the set of NZCs.

15. The method of any of claims 1 to 14, further comprising receiving (500-B), from a network node, a configuration of:

(a) a total number of DD basis vectors to be used for the CSI; or

(b) a set of parameters comprising: (i) a number of spatial beams, (ii) number of FD basis vectors, (iii) a number of DD basis vectors, or (iv) any one or more of (i)- (iii), to be used for the CSI; or

(c) both (a) and (b);

16. The method of any of claims 1 to 15, wherein the precoding matrix indicator further comprises a single NZC bitmap of size 2LM_V Q for each of the number of MIMO layers, where L is the number of spatial beams, M_v is the number of FD basis vectors, and Q is the number of DD basis vectors.

17. The method of any of claims 1 to 15, wherein the precoding matrix indicator further comprises, for each of the number of MIMO layers, a separate NZC bitmap corresponding to each of the one or more DD basis vectors, wherein each NZC bitmap is of size 2LM_V, where L is the number of spatial beams and M_v is the number of FD basis vectors.

18. A user equipment, UE, adapted to: receive (5000-A; 500-B) a Channel State Information, CSI, report configuration for predicted precoder matrix indication, PMI, wherein the configuration comprises an indication of one or more non-zero power CSI reference signals, NZP CSI-RS, resources for channel measurement; determine (504-A; 502-B) Channel State Information, CSI, to be reported, wherein the CSI comprises at least a rank indicator, RI, indicating a number of Multiple Input Multiple Output, MIMO, transmission layers, and a PMI, wherein the PMI comprises information about one or more spatial beams or spatial domain basis vectors, information about one or more Frequency Domain, FD, basis vectors for each of the number of MIMO transmission layers, and information about one or more Doppler Domain, DD, basis vectors for each of the number of MIMO transmission layers, wherein the PMI further comprises information for determining a set of non-zero coefficients, NZCs, wherein each of the NZCs is associated to one of the number of MIMO transmission layers, one of the one or more spatial beams, one of the one or more FD basis vectors for the one of the number of MIMO transmission layers, and one of the one or more DD basis vectors for the one of the number of MIMO transmission layers; report (504-B) the CSI, wherein: coefficients comprised in the set of NZCs are each indexed by a MIMO layer related index, a spatial beam related index, a FD basis related index, and a DD related index; and each of the coefficients is assigned a priority in accordance with a priority order, from high to low, given in increasing order of first the MIMO layer related index over the number of MIMO layers, second the spatial beam related index, third the FD basis related index, and fourth the DD basis related index.

19. The UE of claim 18 further adapted to perform the method of any of claims 2 to 17.

20. A user equipment, UE, (700) comprising: a communication interface (712) comprising a transmitter (718) and a receiver (720); and processing circuitry (702) associated with the communication interface (712), the processing circuitry (702) configured to cause the UE (700) to: receive (5000-A; 500-B) a Channel State Information, CSI, report configuration for predicted precoder matrix indication, PMI, wherein the configuration comprises an indication of one or more non-zero power CSI reference signals, NZP CSI-RS, resources for channel measurement; determine (504-A; 502-B) Channel State Information, CSI, to be reported, wherein the CSI comprises at least a rank indicator, RI, indicating a number of Multiple Input Multiple Output, MIMO, transmission layers, and a PMI, wherein the PMI comprises information about one or more spatial beams or spatial domain basis vectors, information about one or more Frequency Domain, FD, basis vectors for each of the number of MIMO transmission layers, and information about one or more Doppler Domain, DD, basis vectors for each of the number of MIMO transmission layers, wherein the PMI further comprises information for determining a set of non-zero coefficients, NZCs, wherein each of the NZCs is associated to one of the number of MIMO transmission layers, one of the one or more spatial beams, one of the one or more FD basis vectors for the one of the number of MIMO transmission layers, and one of the one or more DD basis vectors for the one of the number of MIMO transmission layers; report (504-B) the CSI, wherein: coefficients comprised in the set of NZCs are each indexed by a MIMO layer related index, a spatial beam related index, a FD basis related index, and a DD related index; and each of the coefficients is assigned a priority in accordance with a priority order, from high to low, given in increasing order of first the MIMO layer related index over the number of MIMO layers, second the spatial beam related index, third the FD basis related index, and fourth the DD basis related index.

21. The UE of claim 20, wherein the processing circuitry (702) is further configured to cause the UE (700) to perform the method of any of claims 2 to 17.

22. A method performed by a network node, the method comprising: transmitting (500-A; 500-C) a Channel State Information, CSI, report configuration for predicted precoder matrix indication, PMI, to a User Equipment, UE, wherein the configuration comprising an indication of one or more non-zero power CSI reference signals, NZP CSI-RS, resources for channel measurement; and receiving (506-A; 502-C) a report of Channel State Information, CSI, from the UE, wherein the CSI comprises at least a rank indicator, RI, indicating a number of Multiple Input Multiple Output, MIMO, transmission layers, and a PMI, wherein: the PMI comprises information about one or more spatial beams or spatial domain basis vectors, information about one or more Frequency Domain, FD, basis vectors for each of the number of MIMO transmission layers, and information about one or more Doppler Domain, DD, basis vectors for each of the number of MIMO transmission layers; the PMI further comprises information for determining a set of non-zero coefficients, NZCs, wherein each of the NZCs is associated to one of the number of MIMO transmission layers, one of the one or more spatial beams, one of the one or more FD basis vectors for the one of the number of MIMO transmission layers, and one of the one or more DD basis vectors for the one of the number of MIMO transmission layers; coefficients comprised in the set of NZCs are each indexed by a MIMO layer related index, a spatial beam related index, a FD basis related index, and a DD related index; and each of the coefficients is assigned a priority in accordance with a priority order, from high to low, given in increasing order of first the MIMO layer related index over the number of MIMO layers, second the spatial beam related index, third the FD basis related index, and fourth the DD basis related index.

23. A network node adapted to: transmit (500-A; 500-C) a Channel State Information, CSI, report configuration for predicted precoder matrix indication, PMI, to a User Equipment, UE, wherein the configuration comprising an indication of one or more non-zero power CSI reference signals, NZP CSI-RS, resources for channel measurement; and receive (506-A; 502-C) a report of Channel State Information, CSI, from the UE, wherein the CSI comprises at least a rank indicator, RI, indicating a number of Multiple Input Multiple Output, MIMO, transmission layers, and a PMI, wherein: the PMI comprises information about one or more spatial beams or spatial domain basis vectors, information about one or more Frequency Domain, FD, basis vectors for each of the number of MIMO transmission layers, and information about one or more Doppler Domain, DD, basis vectors for each of the number of MIMO transmission layers; the PMI further comprises information for determining a set of non-zero coefficients, NZCs, wherein each of the NZCs is associated to one of the number of MIMO transmission layers, one of the one or more spatial beams, one of the one or more FD basis vectors for the one of the number of MIMO transmission layers, and one of the one or more DD basis vectors for the one of the number of MIMO transmission layers; coefficients comprised in the set of NZCs are each indexed by a MIMO layer related index, a spatial beam related index, a FD basis related index, and a DD related index; and each of the coefficients is assigned a priority in accordance with a priority order, from high to low, given in increasing order of first the MIMO layer related index over the number of MIMO layers, second the spatial beam related index, third the FD basis related index, and fourth the DD basis related index.

24. A network node comprising processing circuitry configured to cause the network node to: transmit (500-A; 500-C) a Channel State Information, CSI, report configuration for predicted precoder matrix indication, PMI, to a User Equipment, UE, wherein the configuration comprising an indication of one or more non-zero power CSI reference signals, NZP CSI-RS, resources for channel measurement; and receive (506-A; 502-C) a report of Channel State Information, CSI, from the UE, wherein the CSI comprises at least a rank indicator, RI, indicating a number of Multiple Input Multiple Output, MIMO, transmission layers, and a PMI, wherein: the PMI comprises information about one or more spatial beams or spatial domain basis vectors, information about one or more Frequency Domain, FD, basis vectors for each of the number of MIMO transmission layers, and information about one or more Doppler Domain, DD, basis vectors for each of the number of MIMO transmission layers; the PMI further comprises information for determining a set of non-zero coefficients, NZCs, wherein each of the NZCs is associated to one of the number of MIMO transmission layers, one of the one or more spatial beams, one of the one or more FD basis vectors for the one of the number of MIMO transmission layers, and one of the one or more DD basis vectors for the one of the number of MIMO transmission layers; coefficients comprised in the set of NZCs are each indexed by a MIMO layer related index, a spatial beam related index, a FD basis related index, and a DD related index; and each of the coefficients is assigned a priority in accordance with a priority order, from high to low, given in increasing order of first the MIMO layer related index over the number of MIMO layers, second the spatial beam related index, third the FD basis related index, and fourth the DD basis related index.