Predictive csi enhancements for high speed scenarios

Abstract

The present disclosure relates to predictive CSI enhancement for high speed scenarios. Apparatuses and methods are provided for a user equipment (UE) to report channel state information (CSI) to a base station. The UE sends UE capability signaling to the base station to indicate support for a codebook for high speed scenarios. The UE processes configuration information from the base station for CSI reporting using the codebook. The configuration information indicates measurement resources for one or more downlink (DL) channels. The UE measures channel responses and interference using the measurement resources, generates CSI feedback for at least one ray from the base station to the UE using the codebook, and reports the CSI feedback to the base station.

Description

TECHNICAL FIELD

[0001] The present application relates generally to wireless communication systems, including channel state information (CSI) feedback. BACKGROUND

[0002] Wireless mobile communication technology uses various standards and protocols to transmit data between base stations and wireless communication devices. Wireless communication system standards and protocols can include, for example, the Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) (such as 4G), 3GPP New Radio (NR) (such as 5G), and IEEE 802.11 standards (commonly referred to as Wi-Fi® within the industry organization) for wireless local area networks (WLANs).

[0003] As contemplated by 3GPP, different wireless communication system standards and protocols can use various radio access networks (RANs) to enable base stations of the RAN (which can also be referred to at times as a RAN node, network node, or simply a node) to communicate with wireless communication devices referred to as user equipment (UE). 3GPP RANs can include, for example, Global System for Mobile Communications (GSM), Enhanced Data Rates for GSM Evolution (EDGE) RAN (GERAN), Universal Terrestrial Radio Access Network (UTRAN), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), and / or Next Generation Radio Access Network (NG-RAN).

[0004] Each RAN can use one or more radio access technologies (RATs) for communication between base stations and UEs. For example, GERAN implements GSM and / or EDGE RAT, UTRAN implements Universal Mobile Telecommunications System (UMTS) RAT or other 3GPP RAT, E-UTRAN implements LTE RAT (which is sometimes referred to simply as LTE), and NG-RAN implements NR RAT (which is sometimes referred to herein as 5G RAT, 5G NR RAT, or simply NR). In certain deployments, E-UTRAN can also implement NR RAT. In certain deployments, NG-RAN can also implement LTE RAT.

[0005] A base station used by a RAN can correspond to that RAN. One example of an E-UTRAN base station is an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B (also commonly denoted as an Evolved Node B, Enhanced Node B, eNodeB, or eNB). One example of an NG-RAN base station is a Next Generation Node B (sometimes also referred to as a gNodeB or gNB).

[0006] ​The RAN, through its connection to the core network (CN), together with the external entities, provides communication services to the users. For example, an E-UTRAN can utilize an Evolved Packet Core (EPC), while a NG-RAN can utilize a 5G Core (5GC). BRIEF DESCRIPTION OF DRAWINGS

[0007] To facilitate discussion, one or more of the most significant digits in a reference number refers to the drawing figure in which the element was first introduced.

[0008] FIG. 1 An example antenna structure for a gNB is shown in accordance with one embodiment.

[0009] FIG. 2 An example of spatial beam selection is shown in accordance with one embodiment.

[0010] FIG. 3 A conceptual design for a CSI precoder is shown in accordance with certain embodiments.

[0011] FIG. 4 An example variation of spatial beams is shown in accordance with one embodiment.

[0012] FIG. 5 An example variation of relative delay and / or frequency offset is shown in accordance with one embodiment.

[0013] FIG. 6 is a flow diagram illustrating a method for CSI reporting with a new codebook design in accordance with one embodiment.

[0014] FIG. 7 Constraints between parameters of a wireless channel / precoder are shown in accordance with one embodiment.

[0015] FIG. 8 is a flow diagram of a method for a UE to report CSI to a base station in accordance with one embodiment.

[0016] FIG. 9 is a flow diagram of a method for a base station to configure a UE to report CSI in accordance with one embodiment.

[0017] FIG. 10 A non-terrestrial network (NTN) architecture for a wireless communication system is shown in accordance with one embodiment.

[0018] FIG. 11 An NTN architecture for a wireless communication system is shown in accordance with one embodiment.

[0019] FIG. 12 An example architecture for a wireless communication system in accordance with the embodiments disclosed herein is shown.

[0020] FIG. 13 A system for performing signaling between a wireless device and a RAN device connected with a core network of a CN device is shown in accordance with the embodiments disclosed herein. DETAILED DESCRIPTION

[0021] Embodiments are described in terms of UEs. However, references to UEs are provided for illustrative purposes only. Exemplary embodiments can be used with any electronic component that can establish a connection with a network and is configured with hardware, software, and / or firmware for exchanging information and data with the network. Thus, a UE as described herein is used to represent any appropriate electronic component.

[0022] For 3GPP Release 18 (Rel-18), predictive channel state information (CSI) has been proposed to handle high-speed scenarios where high-resolution CSI feedback can be used for multi-user multiple-input and multiple-output (MU-MIMO) pairing. However, the CSI can age due to movement of the transmitter, receiver, or the propagation environment. CSI aging can also occur due to changes in interference. For example, interference can change when there is strong interference present during CSI measurement, but no longer present during physical downlink shared channel (PDSCH) transmission. As another example, strong interference present during PDSCH transmission can not be present during CSI measurement.

[0023] In a first enhancement (Enhancement 1), for channel variations fast enough that the regular CSI feedback scheme from 3GPP Rel-15 / 16 / 17 breaks down, Doppler domain compression can be considered. In addition to the delay domain (which is utilized in 3GPP Rel-16 and Rel-17), the Doppler domain is considered as well, and the basic framework as used in 3GPP Rel-15 / 16 / 17 is more or less maintained.

[0024] However, in a second enhancement (Enhancement 2), for very high-speed scenarios such as using high-altitude platform systems (HAPS) or satellites of gNBs, the model can no longer be valid.

[0025] Example antenna structure for gNB

[0026] FIG. 1 An exemplary antenna structure of a gNB is shown. As shown, regular antennas are placed on a base station antenna array that includes antennas with polarization 0 and antennas with polarization 1 (e.g., +45° and -45°).

[0027] Rel-16 design of Type II codebook

[0028] 3GPP Rel-16 Type II codebook can have the following form:

[0029]

[0030] where p is a polarization index (e.g., P = 0 for a polarization at +45°, and p = 1 for a polarization at -45°), there are B0significant beams for Tx antennas at polarization index 0, and there are B1significant beams for Tx antennas at polarization index 1. For a polarization index p in a three-dimensional coordinate system with zenith angle θ and azimuth angle φ (e.g., θ = 0° points to zenith, and θ = 90° points to the horizontal line), b is a ray index of a ray with exit angle (θ b,p ,φ b,p ), A(θ b,p ,φ b,p ) is an array response to (θ, φ), τ b,p is a relative delay, and a b is a path gain (e.g., using a ray tracing algorithm) including amplitude and phase with respect to ray index b. Assuming a regular antenna element arrangement, (θ b,p ,φ b,p ) can be mapped to (i1, i2, p1, p2), where p1, 0 ≤ p1≤ O1-1 and p2, 0 ≤ p2≤ O2-1 are oversampling factors for vertical and horizontal domains, respectively, and (i1, i2) is a spatial beam index.

[0031] Codebook construction

[0032] The precoder for a layer is given by a P x N3size matrix (for simplicity, also referred to herein as W = W1*W2*W f or W = W1W2Wf), where W is the PMI matrix, W1corresponds to spatial beam selection, corresponds to bitmap design and quantizer design, and corresponds to frequency domain (FD) component selection. P = 2N1N2= spatial domain (SD) dimension. N3= FD dimension. Precoder normalization corresponds to precoding matrix normalization to norm 1 / sqrt(rank) for a given rank and unit.

[0033] For SD compression, L spatial domain basis vectors are selected (mapped to two polarizations, thus 2L in total). Compression in the spatial domain uses where is an N1N2x 1 orthogonal discrete Fourier transform (DFT) vector (e.g., as in Rel-15 Type II).

[0034] For FD compression, compression is via where are M N3x1 size orthogonal DFT vectors. The number of FD components M can be configurable.

[0035] For polar common spatial beam selection, L and M can be configured by the gNB.

[0036] Spatial beam selection

[0037] FIG. 2 An example of spatial beam selection is shown in accordance with certain embodiments. In this example, N1 corresponds to the number of antenna columns at the base station, N2 corresponds to the number of antenna rows at the base station, O1 is a first oversampling factor, O2 is a second oversampling factor, k is a first direction, l is a second direction, n1 denotes a group in the k direction, and n2 denotes a group in the l direction. Spatial beam index (i1, i2) can be used to select a main direction, and spatial beam index (q1, q2) can be used to fine tune the direction. To achieve an orthogonal basis, the same (q1, q2) is used for all selected spatial beams.

[0038] Rel-18 precoder design for enhancement 1

[0039] FIG. 3 A conceptual design for 3GPP Rel-18 CSI precoder design for enhancement 1 is shown in accordance with certain embodiments. As shown, the 3GPP Rel-18 precoder design for enhancement 1 includes a “delta” that is superior to the 3GPP Rel-16 design discussed above. Also shown are the strongest LC coefficients, spatial beams, frequency offsets, and relative delay amounts. In certain such embodiments, all amounts such as delta delay, delta frequency offset, and spatial beams are considered to be constants.

[0040] Rel-18 precoder design for enhancement 2

[0041] FIG. 3 A conceptual design for 3GPP Rel-18 CSI precoder design for enhancement 2 is also shown in accordance with certain embodiments. The 3GPP Rel-18 precoder design for enhancement 2 also includes a “delta” that is superior to the 3GPP Rel-16 design discussed above. Also shown are the time function for high speed scenarios. In certain such embodiments, all amounts such as delta delay, delta frequency offset, and spatial beams are considered to be time functions.

[0042] Variation of spatial beams

[0043] FIG. 4Exemplary variations of spatial beams are shown, according to certain embodiments. In this example, N1 corresponds to the number of antenna columns at the base station, N2 corresponds to the number of antenna rows at the base station, O1 is a first oversampling factor, O2 is a second oversampling factor, k is a first direction, 1 is a second direction, n1 denotes a group in the k direction, and n2 denotes a group in the 1 direction. A spatial beam index (i1, i2) can be used to select a main direction, and a spatial beam index (q1, q2) can be used to fine tune the direction. To achieve an orthogonal basis, the same (q1, q2) is used for all selected spatial beams.

[0044] In FIG. 4 the illustration, it is shown that initially, four spatial beams capture a significant amount of power transmitted from the base station. After a while, the spatial beams capture a majority of the power as indicated by the arrow moves to a new beam.

[0045] Variation of relative delay / frequency offset

[0046] In FIG. 5 the illustration, exemplary variations of relative delay and / or frequency offset are shown, according to certain embodiments, for a signal from the base station 502 to the UE 504. In the illustration, it is shown that the path from the base station 502 to reach the UE 504 (directly or via the reflector 506) initially follows the solid line, and after a while, follows the dashed line. The total path length can change as a result of this, which results in a change in the relative delay. The Doppler shift can also change as a result of the change in the angle of departure and the angle of arrival at the UE, which results in a change in the frequency offset.

[0047] Variation model

[0048] Certain embodiments model variations in spatial beams, relative delay, relative frequency offset. The base station can then track these variations. For example, in one embodiment, the following linear model can be utilized to model spatial beam variations: (θ b,p + Δθ b,p. t, φ b,p + Δφ b,p. t). As another example, in one embodiment, the following linear model can be utilized to model relative delay: τ b,p + Δτ b,p. t. As yet another example, in one embodiment, the following linear model can be utilized to model relative frequency offset: f b,p + Δf b,p. t.

[0049] FIG. 6is a flow diagram illustrating a method for CSI reporting with a new codebook design according to one embodiment. The illustrated process flow between a gNB 602 (or other base station) and a UE 604 is provided to cover modeling and feedback of any spatial beams, relative delays, or relative frequency offsets. As shown, the UE 604 reports a capability (e.g., RRC signaling) to support the new codebook design. The gNB 602 configures the UE for CSI reporting with the new codebook. The configuration of the CSI feedback report can include CSI measurement resources for desired channels and interference (which can be used to determine the number of ports for the new codebook), CSI feedback periodicity and offset for periodic and semi-persistent CSI feedback, trigger state links for the gNB to trigger CSI reporting with the new codebook, and / or a maximum number of rays included in the CSI feedback.

[0050] The UE 604 then performs CSI reporting with the new codebook. For example, the UE measures the channel response / interference with the CSI measurement resources. For at least one ray, the UE reports one or more components as follows: one component is at least one angle of departure and a rate of change of the angle of departure; one component is a relative delay of the ray and a rate of change of the relative delay of the ray; and / or one component is a relative frequency offset of the ray and a rate of change of the relative frequency offset of the ray. The UE can report one or more components for N rays: the UE can report a maximum number of N; and / or the UE can report N.

[0051] Further example embodiments

[0052] Certain embodiments disclosed herein introduce parameters to model in terms of spatial beams, delays, Doppler shifts due to movement of the UE, movement of the base station, or movement of reflectors.

[0053] For NTN, some companies have proposed predictive CSI. Certain embodiments disclosed herein consider extending Type-II CSI reporting to high-speed scenarios such as encountered in NTN.

[0054] For example, consider a high-speed train scenario, i.e., a train moving between two towers, then the delay taps tend to concentrate around two clusters due to transmissions from the two towers, and the Doppler spreads at the two clusters also tend to correspond to transmissions from the two towers. Thus, the constraints introduced in 3GPP Rel-16 for N3>19 can not be suitable for those cases. Separate indication of FD component selection and TD component selection or joint selection of FD / TD components can be considered.

[0055] Then, there can be two clusters for FD components and two clusters for TD components, then the framework from Rel-16 can be replicated, with one center around 0 and the other center around another FD component. Similar TD component selection can be performed.

[0056] Another alternative is to use a bitmap for FD component selection and a bitmap for TD component selection, the bitmaps providing flexible selection of FD / TD components with two or more clusters, however the signaling overhead can be more than a more constrained design.

[0057] When the UE moves (or the main reflector moves), the angle of departure from the gNB, the delay with significant taps, and the Doppler shift can change. The Doppler shift change can be modeled as a HST (High Speed Train) channel model, the spatial beam (angle of departure) change can be modeled with an initial position of the spatial beam (vertical and horizontal beam indices) and a delta spatial beam step (according to the UE / reflector movement) or alternatively or in addition with two positions of the spatial beam. It can be assumed that the change is linear to simplify the model. Other scenarios are considered, such as a high speed train approaching or leaving a train station, acceleration aspects can also be modeled, then a second order polynomial or other model can be used for this purpose. Similarly, for the delay and the Doppler shift, a linear or non-linear model can be applied.

[0058] Alternatively, the UE can report the velocity of the UE relative to a standardized coordinate system to the gNB. However, to impact each beam from the reported velocity of the UE, b can need to be handled separately.

[0059] Assuming a train / UE speed of 360 km / hr, this speed translates to 360 x 10 3 / 3660 = 10 2 meters / second. Assuming that the enhanced Type II codebook can be used for 10 ms to 60 ms, then the distance covered in 10 ms to 60 ms is 10 2 x 10 x 10 -3 meters (or 1.0 meter or 6 meters) or worst case 6.0 meters, which corresponds to 6 / 3e8 = 0.02 microseconds, the delay change can be multiplied if the reflector moves: thus the change can be 0.04 microseconds.

[0060] For the resolution of the enhanced Type II codebook, the time resolution corresponds to the maximum delay difference limited by the frequency domain separation of the CSI-RS tones (e.g., 12 tones at a given numerology as in NR). More specifically, at a SCS of 15 KHz, the maximum delay difference T max is 1 / (15 x 10 3 x 12) = 5.55... . 10 -6seconds, and scaled down proportionally at 30 KHz, 60 KHz, 120 KHz, 240 KHz, etc. The time resolution is determined by N3, and given by T max / N3.

[0061] For enhanced Type II codebook resolution, the time resolution corresponds to the maximum frequency offset difference limited by the time-domain separation of CSI-RS RE locations, assuming a minimum separation of 2 OFDM symbols, roughly (10 -3 / 14 x 2) seconds, and a maximum frequency offset difference of 7000 Hz. And the frequency resolution is given by N4.

[0062] For high-speed train scenarios, the model is still valid within the time span of the feedback (60 ms). However, for NTN communications, since satellites can move fast at 8,100 km / h, then basically all parameters including spatial beams, delay taps, Doppler shifts in the precoder construction are time functions. Assuming normal movement of the transmitter, receiver, and reflector, etc., then all functions behave well and can be modeled with low-order polynomials, exponential functions, sine or cosine functions, or combinations of them. For example, assuming a simple linear model, the spatial beam can be given by (0 b,p + Δ0 b,p. t, φ b,p + Δφ b,p. t) before quantization, and the delay tap can be represented by τ b,p + Δτ b,p. t, and the delay offset can be represented by f b,p + Δf b,p. t.

[0063] However, since there can be a geometric interpretation behind the statistical model, there can be a way to explore the correlation between spatial beams, delays, Doppler shifts by extending Joseph Liberti's model to also consider the Doppler effect. For example, FIG. 7Constraints between parameters of the wireless channel / precoder are shown. For example, once the relative delays and the position of the UE are given, the reflector is constrained on an ellipse with the gNB and the UE as foci, further where the spatial beams i1, i2, q1, q2 have given O1, O2), the reflector is constrained at the intersection of the line and the ellipse, and in addition the orientation of the reflector can be determined, which is constrained by the plane containing the line and the position of the UE. Of course, in real radio propagation conditions, the situation can be more complex, i.e. this model can not work all the time. However, when the model works, e.g. with a certain confidence from delay tap measurements, then the range of variation of the remaining parameters can be greatly reduced, and the signaling overhead involved can be reduced. To handle cases where the constructed model does not work, it is noted that some parameters can be signaled with a certain bitmap (membership) indication whether they cannot be handled in this way, and existing or proposed methods as described below can be considered.

[0064] Assuming the velocity of the object is estimated, the trajectory of the object can be predicted. Here, the movement of the transmitter, receiver, and reflector is perceived by the receiver (UE) itself, and the relevant information can be fed back to the gNB.

[0065] FIG. 8 A flowchart of a method 800 for a UE to report CSI to a base station according to one embodiment. In block 802, the method 800 includes sending, from the UE to the base station, UE capability signaling to indicate codebook support for high-speed scenarios. In block 804, the method 800 includes processing, at the UE, configuration information from the base station for CSI reporting using a codebook. The configuration information indicates measurement resources for one or more DL channels. In block 806, the method 800 includes measuring channel responses and interference using the measurement resources. In block 808, the method 800 includes generating CSI feedback for at least one ray from the base station to the UE using the codebook. In block 810, the method 800 includes reporting the CSI feedback to the base station.

[0066] In certain embodiments of the method 800, the CSI feedback includes components corresponding to one or more of: an exit angle and a first rate of change of the exit angle of the at least one ray; a relative delay and a second rate of change of the relative delay of the at least one ray; and a relative frequency offset and a third rate of change of the relative frequency offset of the at least one ray.

[0067] In certain embodiments of the method 800, spatial beam variations corresponding to the exit angle and the first rate of change of the exit angle are modeled using the following linear model: (θ b,p + Δθ b,p · t, φ b,p + Δφ b,p · t), where p is a polarization index, b is a ray index, θ b,pis the zenith departure angle, φ b,p is the azimuth departure angle, Δθ b,p is the change in the zenith departure angle, φ b,p is the change in the azimuth departure angle, and t is time.

[0068] In certain embodiments of the method 800, the relative delay is modeled with the following linear model: τ b,p + Δτ b,p · t, where p is a polarization index, b is a ray index, τ b,p is the relative delay, Δτ b,p is the change in the relative delay, and t is time.

[0069] In certain embodiments of the method 800, the relative frequency offset is modeled with the following linear model: f b,p + Δf b,p · t, where p is a polarization index, b is a ray index, f b,p is the relative frequency offset, Δf b,p is the change in the relative frequency offset, and t is time.

[0070] In certain embodiments of the method 800, the at least one ray includes N rays, and the method further includes reporting, from the UE to the base station, an indication of a maximum number of the N rays to include in the CSI feedback.

[0071] In certain embodiments of the method 800, the at least one ray includes N rays, and the method further includes reporting, from the UE to the base station, an indication of the N rays to include in the CSI feedback.

[0072] In certain embodiments of the method 800, the configuration information includes one or more of: a CSI periodicity and offset for periodic CSI feedback and semi-persistent CSI feedback; a trigger state linkage for the base station to trigger CSI reporting with a codebook; and a maximum number of rays to include when generating the CSI feedback.

[0073] FIG. 9 is a flowchart of a method 900 for a base station to configure a UE to report CSI, according to an embodiment. In block 902, the method 900 includes receiving, from the UE, UE capability signaling to indicate codebook support for high-speed scenarios. In block 904, in response to the UE capability signal, the method 900 includes sending, from the base station, configuration information to the UE for CSI reporting with a codebook. The configuration information indicates measurement resources for one or more DL channels. In block 906, the method 900 includes receiving, from the UE, CSI feedback of at least one ray from the base station to the UE with the codebook.

[0074] In certain embodiments of the method 900, the CSI feedback includes components corresponding to one or more of: an exit angle and a first rate of change of the exit angle of the at least one ray; a relative delay and a second rate of change of the relative delay; and a relative frequency offset and a third rate of change of the relative frequency offset of the at least one ray.

[0075] In certain embodiments of the method 900, spatial beam variations corresponding to the exit angle and the first rate of change of the exit angle are modeled with the following linear model: (0 b,p + A0 b,p · t, f b,p + Af b,p · t), where p is a polarization index, b is a ray index, 0 b,p is a zenith exit angle, f b,p is an azimuth exit angle, A0 b,p is a change in the zenith exit angle, Af b,p is a change in the azimuth exit angle, and t is time.

[0076] In certain embodiments of the method 900, the relative delay is modeled with the following linear model: T b,p + AT b,p · t, where p is a polarization index, b is a ray index, T b,p is a relative delay, AT b,p is a change in the relative delay, and t is time.

[0077] In certain embodiments of the method 900, the relative frequency offset is modeled with the following linear model: f b,p + Af b,p · t, where p is a polarization index, b is a ray index, f b,p is a relative frequency offset, Af b,p is a change in the relative frequency offset, and t is time.

[0078] In certain embodiments of the method 900, the at least one ray includes N rays, and the method further includes receiving, from the UE, an indication of a maximum number of the N rays included in the CSI feedback.

[0079] In certain embodiments of the method 900, the at least one ray includes N rays, and the method further includes receiving, from the UE, an indication of the N rays included in the CSI feedback.

[0080] In certain embodiments of the method 900, the configuration information includes one or more of: a CSI periodicity and offset for periodic CSI feedback and semi-persistent CSI feedback; a trigger state linkage for the base station to trigger CSI reporting with a codebook; and a maximum number of rays to include when generating CSI feedback.

[0081] FIG. 10 A non-terrestrial network (NTN) architecture 1000 of a wireless communication system is shown in accordance with one embodiment. The NTN architecture 1000 includes a core network (CN) 1002, terrestrial base stations 1004, a satellite gateway 1006, satellites 1008, and UEs 1010. The terrestrial base stations 1004, the satellite gateway 1006, and the satellites 1008 can be included in a RAN 1012.

[0082] In some embodiments, the RAN 1012 includes an E-UTRAN, the CN 1002 includes an EPC, and the terrestrial base stations 1004 include eNBs. In these cases, the CN links 1014 connecting the CN 1002 and the terrestrial base stations 1004 can include S1 interfaces.

[0083] In some embodiments, the RAN 1012 includes an NG-RAN, the CN 1002 includes a 5GC, and the terrestrial base stations 1004 include gNBs or next generation eNBs (ng- eNBs). In such cases, the CN links 1014 connecting the CN 1002 and the terrestrial base stations 1004 can include NG interfaces.

[0084] The NTN architecture 1000 shows an architecture based on a “bent pipe” or “transparent” satellite. In such bent pipe systems, the terrestrial base stations 1004 communicate with the satellites 1008 using the satellite gateway 1006 over the feeder links 1016. The satellites 1008 can be equipped with one or more antennas capable of broadcasting a cell according to the RAN 1012, and the UEs 1010 can be equipped with one or more antennas capable of communicating with the satellites 1008 via a Uu interface over the cell (e.g., mobile parabolic antennas, omnidirectional phased array antennas, etc.), which can be considered to use the illustrated serving links 1018. The payload located on the satellites 1008 then forwards data between the satellite gateway 1006 and the UEs 1010 transparently using the feeder links 1016 between the satellite gateway 1006 and the satellites 1008 and the serving links 1018 between the satellites 1008 and the UEs 1010. The payload can perform RF conversion and / or amplification in both uplink (UL) and downlink (DL) to enable this communication.

[0085] In FIG. 10In the illustrated embodiment, the terrestrial base station 1004 is shown without the capability to directly communicate wirelessly with UEs over the terrestrial wireless communications. However, it is contemplated that in other embodiments such a terrestrial base station using the satellite gateway 1006 to communicate with the satellite 1008 can also have this functionality (i.e., as will be described below FIG. 12 in the terrestrial base station 1212 and the terrestrial base station 1214).

[0086] FIG. 11 An NTN architecture 1100 of a wireless communication system is shown in accordance with one embodiment. The NTN architecture 1100 includes a CN 1102, a satellite gateway 1104, a satellite base station 1106, and a UE 1108. The satellite gateway 1104 and the satellite base station 1106 can be included in a RAN 1110.

[0087] In some embodiments, the RAN 1110 includes an E-UTRAN, and the CN 1102 includes an EPC. In these cases, the CN link 1112 connecting the CN 1102 and the satellite gateway 1104 can include an S1 interface.

[0088] In some embodiments, the RAN 1110 includes an NG-RAN, and the CN 1102 includes a 5GC. In such cases, the CN link 1112 connecting the CN 1102 and the satellite gateway 1104 can include an NG interface.

[0089] The NTN architecture 1000 implements an architecture based on a “regenerative” satellite. In such a regenerative system, the functions of the base stations reside on satellite base station 1106, and communication between these base station functions and CN 1102 occurs by forwarding to satellite base station 1106 via interfaces (e.g., S1 interface and / or NG interface) discovered on CN link 1112 through satellite gateway 1104 and feeder link 1114. Satellite base station 1106 may be equipped with one or more antennas capable of broadcasting the cell according to RAN 1110, and UE 1108 may be equipped with one or more antennas (e.g., mobile parabolic antenna, omnidirectional phased array antenna, etc.) capable of communicating with satellite base station 1106 via the Uu interface on the cell (such communication may be considered to use the illustrated service link 1116). The payload located on satellite base station 1106 then forwards data between satellite gateway 1104 and UE 1108 using feeder link 1114 between satellite gateway 1104 and satellite base station 1106, and service link 1116 between satellite base station 1106 and UE 1108. The payload can perform RF conversion and / or amplification in both uplink (UL) and downlink (DL) to enable this communication, and implement the functions of the base station (e.g., as an eNB, ng-eNB, or gNB of type RAN 1110), since these are already located on satellite base station 1106.

[0090] In an NTN architecture implementation that also uses NG-RAN with Integrated Access and Backhaul (IAB), it is possible that the gNB Control Unit (CU) function can be located on the ground and can use a satellite gateway to communicate with the satellite hosting the corresponding gNB Donor Unit (DU) function, wherein the F1 interface between the CU and DU is supported by feeder link 1114. In this case, the CU and DU can each be understood as part of the NG-RAN.

[0091] FIG. 12 An exemplary architecture of a wireless communication system 1200 according to an embodiment disclosed herein is shown. The description provided below is for an exemplary wireless communication system 1200 operating in conjunction with LTE system standards and / or 5G or NR system standards provided in 3GPP technical specifications and other 3GPP documents.

[0092] like FIG. 12 As shown, the wireless communication system 1200 includes UE 1202 and UE 1204 (but any number of UEs may be used). In this example, UE 1202 and UE 1204 are shown as smartphones (e.g., handheld touchscreen mobile computing devices capable of connecting to one or more cellular networks), but may also include any mobile or non-mobile computing device configured for wireless communication.

[0093] The UEs 1202 and 1204 can be configured to communicate with a RAN 1206. In embodiments, the RAN 1206 can be an NG-RAN, an E-UTRAN, etc. The UEs 1202 and 1204 utilize connections (or channels) 1208 and 1210, respectively, with the RAN 1206 to communicate with the core network 1224. The connections (or channels) 1208 and 1210 are illustrated as an air interface to enable communicative coupling between the respective UEs 1202 and 1204 and the RAN 1206. In embodiments, the air interface utilizes long term evolution (LTE) and / or 5G NR technologies. In some embodiments, the air interface utilizes one or more OFDM, FDM, CDMA, TDMA, TDD or other FIG. 10 The NTN architecture 1000 and FIG. 11 The NTN architecture 1100 described in the manner (and with the appropriate elements) of

[0094] In this example, the connections 1208 and 1210 are air interfaces that implement the communicative coupling between the UEs 1202 and 1204 and the RAN 1206, respectively, and can be consistent with RAN 1206 employing 5G NR technologies. In some embodiments, the connections 1208 and 1210 can include service links between their respective UEs 1202, 1204 and one or more of the satellite base stations 1236, 1238 and the satellite 1242.

[0095] In some embodiments, the UEs 1202 and 1204 can also be configured to directly exchange communication data via a sidelink interface 1216.

[0096] The UE 1204 is illustrated as being configured to access an access point (shown as AP 1218) via connection 1220. The connection 1220 can comprise a local wireless connection, such as a connection consistent with any IEEE 802.11 protocol, Bluetooth connection, etc. In some embodiments, the connection 1220 can comprise a wired connection, such as a connection consistent with an Ethernet network, etc. The AP 1218 can in turn be coupled to the core network 1224 via connection 1222. In certain embodiments, the AP 1218 can be configured to provide a mobility management function (e.g., RAN 1206) and / or access management function (e.g., core network 1224) for the UEs 1202 and 1204. In this example, the AP 1218 can not be connected to another network (e.g., Internet) through the CN 1224.

[0097] In embodiments, the UEs 1202 and 1204 can be configured to communicate using orthogonal frequency division multiplexing (OFDM) communication signals with each other, with the terrestrial base stations 1212, 1214, with the satellite base stations 1236, 1238, and / or with the satellite 1242, although the scope of the embodiments can not be limited in this respect. The OFDM signals can include orthogonal frequency divisional multiple access (OFDMA) signals, single carrier frequency division multiple access (SC-FDMA) signals, and / or the like.

[0098] In some embodiments, all or a portion of the terrestrial base station 1212, the terrestrial base station 1214, the satellite base station 1236, and / or the satellite base station 1238 can be implemented as one or more software entities running on a server computer as part of a virtual network.

[0099] Also, or in other embodiments, the terrestrial base station 1212 or the terrestrial base station 1214 can be configured to communicate with each other via the interface 1222. In embodiments where the wireless communication system 1200 is an LTE system (e.g., when the CN 1224 is an EPC), the interface 1222 can be an X2 interface. The X2 interface can be defined between two or more base stations (e.g., two or more eNBs, etc.) connected to the EPC and / or between two eNBs connected to the EPC. It is contemplated that an inter-satellite link (ISL) can carry the X2 interface between two satellite base stations.

[0100] In embodiments where the wireless communication system 1200 is an NR system (e.g., when the CN 1224 is a 5GC), the interface 1222 can be an Xn interface. The Xn interface is defined between two or more base stations connected to the 5GC (e.g., the CN 1224). For example, the Xn interface can be between two or more gNBs connected to the 5GC, between a gNB and an eNB connected to the 5GC, between two eNBs connected to the 5GC, and / or between two or more satellite base stations via an ISL (as in the interface 1240 between the satellite base station 1236 and the satellite base station 1238, for example).

[0101] The RAN 1206 is shown to be communicatively coupled to a CN 1224. The CN 1224 can include one or more network elements 1226, which are configured to provide various data and telecommunications services to customers / subscribers (e.g., users of UEs 1202 and 1204) utilizing the RAN 1206 to connect to the CN 1224. The components of the CN 1224 can be implemented in one physical device or separate physical devices, including components to read and execute instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium). For example, the components of the CN 1224 can be implemented in one or more processors and / or one or more associated memories.

[0102] In embodiments, the CN 1224 can be an EPC and the RAN 1206 can interface with the CN 1224 via an S1 interface 1228. In embodiments, the S1 interface 1228 can be split into two parts, an S1 user plane (S1-U) interface, which carries traffic data between the eNBs 1212, 1214, satellite base station 1236, or interface 1240 and a serving gateway (S-GW), and an S1-MME interface, which is a signaling interface between the eNBs 1212, 1214, satellite base station 1236, or interface 1240 and a mobility management entity (MME).

[0103] In embodiments, the CN 1224 can be a 5GC and the RAN 1206 can interface with the CN 1224 via an NG interface 1228. In embodiments, the NG interface 1228 can be split into two parts, an NG user plane (NG-U) interface, which carries traffic data between the eNBs 1212, 1214, satellite base station 1236, or satellite base station 1238 and a user plane function (UPF), and an S1 control plane (NG-C) interface, which is a signaling interface between the eNBs 1212, 1214, satellite base station 1236, or satellite base station 1238 and an access and mobility management function (AMF).

[0104] Generally, the application server 1230 can be an element of a network that provides content, or other services related to communication services provided by the CN 1224. For example, the application server 1230 can facilitate one or more of the communication services for UEs 1202 and 1204, such as VoIP sessions, group communication sessions, or the like. The application server 1230 can communicate with the CN 1224 through an IP communications interface 1232.

[0105] FIG. 13A system 1300 for performing signaling 1334 between a wireless device 1302 and a RAN device 1318 of a core network connected to a CN device 1336 is shown, in accordance with embodiments disclosed herein. The system 1300 can be part of a wireless communication system as described herein. The wireless device 1302 can be, for example, a UE of the wireless communication system. The RAN device 1318 can be, for example, a base station (e.g., an eNB or gNB) of the wireless communication system as a terrestrial base station or a satellite base station. The CN device 1336 can be one or more devices that make up a CN, as described herein.

[0106] The wireless device 1302 can include one or more processors 1304. The processor(s) 1304 can execute instructions to perform various operations of the wireless device 1302 as described herein. The processor(s) 1304 can include one or more baseband processors implemented using, for example, a central processing unit (CPU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0107] The wireless device 1302 can include memory 1306. The memory 1306 can be a non-transitory computer-readable storage medium that stores instructions 1308 (which can include, for example, instructions for execution by the processor(s) 1304). The instructions 1308 can also be referred to as program code or computer programs. The memory 1306 can also store data used by the processor(s) 1304 and results produced by the processor(s).

[0108] The wireless device 1302 can include one or more transceivers 1310 that can include radio frequency (RF) transmitter and / or receiver circuits that use an antenna 1312 of the wireless device 1302 to facilitate transmission and / or reception of signaling (e.g., the signaling 1334) by the wireless device 1302 with other devices (e.g., the RAN device 1318) in accordance with a corresponding RAT. In some embodiments, the antenna 1312 can include a mobile parabolic antenna, an omni-directional phased array antenna, or some other antenna suitable for communicating with a satellite (e.g., as described above in connection with the UE 1010 of FIG. 1 and the UE 1108 of FIG. 11). FIG. 10 FIG. 11 For the RAN device 1318 as a terrestrial base station, the network device signaling 1334 can occur over a feeder link between the wireless device 1302 and a satellite and a service link between the satellite and the RAN device 1318 (e.g., as described in connection with the UE 1010 of FIG. 1 and the UE 1108 of FIG. 11).

[0109] For the RAN device 1318 as a terrestrial base station, the network device signaling 1334 can occur over a feeder link between the wireless device 1302 and a satellite and a service link between the satellite and the RAN device 1318 (e.g., as described in connection with the UE 1010 of FIG. 1 and the UE 1108 of FIG. 11). FIG. 10 ​signaling 1334 can occur over a feeder link between the wireless device 1302 and the RAN device 1318 (e.g., as described above for the RAN device 1318 as a satellite base station). FIG. 11

[0110] The wireless device 1302 can include one or more antennas 1312 (e.g., one, two, four, or more). For embodiments with multiple antennas 1312, the wireless device 1302 can take advantage of the spatial diversity of these multiple antennas 1312 to send and / or receive multiple different data streams over the same time-frequency resources. This approach can be referred to as, for example, a multiple-input multiple-output (MIMO) approach (referring to the multiple antennas used in this regard at the transmitting device and receiving device sides, respectively). MIMO transmission by the wireless device 1302 can be implemented according to precoding (or digital beamforming) applied to the wireless device 1302, which multiplexes data streams among the antennas 1312 such that each data stream is received at an appropriate signal strength and in a desired location in space (e.g., the location of the receiver associated with that data stream) relative to the other streams. Certain embodiments can use a single-user MIMO (SU-MIMO) approach (where the data streams are all intended for a single receiver) and / or a multi-user MIMO (MU-MIMO) approach (where individual data streams can be intended for individual (different) receivers at different locations in space).

[0111] In certain embodiments with multiple antennas, the wireless device 1302 can implement an analog beamforming technique, whereby the phase of the signals transmitted by the antennas 1312 is adjusted relatively so that the (joint) transmission by the antennas 1312 has directionality (this is sometimes referred to as beam steering).

[0112] The wireless device 1302 can include one or more interfaces 1314. The interfaces 1314 can be used to provide input to and to receive output from the wireless device 1302. For example, the wireless device 1302 as a UE can include interfaces 1314 such as a microphone, a speaker, a touchscreen, buttons, and / or the like for allowing a user of the UE to provide input to the UE and / or to output to the user. Other interfaces of such a UE can be composed of transmitters, receivers, and other circuitry that allow the UE to communicate with other devices (e.g., other than the transceiver 1310 / antennas 1312 already described) and can operate according to known protocols (e.g., Bluetooth®, Bluetooth Low Energy, Wi-Fi, etc.).

[0113] ​​The wireless device 1302 can include a predictive CSI module 1316. The predictive CSI module 1316 can be implemented via hardware, software, or a combination thereof. For example, the predictive CSI module 1316 can be implemented as a processor, circuit, and / or instructions 1308 stored in the memory 1306 and executed by the processor 1304. In some examples, the predictive CSI module 1316 can be integrated within the processor 1304 and / or the transceiver 1310. For example, the predictive CSI module 1316 can be implemented by a combination of software components (for example, executed by a DSP or a general processor) and hardware components (for example, logic gates and circuitry) within the processor 1304 or the transceiver 1310.

[0114] The predictive CSI module 1316 can be used for various aspects of the disclosure, as described herein.

[0115] The RAN device 1318 can include one or more processors 1320. The processor(s) 1320 can execute instructions to perform various operations of the RAN device 1318 as described herein. The processor(s) 1304 can include one or more baseband processors implemented using, for example, CPU, DSP, ASIC, controller, FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0116] The RAN device 1318 can include memory 1322. The memory 1322 can be a non-transitory computer-readable storage medium that stores instructions 1324 (which can include, for example, instructions for execution by the processor(s) 1320). The instructions 1324 can also be referred to as program code or computer programs. The memory 1322 can also store data used by the processor(s) 1320 and results produced by the processor(s).

[0117] The RAN device 1318 can include one or more transceivers 1326, which can include RF transmitter and / or receiver circuits using antennas 1328 of the RAN device 1318 to facilitate transmission and / or reception of signaling (for example, signaling 1334) by the RAN device 1318 with other devices (for example, the wireless device 1302) in accordance with the corresponding RAT.

[0118] The RAN device 1318 can include one or more antennas 1328 (for example, one, two, four or more). In embodiments with multiple antennas 1328, the RAN device 1318 can perform MIMO, digital beamforming, analog beamforming, beam steering, and / or the like as described above.

[0119] For RAN devices 1318 that are land-based stations, one or more of transceiver 1326 and / or antennas 1328 can instead be present on a satellite gateway associated with the base station (e.g., as shown with respect to land-based base station 1004 and satellite gateway 1006 of FIG. 13). For RAN devices 1318 that are satellite-based stations, transceiver 1326 and / or antennas 1328 can be present on a satellite, and one or more of these antennas 1328 can be antennas suitable for satellite communications (such as mobile parabolic antennas, omnidirectional phased array antennas, etc.). FIG. 10

[0120] RAN devices 1318 can include one or more interfaces 1330. Interfaces 1330 can be used to provide input to, or output from, RAN devices 1318. For example, RAN devices 1318 that are base stations can include interfaces 1330 composed of transmitters, receivers, and other circuitry (e.g., in addition to transceivers 1326 / antennas 1328 already described) that enable the base stations to communicate with other equipment in a CN, and / or to communicate with external networks, computers, databases, etc. for the purposes of operating, managing, and maintaining the base station or other equipment operably connected to the base station.

[0121] RAN devices 1318 can include a predictive CSI module 1332. Predictive CSI module 1332 can be implemented via hardware, software, or a combination thereof. For example, predictive CSI module 1332 can be implemented as instructions 1324 stored in memory 1322 and executed by processor 1320, circuitry, and / or a processor. In some examples, predictive CSI module 1332 can be integrated within processor 1320 and / or transceiver 1326. For example, predictive CSI module 1332 can be implemented by a combination of software components (e.g., executed by a DSP or a general processor) and hardware components (e.g., logic gates and circuitry) within processor 1320 or transceiver 1326.

[0122] Predictive CSI module 1332 can be used for various aspects of the present disclosure, for example, as described herein.

[0123] RAN devices 1318 can communicate with CN devices 1336 via interface 1348, which can be similar to interface 1228 of FIG. 12 (e.g., can be an S1 and / or NG interface, either of which can be split into user plane and control plane portions). FIG. 12

[0124] ​​The CN device 1336 can include one or more processors 1338. The processors 1338 can execute instructions to perform various operations for the CN device 1336 as described herein. The processors 1338 can include one or more baseband processors that are implemented using, for example, CPUs, DSPs, ASICs, controllers, FPGA devices, another hardware devices, firmware devices, or any combination thereof configured to perform the operations described herein.

[0125] The CN device 1336 can include a memory 1340. The memory 1340 can be a non-transitory computer-readable storage medium that stores instructions 1342 (which can include, for example, instructions for execution by the processors 1338). The instructions 1342 can also be referred to as program code or computer programs. The memory 1340 can also store data used by the processors 1338 and results of operations performed by the processors.

[0126] The CN device 1336 can include one or more interfaces 1344. The interfaces 1344 can be used to provide input to or output from the CN device 1336. For example, the CN device 1336 can include an interface 1330 that includes transmitters, receivers, and other circuitry that enables the CN device 1336 to communicate with other equipment in the CN and / or to communicate with external networks, computers, databases, etc. for the purpose of operating, managing, and maintaining the CN device 1336 or other equipment operably connected to the CN device.

[0127] The CN device 1336 can include a predictive CSI module 1346. The predictive CSI module 1346 can be implemented via hardware, software, or combinations thereof. For example, the predictive CSI module 1346 can be implemented as a processor, circuit, and / or instructions 1342 stored in the memory 1340 and executed by the processors 1338. In some examples, the predictive CSI module 1346 can be integrated within the processors 1338. For example, the predictive CSI module 1346 can be implemented by a combination of software (executed, for example, by a DSP or a general purpose processor) and hardware components (e.g., logic gates and circuitry) within the processors 1338.

[0128] The predictive CSI module 1346 can be used for various aspects of the disclosure as described herein.

[0129] For one or more embodiments, at least one of the components shown in one or more of the preceding figures can be configured to perform one or more operations, techniques, processes, and / or methods as described herein. For example, a baseband processor as described herein in connection with one or more of the preceding figures can be configured to operate in accordance with one or more of the examples described herein. For another example, circuitry associated with a UE, base station, network element, etc. as described above in connection with one or more of the preceding figures can be configured to operate in accordance with one or more of the examples shown herein.

[0130] Any of the above-described embodiments can be combined with any other embodiment (or combination of embodiments) unless explicitly stated otherwise. The foregoing description of one or more implementations provides functionality and / or technical advantages, but do not limit the scope of implementations. What is claimed as an implementation is defined by the claims.

[0131] Embodiments and implementations of the systems and methods described herein can include various operations, which can be embodied in machine-executable instructions to be executed by a computer system. The computer system can include one or more general-purpose or special-purpose computers (or other electronic devices). The computer system can include hardware components, including specific logic for performing the operations, or can include a combination of hardware, software, and / or firmware.

[0132] It will be recognized that the systems described herein include descriptions of specific implementations. These implementations can be combined, partially combined, separated into multiple systems, or otherwise divided or combined in other ways. Further, it is contemplated that parameters, attributes, aspects, etc. of one implementation can be used in another implementation. For clarity, these parameters, attributes, aspects, etc. are only described in one or more implementations, and it will be recognized that these parameters, attributes, aspects, etc. can be combined with or substituted for parameters, attributes, aspects, etc. of another implementation unless specifically stated otherwise.

[0133] It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled in a way to minimize risk of unintentional or unauthorized access or use of the data, and every effort should be made to secure user's consent to the manner in which their personal information is being collected.

[0134] While the foregoing has been described in some detail for purposes of clarity, it will be apparent that certain changes and modifications can be made without departing from the principles thereof. It should be noted that there are many alternative ways of implementing both the processes and apparatuses described herein. Accordingly, the embodiments of the application are to be considered illustrative and not restrictive, and the description is not to be limited to the details given herein, but can be modified within the scope and equivalents of the appended claims.

Claims

1. A method for a user equipment (UE) to report channel state information (CSI) to a base station, the method comprising: sending, from the UE to the base station, UE capability signaling to indicate support for a codebook for high speed scenarios; processing, at the UE, configuration information from the base station for CSI reporting using the codebook, the configuration information indicating measurement resources for one or more downlink (DL) channels; measuring channel responses and interference using the measurement resources; generating, using the codebook, CSI feedback for at least one ray from the base station to the UE; and reporting the CSI feedback to the base station; wherein the CSI feedback includes components corresponding to one or more of: an angle of departure (AoD) and a first rate of change of the AoD for the at least one ray; a relative delay and a second rate of change of the relative delay for the at least one ray; and a relative frequency offset and a third rate of change of the relative frequency offset for the at least one ray.

2. The method of claim 1, wherein spatial beam variations corresponding to the AoD and the first rate of change of the AoD are modeled using a linear model of:

3. The method of claim 1, wherein the relative delay is modeled using a linear model of: (θ b,p +Δθ b,p ·t,φ b,p +Δφ b,p ·t), where p is a polarization index, b is a beam index, θ b,p is a zenith departure angle, φ b,p is an azimuth departure angle, Δθ b,p is a change in the zenith departure angle, φ b,p is a change in the azimuth departure angle, and t is time.

4. The method of claim 1, wherein the relative frequency offset is modeled using a linear model of: τ b,p + Δτ b,p • t, where p is a polarization index, b is a ray index, τ b,p is the relative delay, Δτ b,p is the change in the relative delay, and t is time. reporting, from the UE to the base station, an indication of a maximum number of the N rays included in the CSI feedback. f b,p + Δf b,p • t, where p is a polarization index, b is a beam index, f b,p is the relative frequency offset, Δf b,p is the change in the relative frequency offset, and t is time.

5. The method of claim 1, wherein the at least one ray comprises N rays, and wherein the method further comprises: reporting, from the UE to the base station, an indication of the N rays included in the CSI feedback.

6. The method of claim 1, wherein the at least one ray comprises N rays, and wherein the method further comprises:

7. The method of claim 1, wherein the configuration information includes one or more of: a CSI periodicity and offset for periodic and semi-persistent CSI feedback; trigger state links for the base station to trigger CSI reporting using the codebook; and a maximum number of rays to include when generating the CSI feedback.

8. A method for a base station to configure a user equipment (UE) to report channel state information (CSI), the method comprising: receiving, from the UE, UE capability signaling to indicate support for a codebook for high speed scenarios; in response to the UE capability signaling, sending, to the UE from the base station, configuration information for CSI reporting using the codebook, the configuration information indicating measurement resources for one or more downlink (DL) channels; and receiving, from the UE, CSI feedback for at least one ray from the base station to the UE using the codebook; wherein the CSI feedback includes components corresponding to one or more of: an angle of departure (AoD) and a first rate of change of the AoD for the at least one ray; a relative delay and a second rate of change of the relative delay for the at least one ray; and a relative frequency offset and a third rate of change of the relative frequency offset for the at least one ray. ​ 9. The method of claim 8, wherein spatial beam variation corresponding to the angle of departure and the first rate of change of the angle of departure is modeled with the following linear model: (θ b,p +Δθ b,p ·t,φ b,p +Δφ b,p ·t), where p is a polarization index, b is a beam index, θ b,p is a zenith departure angle, φ b,p is an azimuth departure angle, Δθ b,p is a change in the zenith departure angle, φ b,p is a change in the azimuth departure angle, and t is time.

10. The method of claim 8, wherein the relative delay is modeled with the following linear model: τ b,p + Δτ b,p • t, where p is a polarization index, b is a ray index, τ b,p is the relative delay, Δτ b,p is the change in the relative delay, and t is time.

11. The method of claim 8, wherein the relative frequency offset is modeled with the following linear model: f b,p + Δf b,p • t, where p is a polarization index, b is a beam index, f b,p is the relative frequency offset, Δf b,p is the change in the relative frequency offset, and t is time.

12. The method of claim 8, wherein the at least one ray comprises N rays, and wherein the method further comprises: receiving, from the UE, an indication of a maximum number of the N rays included in the CSI feedback.

13. The method of claim 8, wherein the at least one ray comprises N rays, and wherein the method further comprises: receiving, from the UE, an indication of the N rays included in the CSI feedback.

14. The method of claim 8, wherein the configuration information comprises one or more of: a CSI periodicity and offset for periodic and semi-persistent CSI feedback; trigger state links for the base station to trigger CSI reporting with the codebook; and a maximum number of rays to include when generating the CSI feedback.

15. An apparatus for reporting channel state information, CSI, the apparatus comprising means, logic, modules, or circuitry for performing the method of any of claims 1-7.

16. A computer-readable medium, the computer-readable medium comprising instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform the method of any of claims 1-14.

17. An apparatus for receiving channel state information, CSI, feedback, the apparatus comprising means, logic, modules, or circuitry for performing the method of any of claims 8-14.

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