CSI-RS Reception for High Mobility

Abstract

A system and method for receiving channel state information (CSI) reference signals (RS) and associated CSI reports are disclosed. In one embodiment, a method performed by a user device (UE) includes receiving first information from a network node that provides CSI-RS configurations associated with a plurality of CSI-RS samples at different points in time, and receiving second information from the network node that configures the UE(312) to report CSI feedback based on the CSI-RS configurations associated with the plurality of CSI-RS samples. The method further includes calculating at least one characteristic of a precoding matrix for each of the plurality of CSI-RS samples according to the second information, and reporting to the network node, via one or more CSI-RS reports, either at least one characteristic of a precoding matrix or information derived therefrom for each of the plurality of CSI-RS samples.

Description

[Technical field]

[0001] [Related Applications] This application claims the benefit of Provisional Patent Application No. 63 / 307,524, filed February 7, 2022, the disclosure of which is hereby incorporated by reference in its entirety.

[0002] [Technical field] The present disclosure relates to cellular communication systems, and more particularly, to channel state information reference signals (CSI-RS) in radio access networks (RANs) of cellular communication systems. [Background technology]

[0003] <Multi-user multiple input multiple output (MU-MIMO)> In MU-MIMO, two or more user equipments (UEs) in the same cell are scheduled together on the same time-frequency resources. That is, two or more independent data streams are transmitted simultaneously to different UEs, and the spatial domain can typically be used to separate the respective streams. By transmitting several streams simultaneously, the capacity of the system can be increased. However, the price is that the signal-to-interference-and-noise ratio (SINR) per stream is reduced, since power has to be shared between the streams and the streams interfere with each other.

[0004] <Channel State Information Reference Signal (CSI-RS)> CSI-RS is defined for measuring and feedback of channel state information (CSI). CSI-RS is transmitted on each antenna port and is used by the UE to measure the downlink channel between each of the transmit antenna ports and each of its receive antenna ports. The transmit antenna ports are also called CSI-RS ports. In the New Radio (NR) of the 3rd Generation Partnership Project (3GPP), the number of supported antenna ports is currently {1, 2, 4, 8, 12, 16, 24, 32}. By measuring the received CSI-RS, the UE can estimate the channel that the CSI-RS traverses, including the radio propagation channel and the antenna gain. The CSI-RS for the above purpose is also called non-zero power (NZP) CSI-RS.

[0005] CSI-RS may be configured to be transmitted in certain resource elements (REs) within a slot and certain slots. Figure 1 shows an example of CSI-RS REs for 12 antenna ports, with one RE per resource block (RB) and per port.

[0006] FIG. 1 shows an example of RE allocation for 12-port CSI-RS in NR.

[0007] In addition, in NR, an interference measurement resource (IMR) is defined for the UE to measure interference. The IMR resource includes 4 Res, either 4 Res adjacent in frequency in the same orthogonal frequency division multiplexing (OFDM) symbol, or 2×2 Res adjacent in time and frequency in a slot. By measuring both the channel based on the NZP CSI-RS and the interference based on the IMR, the UE can estimate the effective channel and noise and interference to determine the CSI, i.e., rank, precoding matrix, and channel quality.

[0008] Furthermore, in NR, a UE may be configured to measure interference based on one or more NZP CSI-RS resources.

[0009] <Tracking Reference Signal (TRS)> Due to oscillator imperfections, transmission and reception may not be synchronized in time and / or frequency, which may cause inter-symbol and intra-symbol interference. In NR, a TRS was introduced that can be used by UEs for synchronization.

[0010] In the 3GPP standard for NR, TRS can be configured if the CSI reporting setting is not configured or if the higher layer parameter 'reportQuantity' in the information element (IE) CSI-ReportConfig associated with all reporting settings linked to the CSI-RS resource set containing TRS is set to 'none', which means that CSI reporting based on measurements in TRS is not supported in NR.

[0011] A TRS is configured via 'trs-Info' in the IE NZP-CSI-RS-ResourceSet in 3GPP Technical Standard (TS) 38.331 V16.6.0 associated with a CSI-RS resource set, for which the UE can assume that antenna ports with the same port index of configured NZP CSI-RS resources in that resource set are identical. From the 3GPP standard point of view, a TRS is standardized as a special type of NZP CSI-RS, and the corresponding NZP CSI-RS resource set containing the TRS has the higher layer parameter 'trs-Info' set to true.

[0012] A TRS is not actually a CSI-RS, but rather a resource set consisting of multiple periodic NZP CSI-RS. More specifically, a TRS consists of four 1-port, density 3 CSI-RS located in two consecutive slots. The CSI-RS in a resource set can be configured with a period of 10, 20, 40 or 80 milliseconds (ms). Note that the exact set of Res used for the TRS CSI-RS can vary. There is always a time domain separation of 4 symbols between two CSI-RS in a slot. Figure 2 shows an example of a TRS burst of two TRS symbols in two adjacent slots.

[0013] NR also supports aperiodic TRS.

[0014] For LTE, the LTE cell-specific reference signal (CRS) served the same purpose as the TRS in that it could be used for synchronization, but it could also be used for CSI reporting, which is not supported for the TRS in NR. However, compared to the LTE CRS, the TRS implies much less overhead, has only one antenna port, and only appears in two slots per TRS period.

[0015] <NRにおけるCSIのフレームワーク> In NR, a UE may be configured with multiple CSI reporting settings (also known as CSI-ReportConfig in 3GPP TS38.331 V16.6.0) and multiple CSI-RS resource settings. Each CSI-RS resource setting may include multiple resource sets, and each resource set may include up to 8 CSI-RS resources. For each CSI reporting setting, the UE may feed back a CSI report.

[0016] Each CSI reporting setting contains at least the following information: CSI-RS resource set for channel measurements · IMR resource set for interference measurement · Optionally, CSI-RS resource set for interference measurement · Behavior in the time domain, i.e., periodic, semi-persistent, or aperiodic reporting · Frequency granularity, i.e., wideband or sub-band · CSI parameters to be reported, such as rank indicator (RI), precoding matrix indicator (PMI), channel quality indicator (CQI), and CSI-RS resource indicator (CRI) when there are multiple CSI-RS resources in the resource set · Codebook type, i.e., type I or II, and codebook subset restriction · Measurement restriction · Sub-band size. One of two sub-band size candidates is indicated, and the value range depends on the bandwidth of the bandwidth part (BWP). One CQI / PMI (when configured for sub-band reporting) is fed back per sub-band

[0017] <Type I and Type II codebooks in NR> The type I codebook (CB) is typically used by the UE to report CSI for single user MIMO (Single User Multiple-Input Multiple-Output) scheduling in NR. On the other hand, the type II CB is typically for more accurate CSI feedback for MU-MIMO scheduling

[0018] For both type I and type II CBs, for each rank, the precoding matrix W is defined in the following form W = W1W2

Equation

[0019] For a type I CB, the precoding vector per MIMO layer is associated with a single DFT beam. On the other hand, for a type II CB, the precoding vector per layer is a linear combination of multiple DFT beams.

[0020] <Extended Type II Codebook in NR> In Release 16 of NR, the type II CB is extended by applying the basis of the frequency-domain (FD) DFT across all sub-bands to reduce the CSI feedback overhead and / or improve the accuracy of CSI. Instead of reporting W2 for each sub-band, a linear combination of DFT basis vectors is used to jointly represent W2 across the entire CSI bandwidth. For each layer, the precoding matrix W across all sub-bands has the following form

Number

[0021] <qcl> Several signals can be transmitted from different antenna ports of the same base station, which may have the same large-scale properties, such as Doppler shift / spread, mean delay rate, or mean delay. The antenna ports are then said to be Quasi-Collocated (QCL).

[0022] If the UE knows that two antenna ports are QCL with respect to a certain parameter (e.g., Doppler spread), the UE can estimate the parameter based on one of the antenna ports and apply the estimation result to receive signals on the other antenna port. Typically, the first antenna port is represented by a measurement reference signal such as a TRS or synchronization signal block (SSB) (known as a source reference signal (RS)), and the second antenna port is a demodulation reference signal (DMRS) (known as a target RS).

[0023] For example, if antenna ports A and B are QCL with respect to average delay, the UE can estimate the average delay from the signal received from antenna port A and assume that the signal received from antenna port B has the same average delay. This is beneficial for demodulation because the UE can know the channel characteristics in advance, which can help the UE to select an appropriate channel estimation filter, for example.

[0024] Information about what assumptions can be made regarding the QCL is signaled from the network to the UE. In NR, four types of QCL relationships between a transmitting source RS and a transmitting target RS are defined: Type A: {Doppler shift, Doppler spread, mean delay, delay spread} Type B: {Doppler shift, Doppler spread} Type C: {average delay, Doppler shift} Type D: {Spatial Rx parameters}

[0025] <Beam management with a unified TCI framework> In NR, downlink beam management is performed by signaling spatial QCL ('Type D') assumptions to the UE via the Transmission Configuration Indicator (TCI) state.

[0026] In NR Release 15 or Release 16, for the physical downlink control channel (PDCCH), the network (NW) configures the UE with a set of PDCCH TCI states by radio resource control (RRC) and activates one TCI state per control resource set (CORESET) by using a medium access control (MAC) control element (CE). For beam management of the physical downlink shared channel (PDSCH), the NW configures the UE with a set of PDSCH TCI states by RRC and activates at most eight TCI states by the MAC CE. After activation, the NW dynamically indicates one of the activated TCI states by using the TCI field in the downlink control information (DCI) when scheduling the PDSCH.

[0027] Such a framework allows the network great flexibility to instruct the UE to receive signals from different spatial directions in the downlink, at the expense of large signaling overhead and slow beam switching. These limitations are especially significant and costly when UE mobility is considered. One example is that beam updating using DCI can only be done for PDSCH, while beam updating for other reference signals / channels requires MAC CE and / or RRC, resulting in extra overhead and latency.

[0028] Furthermore, in most cases, the network transmits and receives both data and control to the UE in the same direction, so using separate frameworks (separate spatial relationships to TCI states) for different channels / signals complicates implementation.

[0029] In Release 17, a common beam framework is introduced to simplify beam management in Frequency Range 2 (FR2), where a common beam represented by a TCI state can be activated / instructed to a UE, and the common beam can be applied to multiple channels / signals, such as PDCCH and PDSCH. The common beam framework is also called the unified TCI state framework.

[0030] The new framework can be configured with the RRC in one of two operating modes: "Joint DL / UL TCI" or "Separate DL / UL TCI". In "Joint DL / UL TCI", one common joint TCI state is used for both downlink (DL) and uplink (UL) signals / channels. In "Separate DL / UL TCI", one common DL-only TCI state is used for DL ​​channels / signals and one common UL-only TCI state is used for UL channels / signals.

[0031] The uniform TCI status can be updated in a similar manner to the TCI status update for PDSCH in Release 15 / 16, i.e. one of the following two options: Two-stage: A number of unified TCI states are configured in the higher layer parameter PDSCH-config using RRC signaling and one of the unified TCI states is activated using MAC CE, or Phase 3: A certain number of unified TCI states are configured in the PDSCH-config using RRC signaling, at most 8 unified TCI states are activated using MAC CE, and one of the activated unified TCI states is indicated using a 3-bit TCI state bitfield in the DCI.

[0032] The one unified TCI state that is activated or indicated will be used in subsequent PDCCH and PDSCH transmissions until a new unified TCI state is activated or indicated.

[0033] Existing DCI formats 1_1 and 1_2 are reused for beam indication both with and without DL allocation. For DCI formats 1_1 and 1_2 with DL allocation, PDSCH acknowledgement (ACK) / negative acknowledgement (NACK) can be used as an indication of successful reception of beam indication. For DCI formats 1_1 and 1_2 without DL allocation, a new ACK / NACK mechanism similar to the one for release of Semi-Persistent Scheduling (SPS) PDSCH with both Type-1 and Type-2 HARQ-ACK codebooks is used, and the UE reports ACK in response to successful reception of beam indication DCI.

[0034] For DCI based beam indication, the first slot in which the indicated TCI state should be applied is at least Y symbols after the last symbol of the DL / UL joint or separate beam indication acknowledgement. Y symbols are configured by the gNB based on the UE capabilities and are also reported on a symbol-by-symbol basis. The value of Y has not yet been determined and is left to RAN4 to decide. Summary of the Invention

[0035] A system and method for channel state information (CSI) reference signal (RS) reception and associated CSI reporting are disclosed. In one embodiment, the method performed by a user equipment (UE) includes receiving, from a network node, first information providing a CSI-RS configuration associated with a plurality of CSI-RS samples at different time points, and receiving, from the network node, second information configuring the UE (312) to report CSI feedback based on the CSI-RS configuration associated with the plurality of CSI-RS samples. The method further includes calculating at least one or more characteristics of a precoding matrix for each CSI-RS sample of the plurality of CSI-RS samples according to the second information, and reporting either the at least one or more characteristics of the precoding matrix for each CSI-RS sample of the plurality of CSI-RS samples or information derived therefrom to the network node via one or more CSI-RS reports. In this manner, performance under mobility scenarios can be improved.

[0036] In one embodiment, the multiple CSI-RS samples are from different times within a single timeslot.

[0037] In one embodiment, the multiple CSI-RS samples are for different time points, the different time points including at least one time point in a first timeslot and at least one time point in a second timeslot different from the first timeslot.

[0038] In one embodiment, the different points in time are either different Orthogonal Frequency Division Multiplexing (OFDM) symbols within a single time slot, the same OFDM symbol within different time slots, or different OFDM symbols within different time slots.

[0039] In one embodiment, the first information includes information configuring the CSI-RS samples as different non-zero power (NZP) CSI-RS resources in an NZP CSI-RS resource set. In another embodiment, the first information includes information configuring NZP CSI-RS resources in an NZP CSI-RS resource set and a parameter indicating that the NZP CSI-RS resources in the NZP CSI-RS resource set should be interpreted by the UE as the CSI-RS samples of the same NZP CSI-RS. In one embodiment, the CSI-RS samples are aperiodic. In one embodiment, the CSI-RS samples are triggered by a single trigger. In one embodiment, the number of CSI-RS samples in the CSI-RS samples is equal to the number of NZP CSI-RS resources in the NZP CSI-RS resource set.

[0040] In an embodiment, the first information further includes information explicitly or implicitly indicating a number of CSI-RS samples in the plurality of CSI-RS samples. In an embodiment, CSI-RS resource mapping differs for at least some of the plurality of NZP CSI-RS resources in the NZP CSI-RS resource set. In an embodiment, time domain locations configured for at least some of the plurality of NZP CSI-RS resources in the NZP CSI-RS resource set differ. In an embodiment, the first information further includes one or more common parameters common to all of the plurality of NZP CSI-RS resources in the NZP CSI-RS resource set.

[0041] In an embodiment, all of the NZP CSI-RS resources in the NZP CSI-RS resource set have the same number M of antenna ports. In an embodiment, the mth (m=0, 1, ..., M-1) antenna port is the same for all of the NZP CSI-RS resources in the NZP CSI-RS resource set.

[0042] In an embodiment, at least two of the NZP CSI-RS resources in the NZP CSI-RS resource set have different numbers of antenna ports.

[0043] In an embodiment, one NZP CSI-RS resource of the plurality of NZP CSI-RS resources in the NZP CSI-RS resource set has a first number of antenna ports and all remaining NZP CSI-RS resources of the plurality of NZP CSI-RS resources in the NZP CSI-RS resource set have a second number of antenna ports. In an embodiment, the second number of antenna ports is less than the first number of antenna ports. In an embodiment, the second number of antenna ports are associated with only a single polarization.

[0044] In an embodiment, the NZP CSI resources in the NZP CSI-RS resource set are periodic, and the same Transmission Configuration Indication (TCI) State Identity (ID) is configured for all of the NZP-CSI resources in the NZP CSI-RS resource set.

[0045] In an embodiment, the NZP CSI resources in the NZP CSI-RS resource set are periodic, and a single parameter indicating a TCI state identity (ID) configured for one of the NZP-CSI resources in the NZP CSI-RS resource set is applicable to all of the NZP-CSI resources in the NZP CSI-RS resource set.

[0046] In an embodiment, the NZP CSI resources in the NZP CSI-RS resource set are periodic, and a single parameter indicating a TCI state ID configured for all of the NZP CSI resources in the NZP CSI-RS resource set is included in an information element defining the NZP CSI-RS resource set.

[0047] In an embodiment, the NZP CSI resources in the NZP CSI-RS resource set are semi-persistent, and the same TCI state ID for all of the NZP CSI resources in the NZP CSI-RS resource set is configured via a medium access control (MAC) control element that activates the NZP CSI-RS resource set.

[0048] In an embodiment, the NZP CSI resources in the NZP CSI-RS resource set are semi-persistent, and a single TCI state ID is configured and applicable to the NZP CSI resources in the NZP CSI-RS resource set via a MAC CE that activates the NZP CSI-RS resource set.

[0049] In an embodiment, the NZP CSI resources in the NZP CSI-RS resource set are semi-persistent, and a single parameter indicating a TCI state ID configured for all of the NZP CSI resources in the NZP CSI-RS resource set is included in an information element defining the NZP CSI-RS resource set.

[0050] In an embodiment, the NZP CSI resources in the NZP CSI-RS resource set are aperiodic, and the same TCI state ID is configured for all of the NZP CSI resources in the NZP CSI-RS resource set.

[0051] In an embodiment, the NZP CSI resources in the NZP CSI-RS resource set are aperiodic, and a single TCI state ID is configured for all of the NZ-CSI resources in the NZP CSI-RS resource set via an information element defining the NZP CSI-RS resource set.

[0052] In one embodiment, a unified TCI state currently activated for the UE applies to all of the NZP CSI resources in the NZP CSI-RS resource set.

[0053] In an embodiment, the first information includes information configuring the plurality of CSI-RS samples via configuration of a single NZP CSI-RS resource and information defining multiple repetitions of the NZP CSI-RS resource corresponding to the plurality of CSI-RS samples. In an embodiment, the information defining the multiple repetitions of the NZP CSI-RS resource includes information indicating one or more time offsets between repetitions of the NZP CSI-RS resource. In an embodiment, the multiple repetitions of the NZP CSI-RS resource are within a single timeslot. In an embodiment, at least one first repetition of the multiple repetitions of the NZP CSI-RS resource is within a first timeslot and at least one second repetition of the multiple repetitions of the NZP CSI-RS resource is within a second timeslot.

[0054] In an embodiment, the CSI feedback is Type I CSI feedback, and for each CSI-RS sample of the plurality of CSI-RS samples, the at least one characteristic of the precoding matrix reported to the network node includes a set of cophasing coefficients (W2).

[0055] In an embodiment, the CSI feedback is Type I CSI feedback, and wherein the at least one or more characteristics of the precoding matrix reported to the network node for one CSI-RS sample of the plurality of CSI-RS samples includes a set of cophasing coefficients (W2), and the at least one or more characteristics of the precoding matrix reported to the network node for each remaining CSI-RS sample of the plurality of CSI-RS samples includes a phase difference of each coefficient of W2 for the remaining CSI-RS sample and a respective coefficient of W2 for the one CSI-RS sample. In an embodiment, the at least one or more characteristics of the precoding matrix reported to the network node for at least one CSI-RS sample of the plurality of CSI-RS samples includes a matrix (W1) containing information of one or more selected Discrete Fourier Transform (DFT) beams.

[0056] In an embodiment, the CSI feedback is Type II CSI feedback, and for each CSI-RS sample of the plurality of CSI-RS samples, the at least one characteristic of the precoding matrix reported to the network node includes a set of cophasing coefficients (W2) and a selected set of frequency domain (FD) basis vectors.

[0057] In an embodiment, the CSI feedback is Type II CSI feedback, and the at least one or more characteristics of the precoding matrix reported to the network node for one CSI-RS sample of the plurality of CSI-RS samples includes a set of cophasing coefficients (W2) and a selected set of FD basis vectors, and for each remaining CSI-RS sample of the plurality of CSI-RS samples, the at least one or more characteristics of the precoding matrix reported to the network node include a phase difference of each coefficient of W2 for the remaining CSI-RS sample, a respective coefficient of W2 for the one CSI-RS sample, and a selected set of FD basis vectors. In an embodiment, the at least one or more characteristics of the precoding matrix reported to the network node for at least one CSI-RS sample of the plurality of CSI-RS samples includes a matrix (W1) containing information of one or more selected DFT beams.

[0058] Corresponding embodiments of a UE are also disclosed. In an embodiment, a UE comprises one or more transmitters, one or more receivers, and a processing circuit associated with the one or more transmitters and the one or more receivers. The processing circuit includes: receiving, from a network node, first information providing a CSI-RS configuration associated with a plurality of CSI-RS samples at different time points, receiving, from the network node, second information configuring the UE (312) to report CSI feedback based on the CSI-RS configuration associated with the plurality of CSI-RS samples, calculating at least one or more characteristics of a precoding matrix for each CSI-RS sample of the plurality of CSI-RS samples according to the second information, and reporting either the at least one or more characteristics of a precoding matrix for each CSI-RS sample of the plurality of CSI-RS samples or information derived therefrom to the network node via one or more CSI-RS reports.

[0059] Also disclosed are embodiments of a method performed by a network node. In one embodiment, the method performed by a network node includes: transmitting, to a UE, first information providing a CSI-RS configuration associated with a plurality of CSI-RS samples at different time points, transmitting, to the UE, second information configuring the UE to report CSI feedback based on the CSI-RS configuration associated with the plurality of CSI-RS samples at different time points, and receiving from the UE either at least one or more characteristics of the precoding matrix or information derived therefrom for each CSI-RS sample of the plurality of CSI-RS samples via one or more CSI-RS reports.

[0060] Corresponding embodiments of a network node are also disclosed. In an embodiment, the network node comprises a processing circuit configured to cause the network node to: transmit, to a UE, first information providing a CSI-RS configuration associated with a plurality of CSI-RS samples at different time points; transmit, to the UE, second information configuring the UE to report CSI feedback based on the CSI-RS configuration associated with the plurality of CSI-RS samples at different time points; and receive from the UE either at least one or more characteristics of the precoding matrix or information derived therefrom for each CSI-RS sample of the plurality of CSI-RS samples via one or more CSI-RS reports. [Brief description of the drawings]

[0061] The accompanying drawing figures, which are incorporated in and constitute a part of this specification, illustrate several aspects of the disclosure and, together with the description, serve to explain the principles of the disclosure. [Figure 1] 1 illustrates an example of channel state information reference signal (CSI-RS) resource elements (REs) for 12 antenna ports, with one RE shown per resource block (RB) and per port; [Diagram 2] 1 shows an example of a tracking reference signal (TRS) burst of two TRS symbols in two adjacent slots; [Diagram 3] 1 illustrates an example of a cellular communication system in which embodiments of the present disclosure may be implemented; [Figure 4] 1 illustrates an example CSI-RS configuration with multiple (e.g., three) samples at different time points t1, t2, and t3 according to one example embodiment of the present disclosure; [Diagram 5] Exemplary phase slots for the coefficients of the cophasing coefficient matrix W2(t) components of the precoding matrix W for type-I and type-II codebooks are shown in FIG. 5; [Figure 6] Shown are exemplary phase slots for the coefficients of W2(t); [Figure 7] 1 illustrates an example of configuring a multi-sample CSI-RS as part of a non-zero power (NZP) CSI-RS resource set according to one embodiment of the present disclosure; [Figure 8] 1 illustrates an example in which three 8-port NZP CSI-RS resources in an NZP CSI-RS resource set are configured as multiple samples of the same NZP CSI-RS, according to one embodiment of the present disclosure; [Figure 9] 1 illustrates an example in which one 8-port NZP CSI-RS resource and two 4-port NZP CSI-RS resources in an NZP CSI-RS resource set are configured as multiple samples of the same NZP CSI-RS, according to one embodiment of the present disclosure; [Figure 10] 1 illustrates an example embodiment in which a parameter, qcl-InfoPeriodicCSI-RS-r18, that provides a TCI state ID for an NZP CSI-RS resource in an NZP CSI-RS resource set, if the NZP CSI-RS resource is periodic, is configured in an information element (IE) called NZP-CSI-RS-ResourceSet; [Figure 11] 1 illustrates an example embodiment in which parameter qcl-info-r18, which includes a single Transmission Configuration Indication (TCI) State Identity (ID), provides the TCI state to be applied to all aperiodic NZP CSI-RS resources in an NZP CSI-RS resource set; [Figure 12] Illustrates an exemplary embodiment in which an 8-port CSI-RS resource is repeated twice within a slot with a gap of three Orthogonal Frequency Division Multiplexing (OFDM) symbols; [Figure 13] 1 illustrates an exemplary embodiment in which a 32-port CSI-RS resource is repeated in two consecutive slots; [Figure 14A] 1 illustrates the operation of a network node and a user equipment (UE) in accordance with at least some embodiments of the present disclosure; [Figure 14B] 1 illustrates the operation of a network node and a user equipment (UE) in accordance with at least some embodiments of the present disclosure; [Figure 15] 1 is a schematic block diagram of an exemplary embodiment of a radio access node; [Figure 16] 1 is a schematic block diagram of an exemplary embodiment of a radio access node; [Figure 17] 1 is a schematic block diagram of an exemplary embodiment of a radio access node; [Figure 18] 1 is a schematic block diagram of an exemplary embodiment of a UE; [Figure 19] 1 is a schematic block diagram of an exemplary embodiment of a UE; [Figure 20] 1 illustrates an example of a communication system in which embodiments of the present disclosure may be implemented; [Figure 21] 21 illustrates an exemplary embodiment of a host computer, a base station, and a UE in FIG. 20 ; [Figure 22] 22 is a flowchart illustrating the operation of the nodes of the communication system of FIG. 20 and FIG. 21 according to an embodiment of the present disclosure. [Figure 23] 22 is a flowchart illustrating the operation of the nodes of the communication system of FIG. 20 and FIG. 21 according to an embodiment of the present disclosure. [Figure 24] 22 is a flowchart illustrating the operation of the nodes of the communication system of FIG. 20 and FIG. 21 according to an embodiment of the present disclosure. [Diagram 25] 22 is a flowchart illustrating the operation of the nodes of the communication system of FIG. 20 and FIG. 21 according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0062] The embodiments described below represent information that will enable those skilled in the art to practice the embodiments and illustrate the best modes 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 present disclosure and recognize applications of those concepts not specifically addressed herein. It should be understood that those concepts and applications fall within the scope of the present disclosure.

[0063] Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings, in which: However, other embodiments are included within the scope of the presently disclosed subject matter, and the disclosed subject matter should not be construed as being limited to only the embodiments set forth herein, but rather, the embodiments are provided as examples to convey the scope of the subject matter to those skilled in the art.

[0064] Generally, all terms used herein should be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and / or a different meaning is suggested from the context of use. All references to an element, apparatus, component, means, step, etc., should be openly interpreted as a reference to at least one instance of that element, apparatus, component, means, step, etc., unless expressly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step, and / or there is an implicit understanding that a step must follow or precede another step. Any feature of any embodiment disclosed herein may be applied to any other embodiment, where appropriate. Similarly, any advantage of any embodiment may be applicable to any other embodiment, and vice versa. Other objects, features, and advantages of the included embodiments will become apparent from the following description.

[0065] Wireless Node: As used herein, a "wireless node" is either a wireless access node or a wireless communication device.

[0066] Radio Access Node: As used herein, a "radio access node," "radio network node," or "radio access network node" is any node in a Radio Access Network (RAN) of a cellular communications network that operates to wirelessly transmit and / or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g., a New Radio (NR) base station (gNB) in a 3rd Generation Partnership Project (3GPP) fifth generation (5G) NR network, or an enhanced or evolved Node B (eNB) in a 3GPP Long Term Evolution (LTE) network), a high power or macro base station, a low power base station (e.g., a micro base station, a pico base station, or a Home eNB), a relay node, a network node implementing a portion of the functionality of a base station (e.g., a network node implementing a gNB central unit (gNB-CU) or a network node implementing a gNB distributed unit (gNB-DU)), or a network node implementing a portion of the functionality of any other type of radio access node.

[0067] Core Network Node: As used herein, a "core network node" is any type of node in a core network or any node that implements a core network function. Some examples of a core network node include, for example, a Mobility Management Entity (MME), a Packet Data Network Gateway (P-GW), a Service Capability Exposure Function (SCEF), or a Home Subscriber Server (HSS), etc. Some other examples of a core network node include a node that implements an Access and Mobility Management Function (AMF), a User Plane Function (UPF), a Session Management Function (SMF), an Authentication Server Function (AUSF), a Network Slice Selection Function (NSSF), a Network Exposure Function (NEF), a Network Function (NF) Repository Function (NRF), a Policy Control Function (PCF), or a Unified Data Management (UDM), etc.

[0068] Communications Device: As used herein, a "communications device" is any type of device that has access to an access network. Some examples of communications devices include, but are not limited to, a mobile phone, a smartphone, a sensor device, a meter, a vehicle, a home appliance, a medical appliance, a media player, a camera, or any type of consumer electronic device, such as, but not limited to, a television, a radio, a lighting device, a tablet computer, a laptop, or a personal computer (PC). A communications device may be a portable, handheld, computer-embedded, or vehicle-mounted mobile device that is enabled to communicate voice and / or data via wireless or wired connections.

[0069] [Wireless Communication Device]: Another type of communication device is a wireless communication device, which may be any type of wireless device that has access to (is served by) a wireless network (e.g., a cellular network). Some examples of wireless communication devices include, but are not limited to, user equipment devices (UEs) in 3GPP networks, machine type communication (MTC) devices, and Internet of Things (IoT) devices. Such wireless communication devices may be or be integrated into mobile phones, smartphones, sensor devices, meters, vehicles, home appliances, medical appliances, media players, cameras, or any type of consumer electronics, such as, but not limited to, televisions, radios, lighting devices, tablet computers, laptops, or PCs. Wireless communication devices may be portable, handheld, computer-embedded, or vehicle-mounted mobile devices that are enabled to communicate voice and / or data over a wireless connection.

[0070] Network Node: As used herein, a "network node" is any node that is part of either the RAN or core network of a cellular communications network / system.

[0071] Transmit / Receive Point (TRP): In some embodiments, a TRP can be either a network node, a radio head, a spatial relation, or a transmission configuration indicator (TCI) state. A TRP can be represented by a spatial relation or a TCI state in some embodiments. In some embodiments, a TRP may use multiple TCI states. In some embodiments, a TRP may be part of a gNB that transmits and receives radio signals to and from a UE according to physical layer attributes and parameters specific to that element. In some embodiments, in multiple TRP (multi-TRP) operation, a serving cell can schedule a UE from two TRPs, providing better physical downlink shared channel (PDSCH) coverage, reliability, and / or data rates. There are two different operation modes for multi-TRP: single downlink control information (DCI) and multi-DCI. For both modes, control of uplink and downlink operation is done by both the physical layer and the medium access control (MAC). In single DCI mode, the UE is scheduled with the same DCI for both TRPs, and in multi-DCI mode, the UE is scheduled with independent DCI from each TRP.

[0072] In some embodiments, a set of Transmission Points (TPs) is a set of geographically collocated transmit antennas (e.g., an antenna array (having one or more antenna elements)) for a cell, a part of a cell, or a TP dedicated to a Positioning Reference Signal (PRS). TPs may include base station (eNB) antennas, remote radio heads (RRHs), remote antennas of a base station, antennas of a PRS-dedicated TP, etc. A cell may be formed by one or more TPs. For homogeneous deployment, each TP may correspond to a cell.

[0073] In some embodiments, a set of TRPs is a geographically collocated set of antennas (e.g., an antenna array (having one or more antenna elements)) that supports the functionality of a TP and / or a Receiving Point (RP).

[0074] It should be noted that the description provided herein focuses on 3GPP cellular communication systems, and therefore 3GPP terminology or terminology similar to 3GPP terminology is often used, however, the concepts disclosed herein are not limited to 3GPP systems.

[0075] It is important to note that although reference may be made to the term "cell" in this description, particularly with respect to 5G NR concepts, a beam may be used instead of a cell, and therefore the concepts described herein are equally applicable to both cells and beams.

[0076] Currently, a challenge exists. Measurements in real deployments have observed that downlink multi-user multiple-input multiple-output (MIMO) precoding performance degrades when one or more of the co-scheduled UEs start moving faster than a few kilometers per hour (km / h) relative to the base station. One of the main reasons is that when this happens, the channel information used in computing the multiple-input multiple-output (MIMO) precoding at the base station becomes stale rather quickly. As a result, the precoder loses its effectiveness in protecting the co-scheduled UEs from interference during transmissions to the intended UEs. Thus, downlink MIMO precoding needs to be made robust to faster UE speeds.

[0077] In 3GPP Pre-Release 18, there have been proposals and discussions with a view to extending Type-I or Type-II Channel State Information (CSI) feedback with time domain / Doppler information. However, the current CSI Reference Signal (CSI-RS) configuration is not suitable for deriving the time domain / Doppler information because the current CSI-RS resource configuration only configures a single CSI-RS sample per resource within a CSI-RS period. In order for the UE to calculate the time domain / Doppler information and send it back as Type-I or Type-II CSI feedback, a CSI-RS resource configuration with multiple samples is needed. How to configure the UE with such a multiple sample CSI-RS is an open problem that needs to be solved.

[0078] Certain aspects of the present disclosure and embodiments thereof may provide solutions to the above or other problems. In order to configure multiple non-zero power (NZP) CSI-RS samples, embodiments related to two different alternative solutions are proposed. These solutions include: The first solution (Solution 1) is based on configuring multiple NZP CSI-RS resources in an NZP CSI-RS resource set, each of the multiple NZP CSI-RS resources representing a single sample. The second solution (Solution 2) is based on configuring a single NZP CSI-RS resource and configuring a number of repetitions associated with the single NZP CSI-RS resource.

[0079] For Solution 1, embodiments of systems and methods are provided for configuring a plurality of NZP CSI-RS samples via configuring a plurality of NZP CSI-RS resources in an NZP CSI-RS resource set, each of the plurality of NZP CSI-RS resources representing one NZP CSI-RS sample. These embodiments may include any one or more of the following characteristics: Details of how to configure an NZP CSI-RS resource set to contain multiple samples of an NZP CSI-RS (this should be distinguished from legacy operation where different NZP CSI-RS resources within an NZP CSI-RS resource set are different NZP CSI-RS) - see Section 3 for various approaches to configuring an NZP CSI-RS resource set for a multi-sample NZP CSI-RS. · Assumptions regarding antenna ports on different NZP CSI-RS resources in an NZP CSI-RS resource set - see details in section 3.1. Details of TCI status indication for different NZP CSI-RS resources in an NZP CSI-RS resource set - For details related to periodic NZP CSI-RS, see Section 3.2 -See Section 3.3 for details related to semi-persistent NZP CSI-RS -See Section 3.4 for details related to aperiodic NZP CSI-RS -See Section 3.5 for details regarding TCI status indication via the Unified TCI Framework · Performing CSI measurements and reporting on multiple samples of the NZP CSI-RS - see sections 1 or 2.

[0080] For Solution 2, embodiments of systems and methods are provided for configuring multiple NZP CSI-RS samples via configuring an NZP CSI-RS resource, where a number of repetitions are associated with a single NZP CSI-RS resource, with each repetition representing a single NZP CSI-RS sample. These embodiments may include one or more of the following characteristics: Details of intra-slot NZP CSI-RS repetition - see section 4.1 Details of inter-slot NZP CSI-RS repetition - see section 4.2 · Performing CSI measurements and reporting on multiple samples of the NZP CSI-RS - see sections 1 or 2.

[0081] Certain embodiments may provide one or more of the following technical advantages: Embodiments of the proposed solution enable CSI measurements for multiple NZP CSI-RS samples, improving performance, for example, under mobility scenarios. Some of the embodiments provide unique ways to configure multiple NZP CSI-RS samples while reducing configuration overhead (e.g., Radio Resource Control (RRC) signaling overhead is reduced).

[0082] FIG. 3 illustrates one example of a cellular communication system 300 in which embodiments of the present disclosure may be implemented. In the embodiment described herein, the cellular communication system 300 is a 5G system (5GS) including Next Generation RAN (NG-RAN) and a 5G Core (5GC). However, the present disclosure is not limited thereto and may be utilized in other types of wireless or cellular communication systems, such as an Evolved Packet System (EPS) including an Evolved Universal Terrestrial RAN (E-UTRAN) and an Evolved Packet Core (EPC). In this example, the RAN includes base stations 302-1 and 302-2, which in 5GS include NR base stations (gNBs) and optionally next generation eNBs (ng-eNBs) (e.g., LTE RAN nodes connected to 5GC) that control corresponding (macro) cells 304-1 and 304-2. The base stations 302-1 and 302-2 are generally referred to herein collectively as base stations 302 and individually as base station 302. Similarly, the (macro) cells 304-1 and 304-2 are generally collectively referred to herein as the plurality of (macro) cells 304, and individually referred to as the (macro) cell 304. The RAN may also include a plurality of low power nodes 306-1 to 306-4 that control corresponding small cells 308-1 to 308-4. The low power nodes 306-1 to 306-4 may be small base stations (such as pico or femto base stations) or remote radio heads (RRHs), and the like. Notably, although not shown, one or more of the small cells 308-1 to 308-4 may alternatively be provided by the base station 302. The low power nodes 306-1 to 306-4 are generally collectively referred to herein as the plurality of low power nodes 306, and individually referred to as the low power node 306. Similarly, small cells 308-1 through 308-4 are generally referred to herein collectively as a plurality of small cells 308, and individually as small cell 308. The cellular communication system 300 also includes a core network 310, referred to as 5G in a 5G system (5GS) or 5GC. The base stations 302 (and optionally the low power nodes 306) are connected to the core network 310.

[0083] The base station 302 and low power node 306 provide service to wireless communication devices 312-1 through 312-5 in corresponding cells 304 and 308. The wireless communication devices 312-1 through 312-5 are generally referred to herein collectively as wireless communication devices 312, and individually as a wireless communication device 312. In the following description, the wireless communication devices 312 are often UEs, although this disclosure is not limited thereto.

[0084] An embodiment description of how multiple CSI-RS samples are used by the UE 312 to enhance Type-I or Type-II codebook-based CSI feedback with time domain / Doppler information is provided first, followed by detailed embodiments for configuration and signaling of CSI-RS with multiple samples.

[0085] FIG. 4 illustrates an exemplary CSI-RS configuration with multiple (e.g., 3) samples at different time instants t1, t2, and t3. The different time instants may be different Orthogonal Frequency Division Multiplexing (OFDM) symbols in the same slot, or the same or different OFDM symbols in different slots. In some embodiments, the time instants may be unevenly spaced (e.g., t2-t1=2 and t3-t2=3). Note that if the CSI-RS is configured as a periodic or semi-persistent CSI-RS, the multiple time instants or samples may be within a CSI-RS period. If the CSI-RS is configured as an aperiodic CSI-RS, the multiple time instants or samples are triggered by a single trigger (e.g., triggered via a single DCI).

[0086] <1 Extension of Type I CSI feedback based on multiple CSI-RS samples>

number

[0087] In one embodiment, W1(t1) and W2(t1) are reported at one reporting time point, while W2(t2) and W2(t3) are reported at separate reporting time points.

[0088] In other embodiments, W1(t1) and W2(t1) are reported at a first reporting time point, while W2(t2) and W2(t3) are reported together at a second reporting time point.

[0089] In yet another embodiment, W1(t1), W2(t1), W2(t2) and W2(t3) are reported together at a single reporting time point.

[0090] In the above embodiment, the reporting time may be reported via either the PUSCH or the PUCCH.

[0091] In one example, using W2(t1), W2(t2) and W2(t3), the network (e.g., a network node, such as base station 302, e.g., a gNB) can derive the phase change for each coefficient of W2 over multiple time points {t1, t2 and t3} and thus estimate the underlying corresponding Doppler frequency or phase gradient over that time period based on some criterion, such as mean square error (MSE). An example phase gradient for the coefficients of W2(t) is shown in FIG. 5. The estimated Doppler frequency or phase gradient can then be used to predict the corresponding coefficients of W2 at future time points.

[0092] Alternatively, instead of reporting W2(t2) and W2(t3), the phase difference of each coefficient of W2 at different time points relative to the first time point is reported. In a further embodiment, the phase gradient of each coefficient of W2 over the time window is reported.

[0093] <2 Extension of Type II CSI Feedback Based on Multiple CSI-RS Samples>

number

[0094] However, since the cophasing coefficients between the selected DFT beam (i.e., spatial domain) and the selected FD basis vectors change at different times, W2 must be calculated and reported at each time point t1, t2, and t3 (i.e., W2(t1), W2(t2), and W2(t3) calculated at times t1, t2, and t3).

[0095] In one embodiment, at a given reporting time, W1(t1), W f (t1) and W2(t1) are reported, while W2(t2) and W2(t3) are reported at separate reporting times.

[0096] In another embodiment, at the first reporting time, W1(t1), W f (t1) and W2(t1) are reported, while at the second reporting time, W2(t2) and W2(t3) are reported together.

[0097] In yet another embodiment, W1(t1), W f (t1), W2(t1), W2(t2) and W2(t3) are reported together.

[0098] In the above embodiment, the reporting time may be reported via either the PUSCH or the PUCCH.

[0099] Using W2(t1), W2(t2) and W2(t3), the network (e.g., a network node, such as base station 302, e.g., a gNB) can derive the phase change for each coefficient of W2 over multiple time points {t1, t2 and t3} and thus estimate the underlying corresponding Doppler frequency or phase gradient over that time period based on some criteria, such as MSE. An example phase gradient for the coefficients of W2(t) is shown in FIG. 6. The estimated Doppler frequency or phase gradient can then be used to predict the corresponding coefficients of W2 at future time points.

[0100] Alternatively, instead of reporting W2(t2) and W2(t3), the phase difference of each coefficient of W2 at different time points relative to the first time point is reported. In a further embodiment, the phase gradient of each coefficient of W2 over the time window is reported.

[0101] <3 Indication of multiple CSI-RS samples via higher layer parameters in the NZP CSI-RS resource set> In one embodiment, the multiple CSI-RS samples are configured to the UE 312 as different NZP CSI-RS resources in an NZP CSI-RS resource set. A higher layer parameter, e.g., in an information element (IE) called NZP-CSI-RS-ResourceSet (see 3GPP TS38.331 V16.6.0 for a definition of the IE NZP-CSI-RS-ResourceSet), may be configured to the UE 312 to inform the UE 312 that the NZP CSI-RS resources configured in the NZP CSI-RS resource set correspond to different samples of the same NZP CSI-RS. An example of such a configuration is given in FIG. 7. In this example, when the higher layer parameter "multisample-r18" is configured as 'on', the NZP CSI-RS resources in the NZP CSI-RS resource set are interpreted by the UE 312 as multiple samples of the same NZP CSI-RS. If "multisample-r18" is configured as 'off' or if "multisample-r18" is absent (i.e., it is not configured), UE312 does not assume that NZP CSI-RS resources in an NZP CSI-RS resource set are multiple samples of the same NZP CSI-RS.

[0102] The number of samples may also need to be configured to the UE 312. In some embodiments, the number of samples is always equal to the number of NZP CSI-RS resources in the configured NZP CSI-RS resource set. In that case, the UE 312 can infer the number of samples from the configured NZP CSI-RS resource set, and thus no explicit signaling is required. In some other embodiments, the number of samples and / or samples to be used for CSI calculation may be explicitly signaled to the UE 312. The signaling may be either separately coded or jointly coded with higher layer parameters for triggering multi-sample CSI-RS. In some embodiments, the explicitly signaled number of samples may be included as a higher layer parameter in the IE NZP-CSI-RS-ResourceSet.

[0103] In some embodiments, the configured CSI-RS resource mapping and / or time domain location for each of the NZP CSI-RS resources in the NZP CSI-RS resource set are different, while other parameters (e.g., other than the CSI-RS resource mapping and / or time domain location) may be similar among the NZP CSI-RS resources in the NZP CSI-RS resource set. Thus, to save signaling overhead, it may not be necessary to signal those other parameters for each of the NZP CSI-RS resources. In some embodiments, those other parameters are configured only for one of the NZP CSI-RS resources (e.g., the first NZP CSI-RS resource in the NZP CSI-RS resource set), and the UE interprets those parameters as applying to all NZP CSI-RS resources in the NZP CSI-RS resource set when the higher layer parameter "multisample-r18" is configured as 'on'.

[0104] FIG. 7 shows an example of configuring a multi-sample CSI-RS as part of an NZP CSI-RS resource set.

[0105] <3.1 Assumptions regarding antenna ports for different NZP CSI-RS resources> In another embodiment, all NZP CSI-RS resources in an NZP CSI-RS resource set have the same number M of antenna ports (i.e., all NZP CSI-RS resources in an NZP CSI-RS resource set are configured with the same value for the higher layer parameter 'nrofPorts' as defined in 3GPP TS38.331 v16.6.0). In this case, when the NZP CSI-RS resources in an NZP CSI-RS resource set are multiple samples of the same NZP CSI-RS, it means that the mth antenna port (m=0,1,...,M-1) for all NZP CSI-RS resources in the NZP CSI-RS resource set is the same. This may be interpreted as the mth antenna port (m=0,1,...,M-1) for all NZP CSI-RS resources in an NZP CSI-RS resource set being transmitted using one of either an antenna element, a sub-array of a set of antenna elements, or a beam. That is, the first antenna port for all NZP CSI-RS resources in an NZP CSI-RS resource set is the same, the second antenna port for all NZP CSI-RS resources in an NZP CSI-RS resource set is the same, etc. Note that the above condition 'same antenna port for all NZP CSI-RS resources in an NZP CSI-RS resource set' shall be satisfied for all M antenna ports. Figure 8 shows an example where three 8-port NZP CSI-RS resources in an NZP CSI-RS resource set are configured as samples of the same NZP CSI-RS. In this example, we have: Port 3000 in the first, second and third NZP CSI-RS resources is the same, Port 3001 in the first, second and third NZP CSI-RS resources is the same, Port 3002 in the first, second and third NZP CSI-RS resources is the same, Port 3003 in the first, second and third NZP CSI-RS resources is the same, Port 3004 in the first, second and third NZP CSI-RS resources is the same, Port 3005 in the first, second and third NZP CSI-RS resources is the same, Port 3006 in the first, second and third NZP CSI-RS resources is the same, Port 3007 on the first, second and third NZP CSI-RS resources is the same

[0106] In yet another embodiment, one of the NZP CSI-RS resources within the NZP CSI-RS resource set is configured with M1 antenna ports, and the remaining NZP CSI-RS resources within the NZP CSI-RS resource set are configured with a smaller number M2 of antenna ports, where M2 < M1. For example, the NZP CSI-RS resource with a larger number of ports may be the NZP CSI-RS resource that occurs earliest in time among the plurality of NZP CSI-RS resources within the NZP CSI-RS resource set (e.g., the earliest NZP CSI-RS resource may correspond to the NZP CSI-RS resource at time t1 in FIG. 4). The advantage here is that for all NZP CSI-RS resources within the NZP CSI-RS resource set except for one of them, a smaller number M2 of antenna ports can be used, so the NZP CSI-RS overhead associated with multi-sample CSI-RS can be reduced. In this mechanism for reducing the overhead for configuring multi-sample CSI-RS, for all NZP CSI-RS resources within the NZP CSI-RS resource set, the m-th antenna port (m = 0, 1,..., M2 - 1) for the first M2 antenna ports is the same. This can be interpreted as the m-th antenna port (m = 0, 1,..., M2 - 1) being transmitted using any one of an antenna element, a sub-array consisting of a set of antenna elements, or a beam for all NZP CSI-RS resources within the NZP CSI-RS resource set. FIG. 9 shows an example in which one 8-port NZP CSI-RS resource and two 4-port NZP CSI-RS resources within the NZP CSI-RS resource set are configured as multiple samples of the same NZP CSI-RS. In this example, there are the following: · Port 3000 in the first, second, and third NZP CSI-RS resources is the same, · Port 3001 in the first, second, and third NZP CSI-RS resources is the same, Port 3002 in the first, second and third NZP CSI-RS resources is the same, Port 3003 in the first, second and third NZP CSI-RS resources is the same

[0107] In another example, the M2 ports may be associated with only a single polarity, and the CSI-RS overhead may be reduced by approximately half. This is effective because the time domain channel attributes (e.g., Doppler) are common to both polarities. In one variation of the above embodiment, M2=1 in the above embodiment, in which case, multiple NZP CSI-RS resources may be configured with a single CSI-RS port, except for one NZP CSI-RS resource in the NZP CSI-RS resource set. In this case, only one NZP CSI-RS resource in the resource set is configured with M1 CSI-RS ports, which is greater than one.

[0108] 3.2 TCI Status Indication for Periodic NZP CSI-RS Resources In some embodiments, if the NZP CSI-RS resources in an NZP CSI-RS resource set are periodic, then qcl-InfoPeriodicCSI-RS, which provides the TCI state ID associated with the NZP CSI-RS as defined in 3GPP TS38.331 v16.6.0, is configured to be identical for all NZP CSI-RS resources in the NZP CSI-RS resource set (i.e., the same value for parameter qcl-InfoPeriodicCSI-RS is configured for all NZP CSI-RS resources in the NZP CSI-RS resource set).

[0109] In an embodiment, if the NZP CSI-RS resource is periodic, the parameter qcl-InfoPeriodicCSI-RS providing the TCI state ID is configured only in the first NZP CSI-RS resource in the NZP CSI-RS resource set (the parameter qcl-InfoPeriodicCSI-RS is not configured in the remaining CSI-RS resources except the first NZP CSI-RS resource in the NZP CSI-RS resource set). Assuming that the NZP CSI-RS resource set is configured for multisample CSI-RS (e.g. the flag 'multisample-r18' is configured as 'on' or present in the NZP CSI-RS resource set), the UE interprets that the TCI state ID provided by the parameter qcl-InfoPeriodicCSI-RS configured in the first NZP CSI-RS resource in the NZP CSI-RS resource set should also apply to the remaining NZP CSI-RS resources in the NZP CSI-RS resource set. An advantage of this embodiment is that it is not necessary to configure qcl-InfoPeriodicCSI-RS on all NZP CSI-RS resources in the NZP CSI-RS resource set, thus saving higher layer signaling overhead.

[0110] In another embodiment, if the NZP CSI-RS resources are periodic, then the parameter qcl-InfoPeriodicCSI-RS-r18 providing the TCI state ID for the NZP CSI-RS resources in the NZP CSI-RS resource set is configured in the IE NZP-CSI-RS-ResourceSet as shown in Figure 10. If the UE 312 is configured with multisample CSI-RS in the NZP CSI-RS resource set (e.g. the flag 'multisample-r18' is configured as 'on' or present in the NZP CSI-RS resource set), then the UE 312 interprets that the TCI state ID provided by the parameter qcl-InfoPeriodicCSI-RS configured in the NZP CSI-RS resource set should apply to all NZP CSI-RS resources in the NZP CSI-RS resource set. If the UE312 is not configured with multisample CSI-RS in the NZP CSI-RS resource set (e.g. the flag 'multisample-r18' is configured as 'off' or is not present in the NZP CSI-RS resource set), then the UE312 may not be configured with the parameter qcl-InfoPeriodicCSI-RS-r18 at the NZP CSI-RS set level (instead, in this case each NZP CSI-RS resource may be configured with qcl-InfoPeriodicCSI-RS for each periodic CSI-RS resource in the NZP CSI-RS resource set).

[0111] 3.3 TCI Status Indication for Semi-Persistent NZP CSI-RS Resources In some embodiments, if an NZP CSI-RS resource in an NZP CSI-RS resource set is semi-persistent, then the same TCI state ID is indicated for all NZP CSI-RS resources at the MAC CE that activates that semi-persistent NZP CSI-RS resource set. For example, if there are N semi-persistent NZP CSI-RS resources in a semi-persistent NZP CSI-RS resource set, then the MAC CE that activates that NZP CSI-RS resource set includes N TCI state IDs set to the same value (each TCI state ID indicates the TCI state to be applied to each of the N NZP CSI-RS resources).

[0112] In another embodiment, when an NZP CSI-RS resource is semi-persistent, only a single TCI state ID is indicated in the MAC CE that activates that semi-persistent NZP CSI-RS resource set. The single TCI state provides the TCI state to be applied to all of the semi-persistent NZP CSI resources in the semi-persistent NZP CSI-RS resource set. An advantage of this embodiment is that multiple TCI state IDs do not need to be signaled in the MAC CE that activates the semi-persistent NZP CSI-RS resource set, thus saving MAC CE signaling overhead.

[0113] In another embodiment, if the NZP CSI-RS resources are semi-persistent, a TCI State ID parameter providing the TCI State ID for all NZP CSI-RS resources in the NZP CSI-RS resource set is configured in the IE NZP-CSI-RS-ResourceSet (similar to the parameter qcl-InfoPeriodicCSI-RS-r18 shown in FIG. 10 ). If the UE 312 is configured with multisample CSI-RS in the NZP CSI-RS resource set (e.g. the flag 'multisample-r18' is configured as 'on' or present in the NZP CSI-RS resource set), the UE 312 interprets that the TCI State ID provided in the NZP CSI-RS resource set should apply to all NZP CSI-RS resources in the NZP CSI-RS resource set.

[0114] 3.4 TCI Status Indication for Aperiodic NZP CSI-RS Resources In some embodiments, if the NZP CSI-RS resources in an NZP CSI-RS resource set are aperiodic, the same TCI state ID is indicated for all NZP CSI-RS resources in that aperiodic NZP CSI-RS resource set. If an uplink DCI triggers an aperiodic CSI-RS resource set, a codepoint in the 'CSI request field' in the uplink DCI will point to one CSI-AperiodicTriggerState as specified in IE CSI-AperiodicTriggerStateList in 3GPP TS38.331 v16.6.0. Each CSI-AperiodicTriggerState will trigger a CSI-AssociatedReportConfigInfo that includes the NZP CSI-RS resource set for channel measurements. If the NZP CSI-RS resource set is aperiodic and configured for multisample CSI-RS (e.g., flag 'multisample-r18' is configured as 'on' or present in the NZP CSI-RS resource set), in some embodiments, a single TCI state ID is provided as part of the CSI-AssociatedReportConfigInfo to be applied to all aperiodic NZP CSI resources in the NZP CSI-RS resource set. An example is shown in Figure 11, where parameter qcl-info-r18 containing a single TCI state ID provides the TCI state to be applied to all aperiodic NZP CSI-RS resources in the NZP CSI-RS resource set. Note that when qcl-info-r18 is configured, the parameter qcl-info that would have provided multiple TCI state IDs (one TCI state ID per aperiodic CSI-RS resource) is not configured in the CSI-AssociatedReportConfigInfo.

[0115] In another embodiment, if the NZP CSI-RS resources are aperiodic, then a TCI State ID parameter providing the TCI State ID for all NZP CSI-RS resources in the NZP CSI-RS resource set is configured in the IE NZP-CSI-RS-ResourceSet (similar to the parameter qcl-InfoPeriodicCSI-RS-r18 shown in FIG. 10 ). If the UE 312 is configured with multisample CSI-RS in the NZP CSI-RS resource set (e.g. the flag 'multisample-r18' is configured as 'on' or present in the NZP CSI-RS resource set), then the UE 312 interprets that the TCI State ID provided in the NZP CSI-RS resource set should apply to all NZP CSI-RS resources in the NZP CSI-RS resource set.

[0116] <3.5 TCI Status Indication via the Unified TCI Framework> In another embodiment, if the NZP CSI-RS resources in the NZP CSI-RS resource set are periodic / semi-persistent / aperiodic, the unified TCI state currently activated for the UE 312 (either "joint DL / UL TCI" or DL ​​TCI state) applies to all NZP CSI resources in the NZP CSI-RS resource set.

[0117] <3.6 Differences from conventional solutions> It should be noted that the above proposed embodiment is different from the case where the parameter 'trs-info' is set to 'true' in the NZP CSI-RS resource set. When 'trs-info' is set to true in the NZP CSI-RS resource set, the NZP CSI-RS resources (which are tracking reference signals or TRS) in the NZP CSI-RS resource set can be used by the UE to derive time domain channel attributes such as Doppler shift and Doppler spread. However, until NR Release 17, the UE does not report any CSI for the TRS resources. With the proposed solution, the UE 312 can use the multi-sample NZP CSI-RS to perform the calculation of the precoding matrix indicator (PMI) corresponding to the extended Type-I or Type-II CSI as described in Solutions 1 and 2 above, and can report the calculated extended Type-I or Type-II CSI to the network. In addition to the PMI, the extended Type-I or Type-II CSI may include one or more of a Rank Indicator (RI), a Layer Indicator (LI) and a Channel Quality Indicator (CQI). Another difference is that the TRS only allows measurements on a single antenna port, while the solution proposed here allows multi-sample measurements on the NZP CSI-RS for M antenna ports, which is greater than one.

[0118] Furthermore, the above proposed embodiment also differs from the case where the parameter 'repetition' is set to 'on' in the NZP CSI-RS resource set. If the parameter 'repetition' is set to 'on', the NZP CSI-RS resources in the NZP CSI-RS resource set may be used by the UE to measure and report Layer 1 RSRP (L1-RSRP) or Layer 1 (L1-SINR). On the other hand, the proposed solution allows the UE to perform PMI calculations corresponding to the extended Type-I or Type-II CSI, as described above.

[0119] <4. Indication of multiple CSI-RS samples via indication of offsets associated with multiple CSI-RS samples> <4.1 Intra-Slot CSI-RS Repetition> In some embodiments, only a single NZP CSI-RS resource may be configured in the NZP CSI-RS resource set. The CSI-RS resource may be triggered and repeated within a slot. The repetition may be either configured in the CSI reporting configuration, dynamically indicated in the DCI triggering the CSI reporting, or activated by the MAC CE activating the CSI reporting. Note that in these embodiments, different repetitions represent different repetitions of the NZP CSI-RS. The number of repetitions may be pre-specified, e.g. fixed to 2 repetitions. Alternatively, the number of repetitions may be linked to the number of CSI-RS ports in the CSI-RS resource. For example, for 16 or 32 CSI-RS ports, the number of repetitions is fixed to 2. For 8 CSI-RS ports, the number of repetitions may be more than 2, e.g. 3 or 4, either one of them may be configured or dynamically indicated in the DCI. Also, the gap between two repetitions may be configured in number of OFDM symbols. An example is shown in Figure 12, where an 8-port CSI-RS resource is repeated twice in a slot with a gap of 3 OFDM symbols. In some embodiments, the gap size and / or number of repetitions is configured by higher layers to the UE (e.g., via RRC). In some embodiments, the gap size and / or number of repetitions may be configured as part of higher layer parameters in any one of the following IEs: The IE called NZP-CSI-RS-Resource defined in 3GPP TS38.331 V16.6.0 IE called CSI-RS-ResourceMapping defined in 3GPP TS38.331 V16.6.0 The IE called NZP-CSI-RS-ResourceSet defined in 3GPP TS38.331 V16.6.0 As part of CSI-AssociatedReportConfigInfo in the IE called CSI-AperiodicTriggerStateList defined in 3GPP TS38.331 V16.6.0 IE called CSI-ReportConfig defined in 3GPP TS38.331 V16.6.0

[0120] In an alternative embodiment, assuming N repetitions (i.e., samples) in a slot, an alternative approach could be to signal a time domain offset (in number of symbols) corresponding to the remaining N-1 samples relative to the first sample.

[0121] In some embodiments, multiple gap sizes may be signaled by the network to the UE 312 to support use cases where the NZP CSI-RS samples are non-uniformly spaced. Considering the example shown in Figure 4, a first gap spacing of two symbols between samples at times t1 and t2 may be configured at higher layers by the network to the UE 312. Additionally, a second gap spacing of three symbols between samples at times t2 and t3 may be configured at higher layers by the network to the UE 312.

[0122] In another embodiment, to support use cases where the NZP CSI-RS samples are non-uniformly spaced, a single gap size may be signaled by the network to the UE 312. In this embodiment, referring to the example shown in Figure 4, the gap spacing between samples of times t1 and t2 is given by a single signaled / configured gap size. The gap spacing between samples of times t2 and t3 is also given by the same single gap size.

[0123] In some embodiments, for a single NZP CSI-RS resource, the firstOFDMSymbolInTimeDomain and firstOFDMSymbolInTimeDomain2 in the CSI-RS-ResourceMapping (as defined in 3GPP TS38.331 V16.6.0) associated with that NZP CSI-RS resource provide the time domain symbol for the first NZP CSI-RS repetition (or first NZP CSI-RS sample) in the slot. The time domain location for the second NZP CSI-RS sample is determined by offsetting firstOFDMSymbolInTimeDomain and firstOFDMSymbolInTimeDomain2 by the sample gap size between the first and second NZP CSI-RS samples (i.e., the time domain location for the second NZP CSI-RS sample is determined by firstOFDMSymbolInTimeDomain+g1 and firstOFDMSymbolInTimeDomain2+g1, where g1 is the sample gap size between the first and second NZP CSI-RS samples).

[0124] The time domain location for the third NZP CSI-RS sample is determined by offsetting firstOFDMSymbolInTimeDomain and firstOFDMSymbolInTimeDomain2 by the sample gap size between the first NZP CSI-RS sample and the second NZP CSI-RS sample and between the second NZP CSI-RS sample and the third NZP CSI-RS sample (i.e., the time domain location for the third NZP CSI-RS sample is determined by firstOFDMSymbolInTimeDomain+g1+g2 and firstOFDMSymbolInTimeDomain2+g1+g2, where g1 is the sample gap size between the second and third NZP CSI-RS samples).

[0125] <4.2 Inter-Slot CSI-RS Repetition> In other embodiments, CSI-RS resources may be triggered to be repeated across slots. The repetition may be configured in the CSI reporting configuration, dynamically indicated in the DCI triggering the CSI reporting, or indicated via the MAC CE activating the CSI reporting. The number of repetitions may be pre-specified, e.g. fixed to 2 repetitions. Alternatively, the number of repetitions may be dynamically indicated in the DCI or indicated via the MAC CE. The same time and frequency resources are used in each of the slots that are repeated for the CSI-RS resources. An example is shown in Figure 13, where a 32-port CSI-RS resource is repeated in two consecutive slots.

[0126] In some embodiments, a configured / indicated / signaled number of repetitions (i.e., samples) are received in adjacent slots. In this embodiment, if the time / frequency resource allocation for a particular NZP CSI-RS sample in a particular slot collides with an SSB or at least one uplink symbol, that particular NZP CSI-RS sample is discarded and CSI is not measured using that NZP CSI-RS sample.

[0127] In other embodiments, a configured / indicated / signaled number of NZP CSI-RS repetitions (i.e., samples) are received in non-adjacent slots. Which slots should carry different numbers of NZP CSI-RS repetitions may be indicated in various ways. For example, a bitmap of predefined length may be used for that purpose. In this bitmap, each bit indicates whether an NZP CSI-RS sample appears in a respective slot. A bit value of 1 may indicate that an NZP CSI-RS sample appears in that respective slot. Alternatively, one or more gap sizes between different samples may be configured to indicate which slots contain NZP CSI-RS samples.

[0128] In a further embodiment, both intra-slot and inter-slot repetition may be configured for the CSI-RS resources associated with the CSI report.

[0129] To ensure accurate CSI measurements, phase continuity between CSI-RS repetitions within a slot or across multiple slots is required.

[0130] <5 Periodic or semi-persistent CSI-RS> The UE 312 can be configured with periodic or semi-persistent CSI-RS. The advantage is that the same CSI-RS can be shared among multiple UEs to save CSI-RS overhead. In this case, the UE 312 needs to determine which samples to use for CSI calculation. In some embodiments, the UE 312 is configured by the network (e.g., a network node, such as the base station 302, e.g., a gNB) as to which samples to use for CSI calculation. For example, such a configuration may explicitly indicate the time-domain location of the CSI-RS samples to be used. In some other embodiments, the UE 312 may be configured with the number of samples to use. The configuration may be either configured in the corresponding CSI reporting configuration or dynamically indicated in the DCI that triggers the CSI reporting.

[0131] <6. Further explanation> Figures 14A and 14B illustrate the operation of a network node 1400 and a UE 312 according to at least some of the embodiments described above. The network node 1400 may be, for example, a base station 302, a RAN node (e.g. gNB-CU) performing at least part of the functionality of the base station 302, or some other network node. Optional steps are represented by dashed lines / boxes. It should be noted that details of the various embodiments described above in sections 1-5 are applicable to the relevant steps of the procedures of Figures 14A and 14B.

[0132] As shown, the network node 1400 provides to the UE 312 first information providing a CSI-RS configuration with multiple CSI-RS samples at different times (step 1402). As mentioned above, in one embodiment ("embodiment A"), step 1402 includes the network node 1400 providing to the UE 1312 an indication of the multiple CSI-RS samples (e.g., indicated as multiple NZP CSI-RS resources in an NZP CSI-RS resource set), e.g., via a higher layer parameter (e.g., a parameter indicating to the UE 312 that the multiple NZP CSI-RS resources in the NZP CSI-RS resource set should be interpreted by the UE 312 as multiple samples of the same CSI-RS) (step 1402A-1). In addition, the network node 1400 may provide to the UE 312 an explicit or implicit indication of the number of CSI-RS samples (step 1402A-2). The network node 1400 may provide information indicating the TCI state ID for those CSI-RS samples (step 1402A-3). Further details regarding steps 1402A-1, 1402A-2 and 1402A-3 and associated embodiments may be found, for example, in section 3 above. Those details apply equally here.

[0133] Alternatively, in another embodiment of step 1402 ("embodiment B"), the network node 140 provides an indication of multiple CSI-RS samples to the UE 312 (step 1402B-1) via providing information indicating multiple repetitions of a single NZP CSI-RS resource (e.g., via indicating a time offset or time gap between multiple repetitions of a single NZP CSI-RS resource). Alternatively, the repetitions of a single NZP CSI-RS resource may be indicated via a CSI reporting configuration, dynamically (e.g., via a DCI triggering a CSI report), or indicated via a MAC CE, etc. Further details regarding step 1402B-1 and associated embodiments may be found, for example, in section 4 above. Those details apply equally here.

[0134] It should also be noted that the information provided to the UE 312 in step 1402 may be transmitted via one or more messages using one or more signaling types (e.g., RRC, MAC, DCI, or a combination of two or more thereof).

[0135] The network node 1400 transmits to the UE 312 second information (e.g., CSI reporting configuration) that configures the UE to report CSI feedback (e.g., Type I or Type II) based on a CSI-RS configuration associated with the plurality of CSI-RS samples (step 1404). The UE 312 calculates at least some characteristics of a precoding matrix for each CSI-RS sample according to the configuration of step 1404 (step 1406) and reports that information or information derived therefrom via one or more CSI-RS reports (step 1408). Details of what information is calculated and reported may be found above, e.g., in Section 1 (Type I) and Section 2 (Type II). Those details apply equally here.

[0136] The network node 1400 may then perform one or more operational tasks based on the CSI report (step 1410). For example, the network node 1400 may utilize the information for downlink MU-MIMO precoding.

[0137] FIG. 15 is a schematic block diagram of a radio access node 1500 according to some other embodiments of the present disclosure. Optional features are represented by dashed boxes. The radio access node 1500 may be, for example, a base station 302 or 306, or a network node implementing all or part of the functionality of the base station 302 or gNB described herein. As shown, the radio access node 1500 includes a control system 1502 including one or more processors 1504 (e.g., a central processing unit (CPU), an application specific integrated circuit (ASIC), and / or a field programmable gate array (FPGA)), a memory 1506, and a network interface 1508. The one or more processors 1504 are also referred to herein as processing circuits. In addition, the radio access node 1500 may include one or more radio units 1510 each including one or more transmitters 1512 and one or more receivers 1514, which are coupled to one or more antennas 1516. The radio unit 1510 may be referred to as, or may be part of, a radio interface circuit. In some embodiments, the radio unit 1510 is external to the control system 1502 and is connected to the control system 1502, for example, via a wired connection (e.g., an optical cable). However, in some embodiments, the radio unit 1510 and potentially the antenna 1516 are integrated with the control system 1502. The one or more processors 1504 operate to provide one or more functions of the radio access node 1500 as described herein. In some embodiments, the functions are implemented in software that is stored, for example, in the memory 1506 and executed by the one or more processors 1504.

[0138] 16 is a schematic block diagram illustrating a virtualized embodiment of a radio access node 1500 according to some embodiments of the present disclosure. The discussion is equally applicable to other types of network nodes. Furthermore, other types of network nodes may have similar virtualized architectures. Again, optional features are represented by dashed boxes.

[0139] As used herein, a "virtualized" radio access node is an implementation of the radio access node 1500 in which at least a portion of the functionality of the radio access node 1500 is implemented as a virtual component (e.g., via a virtual machine running on a physical processing node in a network). As shown, in this example, the radio access node 1500 may include a control system 1502 and / or one or more radio units 1510 as described above. The control system 1502 may be connected to the radio units 1510, for example, via an optical cable. The radio access node 1500 includes one or more processing nodes 1600 coupled to or included as part of a network 1602. If present, the control system 1502 or the radio units are connected to the processing nodes 1600 via the network 1602. Each processing node 1600 includes one or more processors 1604 (e.g., CPUs, ASICs, and / or FPGAs), memory 1606, and a network interface 1608.

[0140] In this example, the radio access node 1500 functions 1610 described herein may be implemented in one or more processing nodes 1600 or distributed across one or more processing nodes 1600, control system 1502, and / or radio unit 1510 in any desired manner. In some specific embodiments, some or all of the radio access node 1500 functions 1610 described herein are implemented as virtual components executed by one or more virtual machines implemented in a virtual environment hosted by the processing node 1600. As will be appreciated by those skilled in the art, additional signaling or communication between the processing node 1600 and the control system 1502 may be used to perform at least some of the desired functions 1610. Notably, in some embodiments, the control system 1502 may not be included, in which case the radio unit 1510 communicates directly with the processing node 1600 via an appropriate network interface.

[0141] In some embodiments, a computer program is provided that includes instructions that, when executed by at least one processor, cause the at least one processor to perform functionality of the radio access node 1500 or a node (e.g., processing node 1600) implementing one or more of the functions 1610 of the radio access node 1500 in a virtual environment in accordance with any of the embodiments described herein. In some embodiments, a carrier is provided that includes the computer program product as described above. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer-readable storage medium (e.g., a non-transitory computer-readable medium such as a memory).

[0142] 17 is a schematic block diagram of a radio access node 1500 according to some other embodiments of the present disclosure. The radio access node 1500 includes one or more modules 1700, each of which is implemented in software. The modules 1700 provide the functionality of the radio access node 1500 described herein. This discussion is equally applicable to the processing nodes of FIG. 16, and the modules 1700 may be implemented in one of the processing nodes 1600, distributed across multiple processing nodes 1600, and / or distributed across the processing nodes 1600 and the control system 1502.

[0143] 18 is a schematic block diagram of a wireless communication device 1800 according to some other embodiments of the present disclosure. As shown, the wireless communication device 1800 includes one or more processors 1802 (e.g., a CPU, an ASIC, and / or an FPGA, etc.), a memory 1804, and one or more transceivers 1806 each including one or more transmitters 1808 and one or more receivers 1810 coupled to one or more antennas 1812. The transceiver 1806 includes radio front-end circuitry connected to the antenna 1812 configured to condition signals exchanged between the antenna 1812 and the processor 1802, as would be understood by one of ordinary skill in the art. The processor 1802 is also referred to herein as a processing circuit. The transceiver 1806 is also referred to herein as a radio circuit. In some embodiments, the above-described functionality of the wireless communication device 1800 may be implemented, fully or partially, in software stored, for example, in the memory 1804 and executed by the processor 1802. It should be noted that wireless communication device 1800 may include additional components not shown in FIG. 18 , such as, for example, one or more user interface components (e.g., a display, buttons, a touch screen, a microphone, and / or a speaker, and / or any other components for enabling input of information into and / or output of information from wireless communication device 1800) and a power source (e.g., a battery and associated power circuitry).

[0144] In some embodiments, a computer program is provided that includes instructions that, when executed by at least one processor, cause the at least one processor to perform the functionality of the wireless communication device 1800 in accordance with any of the embodiments described herein. In some embodiments, a carrier is provided that includes the computer program product as described above. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer-readable storage medium (e.g., a non-transitory computer-readable medium such as a memory).

[0145] 19 is a schematic block diagram of a wireless communication device 1800 according to some other embodiments of the present disclosure. The wireless communication device 1800 includes one or more modules 1900, each of which is implemented in software. The modules 1900 provide the functionality of the wireless communication device 1800 described herein.

[0146] Referring to Fig. 20, according to one embodiment, a communication system includes a telecommunications network 2000, such as a 3GPP type cellular network, including an access network 2002, such as a RAN, and a core network 2004. The access network 2002 includes a number of base stations 2006A, 2006B, 2006C, such as Node B, eNB, gNG, or other types of wireless access points (AP), each of which defines a corresponding coverage area 2008A, 2008B, 2008C. Each base station 2006A, 2006B, 2006C is connectable to the core network 2004 over a wired or wireless connection 2010. A first UE 2012 located in the coverage area 2008C is configured to be wirelessly connected to or paged by the corresponding base station 2006C. A second UE 2014 within the coverage area 2008A can wirelessly connect to the corresponding base station 2006A. Although multiple UEs 2012, 2014 are shown in this example, the disclosed embodiments are equally applicable to situations where there is a single UE within the coverage area or a single UE connecting to the corresponding base station 2006.

[0147] The telecommunications network 2000 is itself connected to a host computer 2016, which may be embodied in standalone server hardware and / or software, a cloud-implemented server, a distributed server, or as a processing resource in a server farm. The host computer 2016 may be owned or controlled by a service provider, or may be operated by or for the service provider. The connections 2018 and 2020 between the telecommunications network 2000 and the host computer 2016 may extend directly from the core network 2004 to the host computer 2016, or may be connected via an optional intermediate network 2022. The intermediate network 2022 may be one or a combination of a public, private, or hosted network, and the intermediate network 2022 may be a backbone network or the Internet, if any, and in particular the intermediate network 2022 may include two or more sub-networks (not shown).

[0148] The communication system of FIG. 20 generally enables connectivity between connected UEs 2012, 2014 and a host computer 2016. The connectivity may be described as an over-the-top (OTT) connection 2024. The host computer 2016 and connected UEs 2012, 2014 are configured to communicate data and / or signaling via the OTT connection 2024 using the access network 2002, the core network 2004, any intermediate networks 2022, and possible further infrastructure (not shown) as intermediate steps. The OTT connection 2024 may be transparent in the sense that participating communication devices en route through the OTT connection 2024 are unaware of the routing of uplink and downlink communications. For example, the base station 2006 may not be informed or need to be informed of the past routing of incoming downlink communications with data originating from the host computer 2016 to be forwarded (e.g., handed over) to the connected UE 2012. Similarly, the base station 2006 does not need to be aware of the future routing of outgoing uplink communications originating from the UE 2012 to the host computer 2016 .

[0149] An exemplary implementation according to one embodiment of the UE, base station and host computer discussed in the previous paragraph will now be described with reference to FIG. 21. In the communication system 2100, the host computer 2102 comprises hardware 2104 including a communication interface 2106 configured to set up and maintain wired or wireless connections with interfaces of different communication devices of the communication system 2100. The host computer 2102 further comprises a processing circuit 2108 that may have storage and / or processing capabilities. Among other things, the processing circuit 2108 may include one or more programmable processors, ASICs, FPGAs or combinations thereof (not shown) adapted to execute instructions. The host computer 2102 further comprises software 2110 stored in or accessible by the host computer 2102 and executable by the processing circuit 2108. The software 2110 includes a host application 2112. The host application 2112 may be operable to provide services to a remote user, such as a UE 2114, connecting via an OTT connection 2116 that terminates at the UE 2114 and the host computer 2102. During the provision of services to the remote user, the host application 2112 may provide user data that is transmitted using the OTT connection 2116.

[0150] The communication system 2100 further includes a base station 2118 provided in the telecommunications system, the base station 2118 comprising hardware 2120 enabling communication with the host computer 2102 and the UE 2114. The hardware 2120 may include a communication interface 2122 for setting up and maintaining wired or wireless connections with interfaces of different communication devices of the communication system 2100, as well as a wireless interface 2124 for setting up and maintaining at least a wireless connection 2126 with a UE 2114 located within a coverage area (not shown in FIG. 21) served by the base station 2118. The communication interface 2122 may be configured to facilitate a connection 2128 to the host computer 2102. The connection 2128 may be direct or may pass through a core network (not shown in FIG. 21) of the telecommunications system and / or one or more intermediate networks outside the telecommunications system. In the illustrated embodiment, the hardware 2120 of the base station 2118 further includes processing circuitry 2130, which may include one or more programmable processors, ASICs, FPGAs, or combinations thereof (not shown) adapted to execute instructions. The base station 2118 further includes software 2132 stored internally or accessible via an external connection.

[0151] The communication system 2100 further includes the UE 2114 already mentioned. The hardware 2134 of the UE 2114 may include a radio interface 2136 configured to set up and maintain a radio connection 2126 with a base station serving the coverage area in which the UE 2114 is currently located. The hardware 2134 of the UE 2114 further includes a processing circuit 2138 adapted to execute instructions, which may include one or more programmable processors, ASICs, FPGAs, or combinations thereof (not shown). The UE 2114 further includes software 2140 stored within or accessible by the UE 2114, the software 2140 being executable by the processing circuit 2138. The software 2140 includes a client application 2142. The client application 2142, with the support of the host computer 2102, may be operable to provide services via the UE 2114 to a human or non-human user. At the host computer 2102, an executing host application 2112 may communicate with an executing client application 2142 via an OTT connection 2116 that terminates at the UE 2114 and the host computer 2102. During the provision of a service to a user, the client application 2142 may receive request data from the host application 2112 and provide user data in response to the request data. The OTT connection 2116 may transport both the request data and the user data. The client application 2142 may interact with the user to generate the user data that it provides.

[0152] It should be noted that the host computer 2102, base station 2118, and UE 2114 shown in Fig. 21 may be similar to or identical to the host computer 2016, one of the base stations 2006A, 2006B, and 2006C, and one of the UEs 2012 and 2014 shown in Fig. 20, respectively. That is to say, the internal workings of these entities may be as shown in Fig. 21, and independently, the surrounding network topology may be that of Fig. 20.

[0153] 21, the OTT connection 2116 is depicted abstractly to illustrate communication between the host computer 2102 and the UE 2114 through the base station 2118 without explicit reference to any intermediate devices and the exact routing of messages through those devices. The routing may be determined by the network infrastructure, which may be configured to hide the routing from the UE 2114 or the service provider operating the host computer 2102, or both. While the OTT connection 2116 is active, the network infrastructure may further make decisions to dynamically change the routing (e.g., based on load balancing considerations or network reconfiguration).

[0154] The wireless connection 2126 between the UE 2114 and the base station 2118 follows the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of the OTT service provided to the UE 2114 using the OTT connection 2116, of which the wireless connection 2126 forms the final segment.

[0155] A measurement procedure may be provided to monitor data rates, latency, and other factors that are improved by one or more embodiments. There may also be optional network functionality to reconfigure the OTT connection 2116 between the host computer 2102 and the UE 2114 in response to measurement variations. The measurement procedure and / or the network functionality to reconfigure the OTT connection 2116 may be implemented in the software 2110 and hardware 2104 of the host computer 2102, or in the software 2140 and hardware 2134 of the UE 2114, or both. In some embodiments, sensors (not shown) may be deployed in or associated with the communication device through which the OTT connection 2116 passes, and these sensors may participate in the measurement procedure by providing values ​​of the monitored quantities exemplified above or other physical quantities from which the monitored quantities may be calculated or estimated by the software 2110, 2140. Reconfiguration of the OTT connection 2116 may include message formats, retransmission settings, preferred routing, etc., which may not affect the base station 2118 and may be unknown or imperceptible to the base station 2118. Such procedures and functionality may be known or practiced in the art. In one embodiment, the measurements may involve proprietary UE signaling that facilitates measurements of throughput, propagation time, latency, etc. by the host computer 2102. The measurements may be implemented by the software 2110 and 2140 sending messages, specifically empty or "dummy" messages, over the OTT connection 2116 while monitoring propagation times, errors, etc.

[0156] FIG. 22 is a flow chart illustrating a method implemented in a communication system according to one embodiment. The communication system includes a host computer, a base station, and a UE, which may be as described with reference to FIG. 20 and FIG. 21. To simplify the disclosure, only reference to the diagram of FIG. 22 will be included in this section. In step 2200, the host computer provides user data. In sub-step 2202 of step 2200 (which may be optional), the host computer provides the user data by executing a host application. In step 2204, the host computer initiates a transmission to the UE carrying the user data. In step 2206 (which may be optional), the base station transmits the user data carried in the host computer initiated transmission to the UE according to the teachings of the embodiments described throughout this disclosure. In step 2208 (which may also be optional), the UE executes a client application associated with the host application executed by the host computer.

[0157] FIG. 23 is a flow chart illustrating a method implemented in a communication system according to one embodiment. The communication system includes a host computer, a base station, and a UE, which may be as described with reference to FIG. 20 and FIG. 21. To simplify the disclosure, only reference to the diagram of FIG. 23 will be included in this section. In step 2300 of the method, the host computer provides user data. In an optional sub-step (not shown), the host computer provides the user data by executing a host application. In step 2302, the host computer initiates a transmission to the UE carrying the user data. The transmission may go through the base station according to the teachings of the embodiments described throughout this disclosure. In step 2304 (which may be optional), the UE receives the user data carried in the transmission.

[0158] FIG. 24 is a flow chart illustrating a method implemented in a communication system according to one embodiment. The communication system includes a host computer, a base station, and a UE, which may be as described with reference to FIG. 20 and FIG. 21. To simplify the disclosure, only reference to the diagram of FIG. 24 will be included in this section. In step 2400 (which may be optional), the UE receives input data provided by the host computer. Additionally or alternatively, in step 2402, the UE provides user data. In sub-step 2404 (which may be optional) of step 2400, the UE provides the user data by executing a client application. In sub-step 2406 (which may be optional) of step 2402, the UE executes a client application that provides the user data in reaction to receiving the input data provided by the host computer. During the provision of the user data, the executed client application may further take into account user input received from a user. Regardless of the specific manner in which the user data is provided, the UE initiates transmission of the user data to the host computer in sub-step 2408 (which may be optional). In step 2410 of the method, the host computer receives user data transmitted from the UE according to the teachings of the embodiments described throughout this disclosure.

[0159] FIG. 25 is a flow chart illustrating a method implemented in a communication system according to one embodiment. The communication system includes a host computer, a base station, and a UE, which may be as described with reference to FIG. 20 and FIG. 21. To simplify the disclosure, only reference to the diagram of FIG. 25 will be included in this section. In step 2500 (which may be optional), the base station receives user data from the UE according to the teachings of the embodiments described throughout this disclosure. In step 2502 (which may be optional), the base station initiates transmission of the received user data to the host computer. In step 2504 (which may be optional), the host computer receives the user data carried in the transmission initiated by the base station.

[0160] Any suitable steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual devices. Each virtual device may include multiple such functional units. The functional units may be implemented via processing circuitry, which may include one or more microprocessors or microcontrollers, and other digital hardware, which may include digital signal processors (DSPs) and special purpose digital logic. The processing circuitry may be configured to execute program code stored in memory, which may include one or more types of memory, such as read-only memory (ROM), random access memory (RAM), cache memory, flash memory devices, optical storage devices, and the like. The program code stored in memory includes program instructions for implementing one or more telecommunications and / or data communication protocols, and instructions for performing one or more of the techniques described herein. In some embodiments, the processing circuitry may be used to cause the respective functional units to perform functions corresponding to the respective functional units in accordance with one or more embodiments of the present disclosure.

[0161] Although the processes in the figures may indicate a particular order of operations performed by certain embodiments of the present disclosure, it should be understood that such orders are exemplary (e.g., alternative embodiments may perform operations in a different order, combine certain operations, overlap certain operations, etc.).

[0162] Some exemplary embodiments of the present disclosure are as follows:

[0163] <Embodiment of Group A> Embodiment 1: A method performed by a user equipment (UE) (312), the method including one or more of the following: Receiving (1402) first information from a network node (1400) providing a channel state information reference signal (CSI-RS) configuration along with a plurality of CSI-RS samples at different times; receiving (1404) second information from the network node (1400) that configures the UE (312) to report channel state information (CSI) feedback based on the CSI-RS configuration associated with the plurality of CSI-RS samples at different times; determining (1406) at least some characteristics of a precoding matrix for each CSI-RS sample of the plurality of CSI-RS samples in accordance with the second information; Reporting (1408) either at least some characteristics of the precoding matrix or information derived therefrom for each CSI-RS sample of the plurality of CSI-RS samples to the network node (1400) via one or more CSI-RS reports.

[0164] Embodiment 2: 2. The method of embodiment 1, wherein the multiple CSI-RS samples are from different times within a single timeslot or slot (also referred to as "timeslot / slot").

[0165] Embodiment 3: 2. The method of embodiment 1, wherein the plurality of CSI-RS samples are for different time points, the different time points including at least one time point in a first time slot / slot and at least one time point in a second time slot / slot different from the first time slot / slot.

[0166] Embodiment 4: A method according to any one of embodiments 1 to 3, wherein the different points in time are (1) different orthogonal frequency division multiplexing (OFDM) symbols within a single time slot / slot, or (2) the same or different OFDM symbols within different time slots / slots.

[0167] Embodiment 5: A method according to any one of embodiments 1 to 4, wherein the first information includes information for configuring the plurality of CSI-RS samples as different NZP CSI-RS resources in an NZP CSI-RS resource set.

[0168] Embodiment 6: A method according to any one of embodiments 1 to 4, wherein the first information includes information constituting a plurality of NZP CSI-RS resources in an NZP CSI-RS resource set and a parameter indicating that the plurality of NZP CSI-RS resources in the NZP CSI-RS resource set should be interpreted by the UE (312) as the plurality of CSI-RS samples of a same NZP CSI-RS.

[0169] Embodiment 7: A method according to any one of embodiments 5 to 6, wherein the first information further includes information explicitly or implicitly indicating a number of CSI-RS samples in the plurality of CSI-RS samples.

[0170] Embodiment 8: 8. The method of any one of embodiments 5 to 7, wherein CSI-RS resource mapping is different for at least some of the NZP CSI-RS resources in the NZP CSI-RS resource set.

[0171] Embodiment 9: 9. The method of any one of embodiments 5 to 8, wherein time domain locations configured for at least some of the plurality of NZP CSI-RS resources in the NZP CSI-RS resource set are different.

[0172] Embodiment 10: A method according to any one of embodiments 5 to 9, wherein the first information further includes one or more common parameters common to all of the plurality of NZP CSI-RS resources in the NZP CSI-RS resource set.

[0173] Embodiment 11: 11. The method of any one of embodiments 5 to 10, wherein all of the plurality of NZP CSI-RS resources in the NZP CSI-RS resource set have the same number of antenna ports.

[0174] Embodiment 12: 11. The method of any one of embodiments 5 to 10, wherein at least two of the plurality of NZP CSI-RS resources in the NZP CSI-RS resource set have different numbers of antenna ports.

[0175] Embodiment 13: 11. A method according to any one of embodiments 5 to 10, wherein one NZP CSI-RS resource of the plurality of NZP CSI-RS resources in the NZP CSI-RS resource set has a first number of antenna ports, and all remaining NZP CSI-RS resources of the plurality of NZP CSI-RS resources in the NZP CSI-RS resource set have a second number of antenna ports.

[0176] Embodiment 14: 14. The method of embodiment 13, wherein the second number of antenna ports is less than the first number of antenna ports.

[0177] Embodiment 15: 15. The method of embodiment 13 or 14, wherein the second number of antenna ports are associated with only a single polarity.

[0178] Embodiment 16: A method according to any one of embodiments 5 to 15, wherein the plurality of NZP CSI resources in the NZP CSI-RS resource set are periodic, and the same TCI state ID is configured for all of the plurality of NZP CSI resources in the NZP CSI-RS resource set.

[0179] Embodiment 17: A method according to any one of embodiments 5 to 15, wherein the NZP CSI resources in the NZP CSI-RS resource set are periodic, and a single parameter indicating a TCI state ID configured for one of the NZP-CSI resources in the NZP CSI-RS resource set is applicable to all of the NZP-CSI resources in the NZP CSI-RS resource set.

[0180] Embodiment 18: A method according to any one of embodiments 5 to 15, wherein the plurality of NZP CSI resources in the NZP CSI-RS resource set are periodic, and a single parameter indicating a TCI state ID configured for all of the plurality of NZP CSI resources in the NZP CSI-RS resource set is included in an information element defining the NZP CSI-RS resource set.

[0181] Embodiment 19: 16. The method of any one of embodiments 5 to 15, wherein the plurality of NZP CSI resources in the NZP CSI-RS resource set are semi-persistent, and a same TCI state ID for the plurality of NZP CSI resources in the NZP CSI-RS resource set is configured via a MAC CE that activates the NZP CSI-RS resource set.

[0182] Embodiment 20: A method according to any one of embodiments 5 to 15, wherein the plurality of NZP CSI resources in the NZP CSI-RS resource set are semi-persistent, and a single TCI state ID is configured and applicable to the plurality of NZP CSI resources in the NZP CSI-RS resource set via a MAC CE that activates the NZP CSI-RS resource set.

[0183] Embodiment 21: A method according to any one of embodiments 5 to 15, wherein the plurality of NZP CSI resources in the NZP CSI-RS resource set are semi-persistent, and a single parameter indicating a TCI state ID configured for all of the plurality of NZP CSI resources in the NZP CSI-RS resource set is included in an information element defining the NZP CSI-RS resource set.

[0184] Embodiment 22: A method according to any one of embodiments 5 to 15, wherein the plurality of NZP CSI resources in the NZP CSI-RS resource set are aperiodic, and the same TCI state ID is configured for all of the plurality of NZP CSI resources in the NZP CSI-RS resource set.

[0185] Embodiment 23: A method according to any one of embodiments 5 to 15, wherein the plurality of NZP CSI resources in the NZP CSI-RS resource set are aperiodic, and a single TCI state ID is configured for all of the plurality of NZP-CSI resources in the NZP CSI-RS resource set via an information element defining the NZP CSI-RS resource set.

[0186] Embodiment 24: 16. The method of any one of embodiments 5 to 15, wherein a unified TCI state currently activated for the UE (312) applies to all of the plurality of NZP CSI resources in the NZP CSI-RS resource set.

[0187] Embodiment 25: A method according to any one of embodiments 1 to 4, wherein the first information includes information for configuring the plurality of CSI-RS samples via configuration of a single NZP CSI-RS resource, and information defining multiple repetitions of the NZP CSI-RS resource corresponding to the plurality of CSI-RS samples.

[0188] Embodiment 26: 26. The method of embodiment 25, wherein the information defining the multiple repetitions of the NZP CSI-RS resource includes information indicating one or more time offsets or time gaps between repetitions of the NZP CSI-RS resource.

[0189] Embodiment 27: 27. The method of embodiment 25 or 26, wherein the multiple repetitions of the NZP CSI-RS resource are within a single timeslot / slot.

[0190] Embodiment 28: 27. The method of embodiment 25 or 26, wherein at least one first repetition of the multiple repetitions of the NZP CSI-RS resource is in a first time slot / slot and at least one second repetition of the multiple repetitions of the NZP CSI-RS resource is in a second time slot / slot.

[0191] Embodiment 29: 29. The method of any of embodiments 1 to 28, wherein the CSI feedback is Type I CSI feedback, and for each CSI-RS sample of the plurality of CSI-RS samples, the at least some characteristics of the precoding matrix reported to the network node include a set of cophasing coefficients (W2).

[0192] Embodiment 30: The method of any one of embodiments 1 to 28, wherein the CSI feedback is Type I CSI feedback; and wherein for a CSI-RS sample of the plurality of CSI-RS samples, the at least some characteristics of the precoding matrix that are reported to the network node include a set of cophasing coefficients (W2); wherein, for each remaining CSI-RS sample of the plurality of CSI-RS samples, the at least some characteristics of the precoding matrix that are reported to the network node include a phase difference of each coefficient of W2 for that remaining CSI-RS sample and the respective coefficient of W2 for the one CSI-RS sample.

[0193] Embodiment 31: A method according to embodiment 29 or 30, wherein for at least one CSI-RS sample of the plurality of CSI-RS samples, the at least some characteristics of the precoding matrix reported to the network node include a matrix (W1) of size 2N×2L containing information of L selected DFT beams.

[0194] Embodiment 32: 29. The method of any of embodiments 1 to 28, wherein the CSI feedback is Type II CSI feedback, and for each CSI-RS sample of the plurality of CSI-RS samples, the at least some characteristics of the precoding matrix reported to the network node include a set of cophasing coefficients (W2) and a selected set of FD basis vectors.

[0195] Embodiment 33: The method of any one of embodiments 1 to 28, wherein the CSI feedback is Type II CSI feedback; For a CSI-RS sample of the plurality of CSI-RS samples, the at least some characteristics of the precoding matrix that are reported to the network node include a set of cophasing coefficients (W2) and a selected set of FD basis vectors; and wherein, for each remaining CSI-RS sample of the plurality of CSI-RS samples, the at least some characteristics of the precoding matrix that are reported to the network node include a phase difference of each coefficient of W2 for that remaining CSI-RS sample, a respective coefficient of W2 for the one CSI-RS sample, and a selected set of FD basis vectors.

[0196] Embodiment 34: A method according to embodiment 32 or 33, wherein for at least one CSI-RS sample of the plurality of CSI-RS samples, the at least some characteristics of the precoding matrix reported to the network node include a matrix (W1) of size 2N×2L containing information of L selected DFT beams.

[0197] Embodiment 35: 13. The method of any of the preceding embodiments, further comprising providing user data and transferring the user data to a host computer via said transmission to said base station.

[0198] <Implementation of Group B> Embodiment 36: A method performed by a network node (1400), comprising: transmitting (1402) to a UE (312) first information providing a channel state information reference signal (CSI-RS) configuration along with a plurality of CSI-RS samples at different times; transmitting (1404) to the UE (312) second information configuring the UE (312) to report channel state information (CSI) feedback based on the CSI-RS configuration along with the plurality of CSI-RS samples at different times; and receiving (1408) from the UE (312) either at least some characteristics of the precoding matrix or information derived therefrom for each CSI-RS sample of the plurality of CSI-RS samples via one or more CSI-RS reports.

[0199] Embodiment 37: 20. The method of any of the preceding embodiments, further comprising obtaining user data and transferring the user data to a host computer or wireless device.

[0200] <Embodiments of Group C> Embodiment 38: 1. A wireless device comprising: a processing circuit configured to perform any of the steps of any of the embodiments of Group A; a power supply circuit configured to supply power to the wireless device.

[0201] Embodiment 39: A base station, a processing circuit configured to perform any of the steps of any of the embodiments of Group B; and a power supply circuit configured to supply power to the base station.

[0202] Embodiment 40: A user equipment (UE), an antenna configured to transmit and receive wireless signals; a radio front-end circuit coupled to the antenna and to a processing circuit and configured to condition signals communicated between the antenna and the processing circuit; the processing circuitry configured to perform any of the steps of any of the embodiments of Group A; an input interface coupled to the processing circuitry and configured to enable input of information to the UE to be processed by the processing circuitry; an output interface connected to the processing circuit and configured to output information processed by the processing circuit from the UE; A UE comprising: a battery coupled to the processing circuit and configured to provide power to the UE.

[0203] Embodiment 41: A communication system including a host computer, the host computer comprising: a processing circuit configured to provide user data; a communication interface configured to transfer the user data to a cellular network for transmission to a user equipment (UE); A communications system, wherein the cellular network includes a base station, the base station having a radio interface and processing circuitry, the processing circuitry of the base station configured to perform any of the steps of any of the Group B embodiments.

[0204] Embodiment 42: The communication system of any preceding embodiment, further comprising the base station.

[0205] Embodiment 43: The communication system of the two preceding embodiments, further comprising the UE configured to communicate with the base station.

[0206] Embodiment 44: The communication system according to the three embodiments described above, the processing circuitry of the host computer is configured to provide the user data by executing a host application; The UE comprises processing circuitry configured to execute a client application associated with the host application.

[0207] Embodiment 45: 1. A method implemented in a communication system including a host computer, a base station, and a user equipment (UE), comprising: providing user data at the host computer; and initiating, at the host computer, a transmission conveying the user data to the UE via a cellular network including the base station, the base station performing any of the steps of any of the Group B embodiments.

[0208] Embodiment 46: 4. The method of any preceding embodiment, further comprising: transmitting, at the base station, the user data.

[0209] Embodiment 47: The method of the two preceding embodiments, wherein the user data is provided by executing a host application on the host computer, the method further comprising executing, on the UE, a client application associated with the host application.

[0210] Embodiment 48: A user equipment (UE) configured to communicate with a base station, the UE comprising a radio interface and a processing circuit configured to perform the methods of the three aforementioned embodiments.

[0211] Embodiment 49: A communication system including a host computer, the host computer comprising: a processing circuit configured to provide user data; a communication interface configured to transfer user data to a cellular network for transmission to a user equipment (UE); A communications system, wherein the UE comprises a radio interface and processing circuitry, and the components of the UE are configured to perform any of the steps of any of the embodiments of Group A.

[0212] Embodiment 50: 4. The communication system of any preceding embodiment, wherein the cellular network further includes a base station configured to communicate with the UE.

[0213] Embodiment 51: The communication system according to the two embodiments described above, the processing circuitry of the host computer is configured to provide the user data by executing a host application; A communications system, wherein the processing circuitry of the UE is configured to execute a client application associated with the host application.

[0214] Embodiment 52: 1. A method implemented in a communication system including a host computer, a base station, and a user equipment (UE), comprising: providing user data at the host computer; and initiating, at the host computer, a transmission conveying the user data to the UE via a cellular network including the base station, wherein the UE performs any of the steps of any of the embodiments of Group A.

[0215] Embodiment 53: 4. The method of any preceding embodiment, further comprising: receiving, at the UE, the user data from the base station.

[0216] Embodiment 54: A communication system including a host computer, the host computer comprising: a communication interface configured to receive user data originating from a transmission from a user equipment (UE) to a base station; A communications system, wherein the UE comprises a radio interface and processing circuitry, the processing circuitry of the UE configured to perform any of the steps of any of the embodiments of Group A.

[0217] Embodiment 55: The communication system of any of the preceding embodiments, further comprising the UE.

[0218] Embodiment 56: The communication system of the two preceding embodiments, further comprising the base station, the base station comprising a radio interface configured to communicate with the UE, and a communication interface configured to transfer the user data carried in a transmission from the UE to the base station to the host computer.

[0219] Embodiment 57: The communication system according to the three embodiments described above, the processing circuitry of the host computer is configured to execute a host application; A communications system, wherein processing circuitry of the UE is configured to provide the user data by executing a client application associated with the host application.

[0220] Embodiment 58: The communication system according to the four embodiments described above, the processing circuitry of the host computer is configured to provide requested data by executing a host application; A communications system, wherein processing circuitry of the UE is configured to provide the user data in response to the request data by executing a client application associated with the host application.

[0221] Embodiment 59: A method implemented in a communications system including a host computer, a base station, and a user equipment (UE), the method including receiving, at the host computer, user data transmitted from the UE to the base station, the UE performing any of the steps of any of the embodiments of Group A.

[0222] Embodiment 60: 4. The method of any preceding embodiment, further comprising: at the UE, providing the user data to the base station.

[0223] Embodiment 61: The method of the two previous embodiments, providing, at the UE, the user data to be transmitted by executing a client application; The method further includes executing, on the host computer, a host application associated with the client application.

[0224] Embodiment 62: The method of any of the three preceding embodiments, executing a client application in the UE; receiving, at the UE, input data to the client application provided by executing a host application associated with the client application at the host computer; A method wherein the user data to be transmitted is provided by the client application in response to the input data.

[0225] Embodiment 63: A communications system including a host computer having a communications interface configured to accept user data derived from a transmission signal from a user equipment (UE) to a base station, the base station having a radio interface and processing circuitry, the processing circuitry of the base station being configured to perform any of the steps of any of the Group B embodiments.

[0226] Embodiment 64: The communication system of any preceding embodiment, further comprising the base station.

[0227] Embodiment 65: The communication system of the two preceding embodiments, further comprising the UE configured to communicate with the base station.

[0228] Embodiment 66: The communication system according to the three embodiments described above, the processing circuitry of the host computer is configured to execute a host application; The UE is configured to provide the user data to be received by the host computer by executing a client application associated with the host application.

[0229] Embodiment 67: A method implemented in a communications system including a host computer, a base station, and a user equipment (UE), the method including receiving, at the host computer, user data from the base station originating from a transmission signal received by the base station from the UE, the UE performing any of the steps of any of the embodiments of Group A.

[0230] 68. Embodiment 68 4. The method of any preceding embodiment, further comprising: receiving, at the base station, the user data from the UE.

[0231] 69. The method of the previous two embodiments, further comprising initiating, at the base station, transmission of the received user data to the host computer.

[0232] Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure, and all such improvements and modifications are deemed to be within the scope of the concepts disclosed herein.< / qcl>

Claims

1. A method performed by a user equipment (UE) (312), comprising: Receiving 1402, from a network node (1400), first information providing a channel state information reference signal (CSI-RS) configuration associated with a plurality of CSI-RS samples at different times; receiving, from the network node (1400), second information configuring the UE (312) to report channel state information (CSI) feedback based on the CSI-RS configuration along with the plurality of CSI-RS samples; determining 1406 at least one characteristic of a precoding matrix for each CSI-RS sample of the plurality of CSI-RS samples according to the second information; and reporting (1408) either the at least one or more characteristics of the precoding matrix or information derived therefrom for each CSI-RS sample of the plurality of CSI-RS samples to the network node (1400) via one or more CSI-RS reports.

2. 2. The method of claim 1, wherein the multiple CSI-RS samples are from different times within a single timeslot.

3. 2. The method of claim 1 , wherein the plurality of CSI-RS samples are for different time points, the different time points including at least one time point in a first timeslot and at least one time point in a second timeslot different from the first timeslot.

4. 4. The method of claim 1, wherein the different points in time are either different Orthogonal Frequency Division Multiplexing (OFDM) symbols in a single time slot, the same OFDM symbol in different time slots, or different OFDM symbols in different time slots.

5. 5. The method of claim 1 , wherein the first information comprises information to configure the CSI-RS samples as different non-zero power (NZP) CSI-RS resources in an NZP CSI-RS resource set.

6. The method according to any one of claims 1 to 4, wherein the first information comprises: a plurality of non-zero power (NZP) CSI-RS resources in a NZP CSI-RS resource set; and a parameter indicating that the NZP CSI-RS resources in the NZP CSI-RS resource set should be interpreted by the UE (312) as the CSI-RS samples of the same NZP CSI-RS; A method comprising:

7. The method according to any one of claims 5 to 6, wherein the plurality of CSI-RS samples are aperiodic.

8. The method of claim 7, wherein the multiple CSI-RS samples are triggered by a single trigger.

9. The method of any one of claims 5 to 8, wherein a number of CSI-RS samples in the plurality of CSI-RS samples is equal to a number of NZP CSI-RS resources in the NZP CSI-RS resource set.

10. The method according to any one of claims 5 to 6, wherein the first information further includes information that explicitly or implicitly indicates a number of CSI-RS samples in the plurality of CSI-RS samples.

11. 11. The method of claim 5, 6 or 10, wherein CSI-RS resource mapping differs for at least some of the NZP CSI-RS resources in the NZP CSI-RS resource set.

12. 12. The method of claim 5, 6 or 11, wherein configured time domain locations for at least some of the NZP CSI-RS resources in the NZP CSI-RS resource set are different.

13. 13. The method of claim 5, 6, or 10-12, wherein the first information further comprises one or more common parameters common to all of the plurality of NZP CSI-RS resources in the NZP CSI-RS resource set.

14. 14. The method of claim 5, 6, or any one of claims 10 to 13, wherein all of the NZP CSI-RS resources in the NZP CSI-RS resource set have the same number M of antenna ports.

15. 15. The method of claim 14, wherein an m-th (m=0, 1, ..., M-1) antenna port is identical for all of the plurality of NZP CSI-RS resources in the NZP CSI-RS resource set.

16. 14. The method of any one of claims 5, 6, or 10-13, wherein at least two of the NZP CSI-RS resources in the NZP CSI-RS resource set have different numbers of antenna ports.

17. 14. The method of any one of claims 5, 6, or 10-13, wherein one NZP CSI-RS resource of the plurality of NZP CSI-RS resources in the NZP CSI-RS resource set has a first number of antenna ports, and all remaining NZP CSI-RS resources of the plurality of NZP CSI-RS resources in the NZP CSI-RS resource set have a second number of antenna ports.

18. 20. The method of claim 17, wherein the second number of antenna ports is less than the first number of antenna ports.

19. 19. The method of claim 17 or 18, wherein the second number of antenna ports are associated with only a single polarization.

20. 20. The method of any one of claims 5, 6, or 10-19, wherein the NZP CSI resources in the NZP CSI-RS resource set are periodic and the same Transmission Configuration Indication (TCI) State Identity (ID) is configured for all of the NZP-CSI resources in the NZP CSI-RS resource set.

21. 20. The method of any one of claims 5, 6, or 10-19, wherein the NZP CSI resources in the NZP CSI-RS resource set are periodic and a single parameter indicating a Transmission Configuration Indication (TCI) State Identity (ID) configured for one of the NZP-CSI resources in the NZP CSI-RS resource set is applicable to all of the NZP-CSI resources in the NZP CSI-RS resource set.

22. 20. The method of any one of claims 5, 6, or 10-19, wherein the NZP CSI resources in the NZP CSI-RS resource set are periodic, and a single parameter indicating a Transmission Configuration Indication (TCI) State Identity (ID) configured for all of the NZP CSI resources in the NZP CSI-RS resource set is included in an information element defining the NZP CSI-RS resource set.

23. 20. The method of any one of claims 5, 6, or 10-19, wherein the NZP-CSI resources in the NZP CSI-RS resource set are semi-persistent and a same Transmission Configuration Indication (TCI) State Identity (ID) for all of the NZP CSI resources in the NZP CSI-RS resource set is configured via a Medium Access Control (MAC) Control Element (CE) that activates the NZP CSI-RS resource set.

24. 20. The method of any one of claims 5, 6, or 10-19, wherein the multiple NZP-CSI resources in the NZP CSI-RS resource set are semi-persistent, and a single Transmission Configuration Indication (TCI) State Identity (ID) is configured and applicable to the multiple NZP CSI resources in the NZP CSI-RS resource set via a Medium Access Control (MAC) Control Element (CE) that activates the NZP CSI-RS resource set.

25. 20. The method of any one of claims 5, 6, or 10-19, wherein the NZP CSI resources in the NZP CSI-RS resource set are semi-persistent, and a single parameter indicating a Transmission Configuration Indication (TCI) State Identity (ID) configured for all of the NZP CSI resources in the NZP CSI-RS resource set is included in an information element defining the NZP CSI-RS resource set.

26. 20. The method of any one of claims 5, 6, or 10-19, wherein the NZP CSI resources in the NZP CSI-RS resource set are aperiodic, and the same Transmission Configuration Indication (TCI) State Identity (ID) is configured for all of the NZP CSI resources in the NZP CSI-RS resource set.

27. 20. The method of any one of claims 5, 6, or 10-19, wherein the NZP CSI resources in the NZP CSI-RS resource set are aperiodic and a single Transmission Configuration Indication (TCI) State Identity (ID) is configured for all of the NZ-CSI resources in the NZP CSI-RS resource set via an information element that defines the NZP CSI-RS resource set.

28. 20. The method of any one of claims 5, 6, or 10-19, wherein a unified transmission configuration indication (TCI) state currently activated for the UE (312) applies to all of the plurality of NZP CSI resources in the NZP CSI-RS resource set.

29. 5. The method of claim 1, wherein the first information comprises information for configuring the plurality of CSI-RS samples via configuration of a single NZP CSI-RS resource, and information defining multiple repetitions of the NZP CSI-RS resource corresponding to the plurality of CSI-RS samples.

30. 30. The method of claim 29, wherein the information defining the multiple repetitions of the NZP CSI-RS resource includes information indicating one or more time offsets between repetitions of the NZP CSI-RS resource.

31. 31. The method of claim 29 or 30, wherein the multiple repetitions of the NZP CSI-RS resource are within a single timeslot.

32. 31. The method of claim 29 or 30, wherein at least one first repetition of the multiple repetitions of the NZP CSI-RS resource is in a first time slot and at least one second repetition of the multiple repetitions of the NZP CSI-RS resource is in a second time slot.

33. The method according to any one of claims 1 to 32, wherein the CSI feedback is a Type I CSI feedback, and the at least one characteristic of the precoding matrix reported to the network node for each CSI-RS sample of the plurality of CSI-RS samples is a cophasing factor (W ２ ).

34. 33. The method according to claim 1, wherein the CSI feedback is a type I CSI feedback; For one CSI-RS sample of the plurality of CSI-RS samples, the at least one characteristic of the precoding matrix reported to the network node is a cophasing factor (W ２ ), For each remaining CSI-RS sample of the plurality of CSI-RS samples, the at least one characteristic of the precoding matrix reported to the network node is W ２ and W ２ The method includes the coefficients of each of the

35. 35. The method of claim 33 or 34, wherein for at least one CSI-RS sample of the plurality of CSI-RS samples, the at least one or more characteristics of the precoding matrix reported to the network node include a matrix (W １ ).

36. The method according to any one of claims 1 to 32, wherein the CSI feedback is a Type II CSI feedback, and the at least one characteristic of the precoding matrix reported to the network node for each CSI-RS sample of the plurality of CSI-RS samples is a cophasing factor (W ２ ) and a selected set of frequency domain (FD) basis vectors.

37. 33. The method according to claim 1, wherein the CSI feedback is a type II CSI feedback; For one CSI-RS sample of the plurality of CSI-RS samples, the at least one characteristic of the precoding matrix reported to the network node is a cophasing factor (W ２ ) and a selected set of frequency domain (FD) basis vectors, For each remaining CSI-RS sample of the plurality of CSI-RS samples, the at least one characteristic of the precoding matrix reported to the network node is W ２ , the phase difference of each coefficient of W ２ and a selected set of frequency domain (FD) basis vectors.

38. 38. The method of claim 36 or 37, wherein for at least one CSI-RS sample of the plurality of CSI-RS samples, the at least one or more characteristics of the precoding matrix reported to the network node include a matrix (W １ ).

39. A User Equipment (UE) (312) adapted to perform the method according to any one of claims 1 to 38.

40. A user equipment (UE) (312, 1800), One or more transmitters (1808); One or more receivers (1810); a processing circuit (1802) associated with the one or more transmitters (1808) and the one or more receivers (1810), the processing circuit (1802) providing to the UE (312, 1800): Receiving 1402, from a network node (1400), first information providing a channel state information reference signal (CSI-RS) configuration associated with a plurality of CSI-RS samples at different times; receiving, from the network node (1400), second information configuring the UE (312) to report channel state information (CSI) feedback based on the CSI-RS configuration along with the plurality of CSI-RS samples; determining 1406 at least one characteristic of a precoding matrix for each CSI-RS sample of the plurality of CSI-RS samples according to the second information; and reporting (1408) to the network node (1400) either at least one or more characteristics of the precoding matrix or information derived therefrom for each CSI-RS sample of the plurality of CSI-RS samples via one or more CSI-RS reports.

41. A UE (312, 1800) as claimed in claim 40, wherein the processing circuit (1802) is configured to cause the UE (312, 1800) to perform a method as claimed in any one of claims 2 to 38.

42. A method performed by a network node (1400), comprising: Transmitting (1402) to a UE (312) first information providing a channel state information reference signal (CSI-RS) configuration along with a plurality of CSI-RS samples at different times; transmitting (1404) to the UE (312) second information configuring the UE (312) to report channel state information (CSI) feedback based on the CSI-RS configuration associated with the plurality of CSI-RS samples at different times; and receiving (1408) from the UE (312) either at least one or more characteristics of the precoding matrix or information derived therefrom for each CSI-RS sample of the plurality of CSI-RS samples via one or more CSI-RS reports.

43. 43. The method of claim 42, wherein the first information comprises information configuring the CSI-RS samples as different non-zero power (NZP) CSI-RS resources within an NZP CSI-RS resource set.

44. 43. The method of claim 42, wherein the first information comprises: a plurality of non-zero power (NZP) CSI-RS resources in a NZP CSI-RS resource set; and a parameter indicating that the NZP CSI-RS resources in the NZP CSI-RS resource set should be interpreted by the UE (312) as the CSI-RS samples of the same NZP CSI-RS; A method comprising:

45. 45. The method of claim 43 or 44, wherein the plurality of CSI-RS samples are aperiodic.

46. 46. ​​The method of claim 45, wherein the multiple CSI-RS samples are triggered by a single trigger.

47. The method of any one of claims 43 to 46, wherein a number of CSI-RS samples in the plurality of CSI-RS samples is equal to a number of NZP CSI-RS resources in the NZP CSI-RS resource set.

48. 48. The method of any one of claims 43 to 47, wherein configured time domain locations for at least some of the NZP CSI-RS resources in the NZP CSI-RS resource set are different.

49. A network node (1400) adapted to perform the method according to any one of claims 42 to 48.

50. A network node (1400, 1500) comprising a processing circuit (1504, 1604), the processing circuit (1504, 1604) providing the network node (1400, 1500) with: Transmitting (1402) to a UE (312) first information providing a channel state information reference signal (CSI-RS) configuration along with a plurality of CSI-RS samples at different times; transmitting (1404) to the UE (312) second information configuring the UE (312) to report channel state information (CSI) feedback based on the CSI-RS configuration associated with the plurality of CSI-RS samples at different times; and receiving (1408) from the UE (312) either at least one or more characteristics of the precoding matrix or information derived therefrom for each CSI-RS sample of the plurality of CSI-RS samples via one or more CSI-RS reports.

51. A network node (1400, 1500) as claimed in claim 50, wherein the processing circuit (1504, 1604) is further configured to cause the network node (1400, 1500) to perform a method as claimed in any one of claims 43 to 48.

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