WO2024026610A1

WO2024026610A1 - Time domain csi window decoupled from measured csi-rs occasions

Info

Publication number: WO2024026610A1
Application number: PCT/CN2022/109377
Authority: WO
Inventors: Jing Dai; Chenxi HAO; Lei Xiao; Faris RASSAM; Liangming WU; Hao Xu
Original assignee: Qualcomm Incorporated
Priority date: 2022-08-01
Filing date: 2022-08-01
Publication date: 2024-02-08
Also published as: WO2024026975A1

Abstract

Systems and methods for decoupling CSI reporting windows from measured CSI-RS occasions are provided. CSI reporting windows are defined based on a CSI reference resource slot, without defining or requiring a CSI measurement window, between the gNB and the UE. The CSI reporting window includes a Doppler Domain/Time Domain basis vector that includes one or both of two segments, one corresponding to multiple CSI-RS occasions before the CSI reference resource slot, and another corresponding to future predictions after the CSI reference resource slot. The CSI reporting window has a length of a number of slots between the CSI reference resource slot and a beginning slot index. A minimum measurement requirement is also defined based on the CSI reference resource slot. The minimum measurement requirement value (i.e., a minimum CSI-RS occasion count) is used to ensure the performance of future predictions.

Description

TIME DOMAIN CSI WINDOW DECOUPLED FROM MEASURED CSI-RS OCCASIONS

TECHNICAL FIELD

This application relates to wireless communication devices, systems, and methods, and more particularly to devices, systems, and methods for decoupling CSI windows from measured CSI-RS occasions.

INTRODUCTION

Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power) . A wireless multiple-access communications system may include a number of base stations (BSs) , each simultaneously supporting communications for multiple communication devices, which may be otherwise known as user equipment (UE) .

Estimating the channel between a BS and a UE to obtain a precoder for a precoding matrix becomes more complicated for higher velocity UEs. This is because UEs in higher velocity circumstances must deal with channel conditions that vary much more quickly than in static situations. Further, the UE and BS need to coordinate as to when the channel state reference signals (CSI-RS) are transmitted and received. While some have proposed standardizing measurement windows in which the UE will be required to measure CSI-RS occasions for a CSI-RS report, this has historically not been required. It would be desirable to leave the implementation up to the UE. Moreover, there is currently no mechanism in place to ensure the quality and performance of estimating future precoder values based on CSI-RS occasions. Therefore, there exists a need for improved methods of coordinating and using CSI-RS occasions.

BRIEF SUMMARY OF SOME EXAMPLES

The following summarizes some aspects of the present disclosure to provide a basic understanding of the discussed technology. This summary is not an extensive overview of all contemplated features of the disclosure and is intended neither to identify key or critical elements of all aspects of the disclosure nor to delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present some concepts of one or more aspects of the disclosure in summary form as a prelude to the more detailed description that is presented later.

One aspect of the present disclosure includes a method of wireless communication, comprising receiving, by a user equipment (UE) from a network unit, a plurality of channel state information reference signal (CSI-RS) occasions for use in a time-domain CSI (TD-CSI) report relative to a reference resource slot. The method further comprises transmitting, by the UE to the network unit in response to the plurality of CSI-RS occasions being equal to or greater than a minimum number of CSI-RS occasions up to the reference resource slot, the TD-CSI report based on the plurality of CSI-RS occasions. The method further comprises wherein the TD-CSI report comprises a report window that includes the reference resource slot and is based on the reference resource slot and defined by at least one of a first segment of a time domain basis vector length and a second segment of the time domain basis vector length. The method further comprises wherein the first segment corresponds to one or more precoder values from the plurality of CSI-RS occasions for the TD-CSI report, and the second segment corresponds to one or more predicted future precoder values based on the plurality of CSI-RS occasions for the TDI-CSI report.

Another aspect of the present disclosure includes a method of wireless communication, comprising transmitting, by a network unit to a user equipment (UE) , a plurality of channel state information reference signal (CSI-RS) occasions for use in a time-domain CSI (TD-CSI) report relative to a reference resource slot. The method further comprises receiving, by the network unit from the UE in response to the plurality of CSI-RS occasions being equal to or greater than a minimum number of CSI-RS occasions up to the reference resource slot, the TD-CSI report based on the plurality of CSI-RS occasions. The method further comprises wherein the TD-CSI report comprises a report window that includes the reference resource slot and is based on the reference resource slot and defined by at least one of a first segment of a time domain basis vector length and a second segment of the time domain basis vector length. The method further comprises wherein the first segment corresponds to one or more precoder values from the plurality of CSI-RS occasions for the TD-CSI report, and the second segment corresponds to one or more predicted future precoder values based on the plurality of CSI-RS occasions for the TDI-CSI report.

Another aspect of the present disclosure includes a user equipment (UE) , comprising a transceiver. The transceiver is configured to receive, from a network unit, a plurality of channel state information reference signal (CSI-RS) occasions for use in a time-domain CSI (TD-CSI) report relative to a reference resource slot. The transceiver is further configured to transmit, to the network unit in response to the plurality of CSI-RS occasions being equal to or greater than a minimum number of CSI-RS occasions up to the reference resource slot, the TD-CSI report based on the plurality of CSI-RS occasions. The UE further includes wherein the TD-CSI report comprises a report window that includes the reference resource slot and is based on the reference resource slot and defined by at least one of a first segment of a time domain basis vector length and a second segment of the time domain basis vector length. The UE further includes wherein the first segment corresponds to one or more precoder values from the plurality of CSI-RS occasions for the TD-CSI report, and the second segment corresponds to one or more predicted future precoder values based on the plurality of CSI-RS occasions for the TDI-CSI report.

Another aspect of the present disclosure includes a network unit comprising a transceiver. The transceiver is configured to transmit, to a user equipment (UE) , a plurality of channel state information reference signal (CSI-RS) occasions for use in a time-domain CSI (TD-CSI) report relative to a reference resource slot. The transceiver is further configured to receive, from the UE in response to the plurality of CSI-RS occasions being equal to or greater than a minimum number of CSI-RS occasions up to the reference resource slot, the TD-CSI report based on the plurality of CSI-RS occasions. The network unit further includes wherein the TD-CSI report comprises a report window that includes the reference resource slot and is based on the reference resource slot and defined by at least one of a first segment of a time domain basis vector length and a second segment of the time domain basis vector length. The network unit further includes wherein the first segment corresponds to one or more precoder values from the plurality of CSI-RS occasions for the TD-CSI report, and the second segment corresponds to one or more predicted future precoder values based on the plurality of CSI-RS occasions for the TDI-CSI report.

Other aspects, features, and embodiments will become apparent to those of ordinary skill in the art, upon reviewing the following description of specific, exemplary aspects in conjunction with the accompanying figures. While features may be discussed relative to certain aspects and figures below, all aspects can include one or more of the advantageous features discussed herein. In other words, while one or more aspects may be discussed as having certain advantageous features, one or more of such features may also be used in accordance with the various aspects discussed herein. In similar fashion, while exemplary aspects may be discussed below as device, system, or method aspects it should be understood that such exemplary aspects can be implemented in various devices, systems, and methods.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a wireless communication network according to some aspects of the present disclosure.

FIG. 2 illustrates an example portion of a wireless communications system that supports RU sharing techniques in wireless communications according to some aspects of the present disclosure.

FIG. 3 illustrates a diagram of a system including a device that supports RU sharing techniques in wireless communications according to some aspects of the present disclosure.

FIG. 4A illustrates a simplified diagram of a static doppler codebook according to some aspects of the present disclosure.

FIG. 4B illustrates a simplified diagram of a dynamic doppler codebook according to some aspects of the present disclosure.

FIG. 5A illustrates a simplified diagram of a reference resource slot according to some aspects of the present disclosure.

FIG. 5B illustrates a simplified diagram of a time domain basis index according to some aspects of the present disclosure

FIG. 6A illustrates a simplified diagram of a CSI reporting window according to some aspects of the present disclosure.

FIG. 6B illustrates a simplified diagram of a CSI reporting window according to some aspects of the present disclosure.

FIG. 7 illustrates a simplified diagram of a CSI reporting window according to some aspects of the present disclosure.

FIG. 8 illustrates a simplified diagram of a CSI reporting window according to some aspects of the present disclosure.

FIG. 9 illustrates a simplified diagram of a CSI reporting window according to some aspects of the present disclosure.

FIG. 10A illustrates a simplified diagram of a CSI reporting window according to some aspects of the present disclosure.

FIG. 10B illustrates a simplified diagram of a CSI reporting window according to some aspects of the present disclosure.

FIG. 11 illustrates a block diagram of a network unit according to some aspects of the present disclosure.

FIG. 12 illustrates a block diagram of a user equipment (UE) according to some aspects of the present disclosure.

FIG. 13 illustrates a simplified protocol diagram according to some aspects of the present disclosure.

FIG. 14 is a flow diagram of a wireless communication method performed by a UE according to some aspects of the present disclosure.

FIG. 15 is a flow diagram of a wireless communication method performed by a network unit according to some aspects of the present disclosure.

DETAILED DESCRIPTION

The detailed description set forth below, in connection with the appended drawings, is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some aspects, well-known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

This disclosure relates generally to wireless communications systems, also referred to as wireless communications networks. In various aspects, the techniques and apparatus may be used for wireless communication networks such as code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) networks, single-carrier FDMA (SC-FDMA) networks, LTE networks, Global System for Mobile Communications (GSM) networks, 5 ^th Generation (5G) or new radio (NR) networks, as well as other communications networks. As described herein, the terms “networks” and “systems” may be used interchangeably.

An OFDMA network may implement a radio technology such as evolved UTRA (E-UTRA) , Institute of Electrical and Electronics Engineers (IEEE) 802.11, IEEE 802.16, IEEE 802.20, flash-OFDM and the like. UTRA, E-UTRA, and GSM are part of universal mobile telecommunication system (UMTS) . In particular, long term evolution (LTE) is a release of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE are described in documents provided from an organization named “3rd Generation Partnership Project” (3GPP) , and cdma2000 is described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2) . These various radio technologies and standards are known or are being developed. For example, the 3rd Generation Partnership Project (3GPP) is a collaboration between groups of telecommunications associations that aims to define a globally applicable third generation (3G) mobile phone specification. 3GPP long term evolution (LTE) is a 3GPP project which was aimed at improving the UMTS mobile phone standard. The 3GPP may define specifications for the next generation of mobile networks, mobile systems, and mobile devices. The present disclosure is concerned with the evolution of wireless technologies from LTE, 4G, 5G, NR, and beyond with shared access to wireless spectrum between networks using a collection of new and different radio access technologies or radio air interfaces.

In particular, 5G networks contemplate diverse deployments, diverse spectrum, and diverse services and devices that may be implemented using an OFDM-based unified, air interface. In order to achieve these goals, further enhancements to LTE and LTE-A are considered in addition to development of the new radio technology for 5G NR networks. The 5G NR will be capable of scaling to provide coverage (1) to a massive Internet of things (IoTs) with an Ultra-high density (e.g., ～1M nodes/km ²) , ultra-low complexity (e.g., ～10s of bits/sec) , ultra-low energy (e.g., ～10+years of battery life) , and deep coverage with the capability to reach challenging locations; (2) including mission-critical control with strong security to safeguard sensitive personal, financial, or classified information, ultra-high reliability (e.g., ～99.9999%reliability) , ultra-low latency (e.g., ～ 1 ms) , and users with wide ranges of mobility or lack thereof; and (3) with enhanced mobile broadband including extreme high capacity (e.g., ～ 10 Tbps/km ²) , extreme data rates (e.g., multi-Gbps rate, 100+ Mbps user experienced rates) , and deep awareness with advanced discovery and optimizations.

A 5G NR communication system may be implemented to use optimized OFDM-based waveforms with scalable numerology and transmission time interval (TTI) ; having a common, flexible framework to efficiently multiplex services and features with a dynamic, low-latency time division duplex (TDD) /frequency division duplex (FDD) design; and with advanced wireless technologies, such as massive multiple input, multiple output (MIMO) , robust millimeter wave (mmWave) transmissions, advanced channel coding, and device-centric mobility. Scalability of the numerology in 5G NR, with scaling of subcarrier spacing, may efficiently address operating diverse services across diverse spectrum and diverse deployments. For example, in various outdoor and macro coverage deployments of less than 3GHz FDD/TDD implementations, subcarrier spacing may occur with 15 kHz, for example over 5, 10, 20 MHz, and the like bandwidth (BW) . For other various outdoor and small cell coverage deployments of TDD greater than 3 GHz, subcarrier spacing may occur with 30 kHz over 80/100 MHz BW. For other various indoor wideband implementations, using a TDD over the unlicensed portion of the 5 GHz band, the subcarrier spacing may occur with 60 kHz over a 160 MHz BW. Finally, for various deployments transmitting with mmWave components at a TDD of 28 GHz, subcarrier spacing may occur with 120 kHz over a 500 MHz BW. In certain aspects, frequency bands for 5G NR are separated into multiple different frequency ranges, a frequency range one (FR1) , a frequency range two (FR2) , and FR2x. FR1 bands include frequency bands at 7 GHz or lower (e.g., between about 410 MHz to about 7125 MHz) . FR2 bands include frequency bands in mmWave ranges between about 24.25 GHz and about 52.6 GHz. FR2x bands include frequency bands in mmWave ranges between about 52.6 GHz to about 71 GHz. The mmWave bands may have a shorter range, but a higher bandwidth than the FR1 bands. Additionally, 5G NR may support different sets of subcarrier spacing for different frequency ranges.

The scalable numerology of the 5G NR facilitates scalable TTI for diverse latency and quality of service (QoS) requirements. For example, shorter TTI may be used for low latency and high reliability, while longer TTI may be used for higher spectral efficiency. The efficient multiplexing of long and short TTIs to allow transmissions to start on symbol boundaries. 5G NR also contemplates a self-contained integrated subframe design with UL/downlink scheduling information, data, and acknowledgement in the same subframe. The self-contained integrated subframe supports communications in unlicensed or contention-based shared spectrum, adaptive UL/downlink that may be flexibly configured on a per-cell basis to dynamically switch between UL and downlink to meet the current traffic needs.

Various other aspects and features of the disclosure are further described below. It should be apparent that the teachings herein may be embodied in a wide variety of forms and that any specific structure, function, or both being disclosed herein is merely representative and not limiting. Based on the teachings herein one of an ordinary level of skill in the art should appreciate that an aspect disclosed herein may be implemented independently of any other aspects and that two or more of these aspects may be combined in various ways. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, such an apparatus may be implemented or such a method may be practiced using other structure, functionality, or structure and functionality in addition to or other than one or more of the aspects set forth herein. For example, a method may be implemented as part of a system, device, apparatus, and/or as instructions stored on a computer readable medium for execution on a processor or computer. Furthermore, an aspect may comprise at least one element of a claim.

The present disclosure describes systems and methods for decoupling CSI reporting windows from measured CSI-RS occasions. This is accomplished by defining the CSI reporting windows so that the UE and gNB understand what the CSI report includes that is sent to the gNB. The CSI reporting window may be defined based on a CSI reference resource slot between the gNB and the UE, without defining or requiring a CSI measurement window. The CSI reporting window may include a Doppler Domain/Time Domain basis vector that is split into two sub-parts, or segments, with one segment corresponding to precoder determinations for multiple CSI-RS occasions before the CSI reference resource slot (repeating over time either on a periodic, semi-periodic, or aperiodic basis) , and another segment corresponding to one or more precoder predictions after the CSI reference resource slot into a future period of time. The CSI reporting window may be defined by a length of the window, e.g. by number of slots between the CSI reference resource slot and a beginning slot index. Further, a minimum measurement requirement may be defined also based on the CSI reference resource slot. The minimum measurement requirement may be configured at the UE a variety of ways, including via RRC signaling, MAC CE, and/or other control signaling. Or, the UE may be preconfigured with a given minimum measurement requirement value and report that to the gNB. However configured, the minimum measurement requirement value (i.e., a minimum CSI-RS occasion count) may be used to ensure the performance of future precoder matrix coefficient value prediction.

Systems and methods described herein provide many advantages. Defining CSI reporting windows according to one or more aspects described herein allows CSI measurement to be left up to UE implementation (i.e., a CSI measurement window does not need to be defined) . This, in turn, reduces the amount of signaling overhead between devices. Further benefits of the present disclosure include higher data rates, improved capacity, and improved spectral efficiency, such as due to the reduced amount of signaling overhead since the gNB and UE do not have to coordinate as much with respect to what the CSI measurement window is or should be.

FIG. 1 illustrates a wireless communication network 100 according to some aspects of the present disclosure. The network 100 may be a 5G network. The network 100 includes a number of base stations (BSs) 105 (individually labeled as 105a, 105b, 105c, 105d, 105e, and 105f) and other network entities. A BS 105 may be a station that communicates with UEs 115 (individually labeled as 115a, 115b, 115c, 115d, 115e, 115f, 115g, 115h, and 115k) and may also be referred to as an evolved node B (eNB) , a next generation eNB (gNB) , an access point, and the like. Each BS 105 may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to this particular geographic coverage area of a BS 105 and/or a BS subsystem serving the coverage area, depending on the context in which the term is used.

A BS 105 may provide communication coverage for a macro cell or a small cell, such as a pico cell or a femto cell, and/or other types of cell. A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell, such as a pico cell, would generally cover a relatively smaller geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell, such as a femto cell, would also generally cover a relatively small geographic area (e.g., a home) and, in addition to unrestricted access, may also provide restricted access by UEs having an association with the femto cell (e.g., UEs in a closed subscriber group (CSG) , UEs for users in the home, and the like) . A BS for a macro cell may be referred to as a macro BS. A BS for a small cell may be referred to as a small cell BS, a pico BS, a femto BS or a home BS. In the example shown in FIG. 1, the

BSs

105d and 105e may be regular macro BSs, while the BSs 105a-105c may be macro BSs enabled with one of three dimension (3D) , full dimension (FD) , or massive MIMO. The BSs 105a-105c may take advantage of their higher dimension MIMO capabilities to exploit 3D beamforming in both elevation and azimuth beamforming to increase coverage and capacity. The BS 105f may be a small cell BS which may be a home node or portable access point. A BS 105 may support one or multiple (e.g., two, three, four, and the like) cells.

The network 100 may support synchronous or asynchronous operation. For synchronous operation, the BSs may have similar frame timing, and transmissions from different BSs may be approximately aligned in time. For asynchronous operation, the BSs may have different frame timing, and transmissions from different BSs may not be aligned in time.

The UEs 115 are dispersed throughout the wireless network 100, and each UE 115 may be stationary or mobile. A UE 115 may also be referred to as a terminal, a mobile station, a subscriber unit, a station, or the like. A UE 115 may be a cellular phone, a personal digital assistant (PDA) , a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a wireless local loop (WLL) station, or the like. In one aspect, a UE 115 may be a device that includes a Universal Integrated Circuit Card (UICC) . In another aspect, a UE may be a device that does not include a UICC. In some aspects, the UEs 115 that do not include UICCs may also be referred to as IoT devices or internet of everything (IoE) devices. The UEs 115a-115d are examples of mobile smart phone-type devices accessing network 100. A UE 115 may also be a machine specifically configured for connected communication, including machine type communication (MTC) , enhanced MTC (eMTC) , narrowband IoT (NB-IoT) and the like. The UEs 115e-115h are examples of various machines configured for communication that access the network 100. The UEs 115i-115k are examples of vehicles equipped with wireless communication devices configured for communication that access the network 100. Some UEs 115 may be energy harvesting UEs. An energy harvesting UE 115 may harvest energy from one or more sources. For example, solar, vibration, thermal, and/or RF energy may be harvested. A UE 115 may be able to communicate with any type of the BSs, whether macro BS, small cell, or the like. In FIG. 1, a lightning bolt (e.g., communication links) indicates wireless transmissions between a UE 115 and a serving BS 105, which is a BS designated to serve the UE 115 on the downlink (DL) and/or uplink (UL) , desired transmission between BSs 105, backhaul transmissions between BSs, or sidelink transmissions between UEs 115.

In operation, the BSs 105a-105c may serve the

UEs

115a and 115b using 3D beamforming and coordinated spatial techniques, such as coordinated multipoint (CoMP) or multi-connectivity. The macro BS 105d may perform backhaul communications with the BSs 105a-105c, as well as small cell, the BS 105f. The macro BS 105d may also transmit multicast services which are subscribed to and received by the

UEs

115c and 115d. Such multicast services may include mobile television or stream video, or may include other services for providing community information, such as weather emergencies or alerts, such as Amber alerts or gray alerts.

The BSs 105 may also communicate with a core network. The core network may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. At least some of the BSs 105 (e.g., which may be an example of a gNB or an access node controller (ANC) ) may interface with the core network through backhaul links (e.g., NG-C, NG-U, etc. ) and may perform radio configuration and scheduling for communication with the UEs 115. In various examples, the BSs 105 may communicate, either directly or indirectly (e.g., through core network) , with each other over backhaul links (e.g., X1, X2, etc. ) , which may be wired or wireless communication links.

The network 100 may also support mission critical communications with ultra-reliable and redundant links for mission critical devices, such as the UE 115e, which may be a drone. Redundant communication links with the UE 115e may include links from the

macro BSs

105d and 105e, as well as links from the small cell BS 105f. Other machine type devices, such as the UE 115f (e.g., a thermometer) , the UE 115g (e.g., smart meter) , and UE 115h (e.g., wearable device) may communicate through the network 100 either directly with BSs, such as the small cell BS 105f, and the macro BS 105e, or in multi-action-size configurations by communicating with another user device which relays its information to the network, such as the UE 115f communicating temperature measurement information to the smart meter, the UE 115g, which is then reported to the network through the small cell BS 105f. The network 100 may also provide additional network efficiency through dynamic, low-latency TDD/FDD communications, such asV2V, V2X, C-V2X communications between a

UE

115i, 115j, or 115k and other UEs 115, and/or vehicle-to-infrastructure (V2I) communications between a

UE

115i, 115j, or 115k and a BS 105.

In some implementations, the network 100 utilizes OFDM-based waveforms for communications. An OFDM-based system may partition the system BW into multiple (K) orthogonal subcarriers, which are also commonly referred to as subcarriers, tones, bins, or the like. Each subcarrier may be modulated with data. In some aspects, the subcarrier spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may be dependent on the system BW. The system BW may also be partitioned into subbands. In other aspects, the subcarrier spacing and/or the duration of TTIs may be scalable.

In some aspects, the BSs 105 can assign or schedule transmission resources (e.g., in the form of time-frequency resource blocks (RB) ) for downlink (DL) and uplink (UL) transmissions in the network 100. DL refers to the transmission direction from a BS 105 to a UE 115, whereas UL refers to the transmission direction from a UE 115 to a BS 105. The communication can be in the form of radio frames. A radio frame may be divided into a plurality of subframes or slots, for example, about 10. Each slot may be further divided into mini-slots. In a FDD mode, simultaneous UL and DL transmissions may occur in different frequency bands. For example, each subframe includes an UL subframe in an UL frequency band and a DL subframe in a DL frequency band. In a TDD mode, UL and DL transmissions occur at different time periods using the same frequency band. For example, a subset of the subframes (e.g., DL subframes) in a radio frame may be used for DL transmissions and another subset of the subframes (e.g., UL subframes) in the radio frame may be used for UL transmissions.

The DL subframes and the UL subframes can be further divided into several regions. For example, each DL or UL subframe may have pre-defined regions for transmissions of reference signals, control information, and data. Reference signals are predetermined signals that facilitate the communications between the BSs 105 and the UEs 115. For example, a reference signal can have a particular pilot pattern or structure, where pilot tones may span across an operational BW or frequency band, each positioned at a pre-defined time and a pre-defined frequency. For example, a BS 105 may transmit cell specific reference signals (CRSs) and/or channel state information –reference signals (CSI-RSs) to enable a UE 115 to estimate a DL channel. A BS 105 may transmit the CSI-RS during multiple occasions, such as on a periodic basis, a semi-periodic (also referred to as semi-persistent) basis, or an aperiodic basis. The semi-periodic and aperiodic CSI-RS may be triggered by physical downlink control channel (PDCCH) transmission. The CSI-RS may each have a given periodicity and offset. In some aspects, CSI-RS may also have a burst periodicity parameter as well as a burst duration parameter (e.g., some integer multiple of a number of CSI-RS occasions) . According to aspects of the present disclosure, a CSI reporting window may be defined based on a CSI reference resource slot between the BS 105 and the UE 115, without defining or requiring a CSI measurement window. The CSI reporting window may include a doppler domain/time domain (DD/TD) basis vector that is split into two sub-parts, or segments, with one segment corresponding to precoder determinations for multiple CSI-RS occasions before the CSI reference resource slot (repeating over time either on a periodic, semi-periodic, or aperiodic basis) , and another segment corresponding to one or more precoder predictions after the CSI reference resource slot into a future period of time. The CSI reporting window may be defined by a length of the window, e.g. by number of slots between the CSI reference resource slot and a beginning slot index. Further, a minimum measurement requirement may be defined also based on the CSI reference resource slot. The minimum measurement requirement may be configured at the UE 115 a variety of ways, including via RRC signaling, MAC CE, and/or other control signaling. Or, the UE 115 may be preconfigured with a given minimum measurement requirement value and report that to the BS 105. Further, which segments the UE 115 provides in the CSI report (e.g., both first and second segments, just the first segment, or just the second segment) may be based on BS 105 configuration (e.g., based on UE capability reported) . Alternatively, the configuration may be predefined for both the BS 105 and the UE 115.

A UE 115 may analogously transmit sounding reference signals (SRSs) to enable a BS 105 to estimate an UL channel. Control information may include resource assignments and protocol controls. Data may include protocol data and/or operational data. In some aspects, the BSs 105 and the UEs 115 may communicate using self-contained subframes. A self-contained subframe may include a portion for DL communication and a portion for UL communication. A self-contained subframe can be DL-centric or UL-centric. A DL-centric subframe may include a longer duration for DL communication than for UL communication. an UL-centric subframe may include a longer duration for UL communication than for UL communication.

In some aspects, the network 100 may be an NR network deployed over a licensed spectrum. The BSs 105 can transmit synchronization signals (e.g., including a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) ) in the network 100 to facilitate synchronization. The BSs 105 can broadcast system information associated with the network 100 (e.g., including a master information block (MIB) , remaining system information (RMSI) , and other system information (OSI) ) to facilitate initial network access. In some aspects, the BSs 105 may broadcast the PSS, the SSS, and/or the MIB in the form of synchronization signal block (SSBs) and may broadcast the RMSI and/or the OSI over a physical downlink shared channel (PDSCH) . The MIB may be transmitted over a physical broadcast channel (PBCH) .

In some aspects, a UE 115 attempting to access the network 100 may perform an initial cell search by detecting a PSS from a BS 105. The PSS may enable synchronization of period timing and may indicate a physical layer identity value. The UE 115 may then receive a SSS. The SSS may enable radio frame synchronization, and may provide a cell identity value, which may be combined with the physical layer identity value to identify the cell. The PSS and the SSS may be located in a central portion of a carrier or any suitable frequencies within the carrier.

After receiving the PSS and SSS, the UE 115 may receive a MIB. The MIB may include system information for initial network access and scheduling information for RMSI and/or OSI. After decoding the MIB, the UE 115 may receive RMSI and/or OSI. The RMSI and/or OSI may include radio resource control (RRC) information related to random access channel (RACH) procedures, paging, control resource set (CORESET) for physical downlink control channel (PDCCH) monitoring, physical UL control channel (PUCCH) , physical UL shared channel (PUSCH) , power control, and SRS.

After obtaining the MIB, the RMSI and/or the OSI, the UE 115 can perform a random access procedure to establish a connection with the BS 105. In some examples, the random access procedure may be a four-step random access procedure. For example, the UE 115 may transmit a random access preamble and the BS 105 may respond with a random access response. The random access response (RAR) may include a detected random access preamble identifier (ID) corresponding to the random access preamble, timing advance (TA) information, an UL grant, a temporary cell-radio network temporary identifier (C-RNTI) , and/or a backoff indicator. Upon receiving the random access response, the UE 115 may transmit a connection request to the BS 105 and the BS 105 may respond with a connection response. The connection response may indicate a contention resolution. In some examples, the random access preamble, the RAR, the connection request, and the connection response can be referred to as message 1 (MSG1) , message 2 (MSG2) , message 3 (MSG3) , and message 4 (MSG4) , respectively. In some examples, the random access procedure may be a two-step random access procedure, where the UE 115 may transmit a random access preamble and a connection request in a single transmission and the BS 105 may respond by transmitting a random access response and a connection response in a single transmission.

After establishing a connection, the UE 115 and the BS 105 can enter a normal operation stage, where operational data may be exchanged. For example, the BS 105 may schedule the UE 115 for UL and/or DL communications. The BS 105 may transmit UL and/or DL scheduling grants to the UE 115 via a PDCCH. The scheduling grants may be transmitted in the form of DL control information (DCI) . The BS 105 may transmit a DL communication signal (e.g., carrying data) to the UE 115 via a PDSCH according to a DL scheduling grant. The UE 115 may transmit an UL communication signal to the BS 105 via a PUSCH and/or PUCCH according to an UL scheduling grant. The connection may be referred to as an RRC connection. When the UE 115 is actively exchanging data with the BS 105, the UE 115 is in an RRC connected state.

In an example, after establishing a connection with the BS 105, the UE 115 may initiate an initial network attachment procedure with the network 100. The BS 105 may coordinate with various network entities or fifth generation core (5GC) entities, such as an access and mobility function (AMF) , a serving gateway (SGW) , and/or a packet data network gateway (PGW) , to complete the network attachment procedure. For example, the BS 105 may coordinate with the network entities in the 5GC to identify the UE, authenticate the UE, and/or authorize the UE for sending and/or receiving data in the network 100. In addition, the AMF may assign the UE with a group of tracking areas (TAs) . Once the network attach procedure succeeds, a context is established for the UE 115 in the AMF. After a successful attach to the network, the UE 115 can move around the current TA. For tracking area update (TAU) , the BS 105 may request the UE 115 to update the network 100 with the UE 115’s location periodically. Alternatively, the UE 115 may only report the UE 115’s location to the network 100 when entering a new TA. The TAU allows the network 100 to quickly locate the UE 115 and page the UE 115 upon receiving an incoming data packet or call for the UE 115.

In some aspects, the BS 105 may communicate with a UE 115 using HARQ techniques to improve communication reliability, for example, to provide a URLLC service. The BS 105 may schedule a UE 115 for a PDSCH communication by transmitting a DL grant in a PDCCH. The BS 105 may transmit a DL data packet to the UE 115 according to the schedule in the PDSCH. The DL data packet may be transmitted in the form of a transport block (TB) . If the UE 115 receives the DL data packet successfully, the UE 115 may transmit a HARQ ACK to the BS 105. Conversely, if the UE 115 fails to receive the DL transmission successfully, the UE 115 may transmit a HARQ NACK to the BS 105. Upon receiving a HARQ NACK from the UE 115, the BS 105 may retransmit the DL data packet to the UE 115. The retransmission may include the same coded version of DL data as the initial transmission. Alternatively, the retransmission may include a different coded version of the DL data than the initial transmission. The UE 115 may apply soft combining to combine the encoded data received from the initial transmission and the retransmission for decoding. The BS 105 and the UE 115 may also apply HARQ for UL communications using substantially similar mechanisms as the DL HARQ.

In some aspects, the network 100 may operate over a system BW or a component carrier (CC) BW. The network 100 may partition the system BW into multiple BWPs (e.g., portions) . A BS 105 may dynamically assign a UE 115 to operate over a certain BWP (e.g., a certain portion of the system BW) . The assigned BWP may be referred to as the active BWP. The UE 115 may monitor the active BWP for signaling information from the BS 105. The BS 105 may schedule the UE 115 for UL or DL communications in the active BWP. In some aspects, a BS 105 may assign a pair of BWPs within the CC to a UE 115 for UL and DL communications. For example, the BWP pair may include one BWP for UL communications and one BWP for DL communications.

In some aspects, the network 100 may operate over a shared channel, which may include shared frequency bands and/or unlicensed frequency bands. For example, the network 100 may be an NR-U network operating over an unlicensed frequency band. In such an aspect, the BSs 105 and the UEs 115 may be operated by multiple network operating entities. To avoid collisions, the BSs 105 and the UEs 115 may employ a listen-before-talk (LBT) procedure to monitor for transmission opportunities (TXOPs) in the shared channel. A TXOP may also be referred to as COT. The goal of LBT is to protect reception at a receiver from interference. For example, a transmitting node (e.g., a BS 105 or a UE 115) may perform an LBT prior to transmitting in the channel. When the LBT passes, the transmitting node may proceed with the transmission. When the LBT fails, the transmitting node may refrain from transmitting in the channel.

An LBT can be based on energy detection (ED) or signal detection. For an energy detection-based LBT, the LBT results in a pass when signal energy measured from the channel is below a threshold. Conversely, the LBT results in a failure when signal energy measured from the channel exceeds the threshold. For a signal detection-based LBT, the LBT results in a pass when a channel reservation signal (e.g., a predetermined preamble signal) is not detected in the channel. Additionally, an LBT may be in a variety of modes. An LBT mode may be, for example, a category 4 (CAT4) LBT, a category 2 (CAT2) LBT, or a category 1 (CAT1) LBT. A CAT1 LBT is referred to a no LBT mode, where no LBT is to be performed prior to a transmission. A CAT2 LBT refers to an LBT without a random backoff period. For instance, a transmitting node may determine a channel measurement in a time interval and determine whether the channel is available or not based on a comparison of the channel measurement against a ED threshold. A CAT4 LBT refers to an LBT with a random backoff and a variable contention window (CW) . For instance, a transmitting node may draw a random number and backoff for a duration based on the drawn random number in a certain time unit.

Deployment of communication systems, such as 5G new radio (NR) systems, may be arranged in multiple manners with various components or constituent parts. In a 5G NR system, or network, a network node, a network entity, a network unit, a mobility element of a network, a radio access network (RAN) node, a core network node, a network element, or a network equipment, such as a base station (BS) , or one or more units (or one or more components) performing base station functionality, may be implemented in an aggregated or disaggregated architecture. For example, a BS 105 (such as a Node B (NB) , evolved NB (eNB) , NR BS, 5G NB, access point (AP) , a transmit receive point (TRP) , or a cell, etc. ) may be implemented as an aggregated base station (also known as a standalone BS or a monolithic BS) or a disaggregated base station.

An aggregated base station may be configured to utilize a radio protocol stack that is physically or logically integrated within a single RAN node. A disaggregated base station may be configured to utilize a protocol stack that is physically or logically distributed among two or more units (such as one or more central or centralized units (CUs) , one or more distributed units (DUs) , or one or more radio units (RUs) ) . In some aspects, a CU may be implemented within a RAN node, and one or more DUs may be co-located with the CU, or alternatively, may be geographically or virtually distributed throughout one or multiple other RAN nodes. The DUs may be implemented to communicate with one or more RUs. Each of the CU, DU and RU also can be implemented as virtual units, i.e., a virtual central unit (VCU) , a virtual distributed unit (VDU) , or a virtual radio unit (VRU) .

Base station-type operation or network design may consider aggregation characteristics of base station functionality. For example, disaggregated base stations may be utilized in an integrated access backhaul (IAB) network, an open radio access network (O-RAN (such as the network configuration sponsored by the O-RAN Alliance) ) , or a virtualized radio access network (vRAN, also known as a cloud radio access network (C-RAN) ) . Disaggregation may include distributing functionality across two or more units at various physical locations, as well as distributing functionality for at least one unit virtually, which can enable flexibility in network design. The various units of the disaggregated base station, or disaggregated RAN architecture, can be configured for wired or wireless communication with at least one other unit.

FIG. 2 shows a diagram illustrating an example disaggregated base station 200 architecture. The disaggregated base station 200 architecture may include one or more central units (CUs) 210 that can communicate directly with a core network 220 via a backhaul link, or indirectly with the core network 220 through one or more disaggregated base station units (such as a Near-Real Time (Near-RT) RAN Intelligent Controller (RIC) 225 via an E2 link, or a Non-Real Time (Non-RT) RIC 215 associated with a Service Management and Orchestration (SMO) Framework 205, or both) . A CU 210 may communicate with one or more distributed units (DUs) 230 via respective midhaul links, such as an F1 interface. The DUs 230 may communicate with one or more radio units (RUs) 240 via respective fronthaul links. The RUs 240 may communicate with respective UEs 115 via one or more radio frequency (RF) access links. In some implementations, the UE 115 may be simultaneously served by multiple RUs 240.

Each of the units, i.e., the CUs 210, the DUs 230, the RUs 240, as well as the Near-RT RICs 225, the Non-RT RICs 215 and the SMO Framework 205, may include one or more interfaces or be coupled to one or more interfaces configured to receive or transmit signals, data, or information (collectively, signals) via a wired or wireless transmission medium. Each of the units, or an associated processor or controller providing instructions to the communication interfaces of the units, can be configured to communicate with one or more of the other units via the transmission medium. For example, the units can include a wired interface configured to receive or transmit signals over a wired transmission medium to one or more of the other units. Additionally, the units can include a wireless interface, which may include a receiver, a transmitter or transceiver (such as a radio frequency (RF) transceiver) , configured to receive or transmit signals, or both, over a wireless transmission medium to one or more of the other units.

In some aspects, the CU 210 may host one or more higher layer control functions. Such control functions can include radio resource control (RRC) , packet data convergence protocol (PDCP) , service data adaptation protocol (SDAP) , or the like. Each control function can be implemented with an interface configured to communicate signals with other control functions hosted by the CU 210. The CU 210 may be configured to handle user plane functionality (i.e., Central Unit –User Plane (CU-UP) ) , control plane functionality (i.e., Central Unit –Control Plane (CU-CP) ) , or a combination thereof. In some implementations, the CU 210 can be logically split into one or more CU-UP units and one or more CU-CP units. The CU-UP unit can communicate bidirectionally with the CU-CP unit via an interface, such as the E1 interface when implemented in an O-RAN configuration. The CU 210 can be implemented to communicate with the DU 230, as necessary, for network control and signaling.

The DU 230 may correspond to a logical unit that includes one or more base station functions to control the operation of one or more RUs 240. In some aspects, the DU 230 may host one or more of a radio link control (RLC) layer, a medium access control (MAC) layer, and one or more high physical (PHY) layers (such as modules for forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, or the like) depending, at least in part, on a functional split, such as those defined by the 3rd Generation Partnership Project (3GPP) . In some aspects, the DU 230 may further host one or more low PHY layers. Each layer (or module) can be implemented with an interface configured to communicate signals with other layers (and modules) hosted by the DU 230, or with the control functions hosted by the CU 210.

Lower-layer functionality can be implemented by one or more RUs 240. In some deployments, an RU 240, controlled by a DU 230, may correspond to a logical node that hosts RF processing functions, or low-PHY layer functions (such as performing fast Fourier transform (FFT) , inverse FFT (iFFT) , digital beamforming, physical random access channel (PRACH) extraction and filtering, or the like) , or both, based at least in part on the functional split, such as a lower layer functional split. In such an architecture, the RU (s) 240 can be implemented to handle over the air (OTA) communication with one or more UEs 115. In some implementations, real-time and non-real-time aspects of control and user plane communication with the RU (s) 240 can be controlled by the corresponding DU 230. In some scenarios, this configuration can enable the DU (s) 230 and the CU 210 to be implemented in a cloud-based RAN architecture, such as a vRAN architecture.

The SMO Framework 205 may be configured to support RAN deployment and provisioning of non-virtualized and virtualized network elements. For non-virtualized network elements, the SMO Framework 205 may be configured to support the deployment of dedicated physical resources for RAN coverage requirements which may be managed via an operations and maintenance interface (such as an O1 interface) . For virtualized network elements, the SMO Framework 205 may be configured to interact with a cloud computing platform (such as an open cloud (O-Cloud) 290) to perform network element life cycle management (such as to instantiate virtualized network elements) via a cloud computing platform interface (such as an O2 interface) . Such virtualized network elements can include, but are not limited to, CUs 210, DUs 230, RUs 240 and Near-RT RICs 225. In some implementations, the SMO Framework 205 can communicate with a hardware aspect of a 4G RAN, such as an open eNB (O-eNB) 211, via an O1 interface. Additionally, in some implementations, the SMO Framework 205 can communicate directly with one or more RUs 240 via an O1 interface. The SMO Framework 205 also may include a Non-RT RIC 215 configured to support functionality of the SMO Framework 205.

The Non-RT RIC 215 may be configured to include a logical function that enables non-real-time control and optimization of RAN elements and resources, Artificial Intelligence/Machine Learning (AI/ML) workflows including model training and updates, or policy-based guidance of applications/features in the Near-RT RIC 225. The Non-RT RIC 215 may be coupled to or communicate with (such as via an A1 interface) the Near-RT RIC 225. The Near-RT RIC 225 may be configured to include a logical function that enables near-real-time control and optimization of RAN elements and resources via data collection and actions over an interface (such as via an E2 interface) connecting one or more CUs 210, one or more DUs 230, or both, as well as an O-eNB, with the Near-RT RIC 225.

In some implementations, to generate AI/ML models to be deployed in the Near-RT RIC 225, the Non-RT RIC 215 may receive parameters or external enrichment information from external servers. Such information may be utilized by the Near-RT RIC 225 and may be received at the SMO Framework 205 or the Non-RT RIC 215 from non-network data sources or from network functions. In some examples, the Non-RT RIC 215 or the Near-RT RIC 225 may be configured to tune RAN behavior or performance. For example, the Non-RT RIC 215 may monitor long-term trends and patterns for performance and employ AI/ML models to perform corrective actions through the SMO Framework 205 (such as reconfiguration via O1) or via creation of RAN management policies (such as A1 policies) .

FIG. 3 shows a diagram of a system 300 including a device 305 that supports RU sharing techniques in wireless communications in accordance with aspects of the present disclosure. The device 305 may communicate with one or more RUs 355. The device 305 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, such as a communications manager 320, a network communications manager 310, a memory 330, code 335, a processor 340, and a RU communications manager 345. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., a bus 350) . One or more of the components of system 300 may perform functions as described herein with reference to FIGS. 4-15, for example functions described as performed by a base station or network unit.

The network communications manager 310 may manage communications with a core network 360 (e.g., via one or more wired backhaul links) . For example, the network communications manager 310 may manage the transfer of data communications for client devices, such as one or more UEs 115.

The memory 330 may include RAM and ROM. The memory 330 may store computer-readable, computer-executable code 335 including instructions that, when executed by the processor 340, cause the device 305 to perform various functions described herein. The code 335 may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, the code 335 may not be directly executable by the processor 340 but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some cases, the memory 330 may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The processor 340 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some cases, the processor 340 may be configured to operate a memory array using a memory controller. In some other cases, a memory controller may be integrated into the processor 340. The processor 340 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 330) to cause the device 305 to perform various functions (e.g., functions or tasks supporting RU sharing techniques in wireless communications) . For example, the device 305 or a component of the device 305 may include a processor 340 and memory 330 coupled to the processor 340, the processor 340 and memory 330 configured to perform various functions described herein.

The RU communications manager 345 may manage communications with RUs 355, and may include a controller or scheduler for controlling communications with UEs 115 in cooperation with RUs 355. For example, the RU communications manager 345 may coordinate scheduling for transmissions to UEs 115. In some examples, the RU communications manager 345 may provide an F1 interface within a wireless communications network technology to provide communication with RUs 355.

The communications manager 320 may support wireless communications at a network node in accordance with examples as disclosed herein. For example, the communications manager 320 may be configured as or otherwise support a means for transmitting, to a first RU, a request for a wireless resource configuration for a first time period. The communications manager 320 may be configured as or otherwise support a means for transmitting, to a second RU, an interference inquiry associated with the wireless resource configuration for the first time period. The communications manager 320 may be configured as or otherwise support a means for receiving, from the second RU, a response to the interference inquiry. The communications manager 320 may be configured as or otherwise support a means for transmitting, based on the response to the interference inquiry, a payload to the first RU for transmission during the first time period.

By including or configuring the communications manager 320 in accordance with examples as described herein, the device 305 may support techniques for RU sharing in which DUs of different MNOs may access wireless resources of other MNOs, which may increase efficiency of resource usage while provide for competition and innovation among different MNOs, may increase the reliability of wireless communications, decrease latency, and enhance user experience.

In some examples, the communications manager 320 may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with other components. Although the communications manager 320 is illustrated as a separate component, in some examples, one or more functions described with reference to the communications manager 320 may be supported by or performed by the processor 340, the memory 330, the code 335, or any combination thereof. For example, the code 335 may include instructions executable by the processor 340 to cause the device 305 to perform various aspects of RU sharing techniques in wireless communications as described herein, or the processor 340 and the memory 330 may be otherwise configured to perform or support such operations.

FIG. 4A illustrates a simplified diagram 400 of a static doppler codebook according to some aspects of the present disclosure. Diagram 400 represents a diagram for an exemplary precoding matrix for a given layer. In diagram 400, element 402 corresponds to the selected spatial domain bases (or beams) . There are L spatial domain bases per polarization, with the example element 402 in diagram 400 having L=2, with the spatial bases (per polarization) being illustrated by the respective columns of element 402. This includes a number of antennas in each of the vertical and horizontal dimensions. With respect to the first polarization, each spatial basis represents a different spatial beam (or spatial domain basis) with a corresponding number of frequency bases. Likewise with respect to the second polarization, each spatial basis represents a different spatial beam with a corresponding number of frequency bases. Together, these numbers of frequency bases allow the value of M overall frequency bases (or taps) to be determined, representing the dimension (horizontally) of the matrix for element 404. The value M also represents the overall frequency bases of the matrix for element 406 (the vertical dimension) with a number N ₃ of frequency units (e.g., number of subbands) .

For each given spatial basis, the corresponding combination coefficient is a linear combination of the corresponding number of frequency bases related to a given polarization in the coefficient matrix of element 404. The value may be determined or selected by the UE 115 and sent in CSI to the BS 105, or may be configured by the BS 105 in the UE 115 by a higher layer signaling such as RRC signaling. The value of a given coefficient in element 404 may be a function of the number of ports in both dimensions (vertical and horizontal) . Or, the value of a given coefficient may be a function of the number of subbands (or both spatial and frequency may be taken into account) .

The UE 115 will measure CSI-RS from a BS 105 and report the spatial domain and frequency domain bases selection (e.g., corresponding to

elements

402 and 406 above, basically the direction of the transmission from the BS 105 and the latency of the transmission for each path) . According to the measurements the UE 115 obtains, the precoder matrix is obtained and reported to the BS 105. While this works well in general for a static channel (where the precoder is presumed to be effective for quite some time) , the channel can vary rather quickly for higher velocity UEs 115.

FIG. 4B illustrates a simplified diagram 430 of a dynamic doppler codebook according to some aspects of the present disclosure. Diagram 430 corresponds to higher velocity UEs 115, where the channel can change very quickly. Even in such situations, however, it can still be presumed that over a short window of time, such a hundreds of milliseconds, that the spatial domain bases and the frequency domain bases do not change very much. Thus, the spatial domain bases and frequency domain bases (e.g., 402 and 406 from FIG. 4A) remain the same for the period in time in question with respect to FIG. 4B. But the coefficient matrix (e.g., 404 of FIG. 4A, 432 of FIG. 4B) can change much more quickly. This larger change in the coefficient matrix is typically due to the Doppler effect as a result of the speed at which the UE 115 is moving (e.g., because the received signal has some change in phase) .

To address this, as shown in FIG. 4B’s diagram 430, a series of coefficient matrices 432 are determined over time 0 to t, with half of those illustrated corresponding to actually observed CSI-RS, and the remaining half corresponding to extrapolated values for coefficient matrices into the future (based on the observed coefficient matrices and underlying measurements) . For example, one or more algorithms at the UE 115 and/or BS 105 may be implemented to extrapolate/predict future precoder matrix information including coefficients, channel information, and precoder matrix selection. This time series of coefficient matrices 432 may be compressed by some time domain bases, illustrated at element 434 of FIG. 4B. After time domain compression, the time series of coefficient matrices is represented by a smaller number of doppler domain (or time domain) bases –for example, in FIG. 4B, the 8 bases at 432 are compressed to 3 bases at 436.

Turning now to FIG. 5A, illustrated is a simplified diagram 500 of a reference resource slot according to some aspects of the present disclosure. The reference resource slot is used according to aspects of the present disclosure to assist in defining the CSI window as well as for imposing a measurement requirement (e.g., a minimum number of CSI occasions for a CSI reporting window) . The reference resource slot, also referred to as a CSI reference resource, is defined for validation testing (e.g., a target bit loss error rate (BLER) of some percentage, such as 10%) , with the reported channel quality indicator (CQI) (and PMI, if also reported) .

For the reference resource slot, the frequency resource is the same as the measured CSI-RS in the frequency domain. For the time resource, a valid downlink slot is used prior to the uplink slot “n”where the CSI is reported. This may be represented, for the determined DL slot, as n-n _{CSI_ref}. A “valid downlink slot” may refer to a slot configured with at least one DL or flexible symbol, and does not fall within a configured measurement gap for the UE. For periodic or semi-persistent reporting, n _{CSI_ref} may be the smallest value that is greater than, or equal to,

for a single CSI-RS, or greater than or equal to

for a multiple CSI-RS, such that the slot n-n _{CSI_ref} corresponds to a valid DL slot. For aperiodic reporting, n _{CSI_ref} may be the smallest value that is greater than or equal to

such that the slot n-n _{CSI_ref} corresponds to a valid DL slot (where Z′is the required processing timeline after the latest CSI-RS occasion to the reporting PUSCH) . Moreover, the PDSCH pattern is assumed and includes used symbols within the slot, DMRS pattern, SCS, layer mapping pattern associated with the reported PMI, and so forth.

This is illustrated in the diagram 500 with the reference resource slot 502, uplink reporting slot 504, the CSI report 506, the n _{CSI_ref} distance as determined above for periodic, semi-persistent, and aperiodic reporting as noted above. In other words, the n _{CSI_ref} is determined as the smallest value that is greater than, or equal to,

for a single CSI-RS, or greater than or equal to

for a multiple CSI-RS for periodic or semi-persistent reporting. Further, the n _{CSI_ref} may be the smallest value that is greater than or equal to

for aperiodic reporting.

FIG. 5B illustrates a simplified diagram 540 of a time domain basis index according to some aspects of the present disclosure. For codebook structures with a time domain or doppler domain basis, the codebook (e.g., a Type II codebook) may include several additional parameters as previously had been the case. For example, additional parameters may include doppler-domain/time-domain basis vector length 550 (including observations 544 and extrapolations 546) , as well as the number of doppler-domain/time-domain basis vectors 552 (e.g., some subset of all the vectors available, corresponding to the five basis vectors 552 illustrated in FIG. 5B) . The parameters may also include, if applicable, the total number of available doppler-domain/time-domain basis vectors 548 (which may not be needed for orthogonal DFT basis sets) , whether explicitly or implicitly (from another factor, such as the oversampling factor) .

With this information from FIGS. 4A through 5B in mind, the rest of the figures are described. By implementing a CSI reporting window according to aspects of the present disclosure, which CSI reporting occasions are measured may be left up to UE implementation, i.e., a measurement window need not be defined. To make the CSI reporting window effective, therefore, in a manner that is decoupled from measured CSI-RS occasions, the CSI reporting window is defined based on a reference resource slot, as is a minimum measurement requirement to ensure channel/precoder prediction/extrapolation performance is at a desired level. Aspects of the present disclosure are applicable to periodic, semi-persistent, and aperiodic CSI-RS. For example, periodic CSI-RS may be defined by periodicity and offset parameters, as well as potentially additional parameters such as periodic burst parameters (with a burst periodicity parameter, a burst duration parameter such as integer multiples of the reference signal periodicity) . As another example, semi-persistent CSI-RS may use the same parameters as for periodic, optionally also including the burst periodicity enhancement as well. Further, aperiodic CSI-RS may include a parameter for a burst over multiple slots.

FIG. 6A illustrates a simplified diagram 600 of a CSI reporting window according to some aspects of the present disclosure. The diagram 600 illustrates a series of slots over which a CSI reporting window is defined. The CSI reporting window begins at starting slot l (a slot index value) , which is determined according to the reference resource slot n _ref introduced with respect to FIG. 5A above.

The diagram 600 includes a PDCCH 608, a reference resource slot n _ref 610, a CSI report 612, uplink reporting slot 614, a number of CSI-RS occasions 616, as well as an identification of a time domain basis length N ₄ 602, which includes two segments, first segment 604 (also referred to as N _4, 1) and second segment 606 (also referred to as N _4, 2) . The first segment 604 includes the CSI-RS measured occasions up to the reference resource slot n _ref 610, while the second segment 606 includes future predicted/estimated CSI-RS measurements after the reference resource slot n _ref 610. To ensure the receiving phase continuity of CSI-RS occasions over time, the measured CSI-RS occasions may be after the PDCCH 608 (i.e., causal) .

As illustrated in FIG. 6A, the reference resource slot n _ref 610 is included as the end slot of the first segment 604. Therefore, the starting slot l may be determined based on the reference resource slot n _ref 610 as

which refers to the reference resource slot n _ref 610 subtracted by the result of the first segment 604 (i.e., the number of slots of the first segment 604) divided by the total number of slots in the TD basis length N ₄ 602, multiplied by the CSI reporting window size W _CSI, plus 1 slot. In this manner, the CSI reporting window may be defined.

In order to provide for adequate channel/precoder prediction/extrapolation performance is at a desired level, a minimum measurement requirement is also defined. For example, the minimum number of CSI-RS occasions N _meas may be defined from the PDCCH 608 (e.g., after the end symbol of PDCCH) to the reference resource slot n _ref 610. In FIG. 6A, this minimum number is inclusive of the reference resource slot n _ref 610. The number of CSI-RS occasions 616 may be compared to the minimum number N _meas, min to determine if N _meas, min is satisfied (e.g., where CSI-RS occasions ≥minimum number N _meas, min) . If satisfied, then the UE may proceed with transmitting the CSI report 612 in the uplink reporting slot 614. If the minimum number of CSI-RS occasions is not satisfied, then the UE may not need to update the CSI report, or may drop the CSI report (e.g., not transmit it at slot 614) . As a result, the minimum number of CSI-RS occasions N _meas, min may depend on the value of the second segment 606 (the value of N _4, 2, or how far away to predict/extrapolate CSI) .

The minimum number of CSI-RS occasions N _meas may be configured a variety of ways. For example, a BS 105 may transmit the value to the UE 115 via RRC signaling (or MAC CE, or other control signaling) . Alternatively, the UE 115 may have been preconfigured with a value for the minimum number of CSI-RS occasions N _meas and report that (e.g., as part of the UE reported capability) to the BS 105. However this value is configured, the value of the minimum number of CSI-RS occasions N _meas may be set based on the value of the second segment 606 (N4, 2) , or the total number of slots in the TD basis length N ₄ 602. As an example, where the UE 115 determines not to predict any values after reference resource slot n _ref 610 (whether determined locally or by instruction from another device such as a BS 105) , the minimum number of CSI-RS occasions N _meas may be equal to 1, since it is expected to be constant over a longer period of time. However, for faster varying channels, such as in the examples described herein, the minimum number of CSI-RS occasions N _meas may be larger and depend on how far into the future the predictions go.

FIG. 6B illustrates a simplified diagram 620 of a CSI reporting window according to some aspects of the present disclosure. For simplicity of discussion, only those differences from diagram 600 of FIG. 6A are discussed. In FIG. 6B, instead of the reference resource slot n _ref 610 being included as the end slot of the first segment 604, the reference resource slot n _ref 610 is included as the starting slot of the second segment 606. Therefore, the starting slot l may be determined based on the reference resource slot n _ref 610 as

which refers to the reference resource slot n _ref 610 subtracted by the result of the first segment 604 (i.e., the number of slots of the first segment 604) divided by the total number of slots in the TD basis length N ₄ 602, multiplied by the CSI reporting window size W _CSI.

FIG. 7 illustrates a simplified diagram 700 of a CSI reporting window according to some aspects of the present disclosure. The simplified diagram 700 illustrates several examples, i.e., example 712, example 714, and example 716, of what the measured CSI-RS occasions may include. As noted previously, which CSI-RS occasions to include for measurement may be up to the UE. As such, the UE may indicate to the gNB beforehand (such as with UE capability reporting) or with the CSI report itself what CSI-RS occasions the UE has included with the CSI report.

Diagram 700 illustrates a PDCCH 702 in a given slot, with a first CSI-RS occasion 704.1 in that same slot. Diagram 700 further illustrates additional CSI-RS occasions 704.2-704.5 in periodic slots (e.g., according to any of a periodic, semi-persistent, or aperiodic CSI-RS configuration) . As explained with respect to FIGs. 6A and 6B, what CSI-RS occasions, are included in the CSI report 710 may be up to UE implementation. Further, which segments the UE provides in the CSI report (e.g., both first and second segments, just the first segment, or just the second segment) may be based on BS configuration (e.g., based on UE capability reported) . Alternatively, the configuration may be predefined for both the BS and the UE.

Example 712 illustrates a scenario where the CSI reporting window 718 is set to include all the CSI-RS occasions from the PDCCH 702 to the reference resource slot n _ref 706. Thus, the length of the first segment 604 (FIG. 6A) , N _4, 1, is equal to the total number of measurement slots available in the time period. The CSI report 710 therefore includes the total number of CSI-RS occasions, i.e., CSI-RS occasions 704.1-704.5. This number of occasions is compared (such as by the UE) to the minimum number of CSI-RS occasions (i.e., N _meas, min) to determine if there are a sufficient number of CSI-RS occasions to ensure a desired level of channel/precoder prediction/extrapolation into the future for a given period of time (corresponding to second segment 606, FIG. 6A) . For example, if the N _meas, min is 4 CSI-RS occasions, then CSI-RS occasions 704.1-704.5, being 5 total CSI-RS occasions, is greater than N _meas, min and therefore the UE will transmit the CSI report 710 at the appropriate time (uplink reporting slot 708) . That CSI report 710, according to example 712, includes all of the available CSI-RS occasions (measurement/observation information about them) as well as the future predictions. Such measurement/observation information may be used at the BS to validate or independently determine the future predictions.

Example 714 illustrates a scenario where the CSI reporting window 720 is set to include less than all of the available CSI-RS occasions from the PDCCH 702 to the reference resource slot n _ref 706. Thus, the length of the first segment 604 (FIG. 6A) , N _4, 1, in example 714 is less than to the total number of measurement slots available in the time period. The CSI report 710 therefore includes the fewer number of CSI-RS occasions, (in this example, CSI-RS occasions 704.2-704.5) . This number of occasions is compared (such as by the UE) to the minimum number of CSI-RS occasions (i.e., N _meas, min) to determine if there are a sufficient number of CSI-RS occasions to ensure a desired level of channel/precoder prediction/extrapolation into the future for a given period of time (corresponding to second segment 606, FIG. 6A) . For example, if the N _meas, min is 4 CSI-RS occasions, then CSI-RS occasions 704.2-704.5, being 4 total CSI-RS occasions, is equal to N _meas, min and therefore the UE will transmit the CSI report 710 at the appropriate time (uplink reporting slot 708) . That CSI report 710, according to example 714, includes less than all of the available CSI-RS occasions (measurement information about them) as well as the future predictions. Such measurement/observation information may be used at the BS to validate or independently determine the future predictions.

Example 716 illustrates a scenario where the CSI reporting window 722 is set to include none of the available CSI-RS occasions from the PDCCH 702 to the reference resource slot n _ref 706. Thus, the first segment 604 (FIG. 6A) , N _4, 1, in example 716 is not included in the CSI report 710. Instead, the CSI report 710 includes none of the available CSI-RS occasions (measurement information about them) , rather only the future predictions. However, the UE still checks whether the number of CSI-RS occasions (from 704.1-704.5) used to determine the future predictions of the CSI reporting window 722 used the same as or more than the minimum number of CSI-RS occasions (i.e., N _meas, min) to determine if there are a sufficient number of CSI-RS occasions to ensure a desired level of channel/precoder prediction/extrapolation into the future for a given period of time (corresponding to second segment 606, FIG. 6A) . For example, if the N _meas, min is 4 CSI-RS occasions, then the UE will determine whether enough of CSI-RS occasions 704.1-704.5 is equal to or greater than N _meas, min - if so, the UE will transmit the CSI report 710 at the appropriate time (uplink reporting slot 708) . If, however, there were fewer than the N _meas, min then the UE may drop or not update the CSI report 710. In this situation, the BS does not receive any past measurement/observation information about the CSI-RS occasions, but rather just the future predictions.

While the above examples 712-716 focused on situations that used slightly more, or just enough, CSI-RS occasions to meet the requirements of N _meas, min, the UE could use as many CSI-RS occasions beyond the minimum as desired to achieve a given level of predict performance.

FIG. 8 illustrates a simplified diagram 800 of a CSI reporting window according to some aspects of the present disclosure. Diagram 800 includes the same slot diagram as was illustrated in FIG. 7, including a PDCCH 802, CSI-RS occasions 804.1-804.5, reference resource slot n _ref 806, uplink reporting slot 808, and CSI report 810. FIG. 8, in particular, illustrates different options for how the reference resource slot is defined.

For the time resource, a latest valid downlink slot is used prior to the uplink reporting slot 808. This is illustrated as slot 812 in FIG. 8 (in other words, while reference resource slot n _ref is identified as at slot 806, according to this definition it would instead be at slot 812) . A “valid downlink slot” may refer to a slot configured with at least one DL or flexible symbol, and does not fall within a configured measurement gap for the UE 115. For aperiodic reporting, slot 812 may be the smallest value that is greater than or equal to

(where Z′is the required processing timeline for the latest CSI-RS occasion to the reporting PUSCH) , such that the latest valid DL slot is selected that is greater than or equal to that value. For semi-persistent reporting, slot 812 may be the latest DL slot that is greater than or equal to 4 or 5 slots prior to the uplink reporting slot 808 (e.g., a PUSCH slot) . However, the value of the timeline Z’ may change for TD CSI without departing from the scope of this disclosure.

Alternatively, the reference resource slot n _ref 806 location may be determined based on the latest CSI-RS occasion that has the smallest slot value that is greater than or equal to

for aperiodic reporting. This is illustrated as slot 814 in FIG. 8 (in other words, while reference resource slot n _ref is identified as at slot 806, according to this other definition it would instead be at slot 814) . For semi-persistent reporting, the slot 714 may be the latest CSI-RS occasion slot that is greater than or equal to 4 or 5 slots prior to the uplink reporting slot 808 (e.g., a PUSCH slot) . However, the value of the timeline Z’ may change for TD CSI without departing from the scope of this disclosure.

FIG. 9 illustrates a simplified diagram 900 of a CSI reporting window according to some aspects of the present disclosure. FIG. 9 corresponds to a situation where a minimum K0 value has been configured to aid with UE power saving efforts (and, thus, the UE does not need to buffer the entire bandwidth of the DL, instead focusing on monitoring/buffering the PDCCH/CORESET for resource elements of the scheduled PDSCH or AP-CSI-RS after PDCCH is decoded) .

Diagram 900, like diagram 800, includes the same slot diagram as was illustrated in FIG. 7, including a PDCCH 902, CSI-RS occasions 904.1-904.4, reference resource slot n _ref 906, uplink reporting slot 908, and CSI report 910. Different from FIGs. 7 and 8, there are fewer CSI-RS occasions (in this illustrated example, one fewer, though other possibilities exist as well) . This is a result of the power saving effort.

When the UE is configured with a minimum K0 value, the UE will not start counting CSI-RS occasions until after that value (e.g., in number of slots) is done. For example, in FIG. 9 this is illustrated as the slots 912 (assuming the minimum K0 value is 5 is this example) after PDCCH 902. This is why there are fewer CSI-RS occasions illustrated in FIG. 9 –because the UE is not counting the CSI-RS occasions between PDCCH 902 and reference resource slot n _ref 908 until after slots 912 have passed. As illustrated, the slots 912 include the slot in which PDCCH 902 is received. As discussed with respect to prior figures, the UE still checks whether the number of CSI-RS occasions (beginning, here, from the minimum K0 slot after the slot where the PDCCH 902 is located up to and including the reference resource slot n _ref 908) is the same as or more than the minimum number of CSI-RS occasions (i.e., N _meas, min) .

FIG. 10A illustrates a simplified diagram 1000 of a CSI reporting window according to some aspects of the present disclosure. For semi-persistent reports (with either periodic CSI-RS or semi-persistent CSI-RS) , there is typically no further PDCCH triggering CSI reporting beyond the first report activation from PDCCH. Accordingly, a virtual PDCCH may be used instead for CSI reporting beyond the first activated report, the virtual PDCCH being a tool by which to count CSI-RS occasions after the first CSI report is sent to a BS. The virtual PDCCH (identified as virtual PDCCH 1018 in FIG. 10A) may be defined, for a subsequent semi-persistent CSI report 1016, as X slots 1012 (X being some nonzero number) prior to the corresponding subsequent reference resource slot n _ref 1014. The value of X slots 1012 may be obtained based on the first report activation from PDCCH, illustrated here as PDCCH 1002. X is obtained as the slot offset 1010 of the triggering PDCCH (here, PDCCH 1002) up to the reference resource slot n _ref 1006, for the first activated report of the semi-persistent report series. This value of X slots 1010 may subsequently be applied as the value of slots 1012 for subsequent CSI reports in the series, resulting in virtual PDCCH 1018 at the slot before X slots 1012 begins. Again, as with other examples, the total number of the plurality of CSI-RS occasions after a virtual PDCCH and up to the reference resource slot, may be greater than or equal to the minimum number of CSI-RS occasions. That is, the UE checks whether the number of CSI-RS occasions (beginning, here, after the slot determined to have virtual PDCCH 1018 to and including the reference resource slot n _ref 1014) is the same as or more than the minimum number of CSI-RS occasions (i.e., N _meas, min) .

FIG. 10B illustrates a simplified diagram 1030 of a CSI reporting window according to some aspects of the present disclosure. FIG. 10B is an alternative to the example of FIG. 10A. Instead of defining the virtual PDCCH 1018 as being X slots 1010 prior to reference resource slot n _ref 1006, in FIG. 10B the virtual PDCCH 1018 is defined as K2 slots 1032 (K2 being the offset between the DL slot where DCI for UL scheduling is received and the UL slot where the first scheduled/activated PUSCH is located) prior to the corresponding subsequent uplink reporting slot 1016. The value of K2 slots 1032 may be obtained based on the first report activation from PDCCH, illustrated here again as PDCCH 1002. K2 is used for the slot offset of the triggering PDCCH (here, PDCCH 1002) up to the UL reporting slot 1008, the first scheduled/activated report for the semi-persistent reported series. This value of K2 slots 1032 may subsequently applied as the value of slots 1034 for subsequent CSI reports in the series, such that the virtual PDCCH 1018 is at the slot before K2 slots 1034 begins. Similar to FIG. 10A’s discussion, the total number of the plurality of CSI-RS occasions after a virtual PDCCH and up to the reference resource slot, may be greater than or equal to the minimum number of CSI-RS occasions, which the UE checks/counts for.

FIG. 11 illustrates a block diagram of a network unit 1100 according to some aspects of the present disclosure. The network unit 1100 may be a BS 105 as discussed in FIG. 1, or be made up of disaggregated units as described with reference to FIGS. 2-3. As shown, the network unit 1100 may include a processor 1102, a memory 1104, a CSI reporting module 1108, a transceiver 1110 including a modem subsystem 1112 and a RF unit 1114, and one or more antennas 1116. These elements may be coupled with one another. The term “coupled” may refer to directly or indirectly coupled or connected to one or more intervening elements. For instance, these elements may be in direct or indirect communication with each other, for example via one or more buses.

The processor 1102 may have various features as a specific-type processor. For example, these may include a CPU, a DSP, an ASIC, a controller, a FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor 1102 may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The memory 1104 may include a cache memory (e.g., a cache memory of the processor 902) , RAM, MRAM, ROM, PROM, EPROM, EEPROM, flash memory, a solid-state memory device, one or more hard disk drives, memristor-based arrays, other forms of volatile and non-volatile memory, or a combination of different types of memory. In some aspects, the memory 1104 may include a non-transitory computer-readable medium. The memory 1104 may store instructions 1106. The instructions 1106 may include instructions that, when executed by the processor 1102, cause the processor11 to perform operations described herein, for example, aspects of FIGS. 4-10B and 13-15. Instructions 1106 may also be referred to as program code. The program code may be for causing a wireless communication device to perform these operations, for example by causing one or more processors (such as processor 1102) to control or command the wireless communication device to do so. The terms “instructions” and “code” should be interpreted broadly to include any type of computer-readable statement (s) . For example, the terms “instructions” and “code” may refer to one or more programs, routines, sub-routines, functions, procedures, etc. “Instructions” and “code” may include a single computer-readable statement or many computer-readable statements.

The CSI reporting module 1108 may be implemented via hardware, software, or combinations thereof. For example, the CSI reporting module 1108 may be implemented as a processor, circuit, and/or instructions 1106 stored in the memory 1104 and executed by the processor 1102. In some examples, the CSI reporting module 1108 can be integrated within the modem subsystem 1112. For example, the CSI reporting module 1108 can be implemented by a combination of software components (e.g., executed by a DSP or a general processor) and hardware components (e.g., logic gates and circuitry) within the modem subsystem 1112. The CSI reporting module 1108 may communicate with one or more components of network unit 1100 to implement various aspects of the present disclosure, for example, aspects of FIGS. 4-10B and 13-15. This may include, for example, processing the information included in CSI reports, and making adjustments to one or more parameters for the channel between the network unit 1100 and the UE 115.

As shown, the transceiver 1110 may include the modem subsystem 1112 and the RF unit 1114. The transceiver 1110 can be configured to communicate bi-directionally with other devices, such as the UEs 115 and/or BS 105 and/or another core network element. The modem subsystem 1112 may be configured to modulate and/or encode data according to a MCS, e.g., a LDPC coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc. The RF unit 1114 may be configured to process (e.g., perform analog to digital conversion or digital to analog conversion, etc. ) modulated/encoded data (e.g., PDCCH DCI, PDSCH, etc. ) from the modem subsystem 1112 (on outbound transmissions) or of transmissions originating from another source such as a UE 115. The RF unit 1114 may be further configured to perform analog beamforming in conjunction with the digital beamforming. Although shown as integrated together in transceiver 1110, the modem subsystem 1112 and/or the RF unit 1114 may be separate devices that are coupled together at the network unit 1100 to enable the network unit 1100 to communicate with other devices.

The RF unit 1114 may provide the modulated and/or processed data, e.g. data packets (or, more generally, data messages that may contain one or more data packets and other information) , to the antennas 1116 for transmission to one or more other devices. The antennas 1116 may further receive data messages transmitted from other devices and provide the received data messages for processing and/or demodulation at the transceiver 1110. The transceiver 1110 may provide the demodulated and decoded data (e.g., PUSCH, PUCCH, etc. ) to the CSI reporting module 1108 for processing. The antennas 1116 may include multiple antennas of similar or different designs in order to sustain multiple transmission links.

In an aspect, the network unit 1100 can include multiple transceivers 1110 implementing different RATs (e.g., NR and LTE) . In an aspect, the network unit 1100 can include a single transceiver 1110 implementing multiple RATs (e.g., NR and LTE) . In an aspect, the transceiver 1110 can include various components, where different combinations of components can implement different RATs.

FIG. 12 is a block diagram of an exemplary UE 1200 according to some aspects of the present disclosure. The UE 1200 may be a UE 115 as discussed in FIGS. 1-10B. As shown, the UE 1200 may include a processor 1202, a memory 1204, a CSI reporting module 1208, a transceiver 1210 including a modem subsystem 1212 and a radio frequency (RF) unit 1214, and one or more antennas 1216. These elements may be coupled with one another. The term “coupled” may refer to directly or indirectly coupled or connected to one or more intervening elements. For instance, these elements may be in direct or indirect communication with each other, for example via one or more buses.

The processor 1202 may include a central processing unit (CPU) , a digital signal processor (DSP) , an application specific integrated circuit (ASIC) , a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor 1202 may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The memory 1204 may include a cache memory (e.g., a cache memory of the processor 1202) , random access memory (RAM) , magnetoresistive RAM (MRAM) , read-only memory (ROM) , programmable read-only memory (PROM) , erasable programmable read only memory (EPROM) , electrically erasable programmable read only memory (EEPROM) , flash memory, solid state memory device, hard disk drives, other forms of volatile and non-volatile memory, or a combination of different types of memory. In an aspect, the memory 1204 includes a non-transitory computer-readable medium. The memory 1204 may store, or have recorded thereon, instructions 1206. The instructions 1206 may include instructions that, when executed by the processor 1202, cause the processor 1202 to perform the operations described herein with reference to a UE 115 in connection with aspects of the present disclosure, for example, aspects of FIGS. 4-10B and 13-15. Instructions 1206 may also be referred to as code, which may be interpreted broadly to include any type of computer-readable statement (s) .

The CSI reporting module 1208 may be implemented via hardware, software, or combinations thereof. For example, the CSI reporting module 1208 may be implemented as a processor, circuit, and/or instructions 1206 stored in the memory 1204 and executed by the processor 1202. In some aspects, the CSI reporting module 1208 can be integrated within the modem subsystem 1212. For example, the CSI reporting module 1208 can be implemented by a combination of software components (e.g., executed by a DSP or a general processor) and hardware components (e.g., logic gates and circuitry) within the modem subsystem 1212. The CSI reporting module 1008 may communicate with one or more components of UE 1200 to implement various aspects of the present disclosure, for example, aspects of FIGS. 4-10B and 13-15. This may include, for example, configuring a CSI reporting window based on a reference resource slot n _ref, monitoring CSI-RS occasions, and comparing the number of occasions to a minimum number of CSI-RS occasions based on the reference resource slot n _ref, and transmitting CSI reports including first and/or second segments of a time domain basis length N ₄, where the first segment includes measurements for CSI-RS occasions up to the reference resource slot n _ref, and the second segment includes predicted future values after the reference resource slot n _ref.

As shown, the transceiver 1210 may include the modem subsystem 1212 and the RF unit 1214. The transceiver 1210 can be configured to communicate bi-directionally with other devices, such as the BSs 105. The modem subsystem 1212 may be configured to modulate and/or encode the data from the memory 1204 and/or the CSI reporting module 1208 according to a modulation and coding scheme (MCS) , e.g., a low-density parity check (LDPC) coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc. The RF unit 1214 may be configured to process (e.g., perform analog to digital conversion or digital to analog conversion, etc. ) modulated/encoded data (e.g., PUSCH, PUCCH, etc. ) or of transmissions originating from another source such as a UE 115, or a BS 105. The RF unit 1214 may be further configured to perform analog beamforming in conjunction with the digital beamforming. Although shown as integrated together in transceiver 1210, the modem subsystem 1212 and the RF unit 1214 may be separate devices that are coupled together at the UE 1200 to enable the UE 1200 to communicate with other devices.

The RF unit 1214 may provide the modulated and/or processed data, e.g., data packets (or, more generally, data messages that may contain one or more data packets and other information) , to the antennas 1216 for transmission to one or more other devices. The antennas 1216 may further receive data messages transmitted from other devices. The antennas 1216 may provide the received data messages for processing and/or demodulation at the transceiver 1210. The transceiver 1210 may provide the demodulated and decoded data (e.g., PDCCH, PDSCH, etc. ) to the CSI reporting module 1208 for processing and/or analysis. The antennas 1216 may include multiple antennas of similar or different designs in order to sustain multiple transmission links. Antennas 1216 may include multiple antenna modules, each associated with a different antenna panel. Antenna panels may be used to transmit and/or receive using beamforming techniques.

In an aspect, the UE 1200 can include multiple transceivers 1210 implementing different RATs (e.g., NR and LTE) . In an aspect, the UE 1200 can include a single transceiver 1210 implementing multiple RATs (e.g., NR and LTE) . In an aspect, the transceiver 1210 can include various components, where different combinations of components can implement different RATs.

FIG. 13 illustrates a simplified protocol diagram 1300 according to some aspects of the present disclosure. Diagram 1300 is employed by a network unit 1100 such as a BS 105, discussed with reference to FIG. 1, one or more components of disaggregated base station 200 (e.g., CU 210, DU 230, and/or RU 240) discussed with reference to FIGS. 2-3. Network unit 1100 may utilize one or more components, such as the processor 1102, the memory 104, the CSI reporting module 1108, the transceiver 1110, the modem 1112, and the one or more antennas 1116 shown in FIG. 11, and the UE 115 may utilize one or more components, such as the processor 1202, the memory 1204, the CSI reporting module 1208, the transceiver 1210, the modem 1212, and the one or more antennas 1216 shown in FIG. 12. As illustrated, the signaling diagram 1300 includes a number of enumerated actions, but aspects of FIG. 13 may include additional actions before, after, and in between the enumerated actions. In some aspects, one or more of the enumerated actions may be omitted, combined together, or performed in a different order.

At action 1302, the network unit 1100 transmits a PDCCH to trigger CSI-RS monitoring in a DL slot to the UE 1200. This is illustrated in dashed lines to indicate action 1302 as optional, depending on whether the diagram 1300 relates to a periodic CSI-RS, a semi-periodic CSI-RS, or an aperiodic CSI-RS. For periodic situations, the PDCCH is not necessary to trigger a CSI reporting window according to aspects of the present disclosure. For semi-persistent and aperiodic CSI-RS, the PDCCH may be used as a trigger for when to start a CSI reporting window.

At action 1304, the network unit 1100 transmits one or more CSI-RS during one or more corresponding CSI-RS occasions to the UE 1200. The number of CSI-RS occasions that define a CSI reporting window may depend on whether the CSI report from UE 1200 will include predicted future values or not. The CSI reporting window may extend from some time at or after the PDCCH slot to the reference resource slot n _ref, which may be defined in one of the ways described with respect to other figures above (including after a period K0, or using X slots or K2 slots as the basis of when to start prior to the reference resource slot n _ref or the uplink reporting slot) .

At action 1306, the UE 1200 counts the number of CSI-RS occasions, such as by the CSI reporting module 1208 of FIG. 12. This may be done in order to then compare the number of CSI-RS occasions to a minimum number of CSI-RS occasions for a given CSI reporting window. Further, in some examples the action 1306 may not begin until after some time period (e.g., to support UE power savings) , such as after a K0 number of slots.

At action 1308, the UE 1200 determines one or more precoder values, such as coefficients for a precoder matrix, as well as predicts future precoder values for inclusion in a CSI report. The UE 1200 does so based on the one or more CSI-RS occasions observed and measured at action 1304. While described as occurring after action 1306, this may occur at some overlapping time frame with action 1306.

At action 1310, the UE 1200 transmits the CSI report to the network unit 1100. The UE 1200 does so on the basis that the number of CSI-RS occasions counted as part of action 1306 is greater than or equal to a minimum number of CSI-RS occasions. The CSI report may include a variety of information, including both first and/or second segments of a time domain basis length N ₄, where the first segment includes measurements for CSI-RS occasions up to the reference resource slot n _ref, and the second segment includes predicted future values after the reference resource slot n _ref. If, however, the number of CSI-RS occasions determined from action 1306 is less than the minimum number of CSI-RS occasions, the UE 1200 may instead drop or not update the CSI report for that window of time.

At action 1312, the network unit 1100 finalizes one or more precoder values, such as one or more precoder matrix values like coefficients, for improving communication in the channel to the UE 1200. This is done based on the CSI report received at action 1310.

At action 1314, the network unit 1100 transmits data to the UE 1200 for a given period of time using the precoder matrix values determined at action 1312.

FIG. 14 is a flow diagram illustrating a wireless communication method 1400 according to some aspects of the present disclosure. Aspects of the method 1400 can be executed by a computing device (e.g., a processor, processing circuit, and/or other suitable component) of a wireless communication device or other suitable means for performing the blocks. In one aspect, a UE 105 may perform the method 1400 utilizing components such as the processor 1202, the memory 1204, the CSI reporting module 1208, the transceiver 1210, the modem 1212, and the one or more antennas 1216 shown in FIG. 12. As illustrated, the method 1400 includes a number of enumerated blocks, but aspects of the method 1400 may include additional blocks before, after, and in between the enumerated blocks. In some aspects, one or more of the enumerated blocks may be omitted or performed in a different order.

At block 1402, the UE 1200 receives a PDCCH from a network unit, such as network unit 1100, BS 105, etc. As explained with respect to action 1302 of FIG. 13, this is illustrated in dashed lines to indicate block 1402 as optional related to aspects of the present disclosure, depending on whether this relates to a periodic CSI-RS, a semi-periodic CSI-RS, or an aperiodic CSI-RS. For periodic situations, the PDCCH is not necessary to trigger a CSI reporting window according to aspects of the present disclosure. For semi-persistent and aperiodic CSI-RS, the PDCCH may be used as a trigger for when to start a CSI reporting window.

At block 1404, the UE 1200 receives one or more CSI-RS occasions. The number of CSI-RS occasions that define a CSI reporting window may depend on whether the CSI report from UE 1200 will include predicted future values or not. The CSI reporting window may extend from some time at or after the PDCCH slot to the reference resource slot n _ref, which may be defined in one of the ways described with respect to other figures above (including after a period K0, or using X slots or K2 slots as the basis of when to start prior to the reference resource slot n _ref or the uplink reporting slot) .

At block 1406, the UE 1200 counts the number of CSI-RS occasions, such as by the CSI reporting module 1208 of FIG. 12, as discussed with respect to action 1306 of FIG. 13. That is, counting may be done in order to compare the number of CSI-RS occasions to a minimum number of CSI-RS occasions for a given CSI reporting window (that minimum number being configured, for example, by RRC, MAC CE, or other signaling) . Thus, the counting may occur concurrent or near in time to the reception of the CSI-RS occasions at block 1404.

At block 1408, the UE 1200 compares the number of CSI-RS occasions determined from block 1406 to the minimum number of CSI-RS occasions.

At decision block 1410, if the number of CSI-RS occasions is greater than or equal to the minimum number of CSI-RS occasions, then the method 1400 proceeds to block 1414.

At block 1414, the UE 1200 predicts one or more future precoder values (e.g., future precoder matrix coefficient values) based on the CSI-RS occasions within the CSI reporting window.

At block 1416, the UE 1200 determines which segments to use for the time domain CSI report that will be sent to the network unit 1100. Segments here refers to first and second segments of a time domain basis length N ₄, where the first segment includes measurements for CSI-RS occasions up to the reference resource slot n _ref, and the second segment includes predicted future values after the reference resource slot n _ref. In some examples, the CSI report may include measurement information for the first segment and the predicted values for the second segment, while in other examples the CSI report may include only the predicted values for the second segment.

Returning to decision block 1410, if the number of CSI-RS occasions is less than the minimum number of CSI-RS occasions, then the method 1400 proceeds instead to block 1412. At block 1412, the UE 1200 either drops or does not update the CSI report for that CSI reporting window.

From either block 1412 or block 1416, the method 1400 proceeds to block 1418. At block 1418, the UE 1200 transmits the CSI report to the network unit 1100 (unless the UE 1200 is dropping the report, in which case the method ends until the next CSI reporting window) .

At block 1420, the UE 1200 receives downlink data transmissions with one or more precoders applied according to the information the UE 1200 included in the CSI report sent at block 1418.

According to aspects of the present disclosure, the CSI reporting window may be defined based on a CSI reference resource slot between the network unit 1100 and the UE 1200, without defining or requiring a CSI measurement window. The CSI reporting window may include a DD/TD basis vector that is split into two sub-parts, or segments, with one segment corresponding to precoder determinations for multiple CSI-RS occasions before the CSI reference resource slot (repeating over time either on a periodic, semi-periodic, or aperiodic basis) , and another segment corresponding to one or more precoder predictions after the CSI reference resource slot into a future period of time. The CSI reporting window may be defined by a length of the window, e.g. by number of slots between the CSI reference resource slot and a beginning slot index. Further, a minimum measurement requirement may be defined also based on the CSI reference resource slot. The minimum measurement requirement may be configured at the UE 1200 a variety of ways, including via RRC signaling, MAC CE, and/or other control signaling. Or, the UE 1200 may be preconfigured with a given minimum measurement requirement value and report that to the network unit 1100.

FIG. 15 is a flow diagram illustrating a wireless communication method 1500 according to some aspects of the present disclosure. Aspects of the method 1500 can be executed by a computing device (e.g., a processor, processing circuit, and/or other suitable component) of a wireless communication device or other suitable means for performing the blocks. In one aspect, a BS 105, a CU 210 and/or DU 230, or network unit 1100, may perform the method 1500 utilizing components such as the processor 1102, the memory 104, the CSI reporting module 1108, the transceiver 1110, the modem 1112, and the one or more antennas 1116 shown in FIG. 11. As illustrated, the method 1500 includes a number of enumerated blocks, but aspects of the method 1500 may include additional blocks before, after, and in between the enumerated blocks. In some aspects, one or more of the enumerated blocks may be omitted or performed in a different order.

At block 1502, the network unit 1100 transmits a PDCCH to a UE 1200 to trigger CSI-RS monitoring in a DL slot. This is illustrated in dashed lines to indicate block 1502 as optional, depending on whether the method 1500 relates to a periodic CSI-RS, a semi-periodic CSI-RS, or an aperiodic CSI-RS as discussed above.

At block 1504, the network unit 1100 receives a CSI report from the UE 1200. The CSI report will have been based on the CSI-RS occasions the UE 1200 monitored within a CSI reporting window (e.g., extending from after a PDCCH, or a number of slots before the reference resource slot n _ref) up to the reference resource slot n _ref. The CSI report will include valid data if the CSI reporting window included at least a minimum number of CSI-RS occasions. Otherwise, the CSI report is either not received (the UE 1200 drops it) such that method 1500 ends until a next CSI reporting window has concluded, or is not updated.

At decision block 1506, if the CSI report includes valid data (instead of non-updated data, corresponding to a situation where the number of CSI-RS occasions in the CSI reporting window was less than the minimum number of CSI-RS occasions) , then the method 1500 proceeds to decision block 1510.

At decision block 1510, if the CSI report includes the measurement information from a first segment of a time domain basis length N ₄, which includes measurements for CSI-RS occasions up to the reference resource slot n _ref, then method 1500 proceeds to block 1512.

At block 1512, the network unit 1100 analyzes the data (the measurements for CSI-RS occasions, also referred to as historical data of the CSI-RS reporting window) to determine estimated future precoder values (such as precoder matrix coefficients) . This may occur where the network unit 1100 does not trust the calculations of the UE 1200 that is transmitting the CSI report, and seeks to do its own calculation of the predicted future values. The method 1500 then proceeds to block 1514 as discussed below.

Returning to decision block 1506, if instead the CSI report includes non-updated data, the method 1500 proceeds to block 1508. At block 1508, the network unit 1100 discards the relevant non-updated data of the CSI report, since this corresponds to a situation where the number of CSI-RS occasions within the CSI reporting window was less than the minimum number of CSI-RS occasions. The method 1500 then proceeds to block 1514 as discussed below.

Returning to decision block 1510, if the CSI report does not include first segment information, i.e., measurements for CSI-RS occasions up to the reference resource slot n _ref, then method 1500 proceeds to block 1514.

At block 1514, the network unit 1100 implements the estimated future precoder values for downlink data transmissions until at least the next CSI reporting window.

Further aspects of the present disclosure include the following:

Aspect 1. A method of wireless communication, comprising:

receiving, by a user equipment (UE) from a network unit, a plurality of channel state information reference signal (CSI-RS) occasions for use in a time-domain CSI (TD-CSI) report relative to a reference resource slot; and

transmitting, by the UE to the network unit in response to the plurality of CSI-RS occasions being equal to or greater than a minimum number of CSI-RS occasions up to the reference resource slot, the TD-CSI report based on the plurality of CSI-RS occasions,

wherein the TD-CSI report comprises a report window that includes the reference resource slot and is based on the reference resource slot and defined by at least one of a first segment of a time domain basis vector length and a second segment of the time domain basis vector length, and

wherein the first segment corresponds to one or more precoder values from the plurality of CSI-RS occasions for the TD-CSI report, and the second segment corresponds to one or more predicted future precoder values based on the plurality of CSI-RS occasions for the TDI-CSI report.

Aspect 2. The method of aspect 1, further comprising:

dropping or not updating, by the UE, the TD-CSI report in response to the plurality of CSI-RS occasions being less than the minimum number of CSI-RS occasions.

Aspect 3. The method of any of aspects 1-2, wherein the reference resource slot is defined as an end slot corresponding to the first segment.

Aspect 4. The method of any of aspects 1-2, wherein the reference resource slot is defined as a beginning slot corresponding to the second segment.

Aspect 5. The method of any of aspects 1-4, wherein a number of the one or more precoder values included in the TD-CSI report is less than or equal to a total number of the plurality of CSI-RS occasions after a physical downlink control channel (PDCCH) and up to the reference resource slot, and greater than or equal to the minimum number of CSI-RS occasions.

Aspect 6. The method of any of aspects 1-4, wherein the TD-CSI report comprises only the one or more predicted future precoder values.

Aspect 7. The method of any of aspects 1-6, wherein the reference resource slot comprises a latest valid downlink slot greater than a minimum timeline value prior to an uplink report slot.

Aspect 8. The method of any of aspects 1-6, wherein the reference resource slot comprises a latest slot having a CSI-RS occasion greater than a minimum timeline value prior to an uplink report slot.

Aspect 9. The method of any of aspects 1-8, wherein the UE is configured with a minimum K0 value, and the method further comprising:

counting, by the UE, a total number of the plurality of CSI-RS occasions from a number of slots corresponding to the minimum K0 value after a physical downlink control channel (PDCCH) slot up to the reference resource slot, to determine whether the total number of the plurality of CSI-RS occasions is greater than or equal to the minimum number of CSI-RS occasions.

Aspect 10. The method of any of aspects 1-9, wherein the plurality of CSI-RS occasions are semi-periodic, the method further comprising:

counting, by the UE, a total number of the plurality of CSI-RS occasions after a virtual physical downlink control channel (PDCCH) up to the reference resource slot, to determine whether the total number of the plurality of CSI-RS occasions is greater than or equal to the minimum number of CSI-RS occasions,

wherein the virtual PDCCH is identified as a number of slots prior to a subsequent reference resource slot, the number of slots comprising a slot offset from a PDCCH to a first reference resource slot.

Aspect 11. The method of any of aspects 1-9, wherein the plurality of CSI-RS occasions are semi-periodic, the method further comprising:

wherein the virtual PDCCH is identified as a number of slots prior to a subsequent uplink report slot, the number of slots comprising a slot offset of a PDCCH to a first uplink report slot.

Aspect 12. A method of wireless communication, comprising:

transmitting, by a network unit to a user equipment (UE) , a plurality of channel state information reference signal (CSI-RS) occasions for use in a time-domain CSI (TD-CSI) report relative to a reference resource slot; and

receiving, by the network unit from the UE in response to the plurality of CSI-RS occasions being equal to or greater than a minimum number of CSI-RS occasions up to the reference resource slot, the TD-CSI report based on the plurality of CSI-RS occasions,

wherein the TD-CSI report comprises a report window that includes the reference resource slot and is based on the reference resource slot and defined by at least one of a first segment of a time domain basis vector length and a second segment of the time domain basis vector length, and wherein the first segment corresponds to one or more precoder values from the plurality of CSI-RS occasions for the TD-CSI report, and the second segment corresponds to one or more predicted future precoder values based on the plurality of CSI-RS occasions for the TDI-CSI report.

Aspect 13. The method of aspect 12, wherein the reference resource slot is defined as an end slot corresponding to the first segment.

Aspect 14. The method of aspect 12, wherein the reference resource slot is defined as a beginning slot corresponding to the second segment.

Aspect 15. The method of any of aspects 12-14, wherein a number of the one or more precoder values included in the TD-CSI report is less than or equal to a total number of the plurality of CSI-RS occasions after a physical downlink control channel (PDCCH) and up to the reference resource slot, and greater than or equal to the minimum number of CSI-RS occasions.

Aspect 16. The method of any of aspects 12-14, wherein the TD-CSI report comprises only the one or more predicted future precoder values.

Aspect 17. The method of any of aspects 12-16, wherein the reference resource slot comprises a latest valid downlink slot greater than a minimum timeline value prior to an uplink report slot.

Aspect 18. The method of any of aspects 12-16, wherein the reference resource slot comprises a latest slot having a CSI-RS occasion greater than a minimum timeline value prior to an uplink report slot.

Aspect 19. The method of any of aspects 12-18, further comprising:

transmitting, to the UE, a physical downlink control channel (PDCCH) to trigger a beginning of a new report window.

Aspect 20. A user equipment (UE) , comprising:

a transceiver configured to:

receive, from a network unit, a plurality of channel state information reference signal (CSI-RS) occasions for use in a time-domain CSI (TD-CSI) report relative to a reference resource slot; and

transmit, to the network unit in response to the plurality of CSI-RS occasions being equal to or greater than a minimum number of CSI-RS occasions up to the reference resource slot, the TD-CSI report based on the plurality of CSI-RS occasions,

Aspect 21. The UE of aspect 20, wherein the transceiver is further configured to:

drop or not update the TD-CSI report in response to the plurality of CSI-RS occasions being less than the minimum number of CSI-RS occasions.

Aspect 22. The UE of any of aspects 20-21, wherein the reference resource slot is defined as an end slot corresponding to the first segment.

Aspect 23. The UE of any of aspects 20-21, wherein the reference resource slot is defined as a beginning slot corresponding to the second segment.

Aspect 24. The UE of any of aspects 20-23, wherein a number of the one or more precoder values included in the TD-CSI report is less than or equal to a total number of the plurality of CSI-RS occasions after a physical downlink control channel (PDCCH) and up to the reference resource slot, and greater than or equal to the minimum number of CSI-RS occasions.

Aspect 25. The UE of any of aspects 20-23, wherein the TD-CSI report comprises only the one or more predicted future precoder values.

Aspect 26. The UE of any of aspects 20-25, wherein the reference resource slot comprises a latest valid downlink slot greater than a minimum timeline value prior to an uplink report slot.

Aspect 27. The UE of any of aspects 20-25, wherein the reference resource slot comprises a latest slot having a CSI-RS occasion greater than a minimum timeline value prior to an uplink report slot.

Aspect 28. The UE of any of aspects 20-27, wherein the UE is configured with a minimum K0 value, and the UE further includes a processor configured to:

count a total number of the plurality of CSI-RS occasions from a number of slots corresponding to the minimum K0 value after a physical downlink control channel (PDCCH) slot up to the reference resource slot, to determine whether the total number of the plurality of CSI-RS occasions is greater than or equal to the minimum number of CSI-RS occasions.

Aspect 29. The UE of any of aspects 20-28, wherein the plurality of CSI-RS occasions are semi-periodic, further comprising a processor configured to:

count a total number of the plurality of CSI-RS occasions beginning at a virtual physical downlink control channel (PDCCH) up to the reference resource slot, to determine whether the total number of the plurality of CSI-RS occasions is greater than or equal to the minimum number of CSI-RS occasions,

wherein the virtual PDCCH is identified as a number of slots prior to a subsequent reference resource slot, the number of slots comprising a slot offset from a PDCCH to the first reference resource slot.

Aspect 30. The UE of any of aspects 20-28, wherein the plurality of CSI-RS occasions are semi-periodic, further comprising a processor configured to:

count a total number of the plurality of CSI-RS occasions fter a virtual physical downlink control channel (PDCCH) and up to the reference resource slot, to determine whether the total number of the plurality of CSI-RS occasions is greater than or equal to the minimum number of CSI-RS occasions

Aspect 31. A network unit, comprising:

a transceiver configured to:

transmit, to a user equipment (UE) , a plurality of channel state information reference signal (CSI-RS) occasions for use in a time-domain CSI (TD-CSI) report relative to a reference resource slot; and

receive, from the UE in response to the plurality of CSI-RS occasions being equal to or greater than a minimum number of CSI-RS occasions up to the reference resource slot, the TD-CSI report based on the plurality of CSI-RS occasions,

Aspect 32. The network unit of aspect 31, wherein the reference resource slot is defined as an end slot corresponding to the first segment.

Aspect 33. The network unit of aspect 31, wherein the reference resource slot is defined as a beginning slot corresponding to the second segment.

Aspect 34. The network unit of any of aspects 31-33, wherein a number of the one or more precoder values included in the TD-CSI report is less than or equal to a total number of the plurality of CSI-RS occasions after a physical downlink control channel (PDCCH) and up to the reference resource slot, and greater than or equal to the minimum number of CSI-RS occasions.

Aspect 35. The network unit of any of aspects 31-33, wherein the TD-CSI report comprises only the one or more predicted future precoder values.

Aspect 36. The network unit of any of aspects 31-35, wherein the reference resource slot comprises a latest valid downlink slot greater than a minimum timeline value prior to an uplink report slot.

Aspect 37. The network unit of any of aspects 31-35, wherein the reference resource slot comprises a latest slot having a CSI-RS occasion greater than a minimum timeline value prior to an uplink report slot.

Aspect 38. The network unit of any of aspects 31-37, wherein the transceiver is further configured to:

transmit, to the UE, a physical downlink control channel (PDCCH) to trigger a beginning of a new report window.

Information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The various illustrative blocks and modules described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration) .

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described above can be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Also, as used herein, including in the claims, “or” as used in a list of items (for example, a list of items prefaced by a phrase such as “at least one of” or “one or more of” ) indicates an inclusive list such that, for example, a list of [at least one of A, B, or C] means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) .

As those of some skill in this art will by now appreciate and depending on the particular application at hand, many modifications, substitutions and variations can be made in and to the materials, apparatus, configurations and methods of use of the devices of the present disclosure without departing from the spirit and scope thereof. In light of this, the scope of the present disclosure should not be limited to that of the particular aspects illustrated and described herein, as they are merely by way of some examples thereof, but rather, should be fully commensurate with that of the claims appended hereafter and their functional equivalents.

Claims

A method of wireless communication, comprising:

receiving, by a user equipment (UE) from a network unit, a plurality of channel state information reference signal (CSI-RS) occasions for use in a time-domain CSI (TD-CSI) report relative to a reference resource slot; and

transmitting, by the UE to the network unit in response to the plurality of CSI-RS occasions being equal to or greater than a minimum number of CSI-RS occasions up to the reference resource slot, the TD-CSI report based on the plurality of CSI-RS occasions,

wherein the TD-CSI report comprises a report window that includes the reference resource slot and is based on the reference resource slot and defined by at least one of a first segment of a time domain basis vector length and a second segment of the time domain basis vector length, and

wherein the first segment corresponds to one or more precoder values from the plurality of CSI-RS occasions for the TD-CSI report, and the second segment corresponds to one or more predicted future precoder values based on the plurality of CSI-RS occasions for the TDI-CSI report.
The method of claim 1, further comprising:

dropping or not updating, by the UE, the TD-CSI report in response to the plurality of CSI-RS occasions being less than the minimum number of CSI-RS occasions.
The method of claim 1, wherein the reference resource slot is defined as an end slot corresponding to the first segment, or as a beginning slot corresponding to the second segment.
The method of claim 1, wherein a number of the one or more precoder values included in the TD-CSI report is less than or equal to a total number of the plurality of CSI-RS occasions after a physical downlink control channel (PDCCH) and up to the reference resource slot, and greater than or equal to the minimum number of CSI-RS occasions.
The method of claim 1, wherein the TD-CSI report comprises only the one or more predicted future precoder values.
The method of claim 1, wherein the reference resource slot comprises a latest valid downlink slot greater than a minimum timeline value prior to an uplink report slot, or a latest slot having a reference signal occasion greater than the minimum timeline value prior to the uplink report slot.
The method of claim 1, wherein the UE is configured with a minimum K0 value, and the method further comprising:

counting, by the UE, a total number of the plurality of CSI-RS occasions from a number of slots corresponding to the minimum K0 value after a physical downlink control channel (PDCCH) slot up to the reference resource slot, to determine whether the total number of the plurality of CSI-RS occasions is greater than or equal to the minimum number of CSI-RS occasions.
The method of claim 1, wherein the plurality of CSI-RS occasions are semi-periodic, the method further comprising:

counting, by the UE, a total number of the plurality of CSI-RS occasions after a virtual physical downlink control channel (PDCCH) up to the reference resource slot, to determine whether the total number of the plurality of CSI-RS occasions is greater than or equal to the minimum number of CSI-RS occasions,

wherein the virtual PDCCH is identified as a number of slots prior to a subsequent reference resource slot, the number of slots comprising a slot offset from a PDCCH to a first reference resource slot .
The method of claim 1, wherein the plurality of CSI-RS occasions are semi-periodic, the method further comprising:

counting, by the UE, a total number of the plurality of CSI-RS occasions after a virtual physical downlink control channel (PDCCH) up to the reference resource slot, to determine whether the total number of the plurality of CSI-RS occasions is greater than or equal to the minimum number of CSI-RS occasions,

wherein the virtual PDCCH is identified as a number of slots prior to a subsequent uplink report slot, the number of slots comprising a slot offset of a PDCCH to a first uplink report slot,
A method of wireless communication, comprising:

transmitting, by a network unit to a user equipment (UE) , a plurality of channel state information reference signal (CSI-RS) occasions for use in a time-domain CSI (TD-CSI) report relative to a reference resource slot; and

receiving, by the network unit from the UE in response to the plurality of CSI-RS occasions being equal to or greater than a minimum number of CSI-RS occasions up to the reference resource slot, the TD-CSI report based on the plurality of CSI-RS occasions,

wherein the TD-CSI report comprises a report window that includes the reference resource slot and is based on the reference resource slot and defined by at least one of a first segment of a time domain basis vector length and a second segment of the time domain basis vector length, and

wherein the first segment corresponds to one or more precoder values from the plurality of CSI-RS occasions for the TD-CSI report, and the second segment corresponds to one or more predicted future precoder values based on the plurality of CSI-RS occasions for the TDI-CSI report.
The method of claim 10, wherein the reference resource slot is defined as an end slot corresponding to the first segment, or as a beginning slot corresponding to the second segment.
The method of claim 10, wherein a number of the one or more precoder values included in the TD-CSI report is less than or equal to a total number of the plurality of CSI-RS occasions after a physical downlink control channel (PDCCH) and up to the reference resource slot, and greater than or equal to the minimum number of CSI-RS occasions.
The method of claim 10, wherein the TD-CSI report comprises only the one or more predicted future precoder values.
The method of claim 10, wherein the reference resource slot comprises a latest valid downlink slot greater than a minimum timeline value prior to an uplink report slot, or a latest slot having a reference signal occasion greater than the minimum timeline value prior to the uplink report slot.
The method of claim 10, further comprising:

transmitting, to the UE, a physical downlink control channel (PDCCH) to trigger a beginning of a new report window.
A user equipment (UE) , comprising:

a transceiver configured to:

receive, from a network unit, a plurality of channel state information reference signal (CSI-RS) occasions for use in a time-domain CSI (TD-CSI) report relative to a reference resource slot; and

transmit, to the network unit in response to the plurality of CSI-RS occasions being equal to or greater than a minimum number of CSI-RS occasions up to the reference resource slot, the TD-CSI report based on the plurality of CSI-RS occasions,

wherein the TD-CSI report comprises a report window that includes the reference resource slot and is based on the reference resource slot and defined by at least one of a first segment of a time domain basis vector length and a second segment of the time domain basis vector length, and

wherein the first segment corresponds to one or more precoder values from the plurality of CSI-RS occasions for the TD-CSI report, and the second segment corresponds to one or more predicted future precoder values based on the plurality of CSI-RS occasions for the TDI-CSI report.
The UE of claim 16, wherein the transceiver is further configured to:

drop or not update the TD-CSI report in response to the plurality of CSI-RS occasions being less than the minimum number of CSI-RS occasions.
The UE of claim 16, wherein the reference resource slot is defined as an end slot corresponding to the first segment, or as a beginning slot corresponding to the second segment.
The UE of claim 16, wherein a number of the one or more precoder values included in the TD-CSI report is less than or equal to a total number of the plurality of CSI-RS occasions after a physical downlink control channel (PDCCH) and up to the reference resource slot, and greater than or equal to the minimum number of CSI-RS occasions.
The UE of claim 16, wherein the TD-CSI report comprises only the one or more predicted future precoder values.
The UE of claim 16, wherein the reference resource slot comprises a latest valid downlink slot greater than a minimum timeline value prior to an uplink report slot, or a latest slot having a reference signal occasion greater than the minimum timeline value prior to the uplink report slot.
The UE of claim 16, wherein the UE is configured with a minimum K0 value, and the UE further includes a processor configured to:

count a total number of the plurality of CSI-RS occasions from a number of slots corresponding to the minimum K0 value after a physical downlink control channel (PDCCH) slot up to the reference resource slot, to determine whether the total number of the plurality of CSI-RS occasions is greater than or equal to the minimum number of CSI-RS occasions.
The UE of claim 16, wherein the plurality of CSI-RS occasions are semi-periodic, further comprising a processor configured to:

count a total number of the plurality of CSI-RS occasions after a virtual physical downlink control channel (PDCCH) up to the reference resource slot, to determine whether the total number of the plurality of CSI-RS occasions is greater than or equal to the minimum number of CSI-RS occasions,

wherein the virtual PDCCH is identified as a number of slots prior to a subsequent reference resource slot, the number of slots comprising a slot offset from a PDCCH to the first reference resource slot.
The UE of claim 16, wherein the plurality of CSI-RS occasions are semi-periodic, further comprising a processor configured to:

count a total number of the plurality of CSI-RS occasions after a virtual physical downlink control channel (PDCCH) and up to the reference resource slot, to determine whether the total number of the plurality of CSI-RS occasions is greater than or equal to the minimum number of CSI-RS occasions,

wherein the virtual PDCCH is identified as a number of slots prior to a subsequent uplink report slot, the number of slots comprising a slot offset of a PDCCH to a first uplink report slot.
A network unit, comprising:

a transceiver configured to:

transmit, to a user equipment (UE) , a plurality of channel state information reference signal (CSI-RS) occasions for use in a time-domain CSI (TD-CSI) report relative to a reference resource slot; and

receive, from the UE in response to the plurality of CSI-RS occasions being equal to or greater than a minimum number of CSI-RS occasions up to the reference resource slot, the TD-CSI report based on the plurality of CSI-RS occasions,

wherein the TD-CSI report comprises a report window that includes the reference resource slot and is based on the reference resource slot and defined by at least one of a first segment of a time domain basis vector length and a second segment of the time domain basis vector length, and

wherein the first segment corresponds to one or more precoder values from the plurality of CSI-RS occasions for the TD-CSI report, and the second segment corresponds to one or more predicted future precoder values based on the plurality of CSI-RS occasions for the TDI-CSI report.
The network unit of claim 25, wherein the reference resource slot is defined as an end slot corresponding to the first segment, or as a beginning slot corresponding to the second segment.
The network unit of claim 25, wherein a number of the one or more precoder values included in the TD-CSI report is less than or equal to a total number of the plurality of CSI-RS occasions after a physical downlink control channel (PDCCH) and up to the reference resource slot, and greater than or equal to the minimum number of CSI-RS occasions.
The network unit of claim 25, wherein the TD-CSI report comprises only the one or more predicted future precoder values.
The network unit of claim 25, wherein the reference resource slot comprises a latest valid downlink slot greater than a minimum timeline value prior to an uplink report slot, or a latest slot having a reference signal occasion greater than the minimum timeline value prior to the uplink report slot.
The network unit of claim 25, wherein the transceiver is further configured to:

transmit, to the UE, a physical downlink control channel (PDCCH) to trigger a beginning of a new report window.