Csi processing for pdsch and dmrs based channel state information (csi)

Abstract

The present disclosure provides systems, methods, and apparatus, including computer programs encoded on computer storage media, for transmitting a channel state information (CSI) report from a user equipment (UE). The CSI report can be a UE-initiated CSI report or can be based on a downlink grant. The UE can determine to transmit the CSI report based on measurements using a physical downlink control channel (PDSCH) and / or a demodulation reference signal (DMRS). The UE can determine a reference resource for CSI feedback. The UE can calculate a channel quality indicator (CQI) based on the reference resource. The UE can transmit the CQI in the CSI report on an uplink resource.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to user equipment (UE) channel state information (CSI) processing for UE-initiated CSI and downlink grant CSI. BACKGROUND

[0002] Wireless communication systems are widely deployed to provide various communication services such as voice, video, data, messaging, broadcast, etc. These wireless communication systems can be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources. Examples of such multiple-access systems include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single-Carrier Frequency Division Multiple Access (SC-FDMA) systems, and Time Division Synchronous Code Division Multiple Access (TD-SCDMA) systems.

[0003] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example of a telecommunication standard is 5G New Radio (NR). 5G NR is a set of enhancements to the LTE mobile standard promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with SUMMARY

[0004] The systems, methods, and devices of the present disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.

[0005] One innovative aspect of the subject matter described in this disclosure can be implemented in a method of wireless communication at an apparatus of a user equipment (UE). The method can include determining to transmit a channel state information (CSI) report based on a measurement using a physical downlink control channel (PDSCH) and / or a demodulation reference signal (DMRS). The method can include determining a reference resource for CSI feedback. The method can include calculating a channel quality indicator (CQI) based on the reference resource. The method can include transmitting the CQI in the CSI report on an uplink resource.

[0006] In some implementations, the reference resource is a slot in which the PDSCH or the DMRS is received.

[0007] In some implementations, calculating the CQI based on the reference resource includes determining an overhead assumption for CQI calculation based on a slot in which the PDSCH and the DMRS are received.

[0008] In some implementations, the overhead assumption includes at least a number of symbols used for control signaling, a number of DMRS symbols and PDSCH symbols, a number of additional DMRS symbols, and resources allocated for a non-zero power (NZP) CSI reference signal (NZP-CSI-RS) and a zero power (ZP) CSI-RS.

[0009] In some implementations, calculating the CQI based on the reference resource includes determining that a CSI reporting band is equal to a frequency domain allocation of the PDSCH and the DMRS.

[0010] In some implementations, the CSI report includes wideband CSI.

[0011] In some implementations, the CSI report includes resource block group (RBG) or physical resource group (PRG) level CQI, where the RBG or PRG includes the same resources as the DMRS and the PDSCH used for channel measurement or interference measurement.

[0012] In some implementations, the CSI report includes RBG or PRG level CQI separately configured in a CSI reporting setting.

[0013] In some implementations, a CSI processing unit (CPU) occupation time starts from a first symbol of an earliest one of the DMRS or the PDSCH used for channel measurement or interference measurement and ends at a last symbol of the uplink resource.

[0014] In some implementations, a DMRS port for the DMRS and the PDSCH is active from a first symbol of the DMRS or the PDSCH used for channel measurement or interference measurement to a last symbol of the uplink resource.

[0015] In some implementations, the uplink resource is separated from a last symbol of the reference resource by at least a number of symbols defined by a CSI timeline, where the CSI timeline is determined based at least in part on a number of CPU occupations or a number of DMRS ports.

[0016] In some implementations, when the CSI is transmitted in a same slot as a HARQ ACK / NACK or in a same PUCCH as the HARQ ACK / NACK, the uplink resource is separated from a last symbol of the reference resource by a larger of a number of symbols defined by a CSI timeline or a number of symbols defined by a HARQ timeline.

[0017] In some implementations, determining the CSI report includes determining a priority of the CSI, wherein the priority of the CSI is based at least in part on a type of downlink measurement resource, whether the CSI report is triggered by the UE in response to CSI measurement, or whether the aperiodic CSI is transmitted on the PUCCH; and determining the resource CSI multiplexing order, dropping order, or omission order based on the priority.

[0018] In some implementations, determining the priority of the CSI includes determining a priority function for the CSI, wherein a value of a factor in the priority function is defined by a type of downlink measurement resource for the CSI.

[0019] In some implementations, determining the priority of the CSI includes determining a priority function for the CSI, wherein a value of a factor in the priority function is defined by a type of trigger for the CSI.

[0020] One innovative aspect of the subject matter described in this disclosure can be implemented in a method of wireless communication at an apparatus of a base station. The method can include configuring a UE with a CSI reporting configuration, the CSI reporting configuration including a downlink measurement resource, the downlink measurement resource including a PDSCH or a DMRS. The method can include transmitting a downlink grant scheduling the PDSCH and the DMRS in a slot. The method can include transmitting the PDSCH and the DMRS in the slot. The method can include receiving, from the UE, a CSI report including a CQI based on the PDSCH or the DMRS on an uplink resource.

[0021] In some implementations, the CQI is based on an overhead assumption for the slot in which the PDSCH and the DMRS are transmitted.

[0022] In some implementations, the overhead assumption includes at least a number of symbols for control signaling, a number of DMRS symbols and PDSCH symbols, a number of additional DMRS symbols, and resources allocated for NZP-CSI-RS and ZP-CSI-RS.

[0023] In some implementations, a CSI reporting band is equal to a frequency domain allocation of the PDSCH and the DMRS.

[0024] In some implementations, the CSI report includes wideband CSI.

[0025] In some implementations, the CSI report includes RBG or PRG level CQI, wherein the RBG or PRG includes the same resources as the DMRS and the PDSCH used for channel measurement or interference measurement.

[0026] In some implementations, the CSI report includes RBG or PRG level CQI separately configured in a CSI reporting setting.

[0027] In some implementations, the CPU occupancy time starts from the first symbol of the earliest one of the DMRS or PDSCH used for channel measurement or interference measurement and ends at the last symbol of the uplink resource.

[0028] In some implementations, the DMRS ports for the DMRS and PDSCH are active from the first symbol of the DMRS or PDSCH used for channel measurement or interference measurement to the last symbol of the uplink resource.

[0029] In some implementations, the uplink resource is separated from the last symbol of the PDSCH or DMRS used for channel measurement or interference measurement by at least a number of symbols defined by a CSI timeline, where the CSI timeline is selected based at least in part on the number of CPU occupancy or the number of DMRS ports.

[0030] In some implementations, when the CSI is transmitted on the same slot as the HARQ ACK / NACK or in the same PUCCH as the HARQ ACK / NACK, the uplink resource is separated from the last symbol of the PDSCH or DMRS used for channel measurement or interference measurement by the greater of a number of symbols defined by a CSI timeline or a number of symbols defined by a HARQ timeline.

[0031] The details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, the drawings, and the claims. Note that the relative dimensions of the following figures can not be drawn to scale. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network.

[0033] Figure 2A FIG. 2 is a diagram illustrating an example of a first frame.

[0034] Figure 2B FIG. 3 is a diagram illustrating an example of DL channels within a subframe.

[0035] Figure 2C FIG. 4 is a diagram illustrating an example of a second frame.

[0036] Figure 2D FIG. 5 is a diagram illustrating an example of a subframe.

[0037] Figure 3 FIG. 6 is a diagram illustrating an example of a base station (BS) and user equipment (UE) in an access network.

[0038] Figure 4 FIG. 7 is a diagram illustrating an example configuration of channel state information (CSI) resources.

[0039] Figure 5 FIG. 1 is a diagram illustrating an example CSI reporting timeline for aperiodic CSI.

[0040] Figure 6 FIG. 2 is a diagram illustrating an example CSI reporting timeline for UE initiated CSI reporting.

[0041] Figure 7 FIG. 3 is a diagram illustrating an example CSI reporting timeline for UE initiated CSI reporting based on CSI reference signals (CSI-RS).

[0042] Figure 8 FIG. 4 is a diagram illustrating an example CSI reporting timeline for UE initiated CSI reporting based on physical downlink shared channel (PDSCH) or demodulation reference signals (DMRS) (PDSCH / DMRS).

[0043] Figure 9 FIG. 5 is a diagram illustrating an example CSI reporting timeline for downlink grant triggered CSI reporting based on CSI-RS.

[0044] Figure 10 FIG. 6 is a diagram illustrating an example CSI reporting timeline for downlink grant triggered CSI reporting based on PDSCH / DMRS.

[0045] Figure 11 FIG. 7 is a diagram illustrating an example configuration based on a DMRS / PDSCH for channel measurement and one interference measurement resource.

[0046] Figure 12 FIG. 8 is a diagram illustrating an example configuration based on a DMRS / PDSCH for channel measurement and two interference measurement resources.

[0047] Figure 13 FIG. 9 is a diagram illustrating an example configuration based on a DMRS / PDSCH for channel measurement and three interference measurement resources.

[0048] Figure 14 FIG. 10 is a diagram illustrating an example mapping of CSI reporting configuration to uplink resources based on a hybrid automatic repeat request (HARQ) process number.

[0049] Figure 15 FIG. 11 is a diagram illustrating an example mapping of CSI reporting settings to uplink resources.

[0050] Figure 16 FIG. 12 is a diagram illustrating an example of a CSI report indicating a related HARQ process number.

[0051] Figure 17is a diagram illustrating an example CSI reporting timeline showing physical uplink control channel (PUCCH) / physical uplink shared channel (PUSCH) resources for UE-initiated CSI.

[0052] Figure 18 is a diagram illustrating an example CSI reporting timeline showing PUCCH / PUSCH resources for downlink grant-based CSI.

[0053] Figure 19 is a diagram illustrating an example CSI reporting timeline based on a slot offset relative to a downlink grant.

[0054] Figure 20 is a diagram illustrating an example CSI reporting timeline based on a slot offset relative to a PDSCH / DMRS.

[0055] Figure 21 is a diagram illustrating an example CSI reporting timeline based on a slot offset relative to a HARQ acknowledgement (ACK) slot.

[0056] Figure 22 is a diagram illustrating an example CSI reporting timeline showing scheduling request (SR) resources.

[0057] Figure 23 is a diagram illustrating an example CSI reporting timeline showing SR resources and PUCCH / PUSCH resources.

[0058] Figure 24 is a diagram illustrating example two-step random access (RACH) messages for CSI reporting.

[0059] Figure 25 is a diagram illustrating an example CSI processing unit occupancy duration and active DMRS duration CSI processing.

[0060] Figure 26 is a diagram illustrating an example CSI processing timeline.

[0061] Figure 27 is a diagram illustrating example communications and components of a base station and a UE.

[0062] Figure 28 is a conceptual data flow diagram illustrating the data flow between different means / components in an example base station.

[0063] Figure 29 is a conceptual data flow diagram illustrating the data flow between different means / components in an example UE.

[0064] Figure 30 is a flow diagram of an example method for a UE to transmit a CSI report based on UE-initiated CSI or downlink grant-based CSI.

[0065] Figure 31 FIG. 16 is a flow diagram of an example method of a base station receiving a CSI report initiated by a UE or a CSI report based on a downlink grant.

[0066] The same reference numbers and designations in different drawings indicate the same elements. DETAILED DESCRIPTION

[0067] For the purpose of describing the innovative aspects of the present disclosure, the following description focuses on certain implementations. However, one skilled in the art will readily recognize that the teachings herein can be applied in a multitude of different ways. Some examples in this disclosure are based on wireless and wired local area network (LAN) communications according to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 wireless standards, the IEEE 802.3 Ethernet standards, and the IEEE 1901 Powerline Communication (PLC) standards. However, the described implementations can be implemented in any device, system or network that is capable of transmitting and receiving RF signals according to any wireless communication standard, including the IEEE 802.11 standards, the Bluetooth standard, Time Division Multiple Access (TDMA), Global System for Mobile Communications (GSM), GSM / General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), Terrestrial Trunked Radio (TETRA), Wideband-CDMA (W-CDMA), Evolution Data Optimized (EV-DO), lxEV-DO, EV-DO Rev A, EV-DO Rev R, High Speed Packet Access (HSPA), High Speed Downlink Packet Access (HSDPA), High Speed Uplink Packet Access (HSUPA), Evolved High Speed Packet Access (HSPA+), Long Term Evolution (LTE), AMPS, or other known signals for communicating within a wireless, cellular, or internet of things (IoT) network, such as a system utilizing 3G, 4G, 5G, or further implementations thereof.

[0068] A user equipment (UE) can transmit a channel state information (CSI) report to inform a base station of channel conditions. Traditionally, the UE determines CSI based on a CSI reference signal (CSI-RS) transmitted by the base station and transmits the CSI report on a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH). The UE can be configured to transmit periodic CSI and / or aperiodic CSI. For aperiodic CSI, the base station can transmit an uplink grant that provides PUSCH resources for the CSI report. Conventional CSI reporting techniques can have limitations in terms of feedback latency and overhead. Specifically, although the network can trigger aperiodic CSI to obtain a CSI report in response to a transmission failure (e.g., a negative acknowledgement (NACK) for a physical downlink shared channel (PDSCH)), there can be a latency of at least one frame before the base station can schedule the aperiodic CSI and receive the CSI report. Furthermore, the use of CSI-RS can increase channel overhead.

[0069] In one aspect, the present disclosure uses selected reserved resources to provide UE-initiated CSI reporting and downlink grant-based CSI reporting. For UE-initiated CSI reporting, the UE can determine to transmit a CSI report based on measurements from the main. For downlink grant-based CSI reporting, the base station can transmit a downlink grant that requests a CSI report. Unlike conventional CSI reporting, the CSI report can not use a CSI-RS as a measurement resource. Instead, both UE-initiated CSI reporting and downlink grant-based CSI reporting can utilize a PDSCH and an associated demodulation reference signal (DMRS) as measurement resources. A CSI configuration can designate the PDSCH / DMRS as one or both of a channel measurement resource (CMR) or an interference measurement resource (IMR). The UE can compute a channel quality indicator (CQI) based on a slot in which the PDSCH and DMRS are received. Specifically, an overhead assumption for CQI computation can be based on the slot in which the PDSCH and DMRS are received. In some implementations, a CSI timeline can measure from the slot in which the PDSCH and DMRS are received as a reference resource. Both UE-initiated CSI reporting and downlink grant-based CSI reporting can utilize dedicated uplink resources for the CSI report after the CSI timeline. The CPU occupancy and active DMRS ports can also be determined based on the slot in which the PDSCH and DMRS are received. Thus, the UE can transmit the CSI report based on the PDSCH and / or DMRS.

[0070] Particular implementations of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. A UE can use UE-initiated CSI reporting or downlink grant-based CSI reporting to increase the flexibility of CSI reporting and reduce the latency to adapt to changing channel conditions. For example, when a UE fails to decode a PDSCH, the UE can transmit a CSI report based on the PDSCH and related DMRS as measurement resources. In some cases, the CSI report can be transmitted in the same frame as the PDSCH. Thus, a base station is able to adapt a subsequent PDSCH transmission based on the PDSCH, thereby improving the error rate and throughput. In some implementations, using PDSCH / DMRS as measurement resources can avoid using CSI-RS, thereby reducing the downlink signal overhead. In some cases, HARQ-ACK-based rate adaptation can not be effective due to the following reasons: (1) in a TDD system, there can not be enough UL slots to allow the UE to transmit ACK / NACK, and (2) ACK / NACK is 1 bit, the BS can not have high-resolution information to assist rate adaptation. From these perspectives, the BS can not be aware that the CSI becomes outdated or inaccurate, so the BS can not timely trigger a CSI report. Even if the BS knows that the CSI is inaccurate, the BS needs to send a request and there will be several slots for the UE to process and report the CSI. Thus, the entire timeline from reporting NACK to the BS being aware that the CSI is inaccurate, to obtaining the CSI report can be up to tens of slots. However, UE-initiated CSI feedback can allow the UE to process and timely report the CSI based on DMRS / PDSCH or CSI-RS to shorten the overall timeline to obtain the CSI. Furthermore, downlink grant-triggered CSI can provide more flexibility to the BS than using UL grant to trigger CSI reporting only. It can also enable DMRS / PDSCH based on CSI measurement and reporting, thereby saving CSI-RS overhead and can shorten the overall CSI obtaining timeline.

[0071] Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as "elements"). These elements can be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends on the particular application and design constraints imposed on the overall system.

[0072] By way of example, an element, or any portion of an element, or any combination of elements can be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on a chip (SoC), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system can execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0073] Accordingly, in one or more example implementations, the functions described can be implemented in hardware, software, or any combination thereof. If implemented in software, the functions can be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the aforementioned types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer.

[0074] Figure 1 FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network 100. The wireless communications system (also referred to as a wireless wide area network (WWAN)) includes base stations 102, UEs 104, an Evolved Packet Core (EPC) 160, and another core network 190, such as a 5G Core (5GC). The base stations 102 can include macro cells (high power cellular base stations) or small cells (low power cellular base stations). The macro cells include base stations. The small cells include femtocells, picocells, and microcells.

[0075] In some implementations, one or more UEs 104 can include a CSI transmit (Tx) component 140 that transmits a CSI report using a UE-initiated CSI report or a downlink grant-based CSI report. The CSI Tx component 140 can include a triggering component 144 configured to determine to transmit a CSI report based on a PDSCH and a DMRS, a resource component 146 configured to determine a reference resource for CSI feedback as a slot in which the PDSCH or the DMRS is received, a measurement component 145 configured to compute a CQI based on the reference resource, and a reporting component 147 configured to transmit the CQI in the CSI report on an uplink resource. The CSI Tx component 140 can optionally include a grant component 143 configured to receive a downlink grant that schedules the PDSCH and the DMRS, and a configuration component 141 configured to receive a CSI report configuration related to one or more resource settings that define a downlink measurement resource including the PDSCH or the DMRS. The CSI Tx component 140 can optionally include an activation component 142 configured to receive a command indicating that a UE-initiated CSI report based on measurements is activated.

[0076] In some implementations, one or more base stations 102 can include a CSI receive (Rx) component 120 that receives a UE-initiated CSI report or a downlink grant-based CSI report from a UE. The CSI Rx component 120 can include a configuration component 122, a scheduling component 124, a resource component 125, and a report reception component 126. The configuration component 122 can be configured to configure the UE with a CSI report configuration that includes a downlink measurement resource including a PDSCH or a DMRS. The scheduling component 124 can be configured to transmit a downlink grant that schedules the PDSCH and the DMRS in a slot. A transmitter component can transmit the PDSCH and the DMRS in the slot. The report reception component 126 can be configured to receive, from the UE, a CSI report including a CQI based on the PDSCH or the DMRS on an uplink resource.

[0077] The base stations 102 configured for 4G LTE (collectively referred to as the Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can interface with the EPC 160 through first backhaul links 132 (such as an SI interface) which can be wired or wireless. The base stations 102 configured for 5G R (collectively referred to as Next Generation RAN (NG-RAN)) can interface with the core network 190 through second backhaul links 184, which can be wired or wireless. In addition to other functions, the base stations 102 can perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (such as handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations 102 can communicate directly or indirectly (e.g., through the EPC 160 or core network 190) with each other over third backhaul links 134 (such as an X2 interface). The third backhaul links 134 can be wired or wireless.

[0078] The base stations 102 can wirelessly communicate with the UEs 104. Each of the base stations 102 can provide communication coverage for a respective geographic coverage area 110. There can be overlapping geographic coverage areas 110. For example, a small cell 102' can have a coverage area 110' that overlaps the coverage area 110 of one or more macro base stations 102. A network that includes both small cell and macro cells can be known as a heterogeneous network. A heterogeneous network can also include Home Evolved Node Bs (eNBs) (HeNBs), which can provide service to a restricted group known as a closed subscriber group (CSG). The communication links 112 between the base stations 102 and the UEs 104 can include uplink (UL) (also referred to as reverse link) transmissions from a UE 104 to a base station 102 or downlink (DL) (also referred to as forward link) transmissions from a base station 102 to a UE 104. The communication links 112 can use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, or transmit diversity. The communication links can be through one or more carriers, and each carrier can be a band of frequency waves having a predetermined width and can be used to transmit data between base stations 102 and UEs 104. The carriers can be in the form of Grande Total (GTT) or New Radio (NR) carriers. Transmissions on the carriers can be made according to one or more radio access technologies. The base stations 102 / UEs 104 can use spectrum up to Y MHz (such as 5, 10, 15, 20, 100, 400 MHz, etc.) that is fully reused in each direction. The carriers can be

[0079] Certain UEs 104 can communicate with each other using device-to-device (D2D) communication link 158. The D2D communication link 158 can use the DL / UL WWAN spectrum. The D2D communication link 158 can use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). D2D communication can be through a variety of wireless D2D communications systems, such as for example, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR.

[0080] The wireless communications system can also include a Wi-Fi access point (AP) 150 in communication with Wi-Fi stations (STAs) 152 via communication links 154 in a 5 GHz unlicensed frequency spectrum. When communicating in an unlicensed frequency spectrum, the STAs 152 / AP 150 can perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available.

[0081] The small cells 102' can operate in a licensed and / or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cells 102' can use NR and use the same 5 GHz unlicensed frequency spectrum as used by Wi-Fi APs 150. The use of NR by the small cells 102' in an unlicensed frequency spectrum can increase the throughput and overall coverage of the access network.

[0082] The base stations 102, whether small cell 102' or large cell (e.g., macro base station), can include an eNB, gNodeB (gNB), or other types of base station. Some base stations, such as gNB 180 can operate in one or more frequency bands within the electromagnetic spectrum.

[0083] The electromagnetic spectrum is often subdivided based on frequency / wavelength into various classes, bands, channels, etc. In 5G NR, two initial operating bands have been identified as frequency range designations FR1 (410 MHz - 7. 125 GHz) and FR2 (24.25 GHz - 52.6 GHz). The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “Sub-6 GHz” band in various documents and articles. FR2 also suffers from a similar naming issue, despite being different from the extremely high frequency (EHF) band (30 GHz - 300 GHz) which has been identified by the International Telecommunications Union (ITU) as a “millimeter wave” (mmW) frequency band. FR2 is often referred to (interchangeably) as a millimeter wave frequency band in documents and articles.

[0084] With the above aspects in mind, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like if used herein can broadly represent frequencies less than 6 GHz, can be within FR1, or can include the mid-band frequencies. Further, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like if used herein can broadly represent frequencies that can include the mid-band frequencies, can be within FR2, or can be within the EHF band. Communications using the mmW radio frequency band have extremely high path loss and a short range. The mmW base stations 180 can utilize beamforming 182 with the UEs 104 to compensate for the extremely high path loss and short range.

[0085] The EPC 160 can include a mobility management entity (MME) 162, other MMEs 164, a serving gateway 166, a multimedia broadcast multicast service (MBMS) gateway 168, a broadcast multicast service center (BM-SC) 170, and a packet data network (PDN) gateway 172. The MME 162 can be in communication with a home subscriber server (HSS) 174. The MME 162 is the control node that processes the signaling between the UEs 104 and the EPC 160. Generally, the MME 162 provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the serving gateway 166, which itself is connected to the PDN gateway 172. The PDN gateway 172 provides UE IP address allocation as well as other functions. The PDN gateway 172 and the BM-SC 170 are connected to the IP services 176. The IP services 176 can include the Internet, an intranet, an IP multimedia subsystem (IMS), a PS streaming service, or other IP services. The BM-SC 170 can provide functions for MBMS user service provisioning and delivery. The BM-SC 170 can serve as an entry point for content provider MBMS transmissions, can be used to authorize and initiate MBMS Bearer Services, and can be used to schedule MBMS transmissions. The MBMS gateway 168 can be used to

[0086] The core network 190 can include an access and mobility management function (AMF) 192, other AMFs 193, a session management function (SMF) 194, and a user plane function (UPF) 195. The AMF 192 can be in communication with a unified data management (UDM) 196. The AMF 192 is the control node that processes the signaling between the UEs 104 and the core network 190. Generally, the AMF 192 provides QoS flow and session management. All user Internet protocol (IP) data packets are transferred through the UPF 195. The UPF 195 provides UE IP address allocation as well as other functions. The UPF 195 is connected to the IP services 197. The IP services 197 can include the Internet, an intranet, an IP multimedia subsystem (IMS), a PS streaming service, or other IP services.

[0087] A base station can include or be referred to as a gNB, Node B, eNB, an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a transmit reception point (TRP), or some other suitable terminology. A base station 102 provides an access point to the EPC 160 or core network 190 for a UE 104. Examples of UEs 104 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor / actuator, a display, or any other similar functional device. Some of the UEs 104 can be referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicle, heart monitor, etc.). The UE 104 can also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

[0088] Although the following description can be focused on 5G NR, the concepts described herein can be applicable to other similar areas, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies, including future 6G technologies.

[0089] Figure 2A FIG. 200 is a diagram 200 illustrating an example of a first frame. Figure 2B FIG. 230 is a diagram 230 illustrating an example of DL channels within a subframe. Figure 2C FIG. 250 is a diagram 250 illustrating an example of a second frame. Figure 2D FIG. 280 is a diagram 280 illustrating an example of a subframe. The 5G / NR frame structure can be FDD, where for a particular set of subcarriers (carrier system bandwidth), the subframes within the set are dedicated to either DL or UL, or TDD, where for a particular set of subcarriers (carrier system bandwidth), the subframes within the set are dedicated to both DL and UL. In Figure 2A , 2CIn the examples provided, assume that the 5G / NR frame structure is TDD, subframe 4 is configured with slot format 28 (mostly DL), where D is DL, U is UL, X is flexible for use between DL / UL, and subframe 3 is configured with slot format 34 (mostly UL). While subframes 3, 4 are shown with slot formats 34, 28, respectively, any particular subframe can be configured with any of the various available slot formats 0-61. Slot formats 0, 1 are all DL, UL, respectively. Other slot formats 2-61 include a mix of DL, UL, and flexible symbols. A UE is configured with a slot format (dynamically through DL control information (DCI), or semi-statically / statically through radio resource control (RRC) signaling) through a received slot format indicator (SFI). Note that the following description also applies to 5G / NR frame structure, i.e., TDD.

[0090] Other wireless communication technologies can have different frame structures or different channels. A frame (10 milliseconds (ms)) can be divided into 10 equally sized subframes (1 ms). Each subframe can include one or more slots. A subframe can also include mini-slots, which can contain 7, 4, or 2 symbols. Depending on the slot configuration, each slot can contain 7 or 14 symbols. For slot configuration 0, each slot can include 14 symbols, and for slot configuration 1, each slot can include 7 symbols. A symbol on the DL can be a cyclic prefix (CP) OFDM (CP-OFDM) symbol. A symbol on the UL can be a CP-OFDM symbol (for high throughput scenarios) or a discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbol (also known as single carrier frequency division multiple access (SC-FDMA) symbol) (for power limited scenarios; limited to single stream transmission). The number of slots within a subframe is dependent on the slot configuration and the numerology. For slot configuration 0, different numbers m0to 5 allow for 1, 2, 4, 8, 16, and 32 slots per subframe, respectively. For slot configuration 1, different numbers 0 to 2 allow for 2, 4, and 8 slots per subframe, respectively. Thus, for slot configuration 0 and numerology m, there are 14 symbols / slot and 2mslots / subframe. The subcarrier spacing and symbol length / duration are a function of the numerology. The subcarrier spacing can equal 2^m* 15 kHz, where m is the numerology 0 to 5. As such, numerology m = 0 has a subcarrier spacing of 15 kHz, and numerology m = 5 has a subcarrier spacing of 480 kHz. The symbol length / duration is inversely proportional to the subcarrier spacing. Figures 2A-2D An example of slot configuration 0 is provided, with 14 symbols per slot, numerology m = 2, and 4 slots per subframe. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 microseconds (ps).

[0091] A resource grid can be used to represent the frame structure. Each time slot includes a resource block (RB) (also referred to as physical RBs (PRBs)) that extends 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0092] As Figure 2A illustrated, some of the REs carry reference (pilot) signals (RS) for the UE. The RS can include demodulation RS (DM-RS) (indicated as Rx for one particular configuration where 100x is the port number, but other DM-RS configurations are possible) and channel state information reference signals (CSI-RS) for channel estimation at the UE.

[0093] Figure 2B An example of various DL channels are illustrated. The physical downlink control channel (PDCCH) carries DCI within one or several control channel elements (CCEs), each CCE including nine RE groups (REGs), each REG including four consecutive REs in an OFDM symbol. A primary synchronization signal (PSS) can be within symbol 2 of particular subframes of a frame. The PSS is used by a UE 104 to determine subframe / symbol timing and a physical layer identity. A secondary synchronization signal (SSS) can be within symbol 4 of particular subframes of a frame. The SSS is used by a UE to determine a physical layer cell identity group number and a radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI). Based on the PCI, the UE can determine the locations of the aforementioned DM-RS. The physical broadcast channel (PBCH), which carries a master information block (MIB) that provides system bandwidth, and one system frame number (SFN), can be logically grouped with the PSS and SSS to form a synchronization signal (SS) / PBCH block. The physical downlink shared channel (PDSCH) carries user

[0094] As Figure 2CAs shown, some of the REs carry DM-RS (indicated as R for one particular configuration, but other DM-RS configurations are possible) for channel estimation at the base station. The UE can transmit DM-RS for channel estimation for the physical uplink control channel (PUCCH) and for the physical uplink shared channel (PUSCH). The PUSCH DM-RS can be transmitted in the first one or two symbols of the PUSCH. The PUCCH DM-RS can be transmitted in different configurations depending on whether short or long PUCCHs are transmitted and the particular PUCCH format used. The UE can transmit a sounding reference signal (SRS). The SRS can be transmitted in the last symbol of a subframe. The SRS can have a comb- type structure, and a UE can transmit an SRS on one of the combs. The SRS can be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

[0095] Figure 2D An example of various UL channels within a subframe of a frame is shown. The PUCCH can be located according to the indications in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and HARQ ACK / NACK feedback. The PUSCH carries data, and can additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), or UCI.

[0096] Figure 3FIG. 3 is a diagram of an example of a network architecture. Providing wireless communication coverage for a residential, business, or hot spot area a base station 310 and a UE 350 are examples of the network elements of FIG. 1. In a DL, IP packets from the EPC 160 can be provided to a controller / processor 375. The controller / processor 375 implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller / processor 375 provides RRC layer functionality associated with broadcasting of system information (such as MIB, SIBs), RRC connection control (such as RRC connection paging, RRC connection establishment, RRC connection modification, RRC connection release), inter radio access technology (RAT) mobility, and measurement configuration

[0097] The transmit (TX) processor 316 and the receive (RX) processor 370 implement layer 1 functionality associated with various signal processing functions. Layer 1, which includes a physical (PHY) layer, can include error detection on the transport channels, forward error correction (FEC) coding / decoding of the transport channels, interleaving, rate matching, mapping to physical channels, modulation / demodulation of physical channels, and MIMO antenna processing. The TX processor 316 handles mapping to signal constellations based on various modulation schemes (such as binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols can then be split into parallel streams. Each stream can then be mapped to an OFDM subcarrier, multiplexed with a reference signal (such as pilot) in the time or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator 374 can be used to determine the coding and modulation schemes, as well as for spatial processing. The channel estimate can be derived from a reference signal or channel condition feedback transmitted by the UE 350. Each spatial stream can then be provided to a different antenna 320 via a separate transmitter 318TX. Each transmitter 318TX can modulate an RF carrier with a respective spatial stream for transmission.

[0098] At the UE 350, each receiver 354Rx receives a signal through its respective antenna 352. Each receiver 354RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functionality associated with various signal processing functions. The RX processor 356 can perform spatial processing on the information to recover any spatial streams designated for the UE 350. If multiple spatial streams are designated for the UE 350, they can be combined by the RX processor 356 into a single OFDM symbol stream. The RX processor 356 then converts the OFDM symbol stream from the time domain to the frequency domain using a fast Fourier transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station 310. These soft decisions can be based on channel estimates computed by the channel estimator 358. The soft decisions are then decoded and de-interleaved to recover the data and control signals that were originally transmitted by the base station 310 on the physical channel. The data and control signals are then provided to the controller / processor 359, which implements layer 3 and layer 2 functionality.

[0099] The controller / processor 359 can be associated with a memory 360 that stores program codes and data. The memory 360 can be referred to as a computer-readable medium. In the UL, the controller / processor 359 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the EPC 160. The controller / processor 359 is also responsible for error detection using an ACK or NACK protocol to support HARQ operations.

[0100] Similar to the functionality described in connection with the DL transmission by the base station 310, the controller / processor 359 provides RRC layer functionality associated with system information (such as MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression / decompression, and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs into TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0101] The TX processor 368 can use channel estimates derived by the channel estimator 358 from a reference signal or feedback transmitted by the base station 310 to select the appropriate coding and modulation schemes and facilitate spatial processing. The spatial streams generated by the TX processor 368 can be provided to different antenna 352 via separate transmitters 354TX. Each transmitter 354TX can modulate an RF carrier with a respective spatial stream for transmission.

[0102] The base station 310 processes the UL transmission in a manner similar to that described in connection with the receiver function at the UE 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers information modulated onto an RF carrier and provides the information to a RX processor 370.

[0103] The controller / processor 375 can be associated with a memory 376 that stores program codes and data. The memory 376 can be referred to as a computer-readable medium. In the UL, the controller / processor 375 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 350. IP packets from the controller / processor 375 can be provided to the EPC 160. The controller / processor 375 is also responsible for error detection using an ACK or NACK protocol to support HARQ operations.

[0104] At least one of the TX processor 368, the RX processor 356, and the controller / processor 359 can be configured to perform aspects in connection with the CSI Tx component 140 of FIG. 2. Figure 1 At least one of the TX processor 316, the RX processor 370, and the controller / processor 375 can be configured to perform aspects in connection with the CSI Rx component 120 of FIG. 2.

[0105] At least one of the TX processor 368, the RX processor 356, and the controller / processor 359 can be configured to perform aspects in connection with the CSI Tx component 140 of FIG. 2. Figure 1 At least one of the TX processor 316, the RX processor 370, and the controller / processor 375 can be configured to perform aspects in connection with the CSI Rx component 120 of FIG. 2.

[0106] Figure 4 FIG. 4 is a diagram 400 illustrating an example configuration of CSI resources. The UE 104 can be configured with CSI reporting configuration via RRC signaling. For example, for aperiodic CSI, the UE 104 can be configured with up to 128 trigger states per serving cell, each including one or more CSI reporting configurations. In each trigger state, for each CSI reporting configuration, there can be one active resource set from multiple resource sets. A medium access control (MAC) control element (CE) can select down to 64 active trigger states from the 128 configured trigger states. Downlink control information (DCI) can use a 6-bit CSI request in uplink-related DCI, such as DCI format 0 1, to trigger 1 trigger state from the 64 active trigger states.

[0107] The CSI reporting configuration 410 can include 1 non-zero power CSI-RS (NZP-CSI-RS) resource setting for channel measurement (CMR) 420. The CSI reporting configuration 410 can include 0 to 2 resource settings for interference measurement (IMR). For example, if 1 resource setting IMR is configured, the IMR can be a CSI-RS resource (CSI-IM) setting 430 or a NZP-CSI-RS setting 440 for interference measurement. If 2 resource settings IMR are configured, the IMR should be the CSI-IM setting 430 and the NZP-CSI-RS setting 440.

[0108] Each resource setting can be associated with one or more resource sets. For example, CMR 420 can be associated with NZP CMR resource set 422, CSI-IM 430 can be associated with CSI-IM resource set 432, and NZP IMR 440 can be associated with NZP IMR resource set 442. Each resource set can include one or more resources. For example, NZP CMR resource set 424 can include NZP CMR resource nl 426 (e.g., a first TCI state) and NZP CMR resource n2 428 (e.g., a second TCI state). Similarly, CSI-IM resource set 434 can include CSI-IM resource ml 436 and CSI-IM resource m2 438. Similarly, NZP IMR resource set 444 can include NZP IMR resource sl 446 and NZP IMR resource s2 448. There can be an association in terms of resources between CMR and CSI-IM. That is, NZP CMR resource nl 426 can be associated with CSI-IM resource ml 436, and NZP CMR resource n2 428 can be associated with CSI-IM resource m2 438. For NZP-CSI-RS IMR, any single port in the activated resource is assumed to be an interference layer. The UE can aggregate all interference layers in the CSI computation. In other words, each CMR resource can be associated with all NZP IMR resources.

[0109] Figure 5is a diagram illustrating an example CSI reporting schedule 500 for aperiodic CSI. UE 104 can communicate with base station 102 over a series of frames. In one implementation, each frame can include downlink slots 502, special slots 504, and one or more uplink slots 506. Some downlink slots 502 can include CSI-RS 510. Base station 102 can transmit PDSCH 520 on one or more downlink slots 502. The modulation and coding scheme (MCS) of PDSCH 520 can be based on previously reported CSI from UE 104. If UE 104 cannot decode PDSCH 520, UE 104 can generate a negative acknowledgement (NACK). In some cases, in addition to CSI feedback, base station 102 can adjust the MCS based on ACK / NACK, as CSI feedback can not be frequent. Specifically, if UE 104 transmits an ACK, base station 102 can increase the MCS by a certain level for the next transmission; if UE 104 transmits a NACK, base station 102 can decrease the MCS by another certain level for the next transmission. In one aspect, if the CSI becomes inaccurate, and if there are multiple consecutive PDSCHs to be delivered to the UE, it is likely that the UE will not be able to decode all of these consecutive PDSCHs, as there is no possible HARQ-ACK transmission after the first PDSCH fails, and the base station is not likely to update the MCS for the subsequent PDSCH transmissions. The UE can aggregate the NACKs in PUCCH 530 on one of the uplink slots 506. If base station 102 (e.g., gNB) receives one or more NACKs, base station 102 can determine that the CSI is outdated. For example, the channel quality indicator (CQI) can no longer be accurate. In response to the one or more NACKs, base station 102 can trigger an aperiodic CSI report. The base station can transmit uplink-related DCI 540 on one of the downlink slots 502 in the next frame to request aperiodic CSI feedback. The UE can measure one or more CSI-RS transmissions (e.g., periodic CSI-RS 510) no later than CSI reference resources 512, and generate a CSI report 550 for transmission on PUSCH in an uplink slot 506. Thus, aperiodic CSI can use at least one full frame from the first NACK to transmission of the CSI report.

[0110] Aperiodic CSI can not be flexible because aperiodic CSI is triggered via UL related DCI. In one aspect, the present disclosure provides greater flexibility by providing CSI feedback related to downlink DCI. The DCI can schedule a downlink PDSCH with a DMRS. The DCI can or can not indicate a CSI report. More DCI formats can be used, such as UL DCI 0_1 and DL DCI 1_1. The CSI can be transmitted on reserved uplink resources, not necessarily on dynamically scheduled PUSCH. In some implementations, the CSI can be measured or computed based on the DMRS, which can reduce the overhead of CSI resources. Using the DMRS can also enable a fast timeline. Furthermore, UE initiated CSI feedback can enhance rate control for high Doppler scenarios. For example, in Figure 5 In one aspect, the base station can control whether the UE reports CSI by sending a CSI request. The base station can trigger a new CSI report when it identifies outdated CSI based on a HARQ NACK. The procedure includes a latency between a failed PDSCH and an updated CSI.

[0111] Figure 6 FIG. 6 is a diagram illustrating an example CSI reporting schedule 600 for UE initiated CSI reporting. In one aspect, the present disclosure provides a shortened CSI reporting timeline compared to aperiodic CSI. According to UE initiated CSI reporting, the UE 104 can send a CSI report in response to a spectral efficiency of a downlink transmission satisfying a threshold. The UE 104 can measure the spectral efficiency based on a measurement resource, such as a CSI-RS 510 or any PDSCH 520, which can include a DMRS. For example, the DMRS can be interleaved with the PDSCH on different symbols in the time domain. The PDSCH 520 including the DMRS can be referred to as a PDSCH / DMRS 520. The time and frequency domain resources for the PDSCH / DMRS can be referred to as PDSCH / DMRS resources. The UE 104 can send the CSI report in an uplink slot 506 of the same frame as the HARQ-ACK. For example, the CSI report 550 can be sent in the same slot as the PUCCH 530, or in a later slot. Thus, UE initiated CSI reporting can reduce the duration of the CSI reporting timeline, enabling faster feedback and faster adaptation to channel conditions.

[0112] Figure 7is a diagram illustrating an example CSI reporting schedule 700 for CSI reporting initiated by a UE based on a CSI-RS. A frame can include a downlink slot 502, a special slot 504, and an uplink slot 506. The UE 104 can measure the CSI-RS 510 to determine a CQI or a corresponding feasible MCS. The base station can transmit a DCI 710 on a PUCCH in the downlink slot 502. The DCI 710 can be a downlink grant. In this example, the DCI 710 does not request a CSI report. The DCI 710 can schedule a PDSCH 520 with an MCS. In one aspect, the UE 104 can not be able to decode the PDSCH 520. The UE 104 can measure CSI including a CQI based on the CSI-RS 510. The UE 104 can determine to transmit a CSI report based on the measured CQI or feasible MCS. In some implementations, the CQI or feasible MCS can indicate a measured spectral efficiency, and the UE 104 can compare the measured spectral efficiency to a threshold. The threshold can be based on a spectral efficiency related to the indicated MCS and a rank of the scheduled PDSCH. For example, the threshold can be a threshold difference between the measured spectral efficiency and the spectral efficiency related to the indicated MCS and the rank of the scheduled PDSCH. The UE 104 can transmit a NACK on the PUCCH 530 and can transmit the CSI report 550 in the uplink slot 506.

[0113] Figure 8 is a diagram illustrating an example CSI reporting schedule 800 for CSI reporting initiated by a UE based on a PDSCH / DMRS. Similar to the example above, the frame can include a downlink slot 502, a special slot 504, and an uplink slot 506. The UE 104 can receive a DCI 710. The DCI 710 can be a downlink grant scheduling a PDSCH 520 including a DMRS. In this example, the DCI 710 does not request a CSI report. The UE 104 can measure the PDSCH 520 and the DMRS to determine CSI including a CQI or a corresponding MCS. In one aspect, the UE 104 can not be able to decode the PDSCH 520. The UE 104 can determine to transmit a CSI report based on the measurement. In some implementations, the measurement can be a measured spectral efficiency, such as a CQI or a feasible MCS. The UE 104 can compare the measured spectral efficiency to a threshold. The threshold can be based on a spectral efficiency related to the indicated MCS and a rank of the scheduled PDSCH. For example, the threshold can be a threshold difference between the measured spectral efficiency and the spectral efficiency related to the indicated MCS and the rank of the scheduled PDSCH. The UE 104 can transmit a NACK on the PUCCH 530 and can transmit the CSI report 550 in the uplink slot 506.

[0114] In one aspect, the UE 104 can selectively report CSI if the actual spectral efficiency (SE) measured from the CMR and / or IMR is one threshold value higher or lower than the SE of the scheduled PDSCH 520. The SE of the scheduled PDSCH can be based on the MCS indicated by the DCI 710. The actual SE can refer to the feasible MCS. The CQI can map the feasible MCS to an index. An MCS corresponding to a CQI index can be considered feasible if a single PDSCH transport block with a combination of modulation scheme, target code rate, and transport block size corresponding to the CQI index and occupying a set of downlink physical resource blocks referred to as the CSI reference resource can be received with a transport block error probability no more than a defined rate, such as 0.1 or 0.00001. In some implementations, the decision whether to send a CSI report can be based on the spectral efficiency of the measured MCS (MCS_meas) or the measured CQI (CQI_meas) compared to the spectral efficiency of the indicated MCS (MCS_indi). For example, the UE 104 can determine to send a CSI report if SE[MCS_meas or CQI_meas] - SE[MCS_indi] > a threshold or SE[MCS_meas or CQI_meas] - SE[MCS_indi] < a threshold. In some implementations, the decision whether to send a CSI report can also be based on the measured rank (Rank_meas). For example, the UE 104 can determine to send a CSI report if SE[MCS_meas or CQI_meas] * Rank_meas - SE[MCS_indi] * Rank_indi > a threshold or SE[MCS_meas or CQI] * Rank_meas - SE[MCS_indi] * Rank_indi < a threshold. In some implementations, the decision whether to send a CSI report can also be based on the measured precoding matrix indicator (PMI_meas). For example, the UE 104 can determine to send a CSI report if SE[MCS_meas or CQI_meas] * Rank_meas using PMI_meas - SE[MCS_indi] * Rank_indi > a threshold or SE[MCS_meas or CQI_meas] * Rank_meas using PMI_meas - SE[MCS_indi] * Rank_indi < a threshold. In some aspects, the SE function can be determined based on a table mapping MCS or CQI to spectral efficiency. For example, 3GPP TS 38.214 defines MCS tables 5.1.3.1-1, 5.1.3.1-2, and 5.1.3.1-3 and CQI tables 5.2.2.1-2, 5.2.2.1-3, and 5.2.2.1-4.In one aspect, in the above expression, the term SE[MCS_meas or CQI_meas] can refer to a spectral efficiency determined based on a table. The UE 104 can determine to transmit a CSI report if a difference between the measured spectral efficiency and a spectral efficiency indicated for PDSCH is greater than a threshold.

[0115] In one aspect, UE-initiated CSI reporting can be dynamically activated or deactivated. For example, the base station 102 can transmit an activation / deactivation command and the UE 104 can receive the activation / deactivation command. The activation / deactivation command can be a MAC-CE or DCI. In some implementations, an activation command activates UE-initiated CSI feedback until the UE receives a deactivation command. In some implementations, an activation command activates UE-initiated CSI feedback for multiple CSI reporting opportunities. For example, the activation command can indicate a number of uplink resources on which the UE can transmit UE-initiated CSI reports. The UE-initiated CSI feedback can end after the last possible CSI report without the UE receiving a deactivation command. The use of activation / deactivation commands can allow dedicated UL resources to be used for other purposes when UE-initiated CSI feedback is deactivated.

[0116] Figure 9 FIG. 9 is a diagram illustrating an example CSI reporting schedule 900 for CSI reporting triggered based on a CSI-RS based downlink grant. A frame can include a downlink slot 502, a special slot 504, and an uplink slot 506. The base station can transmit a DCI 710 on a PUCCH in the downlink slot 502. The DCI 710 can be a downlink grant scheduling a PDSCH 520. In this example, the DCI 710 can request a CSI report. The UE 104 can measure a CSI-RS 510 to determine CSI including any combination of CRI, RI, PMI, or CQI. In one aspect, the UE 104 can not be able to decode the PDSCH 520. In response to the request in the DCI 710, the UE 104 can transmit a NACK on the PUCCH 530 and can transmit a CSI report 550 in the uplink slot 506.

[0117] Figure 10is a diagram illustrating an example CSI reporting schedule 1000 for PDSCH / DMRS based downlink grant triggered CSI reporting. A frame can include a downlink slot 502, a special slot 504, and an uplink slot 506. A base station can transmit a DCI 710 on a PUCCH in the downlink slot 502. The DCI 710 can be a downlink grant scheduling a PDSCH 520. In this example, the DCI 710 can request a CSI report. The UE 104 can measure the PDSCH 520 and included DMRS to determine CSI including any combination of CRI, RI, PMI, or CQI. In one aspect, the UE 104 can not be able to decode the PDSCH 520. The UE 104 can transmit a NACK on the PUCCH 530 and can transmit a CSI report 550 in the uplink slot 506.

[0118] Figure 11 is a diagram 1100 illustrating an example configuration 1110 of CSI resources based on DMRS / PDSCH for channel measurement and one interference measurement resource. The CSI reporting configuration 1110 can include a DMRS / PDSCH resource setting 1120 for channel measurement as a CMR. The CSI reporting configuration 1110 can include 1 IMR, such as a DMRS / PDSCH resource setting 1130 for interference measurement, a NZP-CS-RS resource setting 1140 for interference measurement, or a CSI-IM resource setting 1150. If the IMR is a DMRS / PDSCH resource setting 1130 for interference measurement, the interference is a measurement of DMRS resource elements (REs) or PDSCH REs from a channel other than the set of DMRS ports that are transmitting the PDSCH or the channel that is transmitting the PDSCH. For example, let the received signal on the DMRS / PDSCH REs be denoted as y = H * x + n, where H is the channel, x is the pilot if it is a DMRS, x is the data if it is a PDSCH, and n is the interference plus noise. The measurement of the IMR for the DMRS / PDSCH can be the value of n. If the IMR is a CSI-IM 1150, there can be a one-to-one mapping between the CSI-IM resource and the DMRS / PDSCH resource setting 1120 for channel measurement.

[0119] Figure 12is a diagram 1200 illustrating an example configuration 1210 of CSI resources based on DMRS / PDSCH for channel measurement and two interference measurement resources. The CSI reporting configuration 1210 can include a DMRS / PDSCH resource setting 1120 for channel measurement as a CMR. The CSI reporting configuration 1110 can include 2 IMRs selected from a DMRS / PDSCH resource setting 1130 for interference measurement, a NZP-CS-RS resource setting 1140 for interference measurement, or a CSI-IM 1150.

[0120] Figure 13 is a diagram 1300 illustrating an example configuration 1310 of CSI resources based on DMRS / PDSCH for channel measurement and three interference measurement resources. The CSI reporting configuration 1310 can include a DMRS / PDSCH resource setting 1120 for channel measurement as a CMR. The CSI reporting configuration 1110 can include 3 IMRs: a DMRS / PDSCH resource setting 1130 for interference measurement, a NZP-CS-RS resource setting 1140 for interference measurement, and a CSI-IM resource setting 1150.

[0121] Figure 14 is a diagram illustrating an example mapping 1400 of CSI reporting configuration 1110 to uplink resources based on HARQ process number. Although the CSI reporting configuration 1110 including a DMRS / PDSCH resource setting 1120 for channel measurement and a DMRS / PDSCH resource setting 1130 for interference measurement is shown, similar mapping can be used for CSI reporting configurations 1210 and 1310. The DMRS / PDSCH resource setting 1120 for channel measurement can include DMRS / PDSCH for two or more HARQ process numbers 1440, 1442. Each HARQ process number 1440, 1442 can be associated with a respective uplink reserved resource 1450, 1452. Thus, when the UE transmits a CSI report on the uplink reserved resource 1450, 1452, the base station 102 can determine the corresponding HARQ process number and DMRS / PDSCH based on the uplink reserved resource 1450, 1452. The DMRS / PDSCH resource setting 1130 for interference measurement can also be associated with each of the two or more HARQ processes 1440, 1442.

[0122] Figure 15is a diagram illustrating an example mapping 1500 of CSI report configurations to uplink resources. The UE 104 can be configured with CSI report configurations 1110, 1112 for each HARQ process number. Again, although the CSI report configuration 1110 is shown to include a DMRS / PDSCH resource setting 1120 for channel measurement and a DMRS / PDSCH resource setting 1130 for interference measurement, similar mappings can be used for the CSI report configurations 1210 and 1310. The first CSI report configuration 1110 can include a DMRS / PDSCH resource setting 1120 for channel measurement and a DMRS / PDSCH resource setting 1130 for interference measurement, each of which can be related to a first HARQ process number 1440. The first HARQ process number 1440 can be related to a first uplink reserved resource 1450. Similarly, the second CSI report configuration 1112 can include a DMRS / PDSCH 1122 for channel measurement and a DMRS / PDSCH 1132 for interference measurement, each of which can be related to a second HARQ process number 1442. The second HARQ process number 1442 can be related to a first uplink reserved resource 1452. Thus, due to the mapping 1500, when the UE transmits CSI reports on the uplink reserved resources 1450, 1452, the base station 102 can determine the corresponding HARQ process number and DMRS / PDSCH based on the uplink reserved resources 1450, 1452.

[0123] Figure 16Figure 1600 illustrates an example of a CSI report indicating an associated HARQ procedure number. For example, a frame may include downlink time slot 502, special time slot 504, and uplink time slot 506. UE 104 may receive DMRS / PDSCH 1620 and 1622 in two time slots within downlink time slot 502, each DMRS / PDSCH associated with a different HARQ procedure. UE 104 may transmit a HARQ-ACK for each of DMRS / PDSCH 1620 and 1622 in PUCCH 530. The UE may transmit two CSI reports 1650 and 1652 in the corresponding UL resources. In one aspect, there may not be a specific mapping between HARQ procedure numbers and uplink resources. UE 104 may provide the HARQ procedure number along with the CSI report. If there is no mapping between HARQ procedure numbers and uplink resources, each of CSI reports 1650 and 1652 may include an indication of the corresponding HARQ procedure number. Therefore, base station 102, which receives CSI reports 1650 and 1652, can determine the corresponding DMRS / PDSCH 1620 and 1622. If the uplink resources used to carry CQI are specific to each HARQ procedure number, the CSI report may not include an indication of the corresponding HARQ procedure number.

[0124] As mentioned above, for example, regarding Figure 7 and 9 CSI-RS can also be used as CMR. In this case, refer to Figure 4 The described CSI report configuration 410 can be used for UE-initiated CSI feedback or downlink-permission-based CSI feedback. The CSI used for CSI-RS-based reporting can include CRI, PMI, RI, CQI, or any combination thereof configured in CSI report configuration 410.

[0125] In some implementations, the CSI reporting 550 based on UE-initiated CSI feedback or CSI feedback based on downlink grant can utilize capacity-limited uplink resources. The number of bits transmitted in the CSI reporting 550 can be reduced compared to traditional CSI reporting based on uplink grant. For example, in some implementations, the CSI reporting 550 can be a single bit. In one aspect, the single bit, when transmitted, can indicate that the feasible MCS based on the measurements is much less than the configured MCS of the associated PDSCH. That is, MCS meas - MCS indi < threshold, where the threshold is negative. In another implementation, the single bit, when transmitted, can indicate that the measured MCS is much higher than the indicated MCS. In yet another implementation, the single bit, when transmitted, can indicate that the measured MCS is not much different from the indicated MCS, i.e., |MCS meas - MCS indi | > threshold. In one aspect, the comparison of MCS and / or CQI can be based on spectral efficiency. For example, the MCS and / or CQI can be converted to spectral efficiency using the table described above. In another aspect, the single bit can be one of two states (e.g., 0 or 1). The first state can indicate that the feasible MCS is much less than the configured MCS of the associated PDSCH. That is, MCS meas - MCS indi < threshold, where the threshold is negative. The second state can indicate that the feasible MCS is much higher than the configured MCS of the associated PDSCH, i.e., MCS meas - MCS indi > threshold, where the threshold has a positive value. The single-bit CSI reporting can provide only CQI. In some implementations, the single-bit CSI can take into account the rank indicator (RI) as discussed above with respect to reporting thresholds. The single-bit CSI reporting can not account for PMI.

[0126] In some implementations, the CSI reporting 550 can include an explicit CQI report. For example, the CSI reporting 550 can represent the CQI as a 4-bit index of a CQI table or a 2-bit difference from a previously reported CQI value. The CSI reporting 550 can also include an RI indicating the rank used to determine the reported CQI.

[0127] For both UE-initiated CSI reporting and CSI reporting based on DL grant, the base station 102 can configure dedicated uplink resources. In some implementations, the dedicated uplink resources can be PUCCH and / or PUSCH resources. For example, the base station 102 can transmit an RRC configuration message to configure a list of PUCCH or PUSCH resource configurations. Each resource configuration can include at least a frequency domain resource allocation (FDRA), a PUCCH format, and a time domain resource allocation (TDRA). The FDRA can indicate one or more resource elements (REs). The TDRA can indicate a starting symbol and a length in a slot.

[0128] UE 104 can select resources from a list of PUCCH or PUSCH resource configurations used for CSI reporting. For example, in some implementations, UE 104 can determine the PUCCH / PUSCH resource based on either the reporting / resource configuration or the trigger state configuration. There may be a one-to-one mapping between CSI PUCCH / PUSCH and reporting / resource / trigger state configurations. For example, as... Figure 15 As shown, UL reserved resource 1450 can be mapped to CSI report configuration 1110 or DMRS / PDSCH resource setting 1120. In some implementations, PUCCH / PUSCH resources can be determined based on the HARQ-ACK process number. For example, as... Figure 14 As shown, there may be a one-to-one mapping between the CSI PUCCH / PUSCH (e.g., UL resource 1450) and the HARQ-ACK process number 1440. In some implementations, the PUCCH / PUSCH resources are determined via a dedicated field in the DL license. In some implementations, the PUCCH / PUSCH resources used for CSI feedback are based on a resource aspect (one-to-one) mapping to the PUCCH resources used for HARQ-ACK, and the actual PUCCH / PUSCH used for CSI feedback is determined based on the traditional PUCCH resource indicator field provided in the DL DCI. For example, the codepoint in the DL DCI indicates a pair of PUCCH resources for HARQ-ACK and a PUCCH / PUSCH resource for CSI.

[0129] Figure 17is a diagram illustrating an example CSI reporting schedule 1700 for PUCCH or PUSCH resources for UE-initiated CSI. The UE 104 can determine the slot of the PUCCH / PUSCH carrying the CSI report 550 based on the measurement resource. For UE-initiated CSI reporting, the measurement resource can be the PDSCH / DMRS 520. In some implementations, the periodicity and slot offset (relative to slot 0) can be configured via RRC along with the resource configuration. For example, the reserved uplink resources can be configured as configured grant PUSCH or PUCCH resources similar to PUCCH-CSI resources for periodic CSI reporting. As shown, for example, the tenth slot 1710 (slot offset = 9; periodicity (T) = 1 frame) can be configured as a reserved uplink resource. The CSI report 550 can be transmitted on the PUCCH / PUSCH resource on slot s, s+T, s+2T, etc. The UE can transmit the CSI report via the nearest PUCCH that satisfies the CSI timeline. The CSI timeline specifies a minimum gap (Z’) between the UL resource carrying the CSI and the measurement resource, and can also specify a minimum gap (Z) between the UL resource carrying the CSI and the CSI request.

[0130] Figure 18 is a diagram illustrating an example CSI reporting schedule 1800 for PUCCH / PUSCH resources for downlink granted CSI. Similar to the CSI reporting timeline 1700, the tenth slot 1710 (s = 9, T = 1 frame) can be configured as a reserved uplink resource. For downlink granted based CSI, the measurement resource can be the PDSCH / DMRS 520 or CSI-RS 510 after the downlink grant 710. Thus, the PDSCH / DMRS 520 or CSI-RS 510 based CSI report 550 can be transmitted in the tenth slot 1710.

[0131] In some implementations, the slot of the PUCCH carrying the CSI is determined by a slot offset relative to a reference slot. The reference slot can be the slot of the DL-DCI 510, the DMRS / PDSCH 520, or the HARQ-ACK 530. The slot offset can be indicated via a dedicated field in the DL-DCI or via the PDSCH-to-HARQ feedback timing indicator field in the DL-DCI. For example, a codepoint in the PDSCH-to-HARQ feedback timing indicator field can indicate a pair {k0, k0’}, and a list of paired candidates can be provided by RRC. k0 can be the scheduling offset of the HARQ-ACK relative to the PDSCH / DMRS. As discussed herein, k0’ can be the offset of the CSI feedback relative to the reference slot.

[0132] Figure 19is a diagram illustrating an example CSI reporting schedule 1900 that is based on a slot offset (k0') 1910 relative to a downlink grant as a reference slot. A frame can include downlink slots 502, special slots 504, and uplink slots 506. A measurement resource can be a CSI-RS 510 or a DMRS / PDSCH 520. The UE 104 can transmit a HARQ-ACK on a PUCCH 530 in an uplink slot 506 based on a k0 offset with the DMRS / PDSCH 520. The UE 104 can transmit a CSI report 550 in an uplink slot 506 based on a k0' slot offset with the downlink grant 710.

[0133] Figure 20 is a diagram illustrating an example CSI reporting schedule 2000 that is based on a slot offset k0' 2010 relative to a PDSCH / DMRS 520 as a reference slot. A frame can include downlink slots 502, special slots 504, and uplink slots 506. A k0 offset for HARQ-ACK and a k0' offset for CSI reporting can be measured from the PDSCH / DMRS 520.

[0134] Figure 21 is a diagram illustrating an example CSI reporting schedule 2100 that is based on a slot offset 2110 relative to a HARQ-ACK slot as a reference slot. A frame can include downlink slots 502, special slots 504, and uplink slots 506. A HARQ-ACK can be transmitted on a PUCCH 530 in an uplink slot 506 based on a k0 offset with a PDSCH / DMRS 520. An additional k0' offset 2110 can be measured from a slot of the PUCCH 530 to determine a slot for a CSI report 550.

[0135] In another aspect, the reserved uplink resources can be scheduling request (SR) resources. The SR resources can be used for UE-initiated CSI feedback. The base station 102 can configure the UE 104 with SR resources to use to request an uplink grant. The SR resources can be PUCCH resources defined by a periodicity and a slot and symbol offset. The UE 104 can determine the SR resources for CSI reporting per reporting or resource configuration, per HARQ process number, or via a dedicated field in the downlink grant. In one implementation, the SR resources for CSI feedback can be mapped to PUCCH resources for HARQ-ACK in terms of resources (i.e., one-to-one), and the PUCCH resources for CSI feedback can be determined based on a PUCCH resource indicator field included in the downlink grant. For example, a codepoint in the downlink grant can indicate a pair of PUCCH resources for HARQ-ACK and a SR resource for CSI.

[0136] Figure 22 FIG. 22 is a diagram illustrating an example CSI reporting schedule 2200 showing SR resources 2250. A frame can include downlink slots 502, special slots 504, and uplink slots 506. The SR resources 2250 for CSI reporting can be determined based on a reporting configuration of PDSCH / DMRS 520, a measurement resource configuration, or a HARQ process number. In some implementations, a downlink grant can include a codepoint that defines resources for both PUCCH 530 and SR resources 2250. In one aspect, the SR resources 2250 can be a single resource element and can only be able to carry one or two bits. As described above, the UE 104 can transmit a CSI report including a single-bit CQI indication, which can be transmitted on the SR resources 2250.

[0137] Figure 23 FIG. 23 is a diagram illustrating an example CSI reporting schedule 2300 showing SR resources 2250 and PUCCH / PUSCH resources 2350. Adding the PUCCH / PUSCH resources 2350 to the SR resources 2250 can allow for transmission of larger CSI reports, including, for example, full CQI, PMI, and RI. In this example, the SR resources 2250 are used to indicate to the base station that the UE 104 will transmit a CSI report. The slots of the PUCCH / PUSCH resources 2350 can be configured by a slot offset 2352 from the slots of the SR resources 2250. That is, there can be a one-to-one mapping between the SR resources 2250 and the dedicated PUCCH / PUSCH resources 2350. The gap (i.e., slot offset 2352) between the SR resources 2250 and the dedicated PUCCH / PUSCH resources 2350 can be fixed (e.g., defined by a standard document or specification) or RRC configured.

[0138] Figure 24 is a diagram illustrating an example two-step random access (RACH) message 2400 for CSI reporting. Dedicated two-step RACH resources can be configured for UE-initiated CSI feedback. The two-step RACH message can be a RACH msgA and include a msgA preamble 2410 and a msgA payload 2420. The msgA preamble 2410 can include transmitting a preamble on a PRACH 2412. The preamble can be used to identify the UE 104. For example, the preamble can be a contention-free random access preamble assigned to the UE 104. The msgA preamble 2410 can also include a guard time (GT) 2414. The msgA preamble 2410 can be separated from the msgA payload by a transmission gap (TxG) 2416. The msgA payload 2420 can be transmitted on a PUSCH resource. The msgA payload 2420 can carry a UE-initiated CSI report 2422. The CSI report 2422 can be in addition to or in place of the RACH msgA content. The msgA payload 2420 can also include a guard period (GP) 2424.

[0139] In one aspect, UE-initiated CSI feedback using reserved uplink resources and DL grant-based CSI feedback can be applicable when the UE fails to decode a downlink PDSCH. That is, a decoding failure can result in a negative acknowledgement (NACK). If the UE 104 successfully decodes the PDSCH and reports an ACK for the HARQ-ACK process, the UE can not report CSI in the reserved UL resources. The base station 102 can receive the ACK and determine not to decode the reserved uplink resources. If the UE fails to decode the PDSCH and reports a NACK for the HARQ-ACK process, the UE can selectively report CSI in the reserved UL resources. For example, as described above, the UE can report CSI in the reserved UL resources based on measurements satisfying a threshold, or based on an indication in the downlink grant. In some implementations, upon receiving the NACK, the base station 102 can only decode the CSI on the reserved uplink resources.

[0140] In one aspect, both UE-initiated CSI feedback and DL grant-based CSI can implement measurements on DMRS / PDSCH for CSI, which can provide greater flexibility in scheduling CSI reporting and shorten the feedback timeline. The definition of DMRS / PDSCH-based CSI can be different from CSI-RS-based CSI.

[0141] For DMRS-based CSI feedback, the reference resource for CQI reporting is the slot where DMRS / PDSCH is transmitted. The overhead assumption for CQI computation follows the actual transmitted signal in the CSI reference resource (i.e., the slot where DMRS / PDSCH is transmitted), or is based on the default assumption specified in TS 38.214 section 5.2.2.5. The overhead refers to the number of control channels, the number of DMRS+PDSCH symbols, the bandwidth part subcarrier spacing, the bandwidth, the CP length, the presence of CSI-RS or PBCH or SSB, etc.

[0142] The CSI reporting band for DMRS-based CSI is equal to the frequency domain allocation of DMRS / PDSCH for the UE. For DMRS-based CSI, only wideband CSI including CQI and RI can be reported, and the wideband is defined with respect to the FDRA of DMRS / PDSCH. If RBG / PRG level CQI is reported, the PRG / RBG is the same as DMRS / PDSCH used for CSI measurement, or is configured separately in the CSI reporting setting.

[0143] Figure 25 FIG. 2500 is a diagram 2500 illustrating an example CSI process unit (CPU) occupancy duration and active DMRS duration for a CSI process. The total number of CPUs and active DMRS ports depends on the UE capability. That is, the UE 104 is capable of determining a limited number of CSI simultaneously based on the number of CPUs, and can have a limited number of DMRS ports. For DMRS-based CSI feedback, the CPU occupancy is equal to 1 per DMRS / PDSCH resource. The CPU occupancy time starts from the first symbol of the earliest DMRS / PDSCH 520 used for channel measurement and the resource used for interference measurement, and ends at the last symbol of the UL channel carrying the CSI report 550. For DMRS-based CSI feedback, the DMRS ports are referred to as active, and these ports are active from the earliest symbol of the DMRS / PDSCH 520 used for channel measurement or interference measurement to the last symbol of the UL channel carrying the CSI report 550. Thus, the UE 104 and / or the base station 102 can determine whether the UE has resources to compute CSI based on the UE capability and other scheduled CSI computation.

[0144] In one aspect, the UE 104 can use an amount of time to compute CSI and generate a CSI report. Although the present disclosure provides a faster CSI reporting timeline, there can be a minimum amount of time for the UE to generate a CSI report between the measurement resource and the CSI report. Figure 26is a diagram illustrating an example CSI processing timeline 2600. A frame can include downlink slots 502, special slots 504, and uplink slots 506. A CSI report 550 can be based on PDSCH / DMRS 520. A minimum amount of time between PDSCH / DMRS 520 and the CSI report can be defined as a number of symbols (Z’) 2610. For feedback based on a downlink grant, there can also be a minimum amount of time between the downlink grant (e.g., DCI 710) and the CSI report. The minimum amount of time between DCI 710 and the CSI report can be defined as a number of symbols (Z). The minimum amount of time can depend on whether there are multiple CSI reports using CPU or DMRS resources and the complexity of the CSI computation. The latest symbol of the DMRS / PDSCH 520 used for channel / interference measurement should be at least Z’ symbols earlier than the first symbol of the uplink channel carrying the CSI report 550. If there is a single CSI report to send, or if there is a single CSI during the activation time of the DMRS, Z’ can follow the fast timeline of Table 1.

[0145] Table 1

[0146]

[0147] If the conditions of the fast timeline are not met, Z’ follows the slow timeline according to Table 2, where Z’ can be a Z1’ or Z2’ value.

[0148] Table 2

[0149]

[0150] Z’1 can be used for wideband CSI with 4 or fewer DMRS ports, single resource, and Type 1 CSI without PMI. Z’3 can be used for beam management. Z’2 can be used for all other cases.

[0151] If the CSI is transmitted on the same slot as HARQ-ACK, or in the same PUCCH as HARQ-ACK, the CSI timeline should follow the maximum of the Z’ and the timeline of HARQ-ACK, e.g., N1 value.

[0152] When multiple reports are scheduled on the same resource, a conventional CSI report can be associated with a priority for determining which reports to send. The priority of a CSI report can be based on a function of the CSI report trigger (y), the CSI report content (k), the serving cell index, and the report configuration ID. Two CSI reports are considered to be in conflict if the time occupancy of the physical channel scheduled to carry the CSI reports overlap in at least one OFDM symbol and are transmitted on the same carrier. When a UE is configured to send two conflicting CSI reports, the UE can determine whether to multiplex or drop one or more CSI reports based on the priority.

[0153] In one aspect of the disclosure, the priority function can be computed using the resource type used for channel measurement, or based on whether the CSI is UE initiated CSI, or based on whether the A-CSI is transmitted on PUCCH. DMRS / PDSCH based CSI or UE initiated CSI can be set to have the highest priority or the lowest priority. For example, to set DMRS / PDSCH based CSI or UE initiated CSI to the highest priority, the priority function can be defined as: Pri(x, y, k, c, s) = 4 · 2 · N_cells · M_s · x + 2 · N_cells · M_s · y + N_cells · M_s · k + M_s · c + s, where x is equal to 0 if it is DMRS / PDSCH based CSI or UE initiated CSI, and x is equal to 1 if it is non-DMRS / PDSCH based CSI (or non-UE initiated CSI). Alternatively, the CSI report trigger type (y) can be extended to include a value for DMRS / PDSCH based CSI or UE initiated CSI. For example, to set DMRS / PDSCH based CSI or UE initiated CSI to the highest priority, the priority function can be defined as: Pri(y, k, c, s) = 2 · N_cells · M_s · y + N_cells · M_s · k + M_s · c + s, where y is equal to 0 if the CSI is DMRS / PDSCH based CSI or UE initiated CSI, y is equal to 1 if the A-CSI is CSI-RS based; y is equal to 2 for SP-CSI based on CSI-RS on PUSCH; y is equal to 3 for SP CSI based on CSI-RS on PUCCH; and y is equal to 4 for P-CSI based on CSI-RS.

[0154] In contrast, the priority function can be defined to set DMRS / PDSCH based CSI or UE initiated CSI as the lowest priority. For example, to set DMRS / PDSCH based CSI or UE initiated CSI as the lowest priority, the priority function can be defined as: Pri(x, y, k, c, s) = 4 · 2 · N cells · M s · x + 2 · N cells · M s · y + N cells · M s · k + M s · c + s, where x is equal to 0 if the CSI is non-DMRS / PDSCH based CSI or non-UE initiated CSI, and x is equal to 1 if it is DMRS / PDSCH based CSI or UE initiated CSI. As another example, the CSI report trigger type (y) can be extended to include a value for DMRS / PDSCH based CSI or UE initiated CSI. For example, to set DMRS / PDSCH based CSI or UE initiated CSI as the lowest priority, the priority function can be defined as: Pri(y, k, c, s) = 2 · N cells · M s · y + N cells · M s · k + M s · c + s, where y is defined as values 0, 1, 2, and 3 as previously described; and y is equal to 4 for DMRS / PDSCH based CSI or UE initiated CSI. If DMRS / PDSCH based CSI or UE initiated CSI collides with other aperiodic, semi-persistent, or periodic CSI measured on CSI-RS, one of them is dropped depending on which has lower priority. For example, aperiodic CSI on PUCCH can have lower priority than semi-persistent CSI on PUSCH, but higher priority than semi-persistent CSI on PUCCH. For example, using the priority function described above, y can be equal to 0 for aperiodic CSI on PUSCH; y can be equal to 1 for semi-persistent CSI on PUSCH; y can be equal to 2 for aperiodic CSI on PUCCH; and y can be equal to 4 for periodic CSI based on CSI-RS. If aperiodic CSI on PUCCH collides with aperiodic CSI on PUSCH or semi-persistent CSI on PUSCH, the aperiodic CSI on PUCCH can be dropped. If aperiodic CSI on PUCCH collides with semi-persistent CSI on PUCCH or periodic CSI on PUCCH, the colliding CSI can be multiplexed, partially omitted, or dropped based on the priority order from high to low.

[0155] Figure 27 FIG. 2700 is a diagram 2700 illustrating example communications and components of a base station 102 and a UE 104. The UE 104 can include a CSI Tx component 140. The base station 102 can include a CSI Rx component 120.

[0156] As discussed with reference to Figure 1 The CSI Tx component 140 can include a configuration component 141, an activation component 142, a grant component 143, a triggering component 144, a measurement component 145, a resource component 146, and a reporting component 147. The CSI Tx component 140 can also include a receiver component 2770 and a transmitter component 2772. The receiver component 2770 can include, for example, a radio frequency (RF) receiver for receiving signals described herein. The transmitter component 2772 can include, for example, a RF transmitter for transmitting signals described herein. In some implementations, the receiver component 2770 and the transmitter component 2772 can be co-located in a transceiver.

[0157] The CSI Rx component 120 can include a configuration component 122, a scheduling component 124, and a reporting reception component 126 as described above with reference to Figure 1 The CSI Rx component 120 can also optionally include an activation component 123 and a resource component 125. The CSI Rx component 120 can also include a receiver component 2750 and a transmitter component 2752. The receiver component 2750 can include, for example, a RF receiver for receiving signals described herein. The transmitter component 2752 can include, for example, a RF transmitter for transmitting signals described herein. In some implementations, the receiver component 2750 and the transmitter component 2752 can be co-located in a transceiver.

[0158] The configuration component 124 at the base station 102 can configure the UE 104 with a CSI reporting configuration 2710, which can correspond to any of the CSI reporting configurations 410, 1110, 1210, or 1310. The UE 104 can transmit the CSI reporting configuration 2710 as an RRC configuration message.

[0159] The activation component 123 at the base station 102 can transmit an activation / deactivation command 2720. The activation / deactivation command 2720 can activate or deactivate UE-initiated CSI reporting. The activation / deactivation command 2720 can be a MAC-CE.

[0160] The scheduling component 124 can transmit a downlink grant 710 scheduling the PDSCH / DMRS 520. In some implementations, the downlink grant 710 can include a CSI reporting request.

[0161] The transmitter component 2752 can transmit the PDSCH / DMRS 520 and the CSI-RS 510.

[0162] The reporting reception component 126 can receive the CSI report 550 transmitted by the UE 104.

[0163] The configuration component 141 at the UE 104 can receive a CSI reporting configuration 2710.

[0164] The activation component 142 at the UE 104 can receive an activation / deactivation command 2720. The activation component 142 can determine whether UE-initiated CSI feedback is active based on the activation / deactivation command 2720.

[0165] The grant component 143 can receive a downlink grant 710. The grant component 143 can determine resources for a PDSCH / DMRS 520 based on the downlink grant 710.

[0166] The measurement component 145 can perform measurements of the PDSCH / DMRS 520 and / or CSI-RS 510 based on the CSI reporting configuration 2710 and the downlink grant 710.

[0167] The trigger component 144 can determine whether a CSI report has been triggered based on the downlink grant 710 and the measurements of the PDSCH / DMRS 520 and / or CSI-RS 510.

[0168] The resource component 146 can determine uplink resources for reporting a UE-initiated CSI report or a downlink grant-based CSI report.

[0169] The reporting component 147 can generate a CSI report 550 for transmission on the uplink resources. The reporting component 147 can format the CSI report 550 based on the uplink resources, e.g., by basing the size of the CQI field. The reporting component 147 can determine the content of the CSI report 550. For example, the CSI report 550 can include one or more of: a CQI 2740, an RI 2742, a PMI 2744, a HARQ process number 2746, or a resource indicator 2748. If there is a conflict between different CSI reports, the reporting component 147 can determine whether to drop a CSI report based on the priority of the CSI report.

[0170] Figure 28 is a conceptual data flow diagram 2800 illustrating the data flow between different means / components in an example base station 2802, which can be an example of the base station 102 including the CSI Rx component 120.

[0171] The receiver component 2750 can receive uplink signals from the UE 104, including the CSI report 550 and the HARQ ACK / NACK 2730. In some implementations, the receiver component 2750 can receive the UE capability. The receiver component 2750 can provide the CSI report to the report reception component 126. The receiver component 2750 can provide the HARQ ACK / NACK 2730 to the scheduling component 124. The receiver component 2750 can provide the UE capability to the configuration component 122.

[0172] The report reception component 126 can receive the CSI report from the receiver component 2750. The report reception component 126 can extract content from the CSI report based on a format of the CSI report. For example, the report reception component 126 can determine a CQI, an RI, or a PMI. The report reception component 126 can also determine measurement resources corresponding to the CSI report based on a CSI report configuration or an indicator within the CSI report. The report reception component 126 can provide the CQI, the RI, and / or the PMI to the scheduling component 124.

[0173] The configuration component 122 can determine one or more CSI report configurations for the UE 104. For example, the configuration component 122 can determine the CSI report configurations based on a UE capability of the UE 104, such as a number of CPUs and a number of DMRS ports. The configuration component 122 can provide the CSI report configurations to the scheduling component 124 and the resource component 125.

[0174] The resource component 125 can select reserved uplink resources on which the UE 104 can transmit the CSI report. The configuration component 122 can configure the receiver component 2750 to monitor the reserved uplink resources.

[0175] The scheduling component 122 can receive the CSI reporting configuration from the configuration component 122. The scheduling component 122 can receive the HARQ ACK / NACK from the receiver component 2750. The scheduling component 122 can receive the CQI, the RI, and / or the PMI from the report receiving component 126. The scheduling component 122 can determine resources for transmitting the PDSCH / DMRS 520. For example, the scheduling component 122 can determine whether to transmit a retransmission or new data based on the HARQ ACK / NACK. The scheduling component 122 can determine an MCS for the PDSCH / DMRS 520 based on the CQI, the RI, and / or the PMI. In some implementations, the scheduling component 122 can determine whether to request a CSI report. For example, the scheduling component 122 can request a CSI report in response to a HARQ NACK. The scheduling component 122 can generate a downlink grant 710 indicating the resources for the PDSCH / DMRS 520. In some implementations, the downlink grant 710 can request a CSI report. The scheduling component 124 can transmit the downlink grant via the transmitter component 2752.

[0176] The activation component 123 can generate an activation / deactivation command 2720. For example, the activation component 123 can determine to activate UE-initiated CSI feedback in response to high Doppler for the UE or based on changes in a periodic CSI report. Conversely, the activation component 123 can determine to deactivate UE-initiated CSI feedback if there are few changes in the periodic CSI report or if a threshold time has passed since the UE initiated the CSI report.

[0177] Figure 29 is a conceptual data flow diagram 2900 illustrating the data flow between different means / components in an example UE 2904, which can be an example of the UE 104, and includes the CSI Tx component 140.

[0178] The receiver component 2770 can receive uplink signals, such as the CSI reporting configuration message 2610, the activation / deactivation command 2720, the downlink grant 710, the PDSCH / DMRS 520, and the CSI-RS 510. The receiver component 2770 can provide the CSI reporting configuration message 2610 to the configuration component 141. The receiver component 2770 can provide the activation / deactivation command 2720 to the activation component 142. The receiver component 2770 can provide the downlink grant 710 to the grant component 143. The receiver component 2770 can provide the PDSCH / DMRS 520 and / or the CSI-RS 510 to the measurement component 145.

[0179] The configuration component 141 can receive the CSI report configuration message 2610 from the receiver component 2770. The configuration component 141 can store one or more CSI report configurations 410, 1110, 1210, 1310. The configuration component 141 can configure the measurement component 145 to measure the measurement resources based on the CSI report configuration. The configuration component 141 can also configure the resource component 146 with the reserved uplink resources indicated by the CSI report configuration.

[0180] The activation component 142 can receive an activation / deactivation command 2720, which can be a MAC-CE. The activation component 142 can determine whether the UE-initiated CSI report is activated or deactivated based on the activation / deactivation command 2720. The activation component 142 can provide the activation status to the trigger component 144.

[0181] The grant component 143 can receive the downlink grant 710 from the receiver component 2770. The grant component 143 can determine whether the downlink grant 710 requests a CSI report. The grant component 143 can provide the CSI request to the trigger component 144. The grant component 143 can also provide an indication of the measurement resources to the measurement component 145. Specifically, the grant component 143 can indicate when the UE 104 is scheduled to receive the PDSCH / DMRS 520 to be measured for the CSI report.

[0182] The measurement component 145 can receive signals received on the measurement resources (e.g., PDSCH / DMRS 520 or CSI-RS 510) from the receiver component 2770. The measurement component 145 can determine various measurements based on the signals received on the measurement resources. Specifically, the measurement component 145 can determine a feasible MCS and / or CQI measurement. The measurement component 145 can provide the measurements to the trigger component 144.

[0183] The trigger component 144 can determine whether to transmit a CSI report based on the CSI report configuration, the activation status, the downlink grant 710, and / or the measurements. For example, the trigger component 144 can determine to transmit a CSI report in response to the grant component 143 indicating a CSI request. As another example, the trigger component 144 can determine to transmit a CSI report in response to the activation component 142 indicating an activation status and the measurements satisfying a threshold. For example, the trigger component 144 can determine to transmit a UE-initiated CSI report when a measured spectral efficiency of a downlink measurement resource differs from a spectral efficiency indicated for a PDSCH by more than a threshold. The trigger component 144 can provide the CSI signal to the resource component 146 indicating that the CSI report is to be transmitted.

[0184] The resource component 146 can receive the reserved uplink resources from the configuration component 141. The resource component 146 can receive the CSI signal from the trigger component 144. The resource component 146 can select an uplink resource from the reserved uplink resources for transmitting the CSI report. In some implementations, where the CSI report configuration can associate the reserved uplink resources with measurement resources or HARQ process numbers, the resource component 146 can select the relevant resources. In other implementations, the resource component 146 can select the next available uplink resource. The resource component 146 can provide the selected uplink resource to the reporting component 147.

[0185] The reporting component 147 can receive the measurements from the measurement component 145 and the selected uplink resource from the resource component 146. The reporting component 147 can generate the CSI report based on the measurements and the selected uplink resource. For example, the reporting component 147 can determine the content of the CSI report based on the number of available bits of the selected uplink resource. The reporting component 147 can also determine collisions with other CSI reports and determine which CSI reports to transmit based on a priority function for each CSI report.

[0186] Figure 30 is a flowchart of an example method 3000 for a UE reporting CSI on a selected uplink reserved resource. The method 3000 can be performed by a UE, such as the UE 104, which can include the memory 360 and can be the entire UE 104 or a component of the UE 104, such as the CSI Tx component 140, the Tx processor 368, the RX processor 356, or the controller / processor 359. The method 3000 can be performed by the CSI Tx component 140 in communication with the CSI Rx component 120 of the base station 102. Optional blocks are indicated by dashed lines.

[0187] At block 3010, the method 3000 can optionally include receiving one or more CSI reporting configurations related to one or more resource settings. In some implementations, for example, the UE 104, RX processor 356, or controller / processor 359 can execute the CSI Tx component 140 or the configuration component 141 to receive one or more CSI reporting configurations 410, 1110, 1210, or 1310 related to one or more resource settings 1120, 1130, 1140, 1150. In some implementations, the CSI reporting configuration includes a CMR. The CMR can be a DMRS. In some implementations, the CSI reporting configuration includes an IMR. The IMR can be a DMRS. Specifically, if the IMR is a DMRS / PDSCH resource setting 1130 for interference measurement, the interference is a measurement from DMRS resource elements (REs) other than the channel transmitting the DMRS port. In some implementations, the CSI reporting configuration defines a reserved uplink resource 1450, 1452 per CMR Figure 14 ) or per HARQ process number Figure 15 ). In some implementations, the CSI reporting is linked to a single uplink resource and that uplink resource can be used for DMRS / PDSCH related to any HARQ process number, e.g., the uplink resource can be used for process number 1 or process number 2. But the UE needs to report the HARQ process number with the CSI reporting; otherwise, the base station can not be able to determine which DMRS is related to the CSI reporting. Thus, the UE 104, RX processor 356, or controller / processor 359 executing the CSI Tx component 140 or the configuration component 141 can provide means for receiving one or more CSI reporting configurations related to one or more resource settings.

[0188] At block 3020, the method 3000 can optionally include receiving a downlink grant scheduling a PDSCH and a DMRS. In some implementations, for example, the UE 104, RX processor 356, or controller / processor 359 can execute the CSI Tx component 140 or the grant component 143 to receive a downlink grant 710 scheduling a PDSCH / DMRS 520. Thus, the UE 104, RX processor 356, or controller / processor 359 executing the CSI Tx component 140 or the grant component 143 can provide means for receiving a downlink grant scheduling a PDSCH and a DMRS.

[0189] At block 3030, the method 3000 can include determining to transmit a CSI report based on the PDSCH and the DMRS. In some implementations, for example, the UE 104, the TX processor 368, or the controller / processor 359 can execute the CSI Tx component 140 or the trigger component 144 to determine to transmit the CSI report 550 based on the PDSCH or the DMRS. For example, determining to transmit the CSI report can be in response to satisfying a triggering condition. In some implementations, at sub-block 3032, block 3030 can include determining that a measured spectral efficiency satisfies a threshold. In some implementations, at sub-block 3034, block 3030 can include determining to report the CSI when a measured spectral efficiency of a downlink measurement resource differs from a spectral efficiency indicated for the PDSCH by more than a threshold. For example, the measured spectral efficiency can be one of a CQI or a measured feasible MCS. The measured spectral efficiency can be based on a transmission rank, a precoding matrix index, or a combination thereof. In some implementations, at sub-block 3036, block 3030 can include determining to report the CSI in response to determining a NACK for the PDSCH. In some implementations, determining to transmit the CSI report can also be in response to determining a NACK for the PDSCH. Thus, the UE 104, the TX processor 368, or the controller / processor 359 executing the CSI Tx component 140 or the trigger component 144 can provide a means for determining to transmit a CSI report based on the PDSCH and the DMRS.

[0190] At block 3040, the method 3000 can include determining a reference resource for CSI feedback. In some implementations, for example, the UE 104, the TX processor 368, or the controller / processor 359 can execute the CSI Tx component 140 or the resource component 146 to determine the reference resource for CSI feedback. In some implementations, the reference resource can be a slot in which a PDSCH or a DMRS is received. In some implementations, the reference resource can be n_ref slots before a CSI reporting slot. In some implementations, the uplink resource is separated from the last symbol of the reference resource by at least a number of symbols defined by a CSI timeline (e.g., Z’). The CSI timeline can be selected based at least in part on a number of CPU occupations or a number of DMRS ports. The CPU occupation time can start from a first symbol of an earliest one of the DMRS or the PDSCH used for channel measurement or interference measurement and can end at a last symbol of the uplink resource. From the first symbol of the earliest one of the DMRS or the PDSCH used for channel measurement or interference measurement to the last symbol of the uplink resource, the DMRS ports used for the DMRS and the PDSCH can be active. In some implementations, when the CSI is transmitted on the same slot as a HARQ ACK / NACK or in the same PUCCH as the HARQ ACK / NACK, the uplink resource is separated from the last symbol of the reference resource by a larger one of a number of symbols defined by the CSI timeline or a number of symbols defined by a HARQ timeline. Thus, the UE 104, the TX processor 368, or the controller / processor 359 executing the CSI Tx component 140 or the resource component 146 can provide a means for determining a reference resource for CSI feedback as a slot in which a PDSCH or a DMRS is received.

[0191] At block 3050, the method 3000 can include calculating CQI based on the reference resource. In some implementations, for example, the UE 104, the TX processor 368, or the controller / processor 359 can execute the CSI Tx component 140 or the measurement component 145 to calculate CQI based on the reference resource. For example, at sub-block 3052, the block 3050 can include determining an overhead assumption for CQI calculation based on the slots in which the PDSCH and the DMRS are received. In some implementations, the overhead assumption includes at least a number of symbols for control signaling, a number of DMRS symbols and PDSCH symbols, a number of additional DMRS symbols, and resources allocated for NZP-CSI-RS ZP-CSI-RS. As another example, at sub-block 3054, the block 3050 can include determining that a CSI reporting band is equal to a frequency domain allocation of the PDSCH and the DMRS. In some implementations, the CSI report includes only wideband CSI, which can be based on the frequency domain allocation of the PDSCH and the DMRS. In some implementations, the CSI report includes resource block group (RBG) or physical resource group (PRG) level CQI. The RBG or PRG can include the same resources as the DMRS and the PDSCH used for channel measurement or interference measurement. In another implementation, the CSI report can include RBG or PRG level CQI separately configured in the CSI reporting setting. Thus, the UE 104, the TX processor 368, or the controller / processor 359 executing the CSI Tx component 140 or the measurement component 145 can provide a means for calculating CQI based on the reference resource.

[0192] At block 3060, the method 3000 can include transmitting the CQI in the CSI report on the uplink resource. In some implementations, for example, the UE 104, the RX processor 356, or the controller / processor 359 can execute the CSI Tx component 140 or the reporting component 147 to transmit the CSI report 550 on the uplink resource. In some implementations, at sub-block 3062, the block 3060 can include determining a priority of the CSI based at least in part on a type of downlink measurement resource, or whether the CSI is triggered in response to the CSI measurement, or whether the aperiodic CSI is transmitted on the PUCCH. In some implementations, determining the priority of the CSI includes determining a priority function of the CSI. Values of factors in the priority function can be defined by the type of downlink measurement resource of the CSI. In some implementations, values of factors in the priority function are defined by the triggering type of the CSI. In some implementations, at sub-block 3064, the block 3060 can include determining a CSI multiplexing order, a dropping order, or an omission order based on the priority of the CSI. Thus, the UE 104, the RX processor 356, or the controller / processor 359 executing the CSI Tx component 140 or the reporting component 147 can provide means for transmitting the CQI in the CSI report on the uplink resource.

[0193] Figure 31 FIG. 31 is a flow diagram of an example method 3100 of a base station receiving a CSI report based on DMRS and / or PDSCH. The method 3100 can be performed by a base station such as the base station 102, which can include the memory 376 and can be the entire base station 102 or a component of the base station 102 such as the CSI Rx component 120, the TX processor 316, the RX processor 370, or the controller / processor 375. The method 3100 can be performed by the CSI Rx component 120 in communication with the CSI Tx component 140 of the UE 104.

[0194] At block 3110, the method 3100 can include configuring the UE with one or more CSI report configurations including downlink measurement resources including a PDSCH or a DMRS. In some implementations, for example, the base station 102, the controller / processor 375, or the TX processor 316 can execute the CSI Rx component 120 or the configuration component 122 to configure the UE 104 with the CSI report configuration 1110 including downlink measurement resources including a PDSCH or a DMRS 1120. Thus, the base station 102, the controller / processor 375, or the TX processor 316 executing the CSI Rx component 120 or the configuration component 122 can provide a means for configuring the UE with a CSI report configuration including downlink measurement resources including a PDSCH or a DMRS.

[0195] At block 3120, the method 3100 can optionally include transmitting a command indicating that a UE-initiated CSI report based on measurements of the downlink measurement resources is activated. In some implementations, for example, the base station 102, the controller / processor 375, or the TX processor 316 can execute the CSI Rx component 120 or the activation component 123 to transmit a command indicating that a UE-initiated CSI report based on measurements of the downlink measurement resources is activated. Thus, the base station 102, the controller / processor 375, or the TX processor 316 executing the CSI Rx component 120 or the activation component 123 can provide a means for transmitting a command indicating that a UE-initiated CSI report based on measurements of the downlink measurement resources is activated.

[0196] At block 3130, the method 3100 can include transmitting a downlink grant scheduling a PDSCH and a DMRS in a slot. In some implementations, for example, the base station 102, the controller / processor 375, or the TX processor 316 can execute the CSI Rx component 120 or the scheduling component 124 to transmit a downlink grant scheduling a PDSCH and a DMRS in a slot. Thus, the base station 102, the controller / processor 375, or the TX processor 316 executing the CSI Rx component 120 or the scheduling component 124 can provide a means for transmitting a downlink grant scheduling a PDSCH and a DMRS in a slot.

[0197] At block 3140, the method 3100 can include transmitting the PDSCH and the DMRS in the slot. In some implementations, for example, the base station 102, the controller / processor 375, or the TX processor 316 can execute the CSI Rx component 120 or the transmitter component 2752 to transmit the PDSCH and the DMRS in the slot. In some implementations, the base station 102 can monitor each occurrence of the periodic resource because the UE can initiate a CSI report based on any downlink measurement resource. Thus, the base station 102, the controller / processor 375, or the TX processor 316 executing the CSI Rx component 120 or the transmitter component 2752 can provide means for transmitting the PDSCH and the DMRS in the slot.

[0198] At block 3150, the method 3100 can include receiving, from the UE on the uplink resource, the CSI report including the CQI based on the PDSCH or the DMRS. In some implementations, for example, the base station 102, the controller / processor 375, or the TX processor 316 can execute the CSI Rx component 120 or the report reception component 126 to receive, from the UE on the uplink resource, the CSI report including the CQI based on the PDSCH or the DMRS. Thus, the base station 102, the controller / processor 375, or the TX processor 316 executing the CSI Rx component 120 or the report reception component 126 can provide means for receiving, from the UE on the uplink resource, the CSI report including the CQI based on the PDSCH or the DMRS.

[0199] As used herein, a phrase referring to “at least one of’ a list of items refers to any combination of those items, including single members. For example, “at least one of a, b, or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c.

[0200] The various illustrative logics, logical blocks, modules, circuits and algorithm processes described in connection with the implementations disclosed herein can be implemented as electronic hardware, computer software, or combinations of both. The interchangeability of hardware and software has been described generally, in terms of functionality, and illustrated in the various illustrative components, blocks, modules, circuits and processes described above. Whether such functionality is implemented in hardware or software depends on the particular application and design constraints imposed on the overall system.

[0201] The hardware and data processing apparatus used to implement the various illustrative logics, logical blocks, modules and circuits described in connection with the aspects disclosed herein can be implemented or performed with a general purpose single- or multi-chip processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (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 can be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. A processor can also be implemented as a combination of computing devices, such as 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. In some implementations, particular processes and methods can be performed by an ASIC, an FPGA, or other programmable logic device.

[0202] In one or more aspects, the functions described can be implemented in hardware, digital electronic circuitry, computer software, firmware, including the structures disclosed in this specification and their structural equivalents, or in any combination thereof. Implementations of the subject matter described in this specification also can be implemented as one or more computer programs, i.e., one or more modules of computer program instructions, encoded on a computer storage medium for execution by, or to control the operation of, data processing apparatus.

[0203] If implemented in software, the functions can be stored on or transmitted over as one or more instructions or code on a computer-readable medium. The processes of a method or algorithm disclosed herein can be implemented in a processor-executable software module which can reside on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that can be enabled to transfer a computer program from one place to another. Storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. Disk and disc, as used herein, includes compact discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), floppy disks and blu-ray discs where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. Additionally, the operations of a method or algorithm can reside in one or any combination of the memory of computational platform, the central processing unit(s) of the computational platform, the computer program product of a composition of matter, or distributed memory and / or storage devices of any then available type or variation thereof, as can be desired in certain implementations and as can be desired to implement the functionality described herein.

[0204] Various modifications to the implementations described in this disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other implementations without departing from the spirit or scope of this disclosure. Thus, the claims are not intended to be limited to the implementations shown herein, but are to be accorded the widest scope consistent with the spirit and scope of the present disclosure, the principles and novel features disclosed herein.

[0205] Moreover, those skilled in the art will appreciate that the terms "upper" and "lower" are sometimes used for ease of description of the figures and represent relative positions on the figures corresponding to the proper orientation of the pages, and can not reflect the proper orientation of any device that is implemented.

[0206] Certain features described in the context of separate implementations can also be implemented in combination. Conversely, various features described in the context of one implementation can also be implemented separately or in any suitable subcombination. Furthermore, although features can be described above as acting in particular combinations, one or more features from a claimed combination can in some cases be deleted or removed and the claimed combination can be directed to a subcombination or variation of a subcombination.

[0207] Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring such order, nor that all illustrated operations be performed, to achieve desirable results. Further, the drawings can schematically depict one or more example processes in the form of a flowchart. However, other operations that are not depicted can be incorporated in the example processes that are schematically illustrated. For example, one or more additional operations can be performed before, after, simultaneously with, or between any illustrated operation. In certain circumstances, multitasking and parallel processing can be advantageous. Moreover, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems are typically integrated in a single software product or packaged into multiple software products. Additionally, other implementations are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results.

Claims

1. A method of wireless communication, comprising by a user equipment (UE) : determining to transmit a channel state information (CSI) report based on measurements using a physical downlink control channel (PDSCH) and / or a demodulation reference signal (DMRS) ; determining a reference resource for CSI feedback, wherein the reference resource is a time slot in which the PDSCH or the DMRS is received; calculating a channel quality indicator (CQI) based on the reference resource, wherein an overhead assumption for calculating the CQI is determined based on a time slot in which the PDSCH and the DMRS are received; and transmitting the CQI in the CSI report on an uplink resource. 2.The method of claim 1, wherein the overhead assumption comprises at least a number of symbols for control signaling, a number of DMRS symbols and PDSCH symbols, a number of additional DMRS symbols, and resources allocated for a non-zero power (NZP) CSI reference signal (NZP-CSI-RS) and a zero power (ZP) CSI-RS. 3.The method of claim 1, wherein calculating the CQI based on the reference resource comprises determining that a CSI reporting band is equal to a frequency domain allocation of the PDSCH and the DMRS. 4.The method of claim 3, wherein the CSI report comprises a wideband CSI. 5.The method of claim 1, wherein the CSI report comprises a resource block group (RBG) or physical resource group (PRG) level CQI, wherein the RBG or PRG comprises the same resources as the DMRS and the PDSCH used for channel measurement or interference measurement. 6.The method of claim 1, wherein the CSI report comprises an RBG or PRG level CQI separately configured in a CSI reporting setting. 7.The method of claim 1, wherein a CSI processing unit (CPU) occupancy time starts from a first symbol of an earliest one of the DMRS or the PDSCH used for channel measurement or interference measurement and ends at a last symbol of the uplink resource. 8.The method of claim 1, wherein DMRS ports for the DMRS and the PDSCH are active from a first symbol of the DMRS or the PDSCH used for channel measurement or interference measurement to a last symbol of the uplink resource. 9.The method of claim 1, wherein the uplink resource is separated from a last symbol of the reference resource by at least a number of symbols defined by a CSI timeline, wherein the CSI timeline is determined based at least in part on a number of CPU occupancies or a number of DMRS ports. 10.The method of claim 9, wherein when the CSI is transmitted on a same time slot as a HARQ ACK / NACK or in a same PUCCH as the HARQ ACK / NACK, the uplink resource is separated from the last symbol of the reference resource by a larger of a number of symbols defined by the CSI timeline or a number of symbols defined by a HARQ timeline. ​ ​ ​ ​ ​ 11. The method of claim 1, wherein determining to report the CSI comprises: determining a priority of the CSI, wherein the priority of the CSI is based at least in part on a type of downlink measurement resource, whether the CSI report is triggered by the UE in response to CSI measurement, or whether aperiodic CSI is transmitted on PUCCH; and determining a resource CSI multiplexing order, dropping order, or omission order based on the priority.

12. The method of claim 11, wherein determining the priority of the CSI comprises determining a priority function of the CSI, wherein a value of a factor in the priority function is defined by the type of the downlink measurement resource of the CSI.

13. The method of claim 11, wherein determining the priority of the CSI comprises determining a priority function of the CSI, wherein a value of a factor in the priority function is defined by a type of triggering of the CSI.

14. A method of wireless communication, comprising by a base station: configuring a user equipment (UE) with a channel state information (CSI) report configuration, the CSI report configuration comprising a downlink measurement resource, the downlink measurement resource comprising a physical downlink shared channel (PDSCH) or a demodulation reference signal (DMRS); transmitting a downlink grant scheduling the PDSCH and the DMRS in a slot; transmitting the PDSCH and the DMRS in the slot; and receiving, from the UE, a CSI report comprising a channel quality indicator (CQI) based on the PDSCH or the DMRS on an uplink resource, wherein the CQI is based on an overhead assumption of a slot in which the PDSCH and the DMRS are transmitted.

15. The method of claim 14, wherein the overhead assumption comprises at least a number of symbols for control signaling, a number of DMRS symbols and PDSCH symbols, a number of additional DMRS symbols, and resources allocated for non-zero power (NZP) CSI reference signals (NZP-CSI-RS) and zero power (ZP) CSI-RS.

16. The method of claim 14, wherein a CSI reporting band is equal to a frequency domain allocation of the PDSCH and the DMRS.

17. The method of claim 16, wherein the CSI report comprises wideband CSI.

18. The method of claim 14, wherein the CSI report comprises resource block group (RBG) or physical resource group (PRG) level CQI, wherein the RBG or PRG comprises the same resources as the DMRS and the PDSCH used for channel measurement or interference measurement.

19. The method of claim 14, wherein the CSI report comprises RBG or PRG level CQI separately configured in a CSI reporting setting. ​ 20. The method of claim 14, wherein a CSI processing unit (CPU) occupancy time starts from a first symbol of an earliest one of the DMRS or the PDSCH used for channel measurement or interference measurement and ends at a last symbol of the uplink resource.

21. The method of claim 14, wherein a DMRS port for the DMRS and the PDSCH is active from a first symbol of the DMRS or the PDSCH used for channel measurement or interference measurement to a last symbol of the uplink resource.

22. The method of claim 14, wherein the uplink resource is separated from a last symbol of the PDSCH or the DMRS used for channel measurement or interference measurement by at least a number of symbols defined by a CSI timeline, wherein the CSI timeline is selected based at least in part on a number of CPU occupancies or a number of DMRS ports.

23. The method of claim 22, wherein when the CSI is transmitted on a same slot as a HARQ ACK / NACK or in a same PUCCH as the HARQ ACK / NACK, the uplink resource is separated from a last symbol of the PDSCH or the DMRS used for channel measurement or interference measurement by a greater of a number of symbols defined by the CSI timeline or a number of symbols defined by a HARQ timeline.

24. An apparatus for wireless communication, comprising: a processing system configured to perform the method of any of claims 1-13.

25. An apparatus for wireless communication, comprising: means for performing the method of any of claims 1-13.

26. A non-transitory computer-readable medium storing computer-executable code, which when executed by a processor, causes the processor to perform the method of any of claims 1-13.

27. An apparatus for wireless communication, comprising: a processing system configured to perform the method of any of claims 14-23.

28. An apparatus for wireless communication, comprising: means for performing the method of any of claims 14-23.

29. A non-transitory computer-readable medium storing computer-executable code, which when executed by a processor, causes the processor to perform the method of any of claims 14-23.

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