Method and apparatus for periodic channel state feedback reporting

Abstract

Methods, systems, and apparatus for wireless communications are described. A user equipment (UE) may identify a channel state information (CSI) reference resource and related definitions and assumptions for periodic reporting of a joint demodulation reference signal (DMRS) and channel state feedback (CSF) report to a base station. The UE may identify a CSI reference resource slot for dynamically determining one or more parameters associated with the DMRS configuration. The UE may calculate one or more CSF report components based on the DMRS configuration and transmit the components to the base station in the CSF report or the joint DMRS and CSF report with an additional indication of a recommended DMRS configuration included in the report based on the report configuration.

Description

Technical Field

[0001] The following relates to wireless communications, including demodulation reference signal (DMRS) configuration assumptions for channel state information (CSI) reference resources for periodic channel state feedback (CSF) reporting. Background Art

[0002] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcasting, etc. These systems may be able to support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth generation (4G) systems (such as long term evolution (LTE) systems, advanced LTE (LTE-A) systems, or LTE-A Pro systems), and fifth generation (5G) systems that may be referred to as new radio (NR) systems. These systems may use various technologies, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple access communication system may include one or more base stations or one or more network access nodes, each base station or network access node simultaneously supporting the communication of multiple communication devices, which may be referred to as user equipment (UE) in addition. Summary of the invention

[0003] The described technology relates to improved methods, systems, devices and apparatuses that support adaptive demodulation reference signal (DMRS) configuration and are consistent with DMRS adaptive channel state feedback (CSF) reporting, which can be achieved by corresponding assumptions for DMRS configurations for channel state information (CSI) reference resources. In general, the described technology allows user equipment (UE) to identify DMRS configurations for joint DMRS and CSF reporting to a base station based on CSI reference resource definitions and related assumptions. In some cases, the base station may configure the UE to periodically report CSF reports or joint DMRS and CSF reports from the UE. The UE may identify a CSI reference resource time slot for determining one or more parameters and assumptions, which are generally associated with CSF reporting and specifically associated with DMRS configurations assumed for CSF reporting (e.g., time density, frequency density, boost value, or combination). In this way, one or more CSF report components (e.g., channel quality indicator (CQI), etc.) may be defined or determined in accordance with the DMRS configuration used for the identified CSI reference resource or otherwise associated with the identified CSI reference resource. In some examples, a time slot associated with a CSI reference resource (e.g., a CSI reference resource time slot) may be identified or selected based on satisfying one or more validity criteria (e.g., a conventional validity criterion and one or more additional validity criteria). For example, a CSI reference resource time slot may be considered valid based on whether the time slot includes at least one or more configured downlink codewords or flexible codewords, whether the time slot falls within a measurement gap configured for the UE, or both. If a CSI reference resource time slot satisfies these criteria and is also associated with a downlink allocation with a duration greater than a threshold number of codewords, the CSI reference resource time slot may be considered valid for the derivation of a DMRS configuration for the CSI reference resource. In some examples, the CSI reference resource time slot may not satisfy the threshold duration validity criterion. If the threshold duration validity criterion is not satisfied, the UE may derive parameters for the DMRS configuration for the CSI reference resource from the closest previous valid downlink time slot that satisfies the threshold downlink shared channel (e.g., physical downlink shared channel (PDSCH)) allocation duration criterion. Additionally or alternatively, if the threshold duration validity criterion is not met, the UE may use a default DMRS configuration predefined for the CSI reference resource with one or more default parameters. The UE may generate one or more CSF report components based on the DMRS configuration and may transmit these components to the base station in a CSF report or a joint DMRS and CSF report.

[0004] A method of wireless communication at a UE is described. The method may include receiving a configuration for periodic CSF reporting, identifying a DMRS configuration associated with a first CSI reference resource based on receiving the configuration, generating one or more CSF components based on the DMRS configuration associated with the first CSI reference resource, and transmitting an indication of the generated one or more CSF components to a base station in a periodic CSF report. In some examples, generating the one or more CSF components may include calculating the one or more components based on the DMRS configuration.

[0005] An apparatus for wireless communication at a UE is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to: receive a configuration for periodic CSF reporting, identify a DMRS configuration associated with a first CSI reference resource based on receiving the configuration, generate one or more CSF components based on the DMRS configuration associated with the first CSI reference resource, and transmit an indication of the generated one or more CSF components to a base station in a periodic CSF report.

[0006] Another apparatus for wireless communications at a UE is described. The apparatus may include means for receiving a configuration for periodic CSF reporting, identifying a DMRS configuration associated with a first CSI reference resource based on receiving the configuration, generating one or more components based on the DMRS configuration associated with the first CSI reference resource, and transmitting an indication of the generated one or more CSF components to a base station in a periodic CSF report.

[0007] A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to receive a configuration for periodic CSF reporting, identify a DMRS configuration associated with a first CSI reference resource based on receiving the configuration, generate one or more CSF components based on the DMRS configuration associated with the first CSI reference resource, and transmit an indication of the generated one or more CSF components to a base station in a periodic CSF report.

[0008] Some examples of the methods, devices (apparatus), and non-transitory computer-readable media described herein may further include operations, features, apparatus, or instructions for the following actions: identifying a first CSI reference resource time slot corresponding to a first CSI reference resource based on a CSI reference resource time slot offset and a first CSI reference resource time slot validity criterion, and deriving a DMRS configuration hypothesis for CSF evaluation based on a PDSCH allocation on the first CSI reference resource time slot.

[0009] Some examples of the methods, devices (apparatus), and non-transitory computer-readable media described herein may further include operations, features, apparatus, or instructions for the following actions: identifying a second CSI reference resource time slot based on a CSI reference resource time slot offset and a first CSI reference resource time slot validity criterion, and identifying an additional CSI reference resource time slot validity criterion for the second CSI reference resource time slot, wherein the additional CSI reference resource time slot validity criterion includes a minimum threshold number of code elements for PDSCH allocation on the second CSI reference resource time slot.

[0010] Some examples of the methods, devices (apparatus), and non-transitory computer-readable media described herein may further include operations, features, apparatus, or instructions for determining that the additional CSI reference resource time slot validity criteria may not be satisfied for the second CSI reference resource time slot, identifying a first CSI reference resource time slot corresponding to the first CSI reference resource based at least in part on the first CSI reference resource time slot satisfying the additional CSI reference resource time slot validity criteria, satisfying the first CSI reference resource time slot validity criteria, and occurring in a previous time slot closest to the second CSI reference resource time slot, and deriving a DMRS configuration hypothesis for CSF evaluation based on a PDSCH allocation on the first CSI reference resource time slot.

[0011] In some examples of the methods, devices (apparatus), and non-transitory computer-readable media described herein, deriving a DMRS configuration hypothesis for CSF evaluation may include operations, features, apparatus, or instructions for the following actions: deriving one or more parameters corresponding to a first CSI reference resource, explicitly or implicitly defining the one or more parameters, the one or more parameters including the number of frontloaded DMRS symbols, the number of additional DMRS symbols, the position of all DMRS symbols relative to the first symbol allocated by the PDSCH, the DMRS type, or a combination thereof.

[0012] Some examples of the methods, devices (apparatus), and non-transitory computer-readable media described herein may further include operations, features, apparatus, or instructions for determining that the additional CSI reference resource time slot validity criteria may not be met for the second CSI reference resource time slot, and deriving a DMRS configuration hypothesis for CSF evaluation based on a default DMRS configuration that may be predefined for the CSI reference resource hypothesis.

[0013] Some examples of the methods, devices (apparatus), and non-transitory computer-readable media described herein may further include operations, features, apparatus, or instructions for the following actions: for a CSI reference resource definition, identifying a number of frontloaded DMRS symbols from a DMRS configuration associated with a PDSCH allocation on a first CSI reference resource slot corresponding to a first CSI reference resource.

[0014] Some examples of the methods, devices (apparatus), and non-transitory computer-readable media described herein may further include operations, features, apparatus, or instructions for the following actions: for a CSI reference resource definition, identifying a number of additional DMRS symbols and the positions of all DMRS symbols relative to the first symbol of the PDSCH allocation based on a DMRS configuration associated with a PDSCH allocation on a first CSI reference resource slot of a first CSI reference resource and based on a predefined assumption of the duration of the PDSCH allocation.

[0015] A method of wireless communication at a base station is described. The method may include transmitting a configuration for periodic CSF reporting, identifying a DMRS configuration associated with a first CSI reference resource based on transmitting the configuration, receiving an indication of one or more CSF components in the periodic CSF report from a UE, and interpreting the periodic CSF report based on the identified DMRS configuration.

[0016] An apparatus for wireless communication at a base station is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to: transmit a configuration for periodic CSF reporting, identify a DMRS configuration associated with a first CSI reference resource based on transmitting the configuration, receive an indication of one or more CSF components in a periodic CSF report from a UE, and interpret the periodic CSF report based on the identified DMRS configuration.

[0017] Another apparatus for wireless communication at a base station is described. The apparatus may include means for transmitting a configuration for periodic CSF reporting, identifying a DMRS configuration associated with a first CSI reference resource based on transmitting the configuration, receiving an indication of one or more CSF components in the periodic CSF report from a UE, and interpreting the periodic CSF report based on the identified DMRS configuration.

[0018] A non-transitory computer-readable medium storing code for wireless communication at a base station is described. The code may include instructions executable by a processor to transmit a configuration for periodic CSF reporting, identify a DMRS configuration associated with a first CSI reference resource based on transmitting the configuration, receive an indication of one or more CSF components in a periodic CSF report from a UE, and interpret the periodic CSF report based on the identified DMRS configuration.

[0019] Some examples of the methods, devices (apparatus), and non-transitory computer-readable media described herein may further include operations, features, apparatus, or instructions for the following actions: identifying a time slot of a first CSI reference resource based on a CSI reference resource time slot offset and a first CSI reference resource time slot validity criterion.

[0020] Some examples of the methods, devices (apparatus), and non-transitory computer-readable media described herein may further include operations, features, apparatus, or instructions for the following actions: identifying additional CSI reference resource time slot validity criteria for the time slot identified by the first CSI reference resource, wherein the additional CSI reference resource time slot validity criteria includes a minimum threshold number of codewords allocated for the PDSCH on the time slot identified by the first CSI reference resource.

[0021] Some examples of the methods, devices (apparatus), and non-transitory computer-readable media described herein may further include operations, features, apparatus, or instructions for the following actions: identifying a second CSI reference resource based on a CSI reference resource time condition, determining that the additional CSI reference resource time slot validity criteria may not be satisfied for the second CSI reference resource, identifying the first CSI reference resource based at least in part on the first CSI reference resource satisfying the additional CSI reference resource time slot validity criteria and occurring before the second CSI reference resource, and deriving the DMRS configuration based on the first CSI reference resource.

[0022] In some examples of the methods, devices (apparatus), and non-transitory computer-readable media described herein, deriving the DMRS configuration may include operations, features, apparatus, or instructions for the following actions: deriving one or more parameters corresponding to the first CSI reference resource, the one or more parameters including time density, frequency density, boost value, or a combination thereof.

[0023] Some examples of the methods, devices (apparatus), and non-transitory computer-readable media described herein may further include operations, features, apparatus, or instructions for the following actions: identifying a second CSI reference resource based on a CSI reference resource time condition, determining that the additional CSI reference resource time slot validity criteria may not be met for the second CSI reference resource, and deriving the DMRS configuration based on a default DMRS configuration.

[0024] Some examples of the methods, devices (apparatus), and non-transitory computer-readable media described herein may further include operations, features, apparatus, or instructions for the following actions: for a CSI reference resource definition, identifying a number of frontload DMRS codewords from a DMRS configuration associated with a downlink allocation for a first CSI reference resource.

[0025] Some examples of the methods, devices (apparatus), and non-transitory computer-readable media described herein may further include operations, features, apparatus, or instructions for the following actions: for a CSI reference resource definition, identifying a number of additional DMRS symbols from a DMRS configuration associated with a downlink allocation and after a number of frontloaded DMRS symbols and the position of each additional DMRS symbol relative to the starting DMRS symbol. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 and 2 An example of a wireless communication system supporting a dynamic demodulation reference signal (DMRS) configuration assumption for channel state information (CSI) reference resources for periodic channel state feedback (CSF) reporting in accordance with aspects of the present disclosure is illustrated.

[0027] Figure 3 A set of operations supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic channel state feedback (CSF) reporting in accordance with various aspects of the present disclosure are illustrated.

[0028] Figure 4 An example of a process flow supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting in accordance with aspects of the present disclosure is illustrated.

[0029] Figure 5 and 6 A block diagram of an apparatus supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting in accordance with aspects of the present disclosure is shown.

[0030] Figure 7 A block diagram of a communication manager supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting is shown in accordance with aspects of the present disclosure.

[0031] Figure 8 A diagram of a system including devices supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting is shown in accordance with aspects of the present disclosure.

[0032] Fig. 9 and 10 A block diagram of an apparatus supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting in accordance with aspects of the present disclosure is shown.

[0033] Fig.11 A block diagram of a communication manager supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting is shown in accordance with aspects of the present disclosure.

[0034] Fig.12 A diagram of a system including devices supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting is shown in accordance with aspects of the present disclosure.

[0035] Figures 13 to 16 A flow chart illustrating a method of supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting in accordance with aspects of the present disclosure is shown. DETAILED DESCRIPTION

[0036] In some cases, a user equipment (UE) may perform measurements on one or more reference signals to maintain a reliable and efficient link between wireless devices. For example, a channel state information reference signal (CSI-RS) may be used to adapt transmission parameters, and a demodulation reference signal (DMRS) may be used to determine an estimate of a data channel and assist in demodulation and decoding of signals received through the data channel. The UE may provide a periodic or aperiodic joint DMRS and channel state feedback (CSF) report to a base station based on performing measurements on one or more reference signals. For example, the UE may perform a CSF evaluation to determine one or more CSF components, such as a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), etc. for a CSF or joint DMRS and CSF report. In the case of a joint DMRS and CSF report, the UE may signal to the base station a selected or preferred DMRS configuration and a corresponding component in the CSF report calculated assuming the selected DMRS configuration (e.g., the CSF report is consistent with the selected DMRS configuration). In order to provide a higher flexibility for the network scheduler, multiple DMRS configurations and corresponding CQI components, CSF components, or both may be reported. Such a signaling mechanism may be used in the context of an adaptive DMRS framework in which DMRS parameters or configurations may change over time. In some cases, where the report is configured via radio resource control (RRC) for, for example, periodic reporting, there may be no practical option for frequent reconfiguration of reporting parameters without introducing a certain interruption period or high latency in the corresponding report or introducing uncertainty in its interpretation during the reconfiguration period. Additionally, using a smaller report size may be beneficial because DMRS configuration preferences may change relatively slowly based on channel conditions and reception conditions, and repeated indications of the same information may result in inefficient use of channel resources. However, reporting a selected DMRS configuration, or a plurality of DMRS and CQI configuration bundles with several selected DMRS configurations, or a DMRS configuration for reporting, and associated components of a CSF report may involve high signaling overhead with a limited degree of information volume (e.g., because DMRS preferences may not be likely to change frequently), and may not be suitable for periodic reporting.

[0037] As described herein, in order to comply with the dynamics in the adaptive DMRS configuration (e.g., DMRS adaptation in time) for consistent CSF reporting and to maintain low-volume periodic reporting, the UE may utilize the DMRS configuration associated with the resource allocation most recently scheduled by the base station, which may provide a suitable reference for the currently used DMRS configuration (e.g., for use in CSF evaluation-related assumptions), which indicates the most recent DMRS preference of the base station. In addition to CSF ​​reporting consistent with a representative and currently used DMRS configuration, the UE may also report to the network (e.g., a base station) DMRS configuration preferences that may change in time based on changes in channel conditions and UE reception conditions. This technique may provide a high degree of consistency in DMRS and CSF reporting, especially in the context of adaptive DMRS, while reducing the amount of information that the UE includes in the joint CSF and DMRS report. In other words, in periodic reporting, the UE may provide a minimum amount of information with maximum reporting consistency and relevance (e.g., from the perspective of network scheduler preferences). For example, the UE may identify a DMRS configuration based on a CSI reference resource, and may calculate one or more CSF components for joint DMRS and CSF reporting (e.g., a CSF report consistent with a currently used DMRS configuration, accompanied by an indication of a selected or preferred DMRS option) based on the identified DMRS configuration. In this way, the DMRS configuration used for periodic CSF reporting may be defined in a floating manner (e.g., tied to a PDSCH allocation scheduled by the network on a CSI reference resource slot), which may allow the DMRS configuration assumptions used for periodic CSF reporting evaluation to follow a DMRS adaptation process with high consistency and without the need for reconfiguration (e.g., which may be required for periodic CSF reporting). That is, a modified approach to CQI determination in joint DMRS and CSF reporting may define CQI based on the DMRS configuration used for the CSI reference resource. In addition, such techniques may increase the probability of matching (or increase the correlation) between the DMRS assumptions constituting the provided CSF report and the network's immediate scheduling preferences. Such techniques may be applicable to periodic CSF reporting or joint periodic DMRS and CSF reporting due to the reduced signaling overhead involved.

[0038] In some cases, such as for event-driven reporting, for aperiodic reporting, or both, the UE may perform extended joint DMRS and CSF reporting using multiple DMRS and CQI bundles. In some other cases, for periodic reporting, the UE may provide a minimum amount of information with maximum consistency and relevance. If the reported DMRS preference is different from the currently used DMRS configuration (e.g., if the selected DMRS and the reported CSF are inconsistent), the base station may schedule an extended aperiodic joint DMRS and CSF report to receive additional extended information, including a CQI or CSF that is consistent with that previously reported in a periodic report, a selected DMRS option, or both. In some examples, DMRS preference changes may not occur frequently.

[0039] The UE may identify CSI reference resource slots for determining one or more parameters associated with a DMRS configuration assumed for CSF evaluation. In the case of periodic reporting, identifying the slots corresponding to the CSI reference resources may be based on a configured formula, which may be a function of the location of the uplink resources associated with the report, the subcarrier spacing of UL and DL, the CSI report configuration, and other parameters. The identification of valid CSI reference resource slots may be based on satisfying one or more validity criteria. For example, a valid CSI reference resource slot may be associated with a PDSCH allocation with a duration greater than a threshold number of symbols. The threshold duration validity criterion may be satisfied in addition to or in addition to other (e.g., conventional) CSI reference resource slot validity criteria, such as downlink or flexible symbol configuration and UE measurement gap configuration.

[0040] In the event that the initially identified CSI reference resource slot does not meet the threshold duration validity criteria (or any other validity criteria), a fallback option for identifying a DMRS configuration from the CSI reference resource may be defined. If the threshold duration validity criteria are not met, the UE may derive parameters for the DMRS configuration assumption for the CSI reference resource for periodic CSF reporting from the closest previous valid downlink slot (e.g., based on the previously listed validity criteria). Additionally or alternatively, the UE uses a default DMRS configuration for the CSI reference resource with one or more default parameters.

[0041] As part of determining the DMRS configuration to be used as an assumption for CSF report evaluation, the UE may identify one or more parameters associated with the definition of the DMRS configuration (e.g., time density, frequency density, power boost). Additionally or alternatively, the UE may determine one or more parameters related to the DMRS pattern, such as the number of frontloaded DMRS symbols corresponding to the DMRS configuration based on the CSI reference resource (e.g., instead of what is configured by the higher layer parameter maxLength (maximum length) in DMRS-DownlinkConfig (via RRC) and specifies the number of DMRS symbols per DMRS position), the number of additional DMRS symbols (e.g., the number of additional DMRS positions after the frontloaded DMRS configured for PDSCH allocation on the CSI reference resource slot), the DMRS symbol position relative to the first PDSCH symbol allocated based on the DMRS configuration for PDSCH allocation on the CSI reference resource slot, and a certain assumption for the duration of the PDSCH allocation, etc. The UE may calculate one or more CSF components (e.g., CQI, PMI, or RI) based on the determined DMRS configuration, and may additionally determine the most appropriate DMRS configuration for the current channel conditions and reception conditions, and may transmit the CSF components and an optional selected DMRS configuration indication to the base station (e.g., in a joint DMRS and CSF report or in a CSF report).

[0042] Various aspects of the present disclosure are initially described in the context of a wireless communication system. Various aspects of the present disclosure are further described in the context of a process flow depicting a set of operations for determining a DMRS configuration assumed for CSF evaluation based on a CSI reference resource. Various aspects of the present disclosure are further illustrated and described by and with reference to apparatus diagrams, system diagrams, and flow diagrams related to determining a DMRS configuration assumed for CSF evaluation based on a CSI reference resource for periodic CSF reporting.

[0043] Figure 1 An example of a wireless communication system 100 supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting according to various aspects of the present disclosure is illustrated. The wireless communication system 100 may include one or more base stations 105, one or more UEs 115, and a core network 130. In some examples, the wireless communication system 100 may be a long term evolution (LTE) network, an advanced LTE (LTE-A) network, an LTE-A Pro network, or a new radio (NR) network. In some examples, the wireless communication system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission-critical) communications, low latency communications, communications with low-cost and low-complexity devices, or any combination thereof.

[0044] The base stations 105 may be dispersed throughout a geographic area to form the wireless communication system 100, and may be different forms of devices or devices with different capabilities. The base stations 105 and the UEs 115 may communicate wirelessly via one or more communication links 125. Each base station 105 may provide a coverage area 110 over which the UEs 115 and the base stations 105 may establish one or more communication links 125. The coverage area 110 may be an example of a geographic area over which the base stations 105 and the UEs 115 may support communication of signals according to one or more radio access technologies.

[0045] The UEs 115 may be dispersed throughout the coverage area 110 of the wireless communication system 100, and each UE 115 may be stationary or mobile, or stationary and mobile at different times. The UEs 115 may be different forms of devices or devices with different capabilities. Figure 1 Some example UEs 115 are illustrated in FIG. 1. The UEs 115 described herein may be able to communicate with various types of devices, such as other UEs 115, base stations 105, or network equipment (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network equipment), such as Figure 1 as shown in .

[0046] Each base station 105 may communicate with the core network 130, or communicate with each other, or both. For example, the base station 105 may interface with the core network 130 via one or more backhaul links 120 (e.g., via S1, N2, N3 or other interfaces). The base stations 105 may communicate with each other directly (e.g., directly between the base stations 105), or indirectly (e.g., via the core network 130), or directly and indirectly on the backhaul link 120 (e.g., via X2, Xn or other interfaces). In some examples, the backhaul link 120 may be or include one or more wireless links.

[0047] One or more of the base stations 105 described herein may include or may be referred to by a person of ordinary skill in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a B node, an evolved B node (eNB), a next generation B node or a gigabit B node (any of which may be referred to as a gNB), a home B node, a home evolved B node, or other suitable terminology.

[0048] UE 115 may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable term, where a "device" may also be referred to as a unit, a station, a terminal, or a client, etc. UE 115 may also include or may be referred to as a personal electronic device, such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, UE 115 may include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communication (MTC) device, etc., which may be implemented in various objects such as electrical appliances or vehicles, meters, etc.

[0049] The UE 115 described herein may be able to communicate with various types of devices, such as other UEs 115, which may sometimes act as relays, as well as base stations 105 and network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, relay base stations, etc. Figure 1 as shown in .

[0050] The UE 115 and the base station 105 may communicate wirelessly with each other via one or more communication links 125 on one or more carriers. The term "carrier" may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting the communication link 125. For example, a carrier for the communication link 125 may include a portion of a radio frequency spectrum band (e.g., a bandwidth portion (BWP)) that operates according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling for coordinating carrier operations, user data, or other signaling. The wireless communication system 100 may support communication with the UE 115 using carrier aggregation or multi-carrier operation. The UE 115 may be configured to have multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used in conjunction with both frequency division duplex (FDD) and time division duplex (TDD) component carriers.

[0051] In some examples (e.g., in a carrier aggregation configuration), a carrier may also have acquisition signaling or control signaling that coordinates the operation of other carriers. A carrier may be associated with a frequency channel (e.g., an Evolved Universal Mobile Telecommunications System Terrestrial Radio Access (E-UTRA) Absolute Radio Frequency Channel Number (EARFCN)) and may be located according to a channel grid for discovery by UE 115. A carrier may operate in a standalone mode in which initial acquisition and connection may be made by UE 115 via the carrier, or a carrier may operate in a non-standalone mode in which a connection is anchored using a different carrier (e.g., a different carrier of the same or different radio access technology).

[0052] The communication link 125 shown in the wireless communication system 100 may include an uplink transmission from the UE 115 to the base station 105, or a downlink transmission from the base station 105 to the UE 115. A carrier may carry downlink or uplink communications (e.g., in an FDD mode), or may be configured to carry both downlink and uplink communications (e.g., in a TDD mode).

[0053] A carrier may be associated with a particular bandwidth of a radio frequency spectrum, and in some examples, the carrier bandwidth may be referred to as a "system bandwidth" of the carrier or wireless communication system 100. For example, the carrier bandwidth may be one of several determined bandwidths (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 megahertz (MHz)) of a carrier of a particular radio access technology. Devices (e.g., base stations 105, UEs 115, or both) of the wireless communication system 100 may have a hardware configuration that supports communications on a particular carrier bandwidth, or may be configurable to support communications on one of a set of carrier bandwidths. In some examples, the wireless communication system 100 may include a base station 105 or UE 115 that supports simultaneous communications via carriers associated with multiple carrier bandwidths. In some examples, each served UE 115 may be configured to operate on a portion (e.g., subband, BWP) or all of a carrier bandwidth.

[0054] The signal waveform transmitted on the carrier may include multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques, such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system using MCM technology, a resource element may include a code element period (e.g., the duration of a modulation code element) and a subcarrier, where the code element period and the subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the code rate of the modulation scheme, or both). Thus, the more resource elements received by UE 115 and the higher the order of the modulation scheme, the higher the data rate of UE 115 can be. Wireless communication resources may refer to a combination of radio frequency spectrum resources, time resources, and spatial resources (e.g., spatial layers or beams), and the use of multiple spatial layers can further improve the data rate or data integrity of communication with UE 115.

[0055] One or more parameter sets for a carrier may be supported, where the parameter set may include a subcarrier spacing (Δf) and a cyclic prefix. A carrier may be divided into one or more BWPs with the same or different parameter designs. In some examples, a UE 115 may be configured with multiple BWPs. In some examples, a single BWP for a carrier may be active at a given time, and communications for a UE 115 may be limited to the one or more active BWPs.

[0056] The time interval of the base station 105 or the UE 115 can be expressed as a multiple of a basic time unit, and the basic time unit can be, for example, a sampling period T s =1 / (Δf max ·N f ) seconds, where Δf max It can represent the maximum supported subcarrier spacing, and N f The maximum supported discrete Fourier transform (DFT) size may be indicated. Time intervals of communication resources may be organized according to radio frames, each having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023).

[0057] Each frame may include a plurality of consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some examples, a frame may be divided into subframes (e.g., in the time domain), and each subframe may be further divided into a number of time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include a number of code element periods (e.g., depending on the length of the cyclic prefix added before each code element period). In some wireless communication systems 100, a time slot may be further divided into a plurality of mini-time slots containing one or more code elements. Excluding the cyclic prefix, each code element period may contain one or more (e.g., N f ) sampling period. The duration of a symbol period may depend on the subcarrier spacing or the operating band.

[0058] A subframe, slot, mini-slot, or symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communication system 100 and may be referred to as a transmission time interval (TTI). In some examples, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communication system 100 may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs)).

[0059] Physical channels may be multiplexed on a carrier according to various techniques. Physical control channels and physical data channels may be multiplexed on a downlink carrier, for example, using one or more of a time division multiplexing (TDM) technique, a frequency division multiplexing (FDM) technique, or a hybrid TDM-FDM technique. A control region (e.g., a control resource set (CORESET)) for a physical control channel may be defined by a number of symbol periods and may extend across a system bandwidth or a subset of a system bandwidth of a carrier. One or more control regions (e.g., CORESETs) may be configured for a set of UEs 115. For example, one or more of the UEs 115 may monitor or search a control region for control information according to one or more search space sets, and each search space set may include one or more control channel candidates in one or more aggregation levels arranged in a cascaded manner. An aggregation level for a control channel candidate may refer to the number of control channel resources (e.g., control channel elements (CCEs)) associated with coded information for a control information format having a given payload size. The search space sets may include a common search space set configured for transmitting control information to multiple UEs 115 and a UE-specific search space set for transmitting control information to a specific UE 115 .

[0060] Each base station 105 may provide communication coverage via one or more cells (e.g., macro cells, small cells, hot spots, or other types of cells, or any combination thereof). The term "cell" may refer to a logical communication entity used to communicate with a base station 105 (e.g., on a carrier), and may be associated with an identifier (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID), or other) used to distinguish adjacent cells. In some examples, a cell may also refer to a geographic coverage area 110 or a portion of a geographic coverage area 110 (e.g., a sector) on which a logical communication entity operates. The range of such a cell may range from a smaller area (e.g., a structure, a subset of a structure) to a larger area depending on various factors (such as the capabilities of the base station 105). For example, a cell may be or include a building, a subset of a building, or an external space between or overlapping a geographic coverage area 110, as well as other examples.

[0061] A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access to UEs 115 that have service subscriptions with a network provider that supports the macro cell. A small cell may be associated with a lower power base station 105 (compared to a macro cell), and the small cell may operate in the same or different (e.g., licensed, unlicensed) frequency band as the macro cell. A small cell may provide unrestricted access to UEs 115 that have service subscriptions with a network provider, or may provide restricted access to UEs 115 associated with the small cell (e.g., UEs 115 in a closed subscriber group (CSG), UEs 115 associated with users in a home or office). A base station 105 may support one or more cells and may also support communications on one or more cells using one or more component carriers.

[0062] In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., MTC, narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB)) that may provide access to different types of devices.

[0063] In some examples, base stations 105 may be mobile and, therefore, provide communication coverage for mobile geographic coverage areas 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, but the different geographic coverage areas 110 may be supported by the same base station 105. In other examples, overlapping geographic coverage areas 110 associated with different technologies may be supported by different base stations 105. The wireless communication system 100 may include, for example, a heterogeneous network in which different types of base stations 105 provide coverage for various geographic coverage areas 110 using the same or different radio access technologies.

[0064] The wireless communication system 100 may support synchronous or asynchronous operation. For synchronous operation, the base stations 105 may have similar frame timing, and transmissions from different base stations 105 may be approximately aligned in time. For asynchronous operation, the base stations 105 may have different frame timing, and transmissions from different base stations 105 may not be aligned in time in some examples. The techniques described herein may be used for synchronous or asynchronous operation.

[0065] Some UEs 115, such as MTC or IoT devices, may be low-cost or low-complexity devices and may provide automated communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC may refer to data communication technology that allows devices to communicate with each other or with a base station 105 without human intervention. In some examples, M2M communication or MTC may include communications from devices that integrate sensors or meters to measure or capture information and relay such information to a central server or application that utilizes the information or presents the information to a person interacting with the application. Some UEs 115 may be designed to collect information or implement automated behavior of machines or other devices. Examples of applications for MTC devices include: smart metering, inventory monitoring, water level monitoring, equipment monitoring, health care monitoring, field survival monitoring, weather and geographic event monitoring, queue management and tracking, remote security sensing, physical access control, and transaction-based commercial charging.

[0066] Some UEs 115 may be configured to employ a reduced power consumption mode of operation, such as half-duplex communication (e.g., a mode that supports unidirectional communication via transmission or reception but not simultaneous transmission and reception). In some examples, half-duplex communication may be performed with a reduced peak rate. Other power saving techniques for UE 115 include entering a power saving deep sleep mode when not engaged in active communications, operating on a limited bandwidth (e.g., according to narrowband communications), or a combination of these techniques. For example, some UEs 115 may be configured to operate using a narrowband protocol type that is associated with a defined portion or range (e.g., a subcarrier or resource block (RB) set) within a carrier, within a guard band of a carrier, or outside a carrier.

[0067] The wireless communication system 100 may be configured to support ultra-reliable communication or low latency communication or various combinations thereof. For example, the wireless communication system 100 may be configured to support ultra-reliable low latency communication (URLLC) or mission-critical communication. UE 115 may be designed to support ultra-reliable, low latency or critical functions (e.g., mission-critical functions). Ultra-reliable communication may include private communication or group communication, and may be supported by one or more mission-critical services (such as mission-critical push-to-talk (MCPTT), mission-critical video (MCVideo), or mission-critical data (MCData). Support for mission-critical functions may include prioritization of services, and mission-critical services may be used for public safety or general commercial applications. The terms ultra-reliable, low latency, critical mission, and ultra-reliable low latency may be used interchangeably herein.

[0068] In some examples, UE 115 may also be able to communicate directly with other UE 115 over a device-to-device (D2D) communication link 135 (e.g., using a peer-to-peer (P2P) or D2D protocol). One or more UEs 115 utilizing D2D communication may be within a geographic coverage area 110 of a base station 105. Other UEs 115 in such a group may be outside the geographic coverage area 110 of the base station 105, or may not be able to receive transmissions from the base station 105 for other reasons. In some examples, each group of UEs 115 communicating via D2D communication may utilize a one-to-many (1:M) system, in which each UE 115 transmits to each other UE 115 in the group. In some examples, the base station 105 facilitates the scheduling of resources for D2D communication. In other cases, D2D communication is performed between each UE 115 without involving the base station 105.

[0069] In some systems, the D2D communication link 135 can be an example of a communication channel (such as a sidelink communication channel) between vehicles (e.g., UE 115). In some examples, the vehicles can communicate using vehicle-to-everything (V2X) communication, vehicle-to-vehicle (V2V) communication, or some combination of these communications. The vehicles can signal information related to traffic conditions, signal scheduling, weather, safety, emergency situations, or any other information related to the V2X system. In some examples, vehicles in the V2X system can communicate with roadside infrastructure (such as roadside units), or with the network, or both via one or more network nodes (e.g., base station 105) using vehicle-to-network (V2N) communication.

[0070] The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC) or a 5G core (5GC), and the EPC or 5GC may include at least one control plane entity (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) for managing access and mobility, and at least one user plane entity (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), or a user plane function (UPF)) for routing packets or interconnecting to an external network. The control plane entity may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management of UE 115 served by a base station 105 associated with the core network 130. User IP packets may be delivered via a user plane entity, which may provide IP address allocation and other functions. The user plane entity may be connected to a network operator IP service 150. The network operator IP services 150 may include access to the Internet, an intranet, an IP Multimedia Subsystem (IMS), or packet-switched streaming services.

[0071] Some network devices (such as base stations 105) may include subcomponents, such as access network entities 140, which may be examples of access node controllers (ANCs). Each access network entity 140 may communicate with each UE 115 through one or more other access network transport entities 145, which may be referred to as radio heads, smart radio heads, or transmission / reception points (TRPs). Each access network transport entity 145 may include one or more antenna panels. In some configurations, the various functions of each access network entity 140 or base station 105 may be distributed across various network devices (e.g., radio heads and ANCs) or merged into a single network device (e.g., base station 105).

[0072] The wireless communication system 100 may operate using one or more frequency bands, typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Generally, the 300 MHz to 3 GHz region is referred to as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from about 1 decimeter to 1 meter long. UHF waves may be blocked or redirected by buildings and environmental features, but these waves may penetrate various structures sufficiently for macro cells to provide service to UEs 115 located indoors. Transmissions using UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) than transmissions using smaller frequencies and longer waves in the high frequency (HF) or very high frequency (VHF) portions of the spectrum below 300 MHz.

[0073] The wireless communication system 100 may also operate in a super high frequency (SHF) zone using a frequency band from 3 GHz to 30 GHz (also known as a centimeter band) or in an extremely high frequency (EHF) zone of a spectrum (e.g., from 30 GHz to 300 GHz) (also known as a millimeter band). In some examples, the wireless communication system 100 may support millimeter wave (mmW) communications between UE 115 and base station 105, and the EHF antenna of the corresponding device may be smaller and more closely spaced than the UHF antenna. In some examples, this may facilitate the use of antenna arrays within the device. However, the propagation of EHF transmissions may be subject to even greater atmospheric attenuation and a shorter range than SHF or UHF transmissions. The technology disclosed herein may be adopted across transmissions using one or more different frequency zones, and the use of frequency bands specified across these frequency zones may vary by country or regulatory agency.

[0074] The wireless communication system 100 may utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communication system 100 may employ licensed assisted access (LAA), LTE unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band (such as the 5 GHz industrial, scientific, and medical (ISM) band). When operating in an unlicensed radio frequency spectrum band, devices (such as base stations 105 and UEs 115) may employ carrier sensing for conflict detection and avoidance. In some examples, operations in an unlicensed band may be based on a carrier aggregation configuration (e.g., LAA) in coordination with component carriers operating in a licensed band. Operations in an unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, among others.

[0075] The base station 105 or UE 115 may be equipped with multiple antennas, which can be used to employ technologies such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of the base station 105 or UE 115 may be located in one or more antenna arrays or antenna panels that can support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly (such as an antenna tower). In some examples, the antennas or antenna arrays associated with the base station 105 may be located at different geographical locations. The base station 105 may have an antenna array having antenna ports of several rows and columns that the base station 105 can use to support beamforming for communications with the UE 115. Similarly, the UE 115 may have one or more antenna arrays that can support various MIMO or beamforming operations. Additionally or alternatively, the antenna panel may support radio frequency beamforming for signals transmitted via the antenna ports.

[0076] The base station 105 or UE 115 can use MIMO communication to utilize multipath signal propagation and improve spectral efficiency by transmitting or receiving multiple signals via different spatial layers. Such technology may be referred to as spatial multiplexing. For example, the transmitting device may transmit multiple signals via different antennas or different antenna combinations. Similarly, the receiving device may receive multiple signals via different antennas or different antenna combinations. Each of the multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords). Different spatial layers may be associated with different antenna ports for channel measurement and reporting. MIMO technology includes single-user MIMO (SU-MIMO), in which multiple spatial layers are transmitted to the same receiving device; and multi-user MIMO (MU-MIMO), in which multiple spatial layers are transmitted to multiple devices.

[0077] Beamforming (which may also be referred to as spatial filtering, directional transmission, or directional reception) is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station 105, a UE 115) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining signals communicated via antenna elements of an antenna array so that some signals propagating at a particular orientation relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to signals communicated via antenna elements may include the transmitting device or the receiving device applying an amplitude offset, a phase offset, or both to signals carried via antenna elements associated with the device. Adjustments associated with each antenna element may be defined by a set of beamforming weights associated with a particular orientation (e.g., relative to the antenna array of the transmitting device or the receiving device, or relative to some other orientation).

[0078] The base station 105 or the UE 115 may use beam sweeping techniques as part of a beamforming operation. For example, the base station 105 may use multiple antennas or antenna arrays (e.g., antenna panels) to perform beamforming operations for directional communication with the UE 115. Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted multiple times by the base station 105 in different directions. For example, the base station 105 may transmit signals according to different sets of beamforming weights associated with different transmission directions. Transmissions in different beam directions may be used (e.g., by a transmitting device (such as the base station 105) or a receiving device (such as the UE 115)) to identify a beam direction used by the base station 105 for later transmission or reception.

[0079] Some signals, such as data signals associated with a particular recipient device, may be transmitted by base station 105 in a single beam direction, e.g., a direction associated with a recipient device, such as UE 115. In some examples, a beam direction associated with transmissions along a single beam direction may be determined based on signals transmitted in one or more beam directions. For example, UE 115 may receive one or more signals transmitted by base station 105 in different directions and may report to base station 105 an indication of the signal received by UE 115 with the highest signal quality or other acceptable signal quality.

[0080] In some examples, transmission by a device (e.g., by a base station 105 or a UE 115) may be performed using multiple beam directions, and the device may use a combination of digital precoding or radio frequency beamforming to generate a combined beam for transmission (e.g., from the base station 105 to the UE 115). The UE 115 may report feedback indicating precoding weights for one or more beam directions, and the feedback may correspond to a configured number of beams across the system bandwidth or one or more subbands. The base station 105 may transmit a reference signal that may be precoded or unprecoded (e.g., a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS)). The UE 115 may provide feedback for beam selection, which may be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., a multi-panel type codebook, a linear combination type codebook, a port selection type codebook). Although these techniques are described with reference to signals transmitted by base station 105 in one or more directions, UE 115 may use similar techniques to transmit signals multiple times in different directions (e.g., to identify a beam direction for subsequent transmission or reception by UE 115) or to transmit signals in a single direction (e.g., to transmit data to a receiving device).

[0081] A receiving device (e.g., UE 115) may try multiple reception configurations (e.g., directional listening) when receiving various signals (such as synchronization signals, reference signals, beam selection signals, or other control signals) from a base station 105. For example, the receiving device may try multiple reception directions by receiving via different antenna subarrays, processing received signals according to different antenna subarrays, receiving according to different receive beamforming weight sets (e.g., different directional listening weight sets) applied to signals received at multiple antenna elements of an antenna array, or processing received signals according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, any of which may be referred to as "listening" according to different reception configurations or reception directions. In some examples, the receiving device may use a single reception configuration to receive along a single beam direction (e.g., when receiving a data signal). The single reception configuration may be aligned on a beam direction determined based on listening according to different reception configuration directions (e.g., a beam direction determined to have the highest signal strength, the highest signal-to-noise ratio (SNR), or other acceptable signal quality based on listening according to multiple beam directions).

[0082] The wireless communication system 100 can be a packet-based network that operates according to a layered protocol stack. In the user plane, the communication of the bearer or packet data convergence protocol (PDCP) layer can be based on IP. The radio link control (RLC) layer can perform packet segmentation and reorganization to communicate on the logical channel. The media access control (MAC) layer can perform priority handling and multiplex the logical channel into the transport channel. The MAC layer can also use error detection technology, error correction technology, or both to support the retransmission of the MAC layer to improve link efficiency. In the control plane, the radio resource control (RRC) protocol layer can provide the establishment, configuration and maintenance of the RRC connection of the radio bearer that supports user plane data between the UE 115 and the base station 105 or the core network 130. In the physical layer, the transport channel can be mapped to the physical channel.

[0083] UE 115 and base station 105 may support retransmission of data to increase the likelihood that the data is successfully received. Hybrid automatic repeat request (HARQ) feedback is a technique for increasing the likelihood of correctly receiving data on communication link 125. HARQ may include a combination of error detection (e.g., using a cyclic redundancy check (CRC)), forward error correction (FEC), and retransmission (e.g., automatic repeat request (ARQ)). HARQ may improve the throughput of the MAC layer in poor radio conditions (e.g., low signal-to-noise ratio conditions). In some examples, a device may support simultaneous slot HARQ feedback, wherein the device may provide HARQ feedback in a specific time slot for data received in a previous symbol in the time slot. In other cases, the device may provide HARQ feedback in a subsequent time slot or according to some other time interval.

[0084] The wireless communication system 100 may support the transmission of reference signals to improve the efficiency and reliability of communication between wireless devices (e.g., base station 105 and UE 115). Reference signals may be transmitted from base station 105 to UE 115, and vice versa. Reference signals transmitted to UE 115 may be referred to as downlink reference signals, and reference signals transmitted to base station 105 may be referred to as uplink reference signals. Reference signals may be used by wireless devices to determine the characteristics of a channel. The characteristics of a channel may also be referred to as channel estimation or channel conditions or channel metrics. Reference signals may include CSI-RS, downlink DMRS, uplink DMRS, sounding reference signals (SRS), tracking reference signals (TRS), and phase tracking reference signals (PTRS).

[0085] The CSI-RS transmission may be used by UE 115 to determine a channel estimate that is used to assist in link adaptation (e.g., by assisting in adaptation of transmission parameters). The channel estimate may be used to determine a signal quality ratio of the channel (e.g., a post-processing signal-to-noise ratio (SNR) or a post-processing signal to interference plus noise ratio (SINR)), a delay spread (τ rms ) or the classification of the channel (or channel type), the precoding matrix to be used for communication on the channel, the rank (or number of spatial layers) to be used for communication on the channel, or any combination thereof. Downlink DMRS transmission may also be used by UE 115 to determine a data channel estimate that may be used to demodulate and decode transmissions received in a data channel. The channel estimate determined using CSI-RS transmission may be different from the channel estimate determined using downlink DMRS transmission. Thus, the downlink DMRS may be transmitted using resources associated with the data resources allocated to the UE 115. TRS transmission may be used by UE 115 for synchronization cycles and for determining medium- and long-term characteristics of the channel, such as Doppler frequency, delay spread, and power delay profile.

[0086] The uplink DMRS may be used by the base station 105 to determine a channel estimate for an uplink channel between the base station and the UE 115 transmitting the uplink DMRS (e.g., so that the base station 105 may perform coherent demodulation of a physical uplink control channel (PUCCH) and a physical uplink shared channel (PUSCH)). For example, each scheduled PUCCH and PUSCH may have its own DMRS, which may assist the base station 105 in demodulation and decoding. The uplink SRS may be used by the base station 105 for uplink link adaptation, uplink transmission parameter selection, and uplink measurements, among other things. In some examples, the uplink SRS may be used by the base station 105 to determine the uplink channel quality over a wide bandwidth so that the base station 105 may perform frequency selective scheduling for the UE 115 transmitting the uplink SRS.

[0087] A reference signal may be transmitted on a communication resource according to a reference signal configuration. The reference signal configuration may indicate which resource elements are allocated for reference signal transmission—resource elements allocated for reference signal transmission may be referred to as pilot resource elements. A group of resource elements (e.g., contiguous resource elements) allocated for reference signal transmission within a symbol period may be referred to as a pilot symbol. In some cases, the reference signal configuration indicates a time interval (Dt) between resource elements allocated for reference signal transmission. t ); The frequency spacing between resource elements allocated to the reference signal (D f ); indicating a power boost parameter (ρ) for transmitting a reference signal resource element relative to the power used to transmit a data resource element p ). Different reference signal configurations may be associated with different combinations of time intervals, frequency intervals, and power boosts—e.g., a first reference signal configuration may be associated with a first time interval, a first frequency interval, and a first power boost, a second reference signal configuration may be associated with a first time interval, a first frequency interval, and a second power boost, and so on.

[0088] The base station 105 may determine the configurations for the different reference signals. In some cases, the base station 105 may determine the downlink or uplink DMRS configuration for the UE 115 by selecting a DMRS configuration from a set of DMRS configurations supported by the UE. The base station 105 then signals the selected DMRS configuration to the UE 115 using dynamic control signaling, such as DCI-based signaling of the selected DMRS configuration, MAC-CE-based activation of the selected DMRS configuration, RRC-based reconfiguration, or any combination. For example, the UE 115 may use MAC-CE-based activation for the selected DMRS option set and supplemental DCI-based selection of one of the activated options per allocation.

[0089] UE 115 uses the demodulation reference signal to determine the signal quality ratio of the data channel. In some cases, UE 115 uses a minimum mean square error (MMSE) equalization or a linear MMSE (LMMSE) filtering approach to obtain the post-processing SINR of the channel. The MMSE approach may include estimating the post-processing SINR for each resource element k of each involved spatial stream l. For example, for each spatial stream l and resource element k included in the communication resource, the post-processing SINR (γ l (k) DMRS ) can be compiled based on the following formula 1:

[0090]

[0091] in It can be the thermal noise variance; It can be the inter-carrier interference variance; can be the channel estimation error variance, and may be an effective estimated channel matrix. The channel estimation error variance may be determined to accommodate noise received together with and inseparable from the channel estimation process and associated with residual thermal noise of the reference signal, modeling errors, and algorithm limitations. Additionally, P may be a precoding matrix and It may be an estimated channel matrix (e.g., DMRS-based channel estimation Precoding is typically transparent to UE 115 and addresses a portion of the channel and obtains a channel estimate including the used precoding option P ). In addition, τ rms can be the delay spread of the channel and f D It can be the Doppler frequency of the channel. In addition, D t It can be the time interval between resource elements used for demodulation reference signal; f may be the frequency spacing between resource elements used for demodulation reference signals; and p p It can be the power level used to transmit reference signal resource elements relative to the power level used to transmit data resource elements. p ) may be the input SNR on the pilot resource element for demodulation reference signal and may be p p function.

[0092] UE 115 may determine an average post-processing SINR for each spatial stream l by applying an averaging operator to the post-processing SINRs determined across resource elements k for spatial stream l. The average post-processing SINR for the DMRS may be referred to as In some examples, UE 115 uses Equation 1 to determine the post-processing SINR of a channel using DMRS, in which case γ l (k) RS It can be expressed as γ l (k) DMRS .

[0093] In some cases, the post-processing SINR of the channel may depend on the DMRS configuration - for example, the post-processing SINR of the channel may be increased or decreased depending on the portion of the channel estimation error that depends on a combination of the channel characteristics and the pilot configuration used for channel estimation. The base station 105 may similarly use Equation 1 to determine the post-processing SINR per resource element and the average post-processing SINR using the uplink reference signal.

[0094] Additionally or alternatively, UE 115 may determine a post-processing signal quality ratio (e.g., SINR) of the channel based on channel characteristics determined using CSI-RS and CSI-IM resources, where the noise estimate is free of a channel estimation error component. - For example, because the noise measured using interference management resources can be isolated from the reference signal. That is, the noise component The noise variance measured using interference management resources can be used Instead,

[0095] For example, for spatial stream l and resource element k, the post-processing SINR (γ l ′(k) CSI-RS ) can be determined using a reference signal based on Equation 2:

[0096]

[0097] UE 115 may determine an average post-processing SINR for each spatial stream l by applying an averaging operator to the post-processing SINR determined for each resource element k. The average post-processing SINR may be referred to as

[0098] The post-processing SINR calculated based on Equation 2 and the actual post-processing SINR expected in the case of PDSCH (defined analytically for the purpose of explanation based on Equation 1) may be different from each other. In some cases, the post-processing SINR representing PDSCH and expected to be obtained using DMRS-based channel estimation (which can be represented by the variable γ DMRS ) and the post-processing SINR calculated based on Equation 2 (which can be represented by the variable γ (CSI-RS) γ can be determined based on CSI-RS and CSI-IM resources. DMRS may be an actual representation (or projection) of the post-processing SINR of the channel and reception conditions of the data resources allocated to UE 115, while γ CSI-RS It can be an estimate of the post-processing SINR based on the channel and reception conditions of the data resource, which are estimated based on the CSI-RS and CSI-IM resources. CSI-RS and γ DMRS The expected difference between can be defined or learned per channel feature set and per given reception condition and can later be used to determine the expected difference between the calculated γ CSI-RS Apply adjustments to estimate γ DMRS In some cases, γ DMRS With γ CSI-RS The difference between may be nonlinear, and γ DMRS A nonlinear function (e.g., γ DMRS =f(γCSI-RS ))) is determined. UE 115 may determine the post-processing SINR value (γ) calculated for the CSI-RS CSI-RS ) and the post-processing SINR value (γ DMRS ) for different combinations of CSI-RS and DMRS configurations. DMRS With γ CSI-RS The differences provided by the corresponding mapping functions between may be based on the configuration of the DMRS and the configuration of the CSI-RS and defined per channel characteristic set and per given input / thermal SNR.

[0099] The wireless communication system 100 may also support reporting information about a channel determined using a reference signal. The UE 115 uses the CSI-RS to determine transmission parameters of the channel, such as a precoding matrix, a rank, and a modulation and coding scheme (MCS). The UE 115 may determine the transmission parameters based on determining that the transmission parameters will maximize a channel metric (e.g., a spectral efficiency metric), based on a post-processing signal quality ratio of the channel (e.g., a post-processing SINR), or both. The UE 115 may indicate the recommended transmission parameters to the base station 105 in a channel state feedback (CSF) report (which may also be referred to as a channel state information (CSI) report), which may have different formats and may include a PMI field that conveys a precoding matrix indicator (PMI), an RI field that conveys a rank indicator (RI), an SLI field that conveys a strongest layer indicator (SLI), and a CQI field that conveys a channel quality indicator (CQI). The base station 105 uses the PMI and RI to determine the precoding matrix and rank to be used for subsequent transmissions, and uses the CQI to determine the MCS for subsequent transmissions.

[0100] As described above, reference signals may be used to determine measurements and estimates of channels to maintain a reliable and effective link between wireless devices (e.g., base station 105 and UE 115). For example, CSI-RS may be used to adapt transmission parameters. In addition, DMRS may be used to determine estimates of data channels (e.g., physical downlink shared channel (PDSCH)) and assist in demodulation and decoding of signals received through data channels. UE 115 may provide periodic or aperiodic joint DMRS and CSF reports to base station 105 based on measurements performed on reference signals. In some cases, UE 115 may select a DMRS option as part of a CSF evaluation procedure and may report the DMRS option to base station 105 (e.g., in a joint DMRS and CSF report). For example, UE 115 may perform a CSF evaluation and may determine CQI, CSF reports, or both with respect to a DMRS configuration, or may be given an assumption of a DMRS configuration addressed for CSF reporting. The DMRS configuration may be selected by the UE 115 from a network-configured list of DMRS options that are considered for DMRS selection and reporting or joint DMRS and CSF reporting. In some cases, the UE 115 may provide an extended aperiodic report that includes a list of several selected DMRS and CQI or CSF bundles. The list of DMRS options to be reported and the corresponding CQI or CSF values ​​and the length of the extended joint DMRS and CSF report (e.g., the number of bundles to be reported) may be configured by the network in a dynamic manner. For example, the base station 105 may dynamically signal to the UE 115 parameters corresponding to the DMRS configuration addressed in the DMRS selection and reporting process for aperiodic DMRS and CSF reporting. In some examples, the DMRS configuration list addressed by UE 115 for DMRS selection, reporting of aperiodic joint DMRS and CSF reporting, or both may be determined based on a signaled DCI CSI triggering state, which may be reconfigured based on RRC signaling, may be dynamically activated or deactivated using MAC-CE signaling, or both.

[0101] As described herein, a UE 115 may identify a DMRS configuration based on a CSI reference resource for periodic reporting, which may allow the UE 115 to determine a DMRS configuration for periodic joint DMRS and CSF reporting. Additionally or alternatively, the UE 115 may identify a DMRS configuration for regular periodic CSF reporting in a floating manner, such as after a DMRS adaptation process occurs (e.g., without requiring RRC reconfiguration in the context of CSF reporting or reporting configuration to capture DMRS adaptation dynamics). In some cases, the UE 115 may determine that a validity condition associated with a CSI reference resource is satisfied. For example, if a time slot in a serving cell (e.g., associated with a base station 105) includes a downlink shared channel (e.g., a physical downlink shared channel (PDSCH)) allocation that lasts greater than a threshold number of symbols, then the time slot may be a valid downlink time slot for a CSI reference resource. If the time slot passes the validity condition (i.e., satisfies the threshold number of symbols), the UE 115 may derive the DMRS configuration for the CSI reference resources corresponding to the time slot from the time slot. If the time slot does not meet the validity condition (i.e., does not meet the threshold number of symbols), the UE 115 may derive a DMRS configuration hypothesis for the CSI reference resources used for periodic CSF reporting from the closest previous valid downlink time slot. Additionally or alternatively, if the time slot does not meet the validity condition, the UE 115 may assume a default predefined DMRS configuration hypothesis for the CSI reference resources used for periodic CSF reporting. In some cases, CSI reporting may be performed based on one of one or more DMRS configuration hypotheses (e.g., CSI reference resource hypotheses), which may be predefined, derived by the UE 115 based on the CSI reference resource time slot, or a combination.

[0102] In some examples, the UE 115 may calculate one or more CSF components (e.g., CQI, PMI, RI, or a combination) based on the DMRS configuration associated with the CSI reference resource. For example, to determine the value of the CQI, the UE 115 may use a post-processing SINR value or an estimated spectral efficiency and a CQI mapping function that is determined assuming a specific DMRS configuration obtained based on tracking one or more DMRS-related parameters from a CSI reference resource slot or equivalent CSI reference resource. The UE 115 may similarly determine the PMI and RI. In addition to the selected DMRS configuration option in the joint periodic DMRS and CSF report to the base station 105, the UE 115 may also include the CSF components determined as described above. In some cases, such as for periodic reporting, the joint DMRS and CSF report may define a CSF consistent with the currently used DMRS option (e.g., for the CSI reference resource) and additionally provide an indication of the selected DMRS configuration. In some other cases, such as for aperiodic reporting, the joint DMRS and CSF report may include a bundled list of selected DMRS options and corresponding CQIs, CSFs, or both.

[0103] Figure 2 An example of a wireless communication system 200 that supports a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting according to aspects of the present disclosure is illustrated. In some examples, the wireless communication system 200 can implement aspects of the wireless communication system 100 and can include a UE 115-a and a base station 105-a having a coverage area 110-a, which can be as described with reference to Figure 1 An example of a UE 115 and a base station 105 having a coverage area 110 is described. In some examples, the UE 115-a may be configured by the base station 105-a via a downlink communication link 205 to periodically transmit feedback reports to the base station 105-a via an uplink communication link 210. For example, the base station 105-a may request a joint periodic DMRS and CSF report 215 or a CSF report from the UE 115-a, and the UE 115-a may determine a DMRS configuration assumption for report evaluation (or some components thereof) based on a CSI reference resource slot 220, which may allow the UE 115-a to efficiently transmit the periodic joint DMRS and CSF report 215 or a CSF report to the base station 105-a. Such techniques may facilitate defining a representative of the currently used DMRS configuration assumed to be used for CQI determination in a floating manner in a timely manner after a DMRS adaptation process, and may allow the UE 115-a to report a CQI or CSF report consistent with the current DMRS configuration.

[0104] In some cases, the base station 105 may transmit a request for feedback to the UE 115 or may schedule a CSF report, which may be included in the CSF request 225. The CSF request 225 may schedule a joint DMRS and CSF report, a CSF report, or both. For example, the base station 105-a may transmit the CSF request 225-a to the UE 115-a via the downlink communication link 205. In some cases, such as for aperiodic reporting, the UE 115 may receive a trigger for a joint DMRS and CSF report (e.g., a CSF request 225). In some other cases, such as for periodic reporting, the UE 115 may receive control signaling (e.g., RRC signaling) that includes scheduling (such as periodicity and configuration) for a joint DMRS and CSF report. In some examples, the UE 115-a may determine a preferred DMRS configuration as part of a CSF report evaluation and reporting, a joint DMRS and CSF report 215, or both. The UE 115 may provide periodic or aperiodic joint DMRS and CSR reporting 215 (e.g., based on triggered, aperiodic or configured, periodic reporting) based on performing one or more measurements on one or more reference signals (e.g., CSI-RS, CSI-IM, TRS, etc.). For example, the UE 115 may perform CSF evaluation and may determine one or more CSF reporting components (e.g., PMI, RI, CQI, or a combination). In some cases, the CSF is evaluated based on one or more DMRS assumptions. In the case of joint periodic DMRS and CSF reporting, the UE 115 may report a CSF consistent with the current DMRS option (e.g., used on the CSI reference resource slot). In the case of extended aperiodic joint DMRS and CSF reporting, the UE may report several bundles of selected DMRS and corresponding CQI / CSF, where the CQI / CSF for each bundle is determined based on the corresponding selected DMRS configuration. DMRS reporting allows UE-assisted DMRS adaptation for the communication link. For aperiodic reporting, the base station 105 may dynamically signal parameters corresponding to the DMRS configurations addressed for DMRS selection and reporting (e.g., dynamically configurable in a corresponding CSI triggering state) in the joint aperiodic DMRS and CSF report 215. The base station 105 may configure a list of DMRS configurations addressed for DMRS selection and reporting (e.g., for periodic and aperiodic DMRS reporting). For aperiodic reporting, the base station 105 may configure a list of DMRS configurations to be addressed based on a bitmap indication configured in a corresponding CSI triggering state, which may allow for flexible reconfiguration.

[0105] In some cases, the current DMRS configuration (e.g., DMRS preference from the perspective of the base station 105-a or UE 115-a) may not change frequently. Thus, for CSF reports consistent with the current DMRS configuration, the UE 115 may determine the DMRS configuration based on the CSI reference resource time slots 220 that meet one or more validity criteria. The time slot or codeword 235 may have a time duration and may be allocated by the base station 105-a for uplink transmission, downlink transmission, or may be flexible (e.g., uplink or downlink). In some cases, the CSI reference resource time slot 220 may be a downlink time slot with a downlink subcarrier spacing. The UE 115 may determine the location of the CSI reference resource time slot 220 based on the time slot offset.

[0106] In some cases, the UE 115 may identify a CSI reference resource slot 220 and determine a rule, which may be associated with a valid downlink slot 230. The UE 115 may define a CSI reference resource hypothesis for CSF evaluation based on the valid CSI reference resource slot 220. For example, the UE 115-a may identify a CSI reference resource slot 220-a that carries a PDSCH assignment with a specific DMRS configuration. Each DMRS symbol 240 may have a position relative to a first symbol 235 of a PDSCH assignment on the CSI reference resource slot 220. In some cases, the UE 115 may determine one or more DMRS-related parameters 220 based on the PDSCH assignment on the CSI reference resource slot 220, based on one or more CSI reference resource hypotheses. For example, the UE 115 may determine (e.g., track) a time density, a frequency density, a boost value, or a combination of DMRS configurations for a PDSCH assignment on the CSI reference resource slot 220 based on one or more CSI reference resource hypotheses. The DMRS configuration may include an indication of one or more parameters, the location of the DMRS symbol 240 relative to the starting symbol 240 of the CSI reference resource slot 220, or both.

[0107] UE 115 may determine whether CSI reference resource slot 220 satisfies validity criteria. For example, the validity criteria may be a slot carrying a PDSCH allocation with a minimum duration. In some cases, the validity criteria may be defined as a downlink shared channel (e.g., PDSCH) allocation having a duration greater than a threshold number of symbols 235. The threshold number of symbols 235 may be predefined. The threshold duration validity criteria may be satisfied in addition to or in addition to other (e.g., conventional) CSI reference resource slot validity criteria, such as downlink or flexible symbol configuration and UE measurement gap configuration. UE 115-a can determine whether the CSI reference resource time slot 220-a meets the validity criteria, and can determine the DMRS configuration based on the PDSCH allocation in the CSI reference resource time slot 220 (for example, for the PDSCH allocation on the CSI reference resource time slot 220-a, the number of front-loaded DMRS codewords should be assumed; the number of additional DMRS codewords 240 and the positions of all DMRS codewords relative to the first codeword of the PDSCH allocation should be assumed based on the DMRS configuration used for the PDSCH allocation on the CSI reference resource time slot 220-a and the PDSCH allocation duration assumption of 12 OFDM codewords; for the PDSCH allocation on the CSI reference resource time slot 220-a, the DMRS type is assumed; the PDSCH allocation defined by the CSI reference resource may include DMRS codewords; for the PDSCH allocation on the CSI reference resource time slot 220-a, the number of DMRS boosting or corresponding DMRS CDM groups without data should be assumed and limited to the selected RI; or a combination). In some cases, the DMRS may be a type A DMRS with two boost value options (e.g., if the DMRS RE is not multiplexed with a data RE or is multiplexed with a data RE) or a type B DMRS with three boost value options (e.g., depending on the multiplexing of data and DMRS REs). In some examples, the number of frontloaded DMRS symbols 245 for the CSI reference resource may be based on the downlink shared channel allocation for the corresponding CSI reference resource slot 220. The UE 115 may determine the number of additional DMRS symbols 245 and the position of the DMRS symbols relative to the first symbol of the downlink shared channel allocation based on the DMRS configuration for the downlink shared channel allocation on the CSI reference resource slot 220 and the predefined downlink shared channel allocation duration (e.g., 12 OFDM symbols). In some cases, one or more downlink shared channel symbols may be DMRS symbols 240.

[0108] As described herein, CSF evaluation (e.g., including CQI evaluation) may be done consistently with a representative current DMRS configuration identified based on a CSI reference resource slot, up to a PDSCH allocation duration assumption, which may vary from allocation to allocation. In some cases, a PDSCH allocation duration of 12 OFDM symbols may be assumed, which may maintain a uniform assumption for all CSF reports regardless of the actual scheduled allocation size on the CSI reference resource slot. The PDSCH allocation duration assumption may be defined as part of the CSI reference resource definition, as described in more detail below.

[0109] The CSI reference resource definition may be defined such that a UE or base station may assume some parameters of the CSI reference resource when configured to report CQI (or other CSF reporting components, such as PMI or RI). For the CSI reference resource definition, some currently defined assumptions relied upon by the UE (and base station) may be modified to support CSF reporting consistent with the DMRS adaptation adopted by the system, so that the DMRS configuration assumptions will be defined in a floating manner and will follow the DMRS adaptation of the PDSCH. This approach may be particularly useful for periodic CSF reporting or periodic joint DMRS and CFS reporting, which may be based on DMRS configuration assumptions derived from the CSI reference resource slot (or equivalently based on the CSI reference resource). Some of the assumptions listed under the CSI reference resource definition may remain unchanged and may be predefined regardless of the PDSCH allocation parameters on the CSI reference resource slot. For example, the UE 115 may assume that the first two OFDM symbols corresponding to the CSI reference resource are occupied by control signaling. This assumption may be made regardless of the PDSCH allocation corresponding to the CSI reference resource slot identified by the UE 115. Furthermore, the UE 115 may assume that the number of PDSCH and DMRS symbols for the CSI reference resources is equal to 12. This assumption may also be made regardless of the actual size of the PDSCH allocation corresponding to the CSI reference resource slot identified by the UE.

[0110] For the CSI reference resource definition, the number of front-loaded DMRS symbols is the same as the PDSCH allocation corresponding to the CSI reference resource slot. In addition, the number of additional DMRS symbols and the position of all DMRS symbols relative to the first symbol of the PDSCH allocation can be assumed based on the DMRS configuration used for the PDSCH allocation on the CSI reference resource slot and the PDSCH allocation duration of 12 OFDM symbols. For the CSI reference resource definition, the DMRS type can be assumed to be the same as the PDSCH allocation on the CSI reference resource slot. In addition, it can be assumed that the PDSCH allocation addressed in the definition of the CSI reference resource contains DMRS symbols and DMRS resource element boosting, or correspondingly, the number of DMRS CDM groups without data is the same as the PDSCH allocation on the CSI reference resource slot and is limited by the selected RI.

[0111] In some examples, UE 115-a may determine that CSI reference resource slot 220-a does not satisfy new validity criteria (e.g., the downlink shared channel allocation of CSI reference resource slot 220-a may have a duration less than a new threshold number of symbols). In such a situation, UE 115-a may use one or more fallback options for DMRS assumptions and CSI reference resource slot determination. For example, UE 115-a may derive a DMRS configuration assumption for CSI reference resources used for periodic CSF reporting from the closest previous slot that is addressed as a replacement CSI reference resource slot 220 and satisfies the new validity condition (e.g., where the downlink shared channel allocation duration is greater than the new threshold number of symbols). For example, UE 115-a may identify replacement CSI reference resource slot 220-b as the closest previous valid CSI reference resource slot 220, where the downlink shared channel allocation duration is greater than the threshold number of symbols (and any other appropriate CSI reference resource slot validity criteria are satisfied). UE 115-a uses CSI reference resource slots 220-b to derive DMRS configuration assumptions for periodic DMRS and CSF reporting 215 (or conventional periodic CSF reporting). In such examples, UE 115-a may use the CSI reference resource definitions and assumptions described above based on CSI reference resource slots 220-b.

[0112] Additionally or alternatively, as a fallback option for not meeting the CSI reference resource slot validity criteria, UE 115-a may assume a predefined default DMRS configuration assumption for the CSI reference resources for periodic CSF reporting. That is, UE 115-a may determine one or more default parameters (e.g., the number of frontloaded DMRS symbols 245, the number of additional DMRS symbols 240, the position of DMRS symbols 240 relative to the first symbol of the PDSCH allocation, DMRS type, DMRS boosting, or a combination) based on the CSI reference resource assumption. In some cases, these assumptions may be configured by base station 105, preconfigured at UE 115, etc.

[0113] In some cases, the UE 115-a may calculate one or more CSF components 250 based on the DMRS configuration associated with the CSI reference resource. For example, the UE 115-a may determine a DMRS configuration to be assumed for CSF evaluation based on the CSI reference resource slot 220 (e.g., CSI reference resource slot 220-a, CSI reference resource slot 220-b, or another valid DL slot), and may calculate PMI, RI, or CQI based on the DMRS configuration. The UE 115-a may report the calculated CSF components to the base station 105-a in a joint DMRS and CSF report 215 or in a CSF report.

[0114] Figure 3 A set of operations supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting according to various aspects of the present disclosure are illustrated. In some examples, process flow 300 may implement various aspects of wireless communication system 100, wireless communication system 200, or both. Various aspects of process flow 300 may be implemented by UE 115, base station 105, or both as described in references 1 and 2. For example, process flow 300 may illustrate a process for determining a DMRS configuration based on a CSI reference resource for joint DMRS and CSF reporting or CSF reporting. Process flow 300 may be related to a process of determining channel characteristics using reference signals, which in turn may be used to determine recommended transmission parameters such as DMRS configuration, precoding matrix, rank, and MCS.

[0115] Those skilled in the art will appreciate that one or more operations described in process flow 300 may be performed earlier or later in the process, omitted, replaced, supplemented, or any combination thereof. Also, additional operations not included in process flow 300 described herein may be included.

[0116] At block 305, a wireless device (e.g., base station 105 or UE 115) may obtain an estimate of a channel between a transmitting device and a receiving device. Estimating the channel may include estimating the channel based on a reference signal (e.g., based on a CSI-RS, an uplink DMRS, an SRS, or a combination thereof). For example, if the wireless device is UE 115, estimating the channel may also include estimating a noise component of the channel based on interference management resources (e.g., based on CSI-IM resources).

[0117] In block 310, the wireless device may obtain an estimate of the Doppler frequency of the channel. The wireless device may estimate the Doppler frequency based on the received reference signal. For example, if the wireless device is a UE, the wireless device may estimate the Doppler frequency of the downlink channel based on the DMRS or TRS. If the wireless device is a base station 105, the wireless device may estimate the Doppler frequency of the uplink channel based on the DMRS or based on a specially configured SRS, as described herein. Alternatively, the base station 105 may determine the Doppler frequency of the uplink channel based on the Doppler frequency reported for the downlink channel. In some cases, the wireless device may also determine the delay spread based on the received reference signal (e.g., DMRS, TRS, or SRS).

[0118] At block 315, the wireless device may determine one or more effective channel matrices based on applying different combinations of precoding matrices and rank assumptions to the channel estimates determined during the channel estimation operation.

[0119] At block 320, the wireless device may classify the channel based on one or more effective channel estimates obtained after applying the tested precoding operation—for example, the channel may be classified according to its frequency selectivity or delay spread characteristics. The wireless device may also determine a delay spread for the channel based on the effective channel estimate. In some examples, the delay spread is determined for the effective channel estimate corresponding to the precoding matrix and rank that have been selected for the channel to optimize link efficiency.

[0120] At block 325, the wireless device may determine one or more post-processing signal quality ratios (e.g., SNR or SINR) based on the effective channel matrix obtained after applying the precoding operation. In some cases, for example, if the received reference signal has been precoded, the precoding operation may be omitted. In some cases, the wireless device may determine the signal quality ratio for each stream l, each resource element k, and each precoding matrix p. The one or more signal quality ratios may be expressed based on Equation 1 (e.g., if the wireless device does not obtain a noise estimate without a channel estimation error component). Additionally or alternatively, the one or more signal quality ratios may be determined based on Equation 2 (e.g., if the wireless device is UE 115) and based on CSI-RS and CSI-IM resources. When a noise estimate can be obtained without a channel estimation error, the wireless device may estimate the post-processing SINR using Equation 2. When a noise estimate cannot be obtained without a channel estimation error component, the wireless device may assume Equation 1 to represent the estimated post-processing SINR. The channel estimate may be represented using a channel matrix.

[0121] At block 330, the wireless device may perform a mapping from the SINR calculated for the received reference signal (e.g., CSI-RS, uplink DMRS, or SRS) to a plurality of SINRs projected for a DMRS configuration set addressed in the DMRS selection procedure for joint DMRS and CSF reporting. The estimated SINR may be represented as As referenced in this article Figure 2 As described, the wireless device may be based on a first set of characteristics of the channel (e.g., delay spread τ rms , Doppler frequency f D and / or noise variance (if the wireless device is a UE), or the delay spread τ rms , Doppler frequency f D The mapping may be identified by an indication of a combination of a received SNR and / or a received SNR (if the wireless device is a base station 105) and a configuration in which the received reference signal has a combination of a time interval, a frequency interval, and a power boost. The Doppler frequency may be determined based on the Doppler estimate. And the noise variance may be determined based on the noise estimate.

[0122] Before performing the mapping, the received reference signal is calculated The resource element set k for each stream l and precoding matrix p may be averaged in some manner. To calculate the SINR for the received reference signal, the wireless device may average the SINR sets calculated for different resource elements according to the selected precoding matrix and rank on a per-stream basis. In some cases, an indication of the precoding matrix and rank is provided to the SINR mapping operation based on a previous or concurrent determination of the precoding matrix and rank. The SINR mapping operation may use the indicated precoding matrix and rank to determine which version of the SINR estimate determined in block 325 to use for SINR mapping.

[0123] At block 335, the wireless device may select one of the DMRS configurations for joint DMRS and CSF reporting. The wireless device may select the DMRS configuration that maximizes the communication metric (such as effective spectral efficiency) of the channel. That is, the wireless device may select the DMRS configuration DMRS_i that produces a greater communication metric than the communication metric of the other DMRS configurations.

[0124] At block 337, the wireless device may determine a DMRS configuration for periodic CSF reporting or periodic joint DMRS and CSF reporting based on the CSI reference resource, as described with reference to Figure 2 As described. For example, the wireless device may track one or more DMRS-related parameters (e.g., time density, frequency density, boost value, or combination) of the CSI reference resource based on the CSI reference resource slot, and may determine the DMRS configuration DMRS_CSI based on these DMRS-related parameters, which are determined based on the PDSCH allocation on the CSI reference resource slot. In some cases, the wireless device may determine whether the CSI reference resource slot is a valid downlink slot for the CSI reference resource based on the duration of the downlink shared channel allocation being greater than a threshold number of symbols. In some examples, if the slot pointed to by the CSI reference resource slot time determination rule is not a valid downlink slot determined by the DMRS assumption or the general CSI reference resource assumption, the wireless device may follow the replacement option (or replace the CSI reference resource slot) to derive the DMRS configuration DMRS_CSI for the CSI reference resource based on the closest previous valid downlink slot from the perspective of the CSI reference resource criteria. In some other examples, if the CSI reference resource slot is not a valid downlink slot for DMRS parameter determination, the wireless device may assume a default DMRS configuration DMRS_CSI for the CSI reference resource.

[0125] At block 340, the wireless device may determine, for example based on the determined signal quality ratio, a precoding matrix and rank that allows for the highest spectral efficiency of the channel compared to other tested precoding and rank hypotheses. As described herein, the selected precoding matrix and rank may be used by an SINR mapping operation to determine an estimated average SINR for received reference signals corresponding to the selected precoding matrix and rank. The wireless device may also determine a corresponding spectral efficiency of the channel associated with the selected precoding matrix and rank. In some cases, a precoding matrix and rank selection operation is not performed.

[0126] At block 345, the wireless device may determine a value for the recommended CQI. The CQI determination may be based on the delay spread τ rms , Doppler frequency f D_max, and the DMRS configuration DMRS_CSI for periodic reporting or the DMRS configuration DMRS_i for aperiodic reporting, the spectrum efficiency SE, or a combination. The CQI determination may also be based on the estimated SE of the effective channel determined during the precoding matrix and rank selection operation. In some cases, the wireless device determines the value of the CQI associated with the MCS optimized for the DMRS configuration and channel conditions. In some cases, for example, if the wireless device is a base station 105, the CQI selection operation is replaced by the MCS selection.

[0127] In block 350, the wireless device may generate a report (e.g., if the wireless device is a UE, a CSF report is generated), which may include an indication of the recommended one or more DMRS configurations. In some examples, generating the report includes generating a CSF report including PMI, RI, CQI, and a DMRS configuration indicator (DMI). The size of the DMI field may be based on the number of DMRS configurations tested / available for communication. In other cases, the CSF report may jointly encode CQI and DMI based on the relationship between the CQI value and the DMRS configuration. The jointly encoded CQI and DMI may be communicated through the CQI field or through the combined CQI / DMI field. By including the jointly encoded CQI and DMI in the CQI field, the CSF report format may not be changed while being used to convey additional data, and joint CQI and DMI decoding may also be used to reduce overhead signaling. In some examples, for example, if the transmitting device is a base station 105, generating the report includes generating a control message recommending that the transmitting device use the indicated DMRS configuration for subsequent transmissions.

[0128] The wireless device may transmit the report to the transmitting device. When the report includes or is a CSF report or a joint DMRS and CSF report, the transmitting device may adapt the transmission parameters based on the received CSF report or joint DMRS and CSF report.

[0129] Figure 4 An example of a process flow 400 supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting in accordance with various aspects of the present disclosure is illustrated. In some examples, process flow 400 may implement aspects of wireless communication system 100, wireless communication system 200, or both, and process flow 300. Process flow 400 may illustrate an example of a UE 115 (such as UE 115-b) or a base station 105 (such as base station 105-b) identifying a DMRS configuration for CSF reporting or joint DMRS and CSF reporting based on CSI reference resources. The following alternative examples may be implemented, in which some of the processes are performed or not performed in an order different from that described. In some cases, each process may include additional features not mentioned below, or further processes may be added.

[0130] At 405, UE 115-b may receive a configuration for periodic CSF reporting or joint DMRS and CSF reporting from base station 105-b. For example, UE 115-b may receive (e.g., via RRC signaling) a CSF report request that configures the UE to transmit periodic CSF reports or joint periodic DMRS and CSF reports. The CSF report request may trigger UE 115-b to perform one or more measurements on one or more reference signals.

[0131] At 410 and 415, UE 115-b and base station 105-b may each identify a DMRS configuration based on the CSI reference resource. In some cases, UE 115-b may identify the DMRS configuration. In some cases, the CSI reference resource may include a number of frontloaded DMRS symbols, a number of additional DMRS symbols, a DMRS type, a DMRS boost, or a combination from a DMRS configuration associated with a downlink shared channel allocation on a CSI reference resource slot associated with the corresponding CSI reference resource. The DMRS type may be based on the DMRS configuration, the CSI reference resource slot, or both.

[0132] At 420 and 425, the UE 115-b and the base station 105-b may identify a CSI reference resource slot for determining a DMRS configuration based on a slot offset and a validity criterion of the CSI reference resource slot, respectively. In some cases, the validity criterion may include a minimum threshold number of symbols for a downlink shared channel (e.g., PDSCH) allocation. In some cases, the UE 115-b may determine that the validity criterion is not met for the CSI reference resource slot. That is, the downlink shared channel allocation for the CSI reference resource slot may be less than the threshold number of symbols. The UE 115-b may identify a replacement CSI reference resource slot to be addressed to obtain a CSI reference resource hypothesis based on a replacement CSI reference resource slot that meets the validity criterion and occurs in a previous slot that is closest to the initial CSI reference resource slot.

[0133] In some cases, UE 115-b and base station 105-b may derive DMRS configuration assumptions for CSF evaluation based on downlink shared channel allocations on CSI reference resource slots (e.g., CSI reference resource slots that meet validity criteria at 420 and 425), respectively. In some cases, UE 115-b may derive one or more parameters corresponding to the CSI reference resource. For example, assuming a predefined PDSCH allocation duration (e.g., a duration of 12 OFDM symbols), a DMRS type (e.g., type A or type B), DMRS boosting or a corresponding number of data-free DMRS CDM groups, or a combination, UE 115-b may define a number of frontloaded DMRS symbols, a number of additional DMRS symbols, and corresponding positions of all DMRS symbols relative to the first symbol of the downlink shared channel allocation. Additionally or alternatively, if the validity criteria are not met for the CSI reference resource slot at 420 and 425, the UE 115-b may derive a DMRS configuration hypothesis for CSF evaluation based on a default DMRS configuration. In some cases, a default DMRS configuration may be predefined for the CSI reference resource hypothesis. The default DMRS configuration may explicitly or implicitly define one or more default parameters (e.g., the number of frontloaded DMRS symbols, the number of additional DMRS symbols, the position of all DMRS symbols relative to the first symbol of a downlink shared channel allocation, DMRS type, DMRS boosting, or a combination).

[0134] At 440, UE 115-b may generate (e.g., calculate) one or more CSF components based on the DMRS configuration. Additionally, UE 115-b may select the most convenient DMRS configuration to be reported in the joint DMRS and CSF report. In some cases, DMRS hypothesis selection may be done based on a DMRS hypothesis list configured by the network for corresponding reporting joint DMRS and CSF reporting.

[0135] At 445, the UE 115-b may transmit a periodic CSF report or a joint DMRS and CSF report to the base station 105-b. The periodic CSF report or the joint DMRS and CSF report may include an indication of one or more components of the CSF and an indication of a recommended DMRS option.

[0136] Figure 5 A block diagram 500 of a device 505 supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting according to aspects of the present disclosure is shown. The device 505 may be an example of aspects of a UE 115 as described herein. The device 505 may include a receiver 510, a communication manager 515, and a transmitter 520. The device 505 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0137] The receiver 510 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to DMRS configuration assumptions for CSI reference resources for periodic CSF reporting, etc.). The information may be passed to other components of the device 505. The receiver 510 may be a reference Figure 8 Examples of aspects of the described transceiver 820. The receiver 510 may utilize a single antenna or utilize a collection of antennas.

[0138] The communication manager 515 may receive a configuration for periodic CSF reporting, identify a DMRS configuration associated with a first CSI reference resource based on receiving the configuration, generate one or more CSF components based on the DMRS configuration associated with the first CSI reference resource, and transmit an indication of the generated one or more CSF components to the base station in a periodic CSF report. The communication manager 515 may be an example of aspects of the communication manager 810 described herein. In some examples, generating the one or more CSF components may include: calculating the one or more components based on the DMRS configuration.

[0139] The actions performed by the communication manager 515 as described herein may be implemented to achieve one or more potential advantages. An implementation may enable a UE to identify a DMRS configuration based on a CSI reference resource in a valid CSI reference resource slot. The identified DMRS configuration may enable the UE to transmit a periodic joint DMRS and CSF report or CSF report with reduced signaling overhead compared to an aperiodic joint DMRS and CSF report or CSF report, which may improve communication latency (e.g., related to non-essential DMRS configuration updates for aperiodic reporting), as well as other advantages.

[0140] Based on implementing DMRS configuration based on CSI reference resources as described herein, a processor of a UE or base station (e.g., a processor controlling receiver 510, communication manager 515, transmitter 520, or a combination thereof) can reduce the impact or likelihood of inefficient resource utilization due to unnecessary non-periodic joint DMRS and CSF reporting or CSF reporting, while ensuring relatively efficient communications. For example, the DMRS configuration identification techniques described herein can utilize validity criteria for CSI reference resource time slots, which can achieve power savings at the UE (e.g., due to less frequent reporting), as well as other benefits.

[0141] The communication manager 515 or its subcomponents may be implemented in hardware, in code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communication manager 515 or its subcomponents may be performed by a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device designed to perform the functions described in the present disclosure, discrete gate or transistor logic, discrete hardware components, or any combination thereof.

[0142] The communication manager 515 or its subcomponents may be physically located at various locations, including being distributed such that portions of functionality are implemented by one or more physical components at different physical locations. In some examples, according to various aspects of the present disclosure, the communication manager 515 or its subcomponents may be separate and distinct components. In some examples, according to various aspects of the present disclosure, the communication manager 515 or its subcomponents may be combined with one or more other hardware components, including but not limited to input / output (I / O) components, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof.

[0143] The transmitter 520 may transmit signals generated by other components of the device 505. In some examples, the transmitter 520 may be co-located with the receiver 510 in a transceiver module. For example, the transmitter 520 may be a reference Figure 8 Examples of aspects of the described transceiver 820. The transmitter 520 may utilize a single antenna or utilize a collection of antennas.

[0144] Figure 6 A block diagram 600 of a device 605 supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting according to aspects of the present disclosure is shown. The device 605 may be an example of aspects of the device 505 or UE 115 as described herein. The device 605 may include a receiver 610, a communication manager 615, and a transmitter 635. The device 605 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0145] The receiver 610 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to dynamic DMRS configuration assumptions for CSI reference resources for periodic CSF reporting, etc.). The information may be passed to other components of the device 605. The receiver 610 may be a reference Figure 8 Examples of aspects of the described transceiver 820. The receiver 610 may utilize a single antenna or utilize a collection of antennas.

[0146] Communications manager 615 may be an example of aspects of communications manager 515 as described herein. Communications manager 615 may include CSF reporting component 620, CSI reference resource component 625, and DMRS configuration component 630. Communications manager 615 may be an example of aspects of communications manager 810 as described herein.

[0147] The CSF reporting component 620 may receive a configuration for periodic CSF reporting. The CSI reference resource component 625 may identify a DMRS configuration associated with a first CSI reference resource based on receiving the configuration. The DMRS configuration component 630 may generate one or more CSF components based on the DMRS configuration associated with the first CSI reference resource. The CSF reporting component 620 may transmit an indication of the generated one or more CSF components to the base station in a periodic CSF report. In some examples, generating the one or more CSF components may include: calculating the one or more components based on the DMRS configuration.

[0148] The transmitter 635 can transmit signals generated by other components of the device 605. In some examples, the transmitter 635 can be co-located with the receiver 610 in a transceiver module. For example, the transmitter 635 can be a reference Figure 8 Examples of aspects of the described transceiver 820. The transmitter 635 may utilize a single antenna or utilize a collection of antennas.

[0149] Figure 7 A block diagram 700 of a communication manager 705 supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting in accordance with aspects of the present disclosure is shown. The communication manager 705 may be an example of aspects of the communication manager 515, the communication manager 615, or the communication manager 810 described herein. The communication manager 705 may include a CSF reporting component 710, a CSI reference resource component 715, a DMRS configuration component 720, and a validity criteria component 725. Each of these modules may communicate directly or indirectly with each other (e.g., via one or more buses).

[0150] CSF reporting component 710 can receive a configuration for periodic CSF reporting. In some cases, the periodic CSF reporting includes periodic joint DMRS and CSF reporting.

[0151] The CSI reference resource component 715 may identify a DMRS configuration associated with the first CSI reference resource based on receiving the configuration. In some examples, for the CSI reference resource definition, the CSI reference resource component 715 may identify a number of frontloaded DMRS symbols from the DMRS configuration associated with a physical downlink shared channel allocation on a first CSI reference resource slot corresponding to the first CSI reference resource.

[0152] In some examples, the CSI reference resource component 715 can identify a first CSI reference resource slot corresponding to the first CSI reference resource based on the CSI reference resource slot offset and the first CSI reference resource slot validity criterion. In some examples, the DMRS configuration component 720 can derive a DMRS configuration hypothesis for CSF evaluation based on a downlink shared channel (e.g., PDSCH) allocation on the first CSI reference resource slot.

[0153] The validity criteria component 725 may identify the second CSI reference resource time slot based on the CSI reference resource time slot offset and the first CSI reference resource time slot validity criteria. In some examples, the CSI reference resource component 715 may identify an additional CSI reference resource time slot validity criteria for the second CSI reference resource time slot, wherein the additional CSI reference resource time slot validity criteria includes a minimum threshold number of symbols for a physical downlink shared channel allocation on the second CSI reference resource time slot.

[0154] In some examples, the validity criteria component 725 may determine that the additional CSI reference resource slot validity criteria are not satisfied for the second CSI reference resource slot. In some examples, the validity criteria component 725 may identify the first CSI reference resource slot corresponding to the first CSI reference resource based at least in part on the first CSI reference resource slot satisfying the additional CSI reference resource slot validity criteria, satisfying the first CSI reference resource slot validity criteria, and occurring in a previous slot closest to the second CSI reference resource slot. In some examples, the DMRS configuration component 720 may derive a DMRS configuration hypothesis for CSF evaluation based on a physical downlink shared channel allocation on the first CSI reference resource slot. In some examples, the DMRS configuration component 720 may derive one or more parameters corresponding to the first CSI reference resource, explicitly or implicitly defining the one or more parameters, the one or more parameters including the number of front-loaded DMRS symbols, the number of additional DMRS symbols, the position of all DMRS symbols relative to the first symbol of the physical downlink shared channel allocation, the DMRS type, or a combination thereof.

[0155] In some examples, the validity criteria component 725 can determine that the additional CSI reference resource slot validity criteria is not satisfied for the second CSI reference resource slot. In some examples, the DMRS configuration component 720 can derive a DMRS configuration hypothesis for CSF evaluation based on a default DMRS configuration predefined for the CSI reference resource hypothesis. In some cases, the default DMRS configuration explicitly or implicitly defines one or more default parameters, the one or more default parameters including the number of frontloaded DMRS symbols, the number of additional DMRS symbols, the position of all DMRS symbols relative to the first symbol of a physical downlink shared channel allocation, the DMRS type, or a combination thereof.

[0156] In some examples, the CSI reference resource component 715 may identify, for a CSI reference resource definition, a number of additional DMRS symbols and the positions of all DMRS symbols relative to a first symbol of a downlink shared channel (e.g., PDSCH) allocation based on a DMRS configuration associated with a physical downlink shared channel allocation on a first CSI reference resource slot of a first CSI reference resource and based on a predefined assumption of the duration of the physical downlink shared channel allocation.

[0157] DMRS configuration component 720 can generate one or more CSF components based on a DMRS configuration associated with a first CSI reference resource.In some cases, the DMRS type is based on a DMRS configuration associated with a physical downlink shared channel allocation on a first CSI reference resource slot of the first CSI reference resource.

[0158] In some examples, CSF reporting component 710 can transmit an indication of the generated one or more CSF components to a base station in a periodic CSF report.

[0159] Figure 8 A diagram of a system 800 including a device 805 supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting according to various aspects of the present disclosure is shown. The device 805 may be an example of a device 505, a device 605, or a UE 115 as described herein or include components of the above devices. The device 805 may include components for two-way voice and data communications, including components for transmitting and receiving communications, including a communication manager 810, an I / O controller 815, a transceiver 820, an antenna 825, a memory 830, and a processor 840. These components may be in electronic communication via one or more buses (e.g., a bus 845).

[0160] The communication manager 810 may receive a configuration for periodic CSF reporting, identify a DMRS configuration associated with a first CSI reference resource based on the received configuration, generate one or more CSF components based on the DMRS configuration associated with the first CSI reference resource, and transmit an indication of the generated one or more CSF components to a base station in a periodic CSF report.

[0161] I / O controller 815 can manage input and output signals of device 805. I / O controller 815 can also manage peripheral devices that are not integrated into device 805. In some cases, I / O controller 815 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 815 can utilize an operating system, such as Or another known operating system. In other cases, I / O controller 815 may represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some cases, I / O controller 815 may be implemented as part of a processor. In some cases, a user may interact with device 805 via I / O controller 815 or via hardware components controlled by I / O controller 815.

[0162] The transceiver 820 may communicate bidirectionally via one or more antennas, wired or wireless links, as described above. For example, the transceiver 820 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 820 may also include a modem to modulate packets and provide the modulated packets to an antenna for transmission, and demodulate packets received from an antenna.

[0163] In some cases, a wireless device may include a single antenna 825. However, in some cases, the device may have more than one antenna 825, which may be capable of transmitting or receiving multiple wireless transmissions concurrently.

[0164] The memory 830 may include random access memory (RAM) and read-only memory (ROM). The memory 830 may store computer-readable, computer-executable code 835 including instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, the memory 830 may include, among other things, a basic I / O system (BIOS) that may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0165] The processor 840 may include an intelligent hardware device (e.g., a general purpose processor, a DSP, a central processing unit (CPU), a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor 840 may be configured to operate a memory array using a memory controller. In other cases, the memory controller may be integrated into the processor 840. The processor 840 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 830) to cause the device 805 to perform various functions (e.g., various functions or tasks supporting dynamic DMRS configuration assumptions for CSI reference resources for periodic CSF reporting).

[0166] The code 835 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting wireless communications. The code 835 may be stored in a non-transitory computer-readable medium, such as a system memory or other type of memory. In some cases, the code 835 may not be directly executed by the processor 840, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0167] Fig. 9 A block diagram 900 of a device 905 supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting according to various aspects of the present disclosure is shown. The device 905 may be an example of various aspects of a base station 105 as described herein. The device 905 may include a receiver 910, a communication manager 915, and a transmitter 920. The device 905 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0168] The receiver 910 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to dynamic DMRS configuration assumptions for CSI reference resources for periodic CSF reporting, etc.). The information may be passed to other components of the device 905. The receiver 910 may be a reference Fig.12 Examples of various aspects of the described transceiver 1220. The receiver 910 may utilize a single antenna or utilize a collection of antennas.

[0169] The communication manager 915 may transmit a configuration for periodic CSF reporting, identify a DMRS configuration associated with a first CSI reference resource based on transmitting the configuration, receive an indication of one or more CSF components in the periodic CSF report from the UE, and interpret the periodic CSF report based on the identified DMRS configuration. The communication manager 915 may be an example of aspects of the communication manager 1210 described herein.

[0170] The communication manager 915 or its subcomponents may be implemented in hardware, in code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communication manager 915 or its subcomponents may be performed by a general purpose processor, DSP, ASIC, FPGA or other programmable logic device designed to perform the functions described in the present disclosure, discrete gate or transistor logic, discrete hardware components, or any combination thereof.

[0171] The communication manager 915 or its subcomponents may be physically located at various locations, including being distributed such that portions of functionality are implemented by one or more physical components at different physical locations. In some examples, according to various aspects of the present disclosure, the communication manager 915 or its subcomponents may be separate and distinct components. In some examples, according to various aspects of the present disclosure, the communication manager 915 or its subcomponents may be combined with one or more other hardware components, including but not limited to input / output (I / O) components, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof.

[0172] The transmitter 920 may transmit signals generated by other components of the device 905. In some examples, the transmitter 920 may be co-located with the receiver 910 in a transceiver module. For example, the transmitter 920 may be a reference Fig.12 Examples of aspects of the described transceiver 1220. The transmitter 920 may utilize a single antenna or utilize a collection of antennas.

[0173] Fig.10 A block diagram 1000 of a device 1005 supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting according to aspects of the present disclosure is shown. The device 1005 may be an example of aspects of the device 905 or base station 105 as described herein. The device 1005 may include a receiver 1010, a communication manager 1015, and a transmitter 1035. The device 1005 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0174] The receiver 1010 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to dynamic DMRS configuration assumptions for CSI reference resources for periodic CSF reporting, etc.). The information may be passed to other components of the device 1005. The receiver 1010 may be a reference Fig.12 Examples of various aspects of the described transceiver 1220. The receiver 1010 may utilize a single antenna or utilize a collection of antennas.

[0175] The communication manager 1015 may be an example of aspects of the communication manager 915 as described herein. The communication manager 1015 may include a CSF reporting component 1020, a CSI reference resource component 1025, and a DMRS configuration component 1030. The communication manager 1015 may be an example of aspects of the communication manager 1210 described herein.

[0176] The CSF reporting component 1020 may transmit a configuration for periodic CSF reporting. The CSI reference resource component 1025 may identify a DMRS configuration associated with a first CSI reference resource based on transmitting the configuration. The CSF reporting component 1020 may receive an indication of one or more CSF components in a periodic CSF report from the UE. The DMRS configuration component 1030 may interpret the periodic CSF report based on the identified DMRS configuration.

[0177] The transmitter 1035 can transmit signals generated by other components of the device 1005. In some examples, the transmitter 1035 can be co-located with the receiver 1010 in a transceiver module. For example, the transmitter 1035 can be a reference Fig.12 Examples of various aspects of the described transceiver 1220. The transmitter 1035 may utilize a single antenna or utilize a collection of antennas.

[0178] Fig.11 A block diagram 1100 of a communication manager 1105 supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting in accordance with aspects of the present disclosure is shown. The communication manager 1105 may be an example of aspects of the communication manager 915, the communication manager 1015, or the communication manager 1210 described herein. The communication manager 1105 may include a CSF reporting component 1110, a CSI reference resource component 1115, a DMRS configuration component 1120, and a validity criteria component 1125. Each of these modules may communicate directly or indirectly with each other (e.g., via one or more buses).

[0179] The CSF reporting component 1110 may transmit a configuration for periodic CSF reporting. The CSI reference resource component 1115 may identify a DMRS configuration associated with a first CSI reference resource based on transmitting the configuration. The validity criteria component 1125 may identify a time slot of the first CSI reference resource based on a CSI reference resource time slot offset and a first CSI reference resource time slot validity criteria.

[0180] In some examples, the CSI reference resource component 1115 may identify an additional CSI reference resource time slot validity criterion for the time slot identified by the first CSI reference resource, wherein the additional CSI reference resource time slot validity criterion includes a minimum threshold number of symbols allocated for a physical downlink shared channel on the time slot identified by the first CSI reference resource. In some examples, the CSI reference resource component 1115 may identify a second CSI reference resource based on a CSI reference resource time condition. In some examples, the validity criterion component 1125 may determine that the additional CSI reference resource time slot validity criterion is not satisfied for the second CSI reference resource. In some examples, the CSI reference resource component 1115 may identify the first CSI reference resource based at least in part on the first CSI reference resource satisfying the additional CSI reference resource time slot validity criterion and occurring before the second CSI reference resource. In some examples, the DMRS configuration component 1120 may derive the DMRS configuration based on the first CSI reference resource. In some examples, the CSI reference resource component 1115 may derive one or more parameters corresponding to the first CSI reference resource, the one or more parameters including time density, frequency density, boost value, or a combination thereof.

[0181] In some examples, validity criteria component 1125 may determine that the additional CSI reference resource time slot validity criteria is not met for the second CSI reference resource. In some examples, DMRS configuration component 1120 may derive the DMRS configuration based on a default DMRS configuration. In some cases, the default DMRS configuration includes one or more default parameters, the one or more default parameters including time density, frequency density, boost value, or a combination thereof.

[0182] In some examples, the CSI reference resource component 1115 may identify, for a CSI reference resource definition, a number of frontloaded DMRS symbols from a DMRS configuration associated with a downlink allocation for a first CSI reference resource.

[0183] In some examples, the CSI reference resource component 1115 may identify, for a CSI reference resource definition, a number of additional DMRS symbols from a DMRS configuration associated with a downlink assignment and after a number of front-loaded DMRS symbols and a position of each additional DMRS symbol relative to a starting DMRS symbol. In some cases, the DMRS type is based on a DMRS configuration associated with a downlink assignment, and the downlink assignment includes one or more DMRS symbols. In some cases, the DMRS configuration includes one or more parameters corresponding to a first CSI reference resource, the one or more parameters including a time density, a frequency density, a boost value, or a combination thereof.

[0184] In some examples, CSF reporting component 1110 can receive an indication of one or more CSF components in a periodic CSF report from the UE. In some cases, the indication of one or more CSF components is associated with a joint DMRS and CSF report. DMRS configuration component 1120 can interpret the periodic CSF report based on the identified DMRS configuration.

[0185] Fig.12 A diagram of a system 1200 including a device 1205 supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting according to various aspects of the present disclosure is shown. The device 1205 may be an example of a device 905, a device 1005, or a base station 105 as described herein or include components thereof. The device 1205 may include components for two-way voice and data communications, including components for transmitting and receiving communications, including a communication manager 1210, a network communication manager 1215, a transceiver 1220, an antenna 1225, a memory 1230, a processor 1240, and an inter-station communication manager 1245. These components may be in electronic communication via one or more buses (e.g., bus 1250).

[0186] The communication manager 1210 may transmit a configuration for periodic CSF reporting, identify a DMRS configuration associated with a first CSI reference resource based on transmitting the configuration, receive an indication of one or more CSF components in the periodic CSF report from the UE, and interpret the periodic CSF report based on the identified DMRS configuration.

[0187] The network communications manager 1215 may manage communications with the core network (eg, via one or more wired backhaul links). For example, the network communications manager 1215 may manage the delivery of data communications for client devices, such as one or more UEs 115.

[0188] The transceiver 1220 may communicate bidirectionally via one or more antennas, wired or wireless links, as described above. For example, the transceiver 1220 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 1220 may also include a modem to modulate packets and provide the modulated packets to an antenna for transmission, and demodulate packets received from an antenna.

[0189] In some cases, a wireless device may include a single antenna 1225. However, in some cases, the device may have more than one antenna 1225, which may be capable of transmitting or receiving multiple wireless transmissions concurrently.

[0190] Memory 1230 may include RAM, ROM, or a combination thereof. Memory 1230 may store computer readable code 1235 including instructions that, when executed by a processor (e.g., processor 1240), cause the device to perform various functions described herein. In some cases, memory 1230 may include, among other things, a BIOS that may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0191] Processor 1240 may include an intelligent hardware device (e.g., a general purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, processor 1240 may be configured to operate a memory array using a memory controller. In some cases, the memory controller may be integrated into processor 1240. Processor 1240 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1230) to cause device 1205 to perform various functions (e.g., functions or tasks supporting dynamic DMRS configuration assumptions for CSI reference resources for periodic CSF reporting).

[0192] The inter-site communication manager 1245 may manage communications with other base stations 105 and may include a controller or scheduler for controlling communications with UE 115 in cooperation with other base stations 105. For example, the inter-site communication manager 1245 may coordinate scheduling of transmissions to UE 115 for various interference mitigation techniques, such as beamforming or joint transmission. In some examples, the inter-site communication manager 1245 may provide an X2 interface within an LTE / LTE-A wireless communication network technology to provide communications between base stations 105.

[0193] The code 1235 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting wireless communications. The code 1235 may be stored in a non-transitory computer-readable medium, such as a system memory or other type of memory. In some cases, the code 1235 may not be directly executed by the processor 1240, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0194] Fig.13 A flow chart illustrating a method 1300 for supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting according to various aspects of the present disclosure is shown. The operations of the method 1300 may be implemented by a UE 115 or a component thereof as described herein. For example, the operations of the method 1300 may be implemented by a UE 115 or a component thereof as described herein. Figures 5 to 8In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0195] At 1305, the UE may receive a configuration for periodic CSF reporting. The operations of 1305 may be performed according to the methods described herein. In some examples, aspects of the operations of 1305 may be performed as described with reference to Figures 5 to 8 The CSF reporting component described is used to perform the

[0196] At 1310, the UE may identify a DMRS configuration associated with a first CSI reference resource based on receiving the configuration. The operations of 1310 may be performed according to the methods described herein. In some examples, aspects of the operations of 1310 may be performed as described with reference to Figures 5 to 8 The described CSI reference resource components are performed.

[0197] At 1315, the UE may generate one or more CSF components based on the DMRS configuration associated with the first CSI reference resource. The operations of 1315 may be performed according to the methods described herein. In some examples, aspects of the operations of 1315 may be performed as described with reference to Figures 5 to 8 The described DMRS configuration component is performed.

[0198] At 1320, the UE may transmit an indication of the generated one or more CSF components to the base station in a periodic CSF report. The operations of 1320 may be performed according to the methods described herein. In some examples, aspects of the operations of 1320 may be performed as described with reference to Figures 5 to 8 The CSF reporting component described is used to perform the

[0199] Fig.14 A flow chart illustrating a method 1400 for supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting according to various aspects of the present disclosure is shown. The operations of the method 1400 may be implemented by a UE 115 or a component thereof as described herein. For example, the operations of the method 1400 may be implemented by a UE 115 or a component thereof as described herein. Figures 5 to 8 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0200] At 1405, the UE may receive a configuration for periodic CSF reporting. The operations of 1405 may be performed according to the methods described herein. In some examples, aspects of the operations of 1405 may be performed as described with reference to Figures 5 to 8 The CSF reporting component described is used to perform the

[0201] At 1410, the UE may identify a DMRS configuration associated with a first CSI reference resource based on receiving the configuration. The operations of 1410 may be performed according to the methods described herein. In some examples, aspects of the operations of 1410 may be performed as described with reference to Figures 5 to 8 The described CSI reference resource components are performed.

[0202] At 1415, the UE may identify a first CSI reference resource slot corresponding to a first CSI reference resource based on the CSI reference resource slot offset and the first CSI reference resource slot validity criterion. The operations of 1415 may be performed according to the methods described herein. In some examples, aspects of the operations of 1415 may be performed as described with reference to Figures 5 to 8 The described CSI reference resource components are performed.

[0203] At 1420, the UE may derive a DMRS configuration hypothesis for CSF evaluation based on a physical downlink shared channel allocation on a first CSI reference resource slot. The operations of 1420 may be performed according to the methods described herein. In some examples, aspects of the operations of 1420 may be performed as described with reference to Figures 5 to 8 The described DMRS configuration component is performed.

[0204] At 1425, the UE may generate one or more CSF components based on the DMRS configuration associated with the first CSI reference resource. The operations of 1425 may be performed according to the methods described herein. In some examples, aspects of the operations of 1425 may be performed as described with reference to Figures 5 to 8 The described DMRS configuration component is performed.

[0205] At 1430, the UE may transmit an indication of the generated one or more CSF components to the base station in a periodic CSF report. The operations of 1430 may be performed according to the methods described herein. In some examples, aspects of the operations of 1430 may be performed as described with reference to Figures 5 to 8 The CSF reporting component described is used to perform the

[0206] Fig.15 A flow chart illustrating a method 1500 for supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting according to aspects of the present disclosure is shown. The operations of the method 1500 may be implemented by a base station 105 or components thereof as described herein. For example, the operations of the method 1500 may be implemented by a base station 105 or components thereof as described herein. Figures 9 to 12 In some examples, the base station may execute an instruction set to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, the base station may use dedicated hardware to perform various aspects of the functions described below.

[0207] At 1505, the base station may transmit a configuration for periodic CSF reporting. The operations of 1505 may be performed according to the methods described herein. In some examples, aspects of the operations of 1505 may be performed as described with reference to Figures 9 to 12 The CSF reporting component described is used to perform the

[0208] At 1510, the base station may identify a DMRS configuration associated with a first CSI reference resource based on transmitting the configuration. The operations of 1510 may be performed according to the methods described herein. In some examples, aspects of the operations of 1510 may be performed as described with reference to Figures 9 to 12 The described CSI reference resource components are performed.

[0209] At 1515, the base station may receive an indication of one or more CSF components in a periodic CSF report from the UE. The operations of 1515 may be performed according to the methods described herein. In some examples, aspects of the operations of 1515 may be performed as described with reference to Figures 9 to 12 The CSF reporting component described is used to perform the

[0210] At 1520, the base station may interpret the periodic CSF report based on the identified DMRS configuration. The operations of 1520 may be performed according to the methods described herein. In some examples, aspects of the operations of 1520 may be described as described with reference to Figures 9 to 12 The described DMRS configuration component is performed.

[0211] Fig.16 A flow chart illustrating a method 1600 for supporting a dynamic DMRS configuration assumption for CSI reference resources for periodic CSF reporting according to aspects of the present disclosure is shown. The operations of the method 1600 may be implemented by a base station 105 or components thereof as described herein. For example, the operations of the method 1600 may be implemented by a base station 105 or components thereof as described herein. Figures 9 to 12 In some examples, the base station may execute an instruction set to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, the base station may use dedicated hardware to perform various aspects of the functions described below.

[0212] At 1605, the base station may transmit a configuration for periodic CSF reporting. The operations of 1605 may be performed according to the methods described herein. In some examples, aspects of the operations of 1605 may be performed as described with reference to Figures 9 to 12 The CSF reporting component described is used to perform the

[0213] At 1610, the base station may identify a DMRS configuration associated with a first CSI reference resource based on transmitting the configuration. The operations of 1610 may be performed according to the methods described herein. In some examples, aspects of the operations of 1610 may be performed as described with reference to Figures 9 to 12 The described CSI reference resource components are performed.

[0214] At 1615, the base station may receive an indication of one or more CSF components in a periodic CSF report from the UE. The operations of 1615 may be performed according to the methods described herein. In some examples, aspects of the operations of 1615 may be performed as described with reference to Figures 9 to 12 The CSF reporting component described is used to perform the

[0215] At 1620, the base station may interpret the periodic CSF report based on the identified DMRS configuration. The operations of 1620 may be performed according to the methods described herein. In some examples, aspects of the operations of 1620 may be as described with reference to Figures 9 to 12 The described DMRS configuration component is performed.

[0216] At 1625, the base station may identify a time slot of the first CSI reference resource based on the CSI reference resource time slot offset and the first CSI reference resource time slot validity criterion. The operations of 1625 may be performed according to the methods described herein. In some examples, aspects of the operations of 1625 may be performed as described with reference to Figures 9 to 12 The described effectiveness criteria components are implemented.

[0217] It should be noted that the methods described herein describe possible implementations, and that the operations and steps may be rearranged or otherwise modified and other implementations are possible. Furthermore, aspects from two or more methods may be combined.

[0218] Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for example purposes, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein may also be applicable to networks other than LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques may be applied to various other wireless communication systems, such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and other systems and radio technologies not explicitly mentioned herein.

[0219] The information and signals described herein may be represented using any of a variety of different techniques and technologies. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout this description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0220] The various illustrative blocks and components described in conjunction with the disclosure herein may be implemented or performed with a general purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0221] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted by a computer-readable medium as one or more instructions or codes. Other examples and implementations fall within the scope of the present disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination thereof. Features that implement the functions may also be physically located in various locations, including being distributed so that parts of the functions are implemented at different physical locations.

[0222] Computer-readable medium includes both non-transient computer storage medium and communication medium, and it includes any medium that facilitates computer program to transfer from one place to another place.Non-transient storage medium can be any available medium that can be accessed by general or special-purpose computer.As an example and not limitation, non-transient computer-readable medium can include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disk (CD) ROM or other optical disk storage, disk storage or other magnetic storage device, or can be used to carry or store instruction or data structure form of desired program code means and can be accessed by general or special-purpose computer or general or special-purpose processor any other non-transient medium.Similarly, any connection is also properly referred to as computer-readable medium.For example, if software is transmitted from website, server or other remote source using coaxial cable, optical fiber cable, twisted pair, digital subscriber line (DSL) or wireless technology such as infrared, radio and microwave, then this coaxial cable, optical fiber cable, twisted pair, DSL or wireless technology such as infrared, radio and microwave are just included in the definition of computer-readable medium. Disk and disc as used herein include 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 are also included within the scope of computer-readable media.

[0223] As used herein (including in the claims), "or" used in a list of items (e.g., a list of items with a phrase such as "at least one of" or "one or more of") indicates an inclusive list, so that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Similarly, as used herein, the phrase "based on" should not be interpreted as referring to a closed set of conditions. For example, an example step described as "based on condition A" may be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on."

[0224] In the accompanying drawings, similar components or features may have the same reference number. In addition, various components of the same type may be distinguished by following the reference number with a dash and a second reference number that distinguishes between similar components. If only the first reference number is used in the specification, the description may apply to any of the similar components having the same first reference number regardless of the second reference number, or other subsequent reference numbers.

[0225] The descriptions set forth herein in conjunction with the accompanying drawings describe example configurations and do not represent all examples that may be implemented or that fall within the scope of the claims. The term "example" as used herein means "used as an example, instance, or illustration" and does not mean "better than" or "better than other examples." This detailed description includes specific details to provide an understanding of the described techniques. However, these techniques may be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0226] The description herein is provided to enable one of ordinary skill in the art to make or use the present disclosure. Various modifications to the present disclosure will be apparent to one of ordinary skill in the art, and the universal principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Thus, the present disclosure is not limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication at a user equipment (UE), comprising: receiving a configuration for periodic channel state feedback reporting; identifying a demodulation reference signal configuration associated with a first channel state information reference resource based at least in part on receiving the configuration; identifying a first channel state information reference resource time slot corresponding to the first channel state information reference resource based at least in part on a channel state information reference resource time slot offset and a first channel state information reference resource time slot validity criterion; generating one or more channel state feedback components based at least in part on the demodulation reference signal configuration associated with the first channel state information reference resource; as well as An indication of the generated one or more channel state feedback components is transmitted in a periodic channel state feedback report.

2. The method of claim 1, further comprising: A demodulation reference signal configuration hypothesis for channel state feedback evaluation is derived based at least in part on a physical downlink shared channel allocation on the first channel state information reference resource slot.

3. The method of claim 1, further comprising: identifying a second channel state information reference resource time slot based at least in part on a channel state information reference resource time slot offset and a first channel state information reference resource time slot validity criterion; as well as An additional channel state information reference resource time slot validity criterion is identified for the second channel state information reference resource time slot, wherein the additional channel state information reference resource time slot validity criterion comprises a minimum threshold number of symbols for a physical downlink shared channel allocation on the second channel state information reference resource time slot.

4. The method of claim 3, further comprising: determining that the additional channel state information reference resource time slot validity criterion is not satisfied for the second channel state information reference resource time slot; identifying the first channel state information reference resource time slot based at least in part on a first channel state information reference resource time slot corresponding to the first channel state information reference resource satisfying the additional channel state information reference resource time slot validity criteria, satisfying the first channel state information reference resource time slot validity criteria, and occurring in a previous time slot that is closest to the second channel state information reference resource time slot; and A demodulation reference signal configuration hypothesis for channel state feedback evaluation is derived based at least in part on the physical downlink shared channel allocation on the first channel state information reference resource slot.

5. The method of claim 4, wherein deriving the demodulation reference signal configuration hypothesis for channel state feedback evaluation comprises: Derive one or more parameters corresponding to the first channel state information reference resource, and define the one or more parameters explicitly or implicitly, wherein the one or more parameters include: the number of front-loaded demodulation reference signal symbols, the number of additional demodulation reference signal symbols, the position of all demodulation reference signal symbols relative to the first symbol allocated to the physical downlink shared channel, the demodulation reference signal type, or a combination thereof.

6. The method of claim 3, further comprising: determining that the additional channel state information reference resource time slot validity criterion is not satisfied for the second channel state information reference resource time slot; as well as A demodulation reference signal configuration hypothesis for channel state feedback evaluation is derived based at least in part on a default demodulation reference signal configuration predefined for a channel state information reference resource hypothesis.

7. The method of claim 6, wherein the default demodulation reference signal configuration explicitly or implicitly defines one or more default parameters, the one or more default parameters comprising: The number of front-loaded demodulation reference signal symbols, the number of additional demodulation reference signal symbols, the position of all demodulation reference signal symbols relative to the first symbol allocated by the physical downlink shared channel, the demodulation reference signal type, or a combination thereof.

8. The method of claim 1, further comprising: For a channel state information reference resource definition, a number of frontloaded demodulation reference signal symbols are identified from the demodulation reference signal configuration associated with a physical downlink shared channel allocation on a first channel state information reference resource slot corresponding to the first channel state information reference resource.

9. The method of claim 1, further comprising: For the channel state information reference resource definition, a number of additional demodulation reference signal codewords and the positions of all demodulation reference signal codewords relative to the first codeword of the physical downlink shared channel allocation on the first channel state information reference resource time slot of the first channel state information reference resource are identified based on the demodulation reference signal configuration associated with the physical downlink shared channel allocation on the first channel state information reference resource and based on a predefined assumption about the duration of the physical downlink shared channel allocation.

10. The method of claim 1, wherein a demodulation reference signal type is based on the demodulation reference signal configuration associated with a physical downlink shared channel allocation on a first channel state information reference resource slot of the first channel state information reference resource.

11. The method of claim 1, wherein the periodic channel state feedback report comprises a periodic joint channel state feedback and demodulation reference signal report.

12. A method for wireless communication at a network node, comprising: transmitting a configuration for periodic channel state feedback reporting; identifying a demodulation reference signal configuration associated with a first channel state information reference resource based at least in part on transmitting the configuration; identifying a time slot for the first channel state information reference resource based at least in part on a channel state information reference resource time slot offset and a first channel state information reference resource time slot validity criterion; receiving an indication of one or more channel state feedback components in a periodic channel state feedback report; as well as The periodic channel state feedback report is interpreted based at least in part on the identified demodulation reference signal configuration.

13. The method of claim 12, further comprising: An additional channel state information reference resource time slot validity criterion is identified for the time slot identified by the first channel state information reference resource, wherein the additional channel state information reference resource time slot validity criterion includes a minimum threshold number of code elements allocated for a physical downlink shared channel on the time slot identified by the first channel state information reference resource.

14. The method of claim 13, further comprising: identifying a second channel state information reference resource based at least in part on the channel state information reference resource time condition; determining that the additional channel state information reference resource time slot validity criterion is not satisfied for the second channel state information reference resource; identifying the first channel state information reference resource based at least in part on the first channel state information reference resource satisfying the additional channel state information reference resource time slot validity criteria and occurring before the second channel state information reference resource; as well as The demodulation reference signal configuration is derived based at least in part on the first channel state information reference resource.

15. The method of claim 14, wherein deriving the demodulation reference signal configuration comprises: One or more parameters corresponding to the first channel state information reference resource are derived, the one or more parameters comprising time density, frequency density, a boost value, or a combination thereof.

16. The method of claim 13, further comprising: identifying a second channel state information reference resource based at least in part on the channel state information reference resource time condition; determining that the additional channel state information reference resource time slot validity criterion is not satisfied for the second channel state information reference resource; as well as The demodulation reference signal configuration is derived based at least in part on a default demodulation reference signal configuration. 17 . The method of claim 16 , wherein the default demodulation reference signal configuration comprises one or more default parameters, the one or more default parameters comprising time density, frequency density, boost value, or a combination thereof.

18. The method of claim 12, further comprising: For a channel state information reference resource definition, a number of frontloaded demodulation reference signal symbols are identified from the demodulation reference signal configuration associated with a downlink allocation for the first channel state information reference resource.

19. The method of claim 12, further comprising: For a channel state information reference resource definition, a number of additional demodulation reference signal symbols are identified from the demodulation reference signal configuration associated with a downlink assignment and after a number of front-loaded demodulation reference signal symbols and a position of each additional demodulation reference signal symbol relative to a starting demodulation reference signal symbol.

20. The method of claim 12, wherein a demodulation reference signal type is based at least in part on the demodulation reference signal configuration associated with a downlink assignment, and the downlink assignment comprises one or more demodulation reference signal symbols.

21. The method of claim 12, wherein the demodulation reference signal configuration comprises one or more parameters corresponding to the first channel state information reference resource, the one or more parameters comprising time density, frequency density, boost value, or a combination thereof.

22. The method of claim 12, wherein the indication of the one or more channel state feedback components is associated with joint channel state feedback and demodulation reference signal reporting.

23. An apparatus for wireless communication at a user equipment (UE), comprising: processor, a memory coupled to the processor; as well as Instructions stored in the memory and executable by the processor to cause the device to: receiving a configuration for periodic channel state feedback reporting; identifying a demodulation reference signal configuration associated with a first channel state information reference resource based at least in part on receiving the configuration; identifying a first channel state information reference resource time slot corresponding to the first channel state information reference resource based at least in part on a channel state information reference resource time slot offset and a first channel state information reference resource time slot validity criterion; generating one or more channel state feedback components based at least in part on the demodulation reference signal configuration associated with the first channel state information reference resource; as well as An indication of the generated one or more channel state feedback components is transmitted in a periodic channel state feedback report.

24. The apparatus of claim 23, wherein the instructions are further executable by the processor to cause the apparatus to: A demodulation reference signal configuration hypothesis for channel state feedback evaluation is derived based at least in part on a physical downlink shared channel allocation on the first channel state information reference resource slot.

25. The apparatus of claim 23, wherein the instructions are further executable by the processor to cause the apparatus to: identifying a second channel state information reference resource time slot based at least in part on the channel state information reference resource time slot offset and the first channel state information reference resource time slot validity criterion; and An additional channel state information reference resource time slot validity criterion is identified for the second channel state information reference resource time slot, wherein the additional channel state information reference resource time slot validity criterion comprises a minimum threshold number of symbols for a physical downlink shared channel allocation on the second channel state information reference resource time slot.

26. The apparatus of claim 25, wherein the instructions are further executable by the processor to cause the apparatus to: determining that the additional channel state information reference resource time slot validity criterion is not satisfied for the second channel state information reference resource time slot; identifying the first channel state information reference resource time slot based at least in part on a first channel state information reference resource time slot corresponding to the first channel state information reference resource satisfying the additional channel state information reference resource time slot validity criteria, satisfying the first channel state information reference resource time slot validity criteria, and occurring in a previous time slot that is closest to the second channel state information reference resource time slot; and A demodulation reference signal configuration hypothesis for channel state feedback evaluation is derived based at least in part on the physical downlink shared channel allocation on the first channel state information reference resource slot.

27. The apparatus of claim 26, wherein the instructions for deriving the demodulation reference signal configuration hypothesis for channel state feedback evaluation are executable by the processor to cause the apparatus to: Deriving one or more parameters corresponding to the first channel state information reference resource, explicitly or implicitly defining the one or more parameters, the one or more parameters comprising: The number of front-loaded demodulation reference signal symbols, the number of additional demodulation reference signal symbols, the position of all demodulation reference signal symbols relative to the first symbol allocated by the physical downlink shared channel, the demodulation reference signal type, or a combination thereof.

28. The apparatus of claim 25, wherein the instructions are further executable by the processor to cause the apparatus to: determining that the additional channel state information reference resource time slot validity criterion is not satisfied for the second channel state information reference resource time slot; and A demodulation reference signal configuration hypothesis for channel state feedback evaluation is derived based at least in part on a default demodulation reference signal configuration predefined for a channel state information reference resource hypothesis.

29. The apparatus of claim 28, wherein the default demodulation reference signal configuration explicitly or implicitly defines one or more default parameters, the one or more default parameters comprising: The number of front-loaded demodulation reference signal symbols, the number of additional demodulation reference signal symbols, the position of all demodulation reference signal symbols relative to the first symbol allocated by the physical downlink shared channel, the demodulation reference signal type, or a combination thereof.

30. The apparatus of claim 23, wherein the instructions are further executable by the processor to cause the apparatus to: For a channel state information reference resource definition, a number of frontloaded demodulation reference signal symbols are identified from the demodulation reference signal configuration associated with a physical downlink shared channel allocation on a first channel state information reference resource slot corresponding to the first channel state information reference resource.

31. The apparatus of claim 23, wherein the instructions are further executable by the processor to cause the apparatus to: For the channel state information reference resource definition, a number of additional demodulation reference signal codewords and the positions of all demodulation reference signal codewords relative to the first codeword of the physical downlink shared channel allocation on the first channel state information reference resource time slot of the first channel state information reference resource are identified based on the demodulation reference signal configuration associated with the physical downlink shared channel allocation on the first channel state information reference resource and based on a predefined assumption about the duration of the physical downlink shared channel allocation.

32. The apparatus of claim 23, wherein a demodulation reference signal type is based on the demodulation reference signal configuration associated with a physical downlink shared channel allocation on a first channel state information reference resource slot of the first channel state information reference resource.

33. The apparatus of claim 23, wherein the periodic channel state feedback reporting comprises periodic joint channel state feedback and demodulation reference signal reporting.

34. An apparatus for wireless communication at a network node, comprising: processor, a memory coupled to the processor; as well as Instructions stored in the memory and executable by the processor to cause the device to perform the following operations: transmitting a configuration for periodic channel state feedback reporting; identifying a demodulation reference signal configuration associated with a first channel state information reference resource based at least in part on transmitting the configuration; identifying a time slot for the first channel state information reference resource based at least in part on a channel state information reference resource time slot offset and a first channel state information reference resource time slot validity criterion; receiving an indication of one or more channel state feedback components in a periodic channel state feedback report; as well as The periodic channel state feedback report is interpreted based at least in part on the identified demodulation reference signal configuration.

35. The apparatus of claim 34, wherein the instructions are further executable by the processor to cause the apparatus to: An additional channel state information reference resource time slot validity criterion is identified for the time slot identified by the first channel state information reference resource, wherein the additional channel state information reference resource time slot validity criterion includes a minimum threshold number of code elements allocated for a physical downlink shared channel on the time slot identified by the first channel state information reference resource.

36. The apparatus of claim 35, wherein the instructions are further executable by the processor to cause the apparatus to: identifying a second channel state information reference resource based at least in part on the channel state information reference resource time condition; determining that the additional channel state information reference resource time slot validity criterion is not satisfied for the second channel state information reference resource; identifying the first channel state information reference resource based at least in part on the first channel state information reference resource satisfying the additional channel state information reference resource time slot validity criteria and occurring before the second channel state information reference resource; as well as The demodulation reference signal configuration is derived based at least in part on the first channel state information reference resource.

37. The apparatus of claim 36, wherein the instructions for deriving the demodulation reference signal configuration are executable by the processor to cause the apparatus to: One or more parameters corresponding to the first channel state information reference resource are derived, the one or more parameters comprising time density, frequency density, a boost value, or a combination thereof.

38. The apparatus of claim 35, wherein the instructions are further executable by the processor to cause the apparatus to: identifying a second channel state information reference resource based at least in part on the channel state information reference resource time condition; determining that the additional channel state information reference resource time slot validity criterion is not satisfied for the second channel state information reference resource; and The demodulation reference signal configuration is derived based at least in part on a default demodulation reference signal configuration.

39. The apparatus of claim 38, wherein the default demodulation reference signal configuration comprises one or more default parameters, the one or more default parameters comprising time density, frequency density, boost value, or a combination thereof.

40. The apparatus of claim 34, wherein the instructions are further executable by the processor to cause the apparatus to: For a channel state information reference resource definition, a number of frontloaded demodulation reference signal symbols are identified from the demodulation reference signal configuration associated with a downlink allocation for the first channel state information reference resource.

41. The apparatus of claim 34, wherein the instructions are further executable by the processor to cause the apparatus to: For a channel state information reference resource definition, a number of additional demodulation reference signal symbols are identified from the demodulation reference signal configuration associated with a downlink assignment and after a number of front-loaded demodulation reference signal symbols and a position of each additional demodulation reference signal symbol relative to a starting demodulation reference signal symbol.

42. The apparatus of claim 34, wherein a demodulation reference signal type is based at least in part on the demodulation reference signal configuration associated with a downlink assignment, and the downlink assignment comprises one or more demodulation reference signal symbols.

43. The apparatus of claim 34, wherein the demodulation reference signal configuration comprises one or more parameters corresponding to the first channel state information reference resource, the one or more parameters comprising a time density, a frequency density, a boost value, or a combination thereof.

44. The apparatus of claim 34, wherein the indication of the one or more channel state feedback components is associated with joint channel state feedback and demodulation reference signal reporting.

45. An apparatus for wireless communication at a user equipment (UE), comprising: means for receiving a configuration for periodic channel state feedback reporting; means for identifying a demodulation reference signal configuration associated with a first channel state information reference resource based at least in part on receiving the configuration; means for identifying a first channel state information reference resource time slot corresponding to the first channel state information reference resource based at least in part on a channel state information reference resource time slot offset and a first channel state information reference resource time slot validity criterion; means for generating one or more channel state feedback components based at least in part on the demodulation reference signal configuration associated with the first channel state information reference resource; as well as Means for transmitting an indication of the generated one or more channel state feedback components in a periodic channel state feedback report.

46. ​​The apparatus of claim 45, further comprising: Means for deriving a demodulation reference signal configuration hypothesis for channel state feedback evaluation based at least in part on a physical downlink shared channel allocation on said first channel state information reference resource slot.

47. The apparatus of claim 45, further comprising: means for identifying a second channel state information reference resource time slot based at least in part on a channel state information reference resource time slot offset and a first channel state information reference resource time slot validity criterion; as well as Means for identifying additional channel state information reference resource time slot validity criteria for the second channel state information reference resource time slot, wherein the additional channel state information reference resource time slot validity criteria comprises a minimum threshold number of symbols for a physical downlink shared channel allocation on the second channel state information reference resource time slot.

48. The apparatus of claim 47, further comprising: means for determining that the additional channel state information reference resource time slot validity criterion is not satisfied for the second channel state information reference resource time slot; means for identifying the first channel state information reference resource time slot based at least in part on a first channel state information reference resource time slot corresponding to the first channel state information reference resource satisfying the additional channel state information reference resource time slot validity criteria, satisfying the first channel state information reference resource time slot validity criteria, and occurring in a previous time slot that is closest to the second channel state information reference resource time slot; as well as Means for deriving a demodulation reference signal configuration hypothesis for channel state feedback evaluation based at least in part on the physical downlink shared channel allocation on the first channel state information reference resource slot.

49. The apparatus of claim 48, wherein the means for deriving the demodulation reference signal configuration hypothesis for channel state feedback evaluation comprises: A device for deriving one or more parameters corresponding to the first channel state information reference resource, explicitly or implicitly defining the one or more parameters, wherein the one or more parameters include: the number of front-loaded demodulation reference signal codewords, the number of additional demodulation reference signal codewords, the position of all demodulation reference signal codewords relative to the first codeword allocated by the physical downlink shared channel, the demodulation reference signal type, or a combination thereof.

50. The apparatus of claim 47, further comprising: means for determining that the additional channel state information reference resource time slot validity criterion is not satisfied for the second channel state information reference resource time slot; as well as Means for deriving a demodulation reference signal configuration hypothesis for channel state feedback evaluation based at least in part on a default demodulation reference signal configuration predefined for a channel state information reference resource hypothesis.

51. The apparatus of claim 50, wherein the default demodulation reference signal configuration explicitly or implicitly defines one or more default parameters, the one or more default parameters comprising: The number of front-loaded demodulation reference signal symbols, the number of additional demodulation reference signal symbols, the position of all demodulation reference signal symbols relative to the first symbol allocated by the physical downlink shared channel, the demodulation reference signal type, or a combination thereof.

52. The apparatus of claim 45, further comprising: Means for identifying, for a channel state information reference resource definition, a number of frontloaded demodulation reference signal symbols from said demodulation reference signal configuration associated with a physical downlink shared channel allocation on a first channel state information reference resource slot corresponding to said first channel state information reference resource.

53. The apparatus of claim 45, further comprising: Means for identifying, for a channel state information reference resource definition, a number of additional demodulation reference signal symbols and the positions of all demodulation reference signal symbols relative to a first symbol of a physical downlink shared channel allocation on a first channel state information reference resource time slot of said first channel state information reference resource and based on a predefined assumption about the duration of the physical downlink shared channel allocation.

54. The apparatus of claim 45, wherein a demodulation reference signal type is based on the demodulation reference signal configuration associated with a physical downlink shared channel allocation on a first channel state information reference resource slot of the first channel state information reference resource.

55. The apparatus of claim 45, wherein the periodic channel state feedback reports comprise periodic joint channel state feedback and demodulation reference signal reports.

56. An apparatus for wireless communication at a network node, comprising: means for transmitting a configuration for periodic channel state feedback reporting; means for identifying a demodulation reference signal configuration associated with a first channel state information reference resource based at least in part on transmitting the configuration; means for identifying a time slot for the first channel state information reference resource based at least in part on a channel state information reference resource time slot offset and a first channel state information reference resource time slot validity criterion; means for receiving an indication of one or more channel state feedback components in a periodic channel state feedback report; as well as Means for interpreting the periodic channel state feedback report based at least in part on the identified demodulation reference signal configuration.

57. The apparatus of claim 56, further comprising: A device for identifying additional channel state information reference resource time slot validity criteria for the time slot identified by the first channel state information reference resource, wherein the additional channel state information reference resource time slot validity criteria includes a minimum threshold number of code elements allocated for a physical downlink shared channel on the time slot identified by the first channel state information reference resource.

58. The apparatus of claim 57, further comprising: means for identifying a second channel state information reference resource based at least in part on a channel state information reference resource time condition; means for determining that the additional channel state information reference resource time slot validity criterion is not satisfied for the second channel state information reference resource; means for identifying the first channel state information reference resource based at least in part on the first channel state information reference resource satisfying the additional channel state information reference resource time slot validity criteria and occurring before the second channel state information reference resource; as well as means for deriving the demodulation reference signal configuration based at least in part on the first channel state information reference resource.

59. The apparatus of claim 58, wherein the means for deriving the demodulation reference signal configuration comprises: Means for deriving one or more parameters corresponding to the first channel state information reference resource, the one or more parameters comprising time density, frequency density, boost value, or a combination thereof.

60. The apparatus of claim 57, further comprising: means for identifying a second channel state information reference resource based at least in part on a channel state information reference resource time condition; means for determining that the additional channel state information reference resource time slot validity criterion is not satisfied for the second channel state information reference resource; as well as Means for deriving the demodulation reference signal configuration based at least in part on a default demodulation reference signal configuration.

61. The apparatus of claim 60, wherein the default demodulation reference signal configuration comprises one or more default parameters, the one or more default parameters comprising time density, frequency density, boost value, or a combination thereof.

62. The apparatus of claim 56, further comprising: Means for identifying, for a channel state information reference resource definition, a number of frontloaded demodulation reference signal symbols from the demodulation reference signal configuration associated with a downlink allocation for the first channel state information reference resource.

63. The apparatus of claim 56, further comprising: Means for identifying, for a channel state information reference resource definition, a number of additional demodulation reference signal symbols from the demodulation reference signal configuration associated with a downlink assignment and following a number of front-loaded demodulation reference signal symbols and a position of each additional demodulation reference signal symbol relative to a starting demodulation reference signal symbol.

64. The apparatus of claim 56, wherein a demodulation reference signal type is based at least in part on the demodulation reference signal configuration associated with a downlink assignment, and the downlink assignment comprises one or more demodulation reference signal symbols.

65. The apparatus of claim 56, wherein the demodulation reference signal configuration comprises one or more parameters corresponding to the first channel state information reference resource, the one or more parameters comprising a time density, a frequency density, a boost value, or a combination thereof.

66. The apparatus of claim 56, wherein the indication of the one or more channel state feedback components is associated with joint channel state feedback and demodulation reference signal reporting.

67. A non-transitory computer-readable medium storing code for wireless communication at a user equipment (UE), the code comprising instructions executable by a processor to: receiving a configuration for periodic channel state feedback reporting; identifying a demodulation reference signal configuration associated with a first channel state information reference resource based at least in part on receiving the configuration; identifying a first channel state information reference resource time slot corresponding to the first channel state information reference resource based at least in part on a channel state information reference resource time slot offset and a first channel state information reference resource time slot validity criterion; generating one or more channel state feedback components based at least in part on the demodulation reference signal configuration associated with the first channel state information reference resource; as well as An indication of the generated one or more channel state feedback components is transmitted in a periodic channel state feedback report.

68. A non-transitory computer readable medium storing code for wireless communication at a network node, the code comprising instructions executable by a processor to: transmitting a configuration for periodic channel state feedback reporting; identifying a demodulation reference signal configuration associated with a first channel state information reference resource based at least in part on transmitting the configuration; identifying a time slot for the first channel state information reference resource based at least in part on a channel state information reference resource time slot offset and a first channel state information reference resource time slot validity criterion; receiving an indication of one or more channel state feedback components in a periodic channel state feedback report; as well as The periodic channel state feedback report is interpreted based at least in part on the identified demodulation reference signal configuration.

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