User equipment (UE) initiated reference signal request

Abstract

User equipment (UE) and base stations (BS) can transmit reference signals (RS) for another device to estimate a channel and perform measurements. The present disclosure provides for a UE to request reference signals, such as channel state information reference signals (CSI-RS) or sounding reference signals (SRS). The BS transmits a radio resource control (RRC) message that configures a UE configuration with one or more trigger states for CSI-RS, SRS, or a combination thereof, and a medium access control (MAC) control element (CE) that activates a subset of the configured trigger states. In one aspect, the UE transmits an uplink request that indicates a trigger state of the UE. The trigger state corresponds to at least one configured RS. The UE and the BS communicate the at least one RS corresponding to the trigger state, for example, based on a grant from the BS or a time offset from the uplink request.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims priority to International Application No. PCT / CN2020 / 112757 entitled “USER EQUIPMENT (UE) INITIATED REFERENCE SIGNAL REQUESTS” filed September 1, 2020, and International Application No. PCT / CN2020 / 112810 entitled “MEDIA ACCESS CONTROL (MAC) CONTROL ELEMENT (CE) BASED ACTIVATION FOR USER EQUIPMENT (UE) INITIATED REFERENCE SIGNAL REQUESTS” filed September 1, 2020, both of which are assigned to the assignee hereof and hereby expressly incorporated by reference in their entirety. TECHNICAL FIELD

[0003] The present disclosure relates to user equipment (UE) initiated reference signal requests.

[0004] DESCRIPTION OF RELATED ART

[0005] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems can employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

[0006] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is 5G New Radio (NR). 5G NR is a continuing mobile broadband evolution promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (such as for Internet of Things (IoT) applications), and other requirements. 5G NR includes services associated with enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra reliable low latency communications (URLLC). Some aspects of 5G NR can be based on the 4G Long Term Evolution (LTE) standard.

[0007] SUMMARY

[0008] The systems, methods, and devices of the disclosure each have several innovative aspects, none of which is, by itself, solely responsible for the desirable attributes disclosed herein.

[0009] One innovative aspect of the subject matter described in this disclosure can be implemented in a method of wireless communication at an apparatus of a user equipment (UE). The method can include transmitting an uplink request for at least one reference signal, the uplink request indicating a triggering state of the UE. The method can include communicating, in response to the uplink request, the at least one reference signal corresponding to the triggering state.

[0010] In some implementations, the method can further include receiving downlink control information (DCI) scheduling the at least one reference signal.

[0011] In some implementations, transmitting the uplink request includes transmitting the uplink request on an uplink resource defined by a mapping from the triggering state to the uplink resource.

[0012] In some implementations, the method further includes receiving a radio resource control (RRC) configuration message indicating one or more CSI triggering states or SRS triggering states for the uplink request for the at least one reference signal, and receiving a medium access control (MAC) control element (CE) activating a subset of the one or more CSI triggering states or SRS triggering states. There is a one-to-one mapping between an activated triggering state and a physical uplink resource, and wherein transmitting the request for the at least one reference signal is on a physical uplink resource corresponding to an indicated triggering state of the UE.

[0013] Another innovative aspect of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus can include means for outputting an uplink request for at least one reference signal, the uplink request indicating a triggering state of the UE. The apparatus can include means for communicating, in response to the uplink request, the at least one reference signal corresponding to the triggering state via the interface. The apparatus can be configured to perform any of the innovative methods.

[0014] Another innovative aspect of the subject matter described in this disclosure can be implemented in a device for wireless communication. The device includes means for transmitting an uplink request for at least one reference signal, the uplink request indicating a triggering state of the UE. The device includes means for communicating at least one reference signal corresponding to the triggering state in response to the uplink request. The device can be configured to perform any of the innovative methods.

[0015] Another innovative aspect of the subject matter described in this disclosure can be implemented in a non-transitory computer-readable medium storing instructions for wireless communication at an apparatus of a UE. The non-transitory computer-readable medium includes instructions for transmitting an uplink request for at least one reference signal, the uplink request indicating a triggering state of the UE. The non-transitory computer-readable medium includes instructions for communicating at least one reference signal corresponding to the triggering state in response to the uplink request. The non-transitory computer-readable medium can include instructions for performing any of the innovative methods.

[0016] One innovative aspect of the subject matter described in this disclosure can be implemented in a method of wireless communication at an apparatus of a base station (BS). The method can include receiving, from a UE, an uplink request for at least one reference signal, the uplink request indicating a triggering state of the UE. The method can include communicating at least one reference signal corresponding to the triggering state in response to the uplink request.

[0017] In some implementations, the method further includes transmitting DCI scheduling the at least one reference signal.

[0018] In some implementations, receiving the uplink request includes determining the triggering state based on a mapping between the triggering state and an uplink resource on which the uplink request is received.

[0019] In some implementations, the method further includes transmitting a RRC configuration message indicating one or more CSI triggering states or SRS triggering states for the uplink request for the at least one reference signal, and transmitting a MAC-CE activating a subset of the one or more CSI triggering states or SRS triggering states. There is a one-to-one mapping between an activated triggering state and a physical uplink resource, and wherein receiving the request for the at least one reference signal is on a physical uplink resource corresponding to an indicated triggering state of the UE.

[0020] Another innovative aspect of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus includes means for receiving, from a UE, an uplink request for at least one reference signal, the uplink request indicating a triggering state of the UE. The apparatus includes means for communicating, in response to the uplink request, at least one reference signal corresponding to the triggering state. The apparatus can be configured to perform any of the innovative methods.

[0021] Another innovative aspect of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus includes means for receiving, from a UE, an uplink request for at least one reference signal, the uplink request indicating a triggering state of the UE. The apparatus includes means for communicating, in response to the uplink request, at least one reference signal corresponding to the triggering state. The apparatus can be configured to perform any of the innovative methods.

[0022] Another innovative aspect of the subject matter described in this disclosure can be implemented in a non-transitory computer-readable medium storing instructions for wireless communication at an apparatus of a BS. The non-transitory computer- readable medium includes instructions for receiving, from a UE, an uplink request for at least one reference signal, the uplink request indicating a triggering state of the UE. The non-transitory computer-readable medium includes instructions for communicating, in response to the uplink request, at least one reference signal corresponding to the triggering state. The non-transitory computer-readable medium can include instructions for performing any of the innovative methods.

[0023] One innovative aspect of the subject matter described in this disclosure can be implemented in a method of wireless communication at an apparatus of a user equipment (UE). The method can include receiving a radio resource control (RRC) configuration message indicating one or more channel state information (CSI) trigger states, one or more sounding reference signal (SRS) trigger states, or a combination thereof for a UE-initiated uplink reference signal (RS) request. The method can include receiving a medium access control (MAC) control element (CE) activating a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof. There can be a one-to-one mapping between the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof and one or more physical uplink resources. The method can include selecting an activated trigger state from the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof. The method can include transmitting the UE-initiated uplink RS request on a physical uplink resource of the one or more physical uplink resources that corresponds to the selected activated trigger state based on the one-to-one mapping.

[0024] In some implementations, the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof are also for downlink scheduled reference signals.

[0025] In some implementations, the MAC-CE also activates a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof for the downlink scheduled reference signals.

[0026] In some implementations, the MAC-CE activates a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof for the uplink RS request.

[0027] In some implementations, the MAC-CE down-selects the subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof for the uplink RS request from a set of one or more CSI trigger states or one or more SRS trigger states for downlink scheduled reference signals.

[0028] In some implementations, the one or more CSI trigger states are separate from CSI trigger state configurations for CSI-RS for downlink scheduling, or the one or more SRS trigger states are separate from SRS trigger state configurations for SRS for downlink scheduling.

[0029] In some implementations, the MAC-CE activates the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof for different component carriers.

[0030] In some implementations, the MAC-CE includes a request identifier (ID), a serving cell ID, and a bandwidth part ID for each of the different component carriers.

[0031] Another innovative aspect of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus includes means for obtaining a RRC configuration message indicating one or more CSI trigger states, one or more SRS trigger states, or a combination thereof for a UE-initiated uplink RS request. The apparatus includes means for obtaining a MAC-CE activating a subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof. There is a one-to-one mapping between the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof and one or more physical uplink resources. The apparatus includes means for selecting an activated trigger state from the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof. The apparatus includes means for outputting the UE-initiated uplink RS request on a physical uplink resource of the one or more physical uplink resources corresponding to the selected activated trigger state. The apparatus can be configured to perform any of the innovative methods.

[0032] Another innovative aspect of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus includes means for receiving a RRC configuration message indicating one or more CSI trigger states, one or more SRS trigger states, or a combination thereof. The apparatus includes means for receiving a MAC-CE activating a subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof. There is a one-to-one mapping between the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof and one or more physical uplink resources. The apparatus includes means for selecting an activated trigger state from the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof. The apparatus includes means for transmitting the UE-initiated uplink RS request on a physical uplink resource of the one or more physical uplink resources corresponding to the selected activated trigger state. The apparatus can be configured to perform any of the innovative methods.

[0033] Another innovative aspect of the subject matter described in this disclosure can be implemented in a non-transitory computer-readable medium storing instructions for wireless communication at an apparatus of a UE. The non-transitory computer- readable medium includes instructions for receiving a RRC configuration message indicating one or more CSI trigger states, one or more SRS trigger states, or a combination thereof for a UE-initiated uplink RS request. The non-transitory computer-readable medium includes instructions for receiving a MAC-CE activating a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof. There is a one-to-one mapping between the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof and one or more physical uplink resources. The non-transitory computer-readable medium includes instructions for selecting an activated trigger state from the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof. The non-transitory computer-readable medium includes instructions for transmitting the UE-initiated uplink RS request on a physical uplink resource of the one or more physical uplink resources corresponding to the selected activated trigger state. The non-transitory computer-readable medium can include instructions for performing any of the innovative methods.

[0034] One innovative aspect of the subject matter described in this disclosure can be implemented in a method of wireless communication at an apparatus of a BS. The method can include transmitting a RRC configuration message indicating one or more CSI trigger states, one or more SRS trigger states, or a combination thereof for a UE-initiated uplink RS request. The method can include transmitting a MAC-CE activating a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, where there is a one-to-one mapping between the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof and one or more physical uplink resources. The method can include receiving the UE-initiated uplink RS request on a physical uplink resource of the one or more physical uplink resources. The method can include determining, based on the one-to-one mapping, that the UE-initiated uplink RS request corresponds to an activated trigger state from the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof.

[0035] In some implementations, the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof are also used for downlink scheduled reference signals.

[0036] In some implementations, the MAC-CE also activates a subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof for the downlink scheduling of reference signals.

[0037] In some implementations, the MAC-CE activates a subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof for the uplink RS request.

[0038] In some implementations, the MAC-CE down-selects a subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof for the uplink RS request from a set of one or more CSI trigger states or one or more SRS trigger states for downlink scheduling of reference signals.

[0039] In some implementations, the one or more CSI trigger states are separate from CSI trigger state configurations for CSI-RS for downlink scheduling, or the one or more SRS trigger states are separate from SRS trigger state configurations for SRS for downlink scheduling.

[0040] In some implementations, the MAC-CE activates the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof for different component carriers.

[0041] In some implementations, the MAC-CE includes a request identifier (ID), a serving cell ID, and a bandwidth part ID for each of the different component carriers.

[0042] Another innovative aspect of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus includes at least one interface and a processing system coupled to the at least one interface. The at least one interface is configured to output a RRC configuration message indicating one or more CSI trigger states, one or more SRS trigger states, or a combination thereof for a UE-initiated uplink RS request. The at least one interface is configured to output a MAC-CE activating a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, where there is a one-to-one mapping between the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof and one or more physical uplink resources. The at least one interface is configured to obtain the UE-initiated uplink RS request on a physical uplink resource of the one or more physical uplink resources. The processing system is configured to determine, based on the one-to-one mapping, that the UE-initiated uplink RS request corresponds to an activated trigger state from the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof. The apparatus can be implemented in a base station (BS). The apparatus can be configured to perform any of the innovative methods.

[0043] Another innovative aspect of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus includes means for transmitting a RRC configuration message indicating one or more CSI trigger states, one or more SRS trigger states, or a combination thereof for a UE-initiated uplink RS request. The apparatus includes means for transmitting a MAC-CE activating a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, where there is a one-to-one mapping between the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof and one or more physical uplink resources. The apparatus includes means for receiving the UE-initiated uplink RS request on a physical uplink resource of the one or more physical uplink resources. The apparatus includes means for determining, based on the one-to-one mapping, that the UE-initiated uplink RS request corresponds to an activated trigger state from the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof. The apparatus can be configured to perform any of the innovative methods.

[0044] Another innovative aspect of the subject matter described in this disclosure can be implemented in a non-transitory computer-readable medium storing instructions for wireless communication at an apparatus of a BS. The non-transitory computer-readable medium includes instructions for transmitting a RRC configuration message indicating one or more CSI trigger states, one or more SRS trigger states, or a combination thereof for a UE-initiated uplink RS request. The non-transitory computer-readable medium includes instructions for transmitting a MAC-CE activating a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, where there is a one-to-one mapping between the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof and one or more physical uplink resources. The non-transitory computer-readable medium includes instructions for receiving the UE-initiated uplink RS request on a physical uplink resource of the one or more physical uplink resources. The non-transitory computer-readable medium includes instructions for determining, based on the one-to-one mapping, that the UE-initiated uplink RS request corresponds to an activated trigger state from the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof. The non-transitory computer-readable medium can include instructions for performing any of the innovative methods.

[0045] Details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, the drawings, and the claims. Note that the relative dimensions of the following drawings can not be drawn to scale. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 is a diagram illustrating an example of a wireless communications system and an access network.

[0048] Figure 2A is a diagram illustrating an example of a first frame.

[0049] Figure 2B is a diagram illustrating an example of DL channels within a subframe.

[0050] Figure 2C is a diagram illustrating an example of a second frame.

[0051] Figure 2D is a diagram illustrating an example of a subframe.

[0052] Figure 3 is a diagram illustrating an example of a base station (BS) and user equipment (UE) in an access network.

[0053] Figure 4is a diagram illustrating example messages between a UE and a BS for requesting a reference signal (RS).

[0054] Figure 5 is a diagram illustrating example messages between a UE and a BS for requesting a sounding reference signal (SRS) transmission by the UE.

[0055] Figure 6 is a diagram illustrating example configurations and resources for SRS requests.

[0056] Figure 7 is a diagram illustrating example messages between a UE and a BS for requesting a channel state information (CSI) RS transmission by the UE.

[0057] Figure 8 is a diagram illustrating example procedures for updating uplink beams with and without UE-initiated uplink reference signal requests.

[0058] Figure 9 is a diagram illustrating an example medium access control (MAC) control element (CE) for activating a trigger state.

[0059] Figure 10 is a diagram illustrating example RS requests using different active trigger states for CSI triggers.

[0060] Figure 11 is a diagram illustrating example RS requests using different active trigger states for SRS triggers.

[0061] Figure 12 is a diagram illustrating a communication example using a MAC-CE to down-select an active trigger state for a UE-initiated RS request.

[0062] Figure 13 is a diagram illustrating an example of trigger state selection for multiple component carriers (CCs).

[0063] Figure 14 is a diagram illustrating an example of CSI processing unit (CPU) occupation for CSI operations for downlink scheduling.

[0064] Figure 15 is a diagram illustrating an example of CPU occupation for CSI operations for UE requests with downlink responses.

[0065] Figure 16 is a diagram illustrating an example of cumulative CPU occupation for CSI operations for UE requests.

[0066] Figure 17is a diagram illustrating an example of CPU utilization for CSI operation for UE request without downlink response.

[0067] Figure 18 is a diagram illustrating example communications and components of a base station and a UE.

[0068] Figure 19 is a conceptual data flow diagram illustrating the data flow between different means / components in an example BS.

[0069] Figure 20 is a conceptual data flow diagram illustrating the data flow between different means / components in an example UE.

[0070] Figure 21 is a flowchart of an example method for a UE to request reference signals.

[0071] Figure 22 is a flowchart of an example method for a BS to receive a UE-initiated request for reference signals.

[0072] Figure 23 is a flowchart of an example method for a UE to request reference signals based on a MAC-CE.

[0073] Figure 24 is a flowchart of an example method for a BS to receive a UE-initiated request for reference signals based on a MAC-CE.

[0074] Like reference numbers and designations in the various drawings indicate like elements.

[0075] DETAILED DESCRIPTION

[0076] The following description is aimed at certain implementations to describe the innovative aspects of the present disclosure. However, a person having ordinary skill in the art will readily recognize that the teachings herein can be applied in a multitude of different ways. Some examples in this disclosure are based on wireless and wired local area network (LAN) communications according to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 wireless standards, IEEE 802.3 Ethernet standards, and IEEE 1901 Powerline Communication (PLC) standards. However, the described implementations can be implemented in any device, system, or network capable of transmitting and receiving RF signals according to any of the following wireless communication protocols: any of the IEEE 802.11 standards, Standard, Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Global System for Mobile Communications (GSM), GSM / General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), Terrestrial Trunked Radio (TETRA), Wideband-CDMA (WCDMA), Evolution Data Optimized (EV-DO), 1xEV-DO, EV-DO Rev A, EV-DO Rev B, High Speed Packet Access (HSPA), High

[0077] User equipment (UE) and base stations can transmit reference signals (RS) for another device to estimate a channel and perform measurements. For example, a base station (BS) can transmit channel state information (CSI)-RS and a UE can transmit sounding reference signals (SRS). Traditionally, a base station configures a UE with a set of RS and indicates when each RS is to be communicated. For example, a UE can be configured to receive periodic CSI, aperiodic (A-CSI), or both. For A-CSI, the base station can transmit an uplink grant that schedules specific resources for A-CSI and provides physical uplink shared channel (PUSCH) resources for a CSI report. Similarly, a UE can be configured to transmit periodic SRS or aperiodic SRS. For aperiodic SRS, a grant can schedule specific resources for the SRS. Traditional RS scheduling techniques can have limitations with respect to feedback latency and overhead. In particular, although the network can trigger aperiodic RS, there can be a delay between the time the UE detects a problem and the time the base station detects the problem and is able to schedule aperiodic CSI or SRS.

[0078] In an aspect, the disclosure provides for UE-initiated requests for reference signals (such as CSI-RS and SRS). A UE can autonomously determine to request a RS from a BS. The UE can transmit an uplink request for at least one reference signal. The uplink request can indicate a triggering state of the BS. For example, the uplink request can be transmitted on an uplink resource mapped to the triggering state. The triggering state can correspond to at least one configured RS, such as a CSI-RS or a SRS. Accordingly, the BS can determine which reference signal is requested. The UE can communicate at least one RS corresponding to the triggering state in response to the uplink request. For example, the UE can transmit a SRS or receive a CSI-RS. In some implementations, the BS can transmit a grant scheduling the RS, such as a downlink control information (DCI) message, in response to the uplink request. In some implementations, the triggering state can be associated with a time offset, and the RS can be transmitted at the time offset after the uplink request, e.g., without a grant from the BS.

[0079] In an aspect, the disclosure also provides for configuration and activation of UE-initiated requests for reference signals (such as CSI-RS and SRS) based on a medium access control (MAC) control element (CE). A BS can transmit a radio resource control (RRC) message configuring a UE with one or more triggering states for CSI, SRS, or a combination thereof. The BS can transmit a MAC-CE activating a subset of the configured triggering states. For example, the MAC-CE can indicate an active subset of triggering states and other configured triggering states can be inactive. The UE can be configured with a one-to-one mapping between one or more active triggering states in the subset and one or more physical uplink resources. For example, each active triggering state can be mapped to a different physical uplink resource. The UE can autonomously determine to request a RS from the BS based on a selected activated triggering state from the subset. The UE can transmit a UE-initiated uplink RS request to the BS on an uplink physical resource corresponding to the selected activated triggering state based on the one-to-one mapping. Accordingly, the BS can determine the requested RS based on the triggering state mapped to the uplink resource on which the uplink RS request is received. The UE and the BS can communicate at least one reference signal corresponding to the triggering state in response to the uplink request. For example, the UE can transmit a SRS or receive a CSI-RS. In some implementations, the BS can transmit a grant scheduling the RS, such as a downlink control information (DCI, or DCI message), in response to the uplink RS request. In some implementations, the triggering state can be associated with a time offset, and the RS can be transmitted at the time offset after the uplink RS request, e.g., without a grant from the BS.

[0080] Particular implementations of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. A UE can use UE-initiated requests for reference signals to increase flexibility in channel measurements. For example, when the UE detects a change in channel conditions, the UE can request a CSI-RS to perform measurements and report updated CSI to the base station. Accordingly, UE-initiated requests for reference signals can reduce latency of CSI reporting. As another example, if the UE determines that a change in beamforming parameters can improve performance, the UE can request a CSI-RS to perform measurements and refine its receive beam. As yet another example, if the UE determines that a change in precoding parameters can improve performance, the UE can request an SRS in order to refine its precoder in uplink transmissions in order for the base station to update its receive parameters. By using a MAC-CE to select a sub-list of active trigger states, the number of trigger states that the UE has to monitor can be reduced to the number of configured trigger states. Additionally, if the active trigger states are mapped to uplink resources, the number of resources reserved for RS requests can be reduced, which can reduce overhead.

[0081] Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as "elements"). These elements can be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends on the particular application and design constraints imposed on the overall system.

[0082] As an example, an element, or any portion of an element, or any combination of elements can be implemented as a "processing system" that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on a chip (SoC), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. A processor can include, or be coupled with, at least one interface that can be used to obtain or output signals. The processor can obtain signals from, and output signals to, the interface. In some implementations, the interface can be a printed circuit board (PCB) trace. In some other implementations, the interface can include a wireless transmitter, a wireless transceiver, or a combination thereof. For example, the interface can include a radio frequency (RF) transceiver that can be implemented as a receiver or transmitter, or both. One or more processors in the processing system can execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0083] Accordingly, in one or more example implementations, the functions described can be implemented in hardware, software, or any combination thereof. If implemented in software, the functions can be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Computer storage media can be non-transitory storage media. Non-transitory storage media do not include signals. Storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the aforementioned types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer.

[0084] Figure 1is a diagram illustrating an example of a wireless communications system and an access network 100. The wireless communications system (also referred to as a wireless wide area network (WWAN)) includes base stations 102, UEs 104, an Evolved Packet Core (EPC) 160, and a 5G Core (5GC) network 190. A base station 102 can include a macro cell (high power cellular base station) or a small cell (low power cellular base station). A macro cell can include a base station. A small cell can include a femto cell, a pico cell, and a micro cell. Base stations 102 can be configured to operate as a Distributed-RAN (D-RAN) or an Open-RAN (O-RAN) architecture, in which functionality is split among multiple units, such as a Central Unit (CU), one or more Distributed Units (DUs) or Radio Units (RUs). Such an architecture can be configured to utilize a protocol stack logically split between one or more units, such as one or more CUs and one or more DUs. In some aspects, a CU can be implemented within an edge RAN node, and in some aspects, one or more DUs can be co-located with a CU or can be geographically distributed in one or more RAN nodes. The DUs can be implemented to communicate with one or more RUs.

[0085] In some implementations, one or more of the UEs 104 can include an uplink (UL) RS request component 140 that transmits an uplink request for at least one reference signal and communicates the requested reference signal. The UL RS request component 140 can include a configuration component 141 configured to receive a RRC configuration message indicating one or more CSI trigger states or one or more SRS trigger states for UE-initiated uplink RS requests. The UL RS request component 140 can include an activation component 142 configured to receive a MAC-CE activating a subset of the one or more CSI trigger states or the one or more SRS trigger states. The UL RS request component 140 can include a request transmitter 143 configured to select an activated trigger state of the one or more activated trigger states. The request transmitter 143 can be configured to transmit a UE-initiated uplink RS request on a physical uplink resource of the one or more physical uplink resources that corresponds to the selected activated trigger state based on a one-to-one mapping. The UL RS request component 140 can optionally include a response receiver 144 configured to receive a grant in response to the uplink request. The UL RS request component 140 can include an RS communication component 145 configured to communicate at least one reference signal corresponding to the trigger state in response to the uplink request. The UL RS request component 140 can optionally include a reporting component 147 configured to transmit a CSI report based on the at least one reference signal.

[0086] In some implementations, one or more of the base stations 102 can include an RS request response component 120 that receives an uplink request for at least one reference signal and communicates the at least one reference signal in response to the request. As Figure 18 and 19As illustrated in the specification, the RS request response component 120 can include a configuration transmitter 1860 configured to transmit a RRC configuration message indicating one or more CSI trigger states or one or more SRS trigger states for a UE-initiated uplink RS request. The RS request response component 120 can include an activation transmitter 1862 configured to transmit a MAC-CE activating a subset of the one or more CSI trigger states or the one or more SRS trigger states. The RS request response component 120 can include a receiver component 1850 configured to receive a UE-initiated uplink RS request on a physical uplink resource of the one or more physical uplink resources. The RS request response component 120 can include a request receiving component 122 configured to receive, from a UE, an uplink request for at least one reference signal indicating a trigger state of the UE. The request receiving component 122 can be configured to determine that the UE-initiated uplink RS request corresponds to one of the activated trigger states based on a one-to-one mapping. The RS request response component 120 can include a RS communication component 124 configured to communicate, in response to the uplink request, the at least one reference signal corresponding to the trigger state.

[0087] The base stations 102 configured for 4G LTE (collectively referred to as the Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can interface with the EPC 160 through first backhaul links 132 (such as an SI interface) which can be wired or wireless. The base stations 102 configured for 5G NR (collectively referred to as Next Generation RAN (NG-RAN)) can interface with the 5G core network 190 through second backhaul links 184, which can be wired or wireless. In addition to other functions, the base stations 102 can perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (such as handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations 102 can communicate directly or indirectly (such as through the EPC 160 or the core network 190) with each other over third backhaul links 134 (such as an X2 interface). The third backhaul links 134 can be wired or wireless.

[0088] The base stations 102 can wirelessly communicate with the UEs 104. Each of the base stations 102 can provide communication coverage for a respective geographic coverage area 110. There can be overlapping geographic coverage areas 110. For example, a small cell 102' can have a coverage area 110' that overlaps with one or more macrocells 102. A network that includes both small cell and macrocells can be known as a heterogeneous network. A heterogeneous network can also include Home Evolved Node Bs (eNBs) (HeNBs), which can provide service to a restricted group known as a closed subscriber group (CSG). The communication links 112 between the base stations 102 and the UEs 104 can include uplink (UL) (also referred to as reverse link) transmissions from a UE 104 to a base station 102 or downlink (DL) (also referred to as forward link) transmissions from a base station 102 to a UE 104. The communication links 112 can use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, or transmit diversity. These communication links can be through one or more carriers, and can be distributed over a system bandwidth that is larger than 20 MHz. For example, the system bandwidth can be larger than 5, 10, 15, 20, 100, 400, etc. MHz. The base stations 102 / UEs 104 can use spectrum up to 7 MHz, such as 5, 10, 15, 20, 100, 400 MHz, etc. in one or more of the frequency regions, DL and UL. The system bandwidth can be divided into multiple (K) frequency carriers, which can also be referred to as sub-carriers or resource blocks (RBs). Each carrier can be a 1.08, 2.16, 4.32, 5.6, 10.64, 16.32, 20, 40, 60, 80, 100, etc. MHz channel and can be used to send data, control information, and / or reference signals to the UEs 104. In one example, K = 110 of the available 8 MHz channels, and in another example K = 100 of the available 20 MHz channels. Assorted other combinations of K and 8 / 20 MHz channels can also be used. The carriers can be arranged to be spectrally overlapping, e.g., using a localized

[0089] Certain UEs 104 can communicate with each other using device-to-device (D2D) communication link 158. The D2D communication link 158 can use the DL / UL WWAN spectrum. The D2D communication link 158 can use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). D2D communication can be through a variety of wireless D2D communications systems, such as for example, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR.

[0090] The wireless communications system can further include a Wi-Fi access point (AP) 150 in communication with Wi-Fi stations (STAs) 152 via communication links 154 in a 5 GHz unlicensed frequency spectrum. When communicating in an unlicensed frequency spectrum, the STAs 152 / AP 150 can perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available.

[0091] The small cell 102' can operate in a licensed or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell 102' can employ NR and use the same 5 GHz unlicensed frequency spectrum as used by the Wi-Fi AP 150. The small cell 102' employing NR in an unlicensed frequency spectrum can boost coverage to, and / or increase capacity for, the access network.

[0092] Whether a small cell 102' or a large cell (such as a macro base station), the base stations 102 can include an eNB, gNodeB (gNB), or other types of base station. Some base stations, such as gNB 180 can operate in one or more frequency bands.

[0093] The electromagnetic spectrum is often subdivided based on frequencies or wavelengths into various classes, bands, channels, and so on. In 5G NR, two initial operating bands have been identified as frequency range designations FR1 (410 MHz - 7. 125 GHz) and FR2 (24.25 GHz - 52.6 GHz). The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “sub-6 GHz band” in various documents and articles. A similar nomenclature issue sometimes occurs with respect to FR2, which is often referred to (interchangeably) as a “millimeter wave” band, despite being different from the extremely high frequency (EHF) band (30 GHz - 300 GHz) which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band.

[0094] With the above aspects in mind, unless specifically stated otherwise, it should be understood that the term sub-6 GHz, or like terms if used herein, can broadly represent frequencies that can be less than 6 GHz, can be within FR1, or can include mid-band frequencies. Furthermore, unless specifically stated otherwise, it should be understood that the term millimeter wave, or like terms if used herein, can broadly represent frequencies that can include mid-band frequencies, can be within FR2, or can be within the EHF band. However, communications utilizing the mmW radio frequency band have extremely high path loss and a short range. The mmW base station 180 can utilize beamforming 182 with the UE 104 to compensate for the high path loss and short range.

[0095] The EPC 160 can include a mobility management entity (MME) 162, other MMEs 164, a serving gateway 166, a multimedia broadcast multicast service (MBMS) gateway 168, a broadcast multicast service center (BM-SC) 170, and a packet data network (PDN) gateway 172. The MME 162 can be in communication with a home subscriber server (HSS) 174. The MME 162 is the control node that processes the signaling between the UEs 104 and the EPC 160. Generally, the MME 162 provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the serving gateway 166, which itself is connected to the PDN gateway 172. The PDN gateway 172 provides UE IP address allocation as well as other functions. The PDN gateway 172 and the BM-SC 170 are connected to the IP services 176. The IP services 176 can include the Internet, an intranet, an IP multimedia subsystem (IMS), a PS streaming service, or other IP services. The BM-SC 170 can provide functions for MBMS user service provisioning and

[0096] The core network 190 can include an access and mobility management function (AMF) 192, other AMFs 193, a session management function (SMF) 194, and a user plane function (UPF) 195. The AMF 192 can be in communication with a unified data management (UDM) 196. The AMF 192 is the control node that processes the signaling between the UEs 104 and the core network 190. Generally, the AMF 192 provides QoS flow and session management. All user Internet protocol (IP) packets are transferred

[0097] A base station can include or be referred to as a gNB, NodeB, eNB, an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a transceiver subunit (TRU), or some other suitable terminology. A base station can be implemented as an aggregated or disaggregated base station and a disaggregated architecture can include one or more components such as a CU, DU, or RU. The base station 102 provides wireless access to the EPC 160 or core network 190 for the UEs 104. Examples of UEs 104 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (such as an MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitch appliance, a health care device, an implant, a sensor / actuator, a display, or any other similar functional device. Some of the UEs 104 can be referred to as IoT devices (such as a parking meter, gas pump, toaster, vehicle, heart monitor, etc.). The UE 104 can also be referred to as a station, a mobile, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

[0098] Although the following description can focus on 5G NR, the concepts described herein can be applicable to other similar areas, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies, including future 6G technologies.

[0099] Figure 2A FIG. 200 is a diagram 200 illustrating an example of a first frame. Figure 2B FIG. 230 is a diagram 230 illustrating an example of DL channels within a subframe. Figure 2C FIG. 250 is a diagram 250 illustrating an example of a second frame. Figure 2D FIG. 280 is a diagram 280 illustrating an example of a subframe. The 5G / NR frame structure can be FDD, where for a particular set of subcarriers (the carrier system bandwidth), the subframes within the set are dedicated to either DL or UL; or TDD, where for a particular set of subcarriers (the carrier system bandwidth), the subframes within the set are dedicated to both DL and UL. By way of example and without limitation, the 5G / NR frame structure can have a Figure 2A , 2CIn the examples provided, a 5G / NR frame structure is assumed to be TDD with subframe 4 configured with slot format 28 (mostly DL) and subframe 3 configured with slot format 34 (mostly UL), where D is DL, U is UL, and X is flexibly used between DL / UL. While subframes 3, 4 are shown with slot formats 34, 28, respectively, any particular subframe can be configured with any of the various available slot formats 0-61. Slot formats 0, 1 are all DL, all UL, respectively. Other slot formats 2-61 include a mix of DL, UL, and flexible symbols. UEs are configured with a slot format (dynamically, by DL control information (DCI), or semi- statically / statically, by radio resource control (RRC) signaling) through a received slot format indicator (SFI). Note that the following description also applies to a 5G / NR frame structure that is TDD.

[0100] Other wireless communication technologies can have different frame structures or different channels. A frame (10 milliseconds (ms)) can be divided into 10 equally sized subframes (1 ms). Each subframe can include one or more slots. A subframe can also include mini-slots, which can contain 7, 4, or 2 symbols. Each slot can contain 7 or 14 symbols, depending on the slot configuration. For slot configuration 0, each slot can contain 14 symbols, whereas for slot configuration 1, each slot can contain 7 symbols. A symbol on the DL can be a cyclic prefix (CP) OFDM (CP-OFDM) symbol. A symbol on the UL can be a CP-OFDM symbol (for high throughput scenarios) or a discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbol (also known as single carrier frequency division multiple access (SC-FDMA) symbol) (for power limited scenarios; limited to single-stream transmission). The number of slots within a subframe is based on the slot configuration and the numerology. For slot configuration 0, different numerologies m, from 0 to 5, allow for 1, 2, 4, 8, 16, and 32 slots per subframe, respectively. For slot configuration 1, different numerologies 0 to 2 allow for 2, 4, and 8 slots per subframe, respectively. Accordingly, for slot configuration 0 and numerology m, there are 14 symbols per slot and 2 μ *15 kHz, where m is the numerology from 0 to 5. As such, numerology m = 0 has a subcarrier spacing of 15 kHz, while numerology m = 5 has a subcarrier spacing of 480 kHz. Symbol length / duration is inversely related to subcarrier spacing. μ *15 kHz, where m is the numerology from 0 to 5. As such, numerology m = 0 has a subcarrier spacing of 15 kHz, while numerology m = 5 has a subcarrier spacing of 480 kHz. Symbol length / duration is inversely related to subcarrier spacing. Figures 2A-2D An example is provided with slot configuration 0 having 14 symbols per slot and numerology m = 2 and 4 slots per subframe. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 microseconds (ps).

[0101] A resource grid can be used to represent the frame structure. Each time slot includes a resource block (RB) (also referred to as physical RB (PRB)) that extends 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (RE). The number of bits carried by each RE depends on the modulation scheme.

[0102] As Figure 2A As x illustrated in , some of the REs carry reference (pilot) signals (RS) for the UE. The RS can include demodulation RS (DM-RS) (indicated as R for one particular configuration) and channel state information reference signals (CSI-RS) for channel estimation at the UE. The RS can also include beam measurement RS (BRS), beam refinement RS (BRRS), and phase tracking RS (PT-RS).

[0103] Figure 2B Examples of various DL channels are illustrated. The physical downlink control channel (PDCCH) carries DCI within one or several control channel elements (CCEs), each CCE including nine RE groups (REGs), each REG including four consecutive REs in an OFDM symbol. A primary synchronization signal (PSS) can be within symbol 2 of particular subframes of a frame. The PSS is used by a UE 104 to determine subframe / symbol timing and physical layer identity. A secondary synchronization signal (SSS) can be within symbol 4 of particular subframes of a frame. The SSS is used by a UE to determine physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI). Based on the PCI, the UE can determine the locations of the aforementioned DM-RS. The physical broadcast channel (PBCH), which carries a master information block (MIB) that provides system bandwidth, and the location to find other system information blocks (SIBs) can be logically grouped with the PSS and SSS to form a synchronization signal (SS) / PBCH block. The physical downlink shared channel (PDSCH) carries user data, broadcast system information such as system information blocks (SIBs), and paging information.

[0104] As Figure 2CAs illustrated in the middle, some of the REs carry DM-RS (indicated as R for one particular configuration, but other DM-RS configurations are possible) for channel estimation at the base station. The UE can transmit DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH). The PUSCH DM-RS can be transmitted in the first or first two symbols of the PUSCH. The PUCCH DM-RS can be transmitted in different configurations depending on whether short or long PUCCHs are transmitted and on the particular PUCCH format used. The UE can transmit a sounding reference signal (SRS). The SRS can be transmitted in the last symbol of a subframe. The SRS can have a comb-structure, and a UE can transmit SRS on one of the combs. The SRS can be used by base stations for channel quality estimation to enable frequency-dependent scheduling on the UL.

[0105] Figure 2D An example of various UL channels within a subframe of a frame is illustrated. The PUCCH can be located as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and HARQ ACK / NACK feedback. The PUSCH carries data, and can additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), or UCI.

[0106] Figure 3is a diagram of an example of a base station 310 and a UE 350 in an access network. In the DL, IP packets from the EPC 160 can be provided to a controller / processor 375. The controller / processor 375 implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller / processor 375 provides RRC layer functionality associated with broadcasting of system information (such as MIB, SIBs), RRC connection control (such as RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter radio access technology (RAT) mobility, and measurement configuration; PDCP layer functionality associated with header compression / decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0107] The transmit (TX) processor 316 and the receive (RX) processor 370 implement layer 1 functionality associated with various signal processing functions. Layer 1, which includes a physical (PHY) layer, can include error detection on the transport channels, forward error correction (FEC) coding / decoding of the transport channels, interleaving, rate matching, mapping to physical channels, modulation / demodulation of physical channels, and MIMO antenna processing. The TX processor 316 handles mapping to signal constellations based on various modulation schemes (such as binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols can be split into parallel streams. Each stream can be mapped to a OFDM subcarrier, multiplexed with a reference signal (such as pilot) in the time or frequency domain, and combined together using an inverse fast Fourier transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator 374 can be used to determine the coding and

[0108] At the UE 350, each receiver 354RX receives a signal through its respective antenna 352. Each receiver 354RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functionality associated with various signal processing functions. The RX processor 356 can perform spatial processing on the information to recover any spatial streams destined for the UE 350. If multiple spatial streams are destined for the UE 350, they can be combined by the RX processor 356 into a single OFDM symbol stream. The RX processor 356 converts the OFDM symbol stream from the time-domain to the frequency domain using a fast Fourier transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station 310. These soft decisions can be based on channel estimates computed by the channel estimator 358. The soft decisions are decoded and de-interleaved to recover the data and control signals that were originally transmitted by the base station 310 on the physical channel. The data and control signals are provided to the controller / processor 359, which implements layer 3 and layer 2 functionality.

[0109] The controller / processor 359 can be associated with a memory 360 that stores program codes and data. The memory 360 can be referred to as a computer-readable medium. In the UL, the controller / processor 359 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the EPC 160. The controller / processor 359 is also responsible for error detection using an ACK or NACK protocol to support HARQ operations.

[0110] Similar to the functionality described in connection with the DL transmission by the base station 310, the controller / processor 359 provides RRC layer functionality associated with system information (such as MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression / decompression, and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0111] Channel estimates derived by the channel estimator 358 from a reference signal or feedback transmitted by the base station 310 can be used by the TX processor 368 to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor 368 can be provided to different antenna 352 via separate transmitters 354TX. Each transmitter 354TX can modulate an RF carrier with a respective spatial stream for transmission.

[0112] The UL transmission is processed at the base station 310 in a manner similar to that described in connection with the receiver function at the UE 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers information modulated onto an RF carrier and provides the information to a RX processor 370.

[0113] The controller / processor 375 can be associated with a memory 376 that stores program codes and data. The memory 376 can be referred to as a computer-readable medium. In the UL, the controller / processor 375 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 350. IP packets from the controller / processor 375 can be provided to the EPC 160. The controller / processor 375 is also responsible for error detection using an ACK or NACK protocol to support HARQ operations.

[0114] At least one of the TX processor 368, the RX processor 356, and the controller / processor 359 can be configured to perform aspects in connection with Figure 1 the UL RS request component 140.

[0115] At least one of the TX processor 316, the RX processor 370, and the controller / processor 375 can be configured to perform aspects in connection with Figure 1 the RS request response component 120.

[0116] Figure 4 is a diagram illustrating example messages between a UE 404 and a BS 402 for requesting a reference signal (RS) 430. The UE 404 can be an example of the UE 104 including the UL RS request component 140 depicted and described in Figure 1 . The BS 402 can be an example of the base station 102 including the RS request response component 120 depicted and described in Figure 1 . The RS 430 can be, for example, a downlink RS 432 (such as a CSI-RS) or an uplink RS 434 (such as an SRS). The UE 404 can transmit a request 410. The request 410 can be a UE-initiated uplink request for a downlink RS 432, an uplink RS 434, or both. For example, a joint request can be used for the UE 404 to transmit an A-SRS for non-codebook-based MIMO after receiving an A-CSI-RS associated with an A-SRS. In some implementations, the BS 402 can optionally transmit a response 420. For example, the response 420 can be a downlink control information (DCI) that schedules or requests a reference signal. In some implementations, the response 420 can not be necessary. For example, the UE 404 can determine resources for the RS 430 based on a mapping according to the request 410. In any case, the UE 410 can transmit or receive the RS 430 based on the request 410.

[0117] Figure 5is a diagram 500 illustrating example messages between a UE 404 and a BS 402 for the UE 404 to request to transmit one or more SRSs 534. The UE 404 can be Figure 1 is an example of a UE 104 including a UL RS request component 140 depicted and described in Figure 1 is an example of a base station 102 including a RS request response component 120 depicted and described in FIG. 1. The UE 404 can transmit a SRS request 510. The SRS request 510 can be an example of a UE initiated uplink request for RS. The SRS request 510 can correspond to a configured SRS trigger state. When configured with an uplink SRS trigger list, the UE 404 can send the SRS request 510 to the BS 402 by indicating one of the configured uplink SRS triggers. There can be a mapping between the SRS request 510 and the SRS trigger.

[0118] For example, the SRS request 510 can be sent on PRACH, PUCCH, or MAC-CE. For example, the PRACH can be contention based, contention free, and can be a two-step PRACH. There can be a one-to-one mapping between the SRS request 510 and the configured SRS trigger. For example, if the uplink resource for the SRS request 510 is PRACH, then a PRACH preamble, a PRACH occasion, or a combination thereof can be mapped one-to-one to the configured SRS trigger. If the uplink resource for the SRS request 510 is PUCCH, then an uplink control information (UCI) codepoint, a PUCCH occasion, or a combination thereof can be mapped one-to-one to the configured SRS trigger. If the uplink resource for the SRS request 510 is MAC-CE, then a bit field of the MAC-CE can be mapped one-to-one to the configured SRS trigger.

[0119] In some implementations, the UE 404 can optionally receive a response 520. For example, the response 520 can be a dynamic grant scheduled by the BS 402, which can be a DCI including the SRS request. When the UE 404 is configured to receive the response 520, the UE 404 can refrain from transmitting the one or more A-SRSs 534 without receiving the response 520. When the UE 404 is not configured to receive the response 520, the UE 404 can transmit the one or more A-SRSs 534 at a fixed time offset after the SRS request 510. The time offset can be fixed by, for example, RRC configuration, a standard document, or a rule. The time offset can be associated with the SRS trigger state.

[0120] After the UE 404 has transmitted the SRS request to the BS 402, the UE 404 can transmit one or more A-SRS 534. The A-SRS 534 can be in one or more SRS resource sets corresponding to the SRS request 510. For example, the configured SRS trigger state can identify one or more SRS resources or SRS resource sets for transmission of the A-SRS 534. The UE 404 can transmit the one or more A-SRS 534 using the SRS resources associated with the SRS request 510.

[0121] Figure 6 is a diagram 600 illustrating example configurations 610 and resources 620 for SRS requests. The configurations 610 can include SRS triggers 612 and corresponding SRS requests 614. The SRS triggers 612 can include an identifier and can identify a resource for transmitting a SRS, such as a SRS sequence, or a number of resource blocks for a SRS. The SRS requests 614 can define resources 620 for transmitting a SRS request, such as the SRS request 510 depicted and described in Figure 5 For example, as illustrated, the resources 620 for each SRS request 614 can be a PUCCH resource. The resources 620 can be a PUCCH occasion defined by a time domain and a frequency domain resource. For example, the first SRS trigger and SRS request associated with ID 00 can be mapped to a PUCCH occasion 622. Additionally, the second SRS trigger and SRS request associated with ID 01 can be mapped to a PUCCH occasion 624, the third SRS trigger and SRS request associated with ID 10 can be mapped to a PUCCH occasion 626, and the fourth SRS trigger and SRS request associated with ID 11 can be mapped to a PUCCH occasion 628. In some other examples, each SRS request 614 can be mapped to a RACH preamble, a PUCCH UCI codepoint, or a MAC-CE bit field.

[0122] Figure 7 is a diagram 700 illustrating example messages between the UE 404 and the BS 402 for the UE requesting a CSI-RS 732. The UE 404 can be the UE 104 Figure 1 depicted and described in FIG. 1. The BS 402 can be the BS 102 Figure 1The example of the BS 102 including the RS request response component 120 is depicted and described. The requested CSI-RS 732 can be considered an aperiodic CSI-RS (A-CSI-RS). The UE 404 can transmit a CSI request 710. The CSI request 710 can be an example of a UE initiated uplink request for RS. The CSI request 710 can correspond to a configured CSI trigger state. The CSI trigger state can be configured with corresponding A-CSI RS resources in one or more CSI resource sets. When configured with a CSI trigger list, the UE 404 can send the CSI request 710 to the BS 402 by indicating one of the configured CSI triggers. There can be a mapping between the CSI request 710 and the CSI trigger.

[0123] For example, the CSI request 710 can be sent on PRACH, PUCCH, or MAC-CE. For example, the PRACH can be contention based, contention free, and can be a two-step PRACH. There can be a one-to-one mapping between the CSI request 710 and the configured CSI trigger. For example, if the uplink resource for the CSI request 710 is PRACH, then a PRACH preamble, a PRACH occasion, or a combination thereof can be mapped one-to-one to the configured CSI trigger. If the uplink resource for the CSI request 710 is PUCCH, then a UCI codepoint, a PUCCH occasion, or a combination thereof can be mapped one-to-one to the configured CSI trigger. If the uplink resource for the CSI request 710 is MAC-CE, then a bit field of the MAC-CE can be mapped one-to-one to the configured CSI trigger.

[0124] In some implementations, the UE 404 can optionally receive a response 720. For example, the response 720 can be a dynamic grant scheduled by the BS 402, which can be a DCI with a CSI request. For example, the DCI can be of format 0 1, and the CSI request can indicate a CSI trigger corresponding to the CSI request 710. When the UE 404 is configured to receive the response 720, the UE 404 can refrain from monitoring the CSI-RS 734 without receiving the response 720. When the UE 404 is not configured to receive the response 720, the UE 404 can monitor the CSI-RS at a fixed time offset after the CSI request 710. The time offset can be fixed by, for example, RRC configuration, a 3GPP standard document, or a rule. The time offset can be associated with the CSI trigger state.

[0125] Figure 8 is a diagram illustrating a procedure for updating an uplink beam or precoder with and without UE initiated uplink reference signal request. The UE 404 can be the UE 404 of FIG. 4. Figure 1An example of a UE 104 including the UL RS request component 140 is depicted and described. The BS 402 can be Figure 1 An example of a base station 102 including the RS request response component 120 is depicted and described. In the first example 800, without a UE-initiated reference signal request, the base station 402 can first transmit an uplink DCI 810. For example, the uplink DCI 810 can have a format 0 1 and can include a CSI request identifying a CSI trigger. The CSI request in the DCI can be referred to as a base station-initiated DCI-based request. Accordingly, the uplink DCI 810 can schedule the UE 404 to receive an A-CSI-RS 820. The UE 404 can perform measurements on the A-CSI-RS 820. For example, the UE 404 can determine that one or more beamforming parameters can be adjusted based on the A-CSI-RS. However, the UE 404 can be unable to transmit an SRS due to lack of scheduling. The UE 404 can wait until the BS 402 transmits a second DCI 830. The DCI 830 can schedule an A-SRS 840. The UE 404 can transmit the A-SRS 840 based on the updated beamforming or precoding parameters.

[0126] In a second example 850, UE 404 can transmit a joint request 860 for reference signals 880 including a SRS and a CSI-RS associated with the SRS. The SRS request 860 can indicate both the SRS and the CSI-RS associated with the SRS. For example, the SRS request 860 can use uplink resources mapped to a SRS trigger that can trigger a SRS transmission based on measurements of the CSI-RS associated with the SRS. If the measurements of the CSI-RS are based on A-CSI-RS, the SRS request 860 can be a joint request for an A-SRS and an A-CSI-RS associated with the A-SRS. In some implementations, BS 402 can transmit a response 870 in response to the request 860. The response 870 can be, for example, a DCI scheduling one or both of the A-CSI-RS 882 and the A-SRS 884. The response 870 can also include a SRS request scheduling the A-SRS 884 and the A-CSI-RS 882 associated with the A-SRS 884. In some implementations, UE 404 can receive the A-CSI-RS 882 at a first fixed time offset after the SRS request 860 and can transmit the A-SRS 884 at a second fixed time offset after the SRS request 860. In some implementations, the second fixed time offset can be greater than the first fixed time offset. In either case, UE 404 can perform measurements on the A-CSI-RS 882. For example, UE 404 can adjust beamforming or precoding parameters based on the A-CSI-RS 882. UE 404 can transmit the A-SRS 884 based on the adjusted beamforming parameters without waiting for a separate scheduling of the SRS. Accordingly, the second example 850 can provide a UE-initiated procedure for updated beamforming parameters that can have less latency than the first example 800.

[0127] Figure 9 is a diagram illustrating a MAC-CE 900 for activating a trigger state. In some implementations, for example, Figure 4 The BS 402 depicted and described in FIG. 10 can configure the UE 404 with a list of trigger states, for example, using RRC signaling. Figure 4 The UE 404 depicted and described in FIG. 10 is configured with a list of trigger states. For example, the BS 402 can transmit an RRC configuration message including a list of CSI trigger states or a list of SRS trigger states.

[0128] For CSI trigger states, the RRC configuration message can define one or more measurement resources, such as a channel measurement resource and one or more interference measurement resources, and can define one or more reporting resources. Example interference measurement resources include zero-power (ZP) CSI-RS and non-zero-power (NZP) CSI-RS. Example reporting resources can be PUCCH or PUSCH, and the PUSCH can be a configured grant based PUSCH without dynamic DCI grant or a PUSCH for message A (msgA) in two-step PRACH procedure. In some implementations, the CSI trigger states can correspond to CSI trigger states that can be triggered via DCI with CSI request. That is, a MAC-CE to select down a sub-list of trigger states for UE initiated uplink CSI request can be reused from a MAC-CE to select down a sub-list of trigger states for BS initiated DCI based CSI request. In some implementations, the MAC-CE can select a CSI trigger sub-list that is common for both UE initiated uplink request and base station initiated DCI based request. In some implementations, the base station 402 can configure a separate list of CSI trigger states for UE initiated uplink CSI request. That is, the MAC-CE can configure a sub-list that is only applicable for UE initiated uplink CSI request.

[0129] For SRS trigger states, the RRC configuration message can define one or more of the following: SRS resource set ID, number of SRS ports, resource type, slot level periodicity, number of OFDM symbols, SRS bandwidth, frequency hopping bandwidth, frequency domain location, configurable shift, cyclic shift, transmission comb value, transmission comb offset, SRS sequence ID, and spatial relation. The MAC-CE 900 can be used to select down a number of active trigger states from a configured trigger state list. In some implementations, the SRS trigger states can correspond to SRS configurations where the resource type is set to aperiodic, and the SRS configuration can be triggered by a DCI including a BS initiated DCI based SRS request. In this case, the SRS trigger state list is common for both UE initiated uplink SRS request and BS initiated DCI based SRS request. In some implementations, the base station can configure a separate list of SRS trigger states for UE RS request. In some implementations, a single list can include trigger states for both CSI-RS and SRS. For example, the trigger states in this single list can share a set of trigger state IDs. In some implementations, the single list can include both trigger states for CSI-RS and trigger states for SRS.

[0130] As illustrated, the MAC-CE 900 can include a plurality of octets or bytes. The first octet can include a reserved bit 910, a serving cell ID 912, and a bandwidth part (BWP) ID 914. The MAC-CE 900 can include a bitmap 920. The bitmap 920 can include a bit corresponding to each configured trigger state. The BS 402 can select up to a maximum number of active trigger states by setting the corresponding bits in the bitmap 920 to a specified value. For example, a value of 1 can indicate an active trigger state, while a value of 0 can indicate an inactive trigger state. Accordingly, the UE 404 can determine a set of active trigger states based on the MAC-CE 900.

[0131] The MAC-CE 900 can be used to activate a sub-list of uplink requests for the UE 404, and the physical resources used to transmit the activated uplink requests can be mapped one-to-one to the requests in the sub-list. Accordingly, the UE 404 can determine which physical resources to use for the requests, and the BS 402 can determine which uplink request was transmitted based on the physical resources on which the request was received.

[0132] Figure 10 is a diagram 1000 illustrating RS requests using different active trigger states indicated by a MAC-CE. The UE 404 can be the UE 104 Figure 1 is an example of a UE 104 including an UL RS request component 140 depicted and described in FIG. 1. The BS 402 can be the base station 102 Figure 1 is an example of a base station 102 including an RS request response component 120 depicted and described in FIG. 1. The UE 404 can receive RRC signaling 1010. The RRC signaling 1010 can configure a list of triggers. For example, the list of triggers can be a CSI trigger list defining CSI trigger states with request IDs 1-8. The UE 404 can receive a MAC-CE 1020. The MAC-CE 1020 can be an example of the MAC-CE 900 including a bitmap 920 indicating active trigger states. For example, the MAC-CE 1020 can activate a sub-list of trigger states including the CSI trigger states with request IDs 1-4. The activated trigger states can be mapped to resources according to a mapping 1040. In this example, the physical resources can be preambles, such as RACH preambles. There can be four (4) available physical resources numbered 0-3 and up to four (4) active CSI trigger states. The request IDs can be mapped to the resources in order. The UE 404 can transmit a reference signal request 1030 using a preamble 1 corresponding to request ID 2 according to the mapping 1040. The base station 402 can receive the UE request 1030 and transmit the requested CSI-RS.

[0133] The base station 402 can transmit a second MAC-CE 1022 that activates a second list of CSI trigger states. For example, the second MAC-CE 1022 can activate the trigger states with request IDs 5-8. The UE 404 can remap the configured resources to active trigger states in order to generate a mapping 1050. The UE 404 can transmit a reference signal request 1032 using the preamble 1 again. At this time, according to the mapping 1050, the preamble 1 can correspond to request ID 6. The base station 402 can receive the UE request 1032 and transmit the requested CSI-RS.

[0134] Figure 11 is a diagram 1100 illustrating RS requests using different active trigger states indicated by a MAC-CE. The UE 404 can be the UE 104 Figure 1 The example of the UE 104 including the UL RS request component 140 depicted and described in FIG. 11. The BS 402 can be the base station 102 Figure 1 The example of the base station 102 including the RS request response component 120 depicted and described in FIG. 11. The UE 404 can receive RRC signaling 1110. The RRC signaling 1110 can configure a list of triggers. For example, the list of triggers can be a list of SRS triggers defining SRS trigger states with request IDs 1-4. The UE 404 can receive a MAC-CE 1120. The MAC-CE 1120 can be an example of the MAC-CE 900 including the bitmap 920 indicating active trigger states. For example, the MAC-CE 1120 can activate a list of trigger states including SRS trigger states with request IDs 1 and 3. The activated trigger states can be mapped to resources according to a mapping 1140. In this example, the physical resources can be transmission occasions, such as PRACH occasions or PUCCH occasions. There can be two (2) available physical resources numbered 0 and 1 and up to two (2) active SRS trigger states. The request IDs can be mapped to resources in order. The UE 404 can transmit a reference signal request 1130 using occasion 0 corresponding to request ID 1 according to the mapping 1140. The base station 402 can receive the SRS (not shown) indicated by request ID 1. The UE 404 can also transmit a reference signal request 1132 using occasion 1 corresponding to request ID 3 according to the mapping 1140. The base station 402 can receive the SRS (not shown) indicated by request ID 3.

[0135] The base station 402 can transmit a second MAC-CE 1122 that activates a second SRS trigger state sub-list. For example, the second MAC-CE 1122 can activate the trigger states with request IDs 2 and 4. The UE 404 can remap the configured resources to active trigger states in order to generate a mapping 1150. The UE 404 can transmit a reference signal request 1134 using occasion 0. At this time, according to the mapping 1150, occasion 0 can correspond to request ID 2. The base station 402 can receive the SRS (not shown) indicated by request ID 2. The UE 404 can also transmit a reference signal request 1136 using occasion 1 corresponding to request ID 4 according to the mapping 1150. The base station 402 can receive the SRS (not shown) indicated by request ID 4.

[0136] Figure 12 FIG. 1200 is an example illustrating communications using a MAC-CE to further down-select active trigger states for UE-initiated uplink RS requests. The UE 404 can be an example of a UE 104 including an UL RS request component 140 depicted and described with reference to FIG. 1. The BS 402 can be an example of a base station 102 including a RS request response component 120 depicted and described with reference to FIG. 1. Figure 1 FIG. 1200 is an example illustrating communications using a MAC-CE to further down-select active trigger states for UE-initiated uplink RS requests. The UE 404 can be an example of a UE 104 including an UL RS request component 140 depicted and described with reference to FIG. 1. The BS 402 can be an example of a base station 102 including a RS request response component 120 depicted and described with reference to FIG. 1. Figure 1 FIG. 1200 is an example illustrating communications using a MAC-CE to further down-select active trigger states for UE-initiated uplink RS requests. The UE 404 can be an example of a UE 104 including an UL RS request component 140 depicted and described with reference to FIG. 1. The BS 402 can be an example of a base station 102 including a RS request response component 120 depicted and described with reference to FIG. 1.

[0137] Figure 13 FIG. 1300 is an example illustrating selection of trigger states for multiple component carriers (CCs). The UE 404 can be an example of a UE 104 including an UL RS request component 140 depicted and described with reference to FIG. 1. The BS 402 can be an example of a base station 102 including a RS request response component 120 depicted and described with reference to FIG. 1. Figure 1 FIG. 1300 is an example illustrating selection of trigger states for multiple component carriers (CCs). The UE 404 can be an example of a UE 104 including an UL RS request component 140 depicted and described with reference to FIG. 1. The BS 402 can be an example of a base station 102 including a RS request response component 120 depicted and described with reference to FIG. 1. Figure 1The example depicted and described includes a base station 102 of the RS request response component 120. The RRC signaling 1310 of the trigger state can configure the trigger state for one or more CCs. For example, the RRC signaling can configure the SRS trigger state on CC1 1312 to include the set {0, 1, 2, 3}. Similarly, the RRC signaling can configure the SRS trigger state on CC2 1314 to include the set {0, 1, 2, 3}. Similarly, the RRC signaling can configure the SRS trigger state on CC3 1316 to include the set {0, 1, 2, 3}.

[0138] The MAC-CE 1320 can down-select a sub-list of activated trigger states that can apply across CCs. For example, the MAC-CE 1320 can select a sub-list that includes SRS trigger 0 on CC1, SRS trigger 2 on CC2, and SRS trigger 3 on CC3. The MAC-CE 1320 can be a different format than the MAC-CE 900 and include a user request ID (such as an SRS trigger state ID), a serving cell ID, and a BWP ID for each active trigger state. As discussed herein, activated trigger states can be mapped to configured uplink resources in order.

[0139] The UE can use a cross-carrier request to request an RS. For example, the UE 404 can transmit a request 1330 on CC1. The request 1330 can indicate an activated trigger state for an uplink request based on a mapping to a configured resource. For example, the request 1330 can be transmitted using a resource that maps to SRS trigger 2 on CC2. The base station 402 can optionally transmit a response 1340 on CC1. The response 1340 can schedule an RS 1350 on CC2. If the UE 404 is not configured to receive the response 1340, the UE 404 can transmit or receive a requested RS 1350 based on an offset from the request 1330. The UE 404 can receive a downlink RS 1352, transmit an uplink RS 1354, or a combination thereof. For example, the downlink RS 1352 can be a CSI-RS and the uplink RS 1354 can be an SRS. In some implementations, the UE 404 can transmit a UE report 1360 based on the RS 1350 (such as a CSI report).

[0140] Figure 14is an example of a diagram illustrating CPU occupation for CSI operations for downlink scheduling. The UE 104 can include hardware resources used to perform CSI operations. For example, the hardware resources can include antenna ports, buffers or memory to store measurements, and processors to perform calculations. The UE can have a maximum number of CSI operations that can be performed concurrently based on the hardware resources. The UE 104 can report a CPU capability to the base station 102 indicating the maximum number of CSI operations that can be performed concurrently. Both the UE 104 and the base station 102 can track CPU occupation to determine a cumulative number of CPU occupation so that the UE can perform up to the maximum number of concurrent CSI operations.

[0141] In the first example 1400, the UE 104 can be scheduled for an aperiodic CSI report by the PDCCH 1412. The UE 104 can measure the A-CSI-RS 1414 to generate a CSI report. For example, the CSI report can include one or more of a channel quality indicator (CQI), a rank indicator (RI), or a precoding matrix indicator (PMI). The UE 104 can transmit the A-CSI report 1416 on resources indicated by the PDCCH 1412. The CPU occupation time 1410 can extend from the first symbol of the PDCCH to the last symbol of the A-CSI report 1416.

[0142] In a second example 1450, the UE 104 can be scheduled to perform CSI measurements without transmitting a CSI report. For example, the CSI measurements can be used to refine a receive beam. The PDCCH 1462 can schedule the UE 104 to receive a CSI-RS 1466 to perform CSI measurements. A minimum amount of time after the PDCCH 1462 can be defined as a number of symbols (Z) 1464. A minimum amount of time after the CSI-RS 1466 can be defined as a number of symbols (Z’) 1468. When a CSI report is configured with no value to transmit, such as for example, when a reportQuantity field associated with the CSI report is set to “none” in RRC signaling, an aperiodic CSI report occupies the CPU(s) from the last symbol after the PDCCH 1462 that triggers the CSI report until the last symbol between the first symbol after the PDCCH 1462 that triggers the CSI report and Z3 symbols after the last symbol of the latest CSI-RS 1466 resource in each CSI-RS 1466 resource used for channel measurements and Z’3 symbols after the last symbol of the CSI-RS 1466 resource. As illustrated, the Z’3 symbols 1468 end after the Z3 symbols 1464, thus the CPU occupancy time 1460 extends from the first symbol of the PDCCH 1462 to the last symbol in the Z’3 symbols 1468. Z3 and Z’3 can be determined from the following table, where μ indicates subcarrier spacing, Xμ is according to the UE reported capability beamReportTiming, and KB is according to the UE reported capability beamSwitchTiming.

[0143] Table 1

[0144]

[0145] Figure 15is a diagram illustrating an example of CPU occupation for CSI operation for UE-requested with downlink response. In the first example 1500, the UE 104 can be configured with a CSI trigger state for uplink request. The UE 104 can monitor a periodic CSI-RS 1512 to determine whether to transmit an uplink request on a CSI request occasion 1514. At least some CPU resources can be utilized to monitor the periodic CSI-RS 1512. Once the CPU is used to trigger the CSI request, the CPU cannot be used for another CSI operation, such as a CSI request or a CSI report. These CPU resources can be released after the CSI request occasion 1514, regardless of whether the UE transmits an uplink request. Accordingly, a CPU occupation time 1510 can extend from a first symbol of the periodic CSI-RS 1512 to a last symbol of the CSI request occasion 1514. The periodic CSI-RS 1512 can be configured to be associated with the CSI request occasion 1514. In the case that the UE 104 transmits an uplink request, the base station 102 can respond by transmitting a PDCCH 1522, which can correspond to the response 420, 720. The PDCCH 1522 can schedule an A-CSI-RS 1524. The UE 104 can measure the A-CSI-RS 1524 to generate an A-CSI report 1526. The UE 104 can apply the same CPU resources used to trigger the CSI request to reporting the A-CSI report 1526 in response to the PDCCH 1522. Accordingly, a CPU occupation time 1520 can extend from a first symbol of the PDCCH 1522 to a last symbol of the A-CSI report 1526.

[0146] In some implementations, the CPU occupation time 1510 and the CPU occupation time 1520 can be applied to the same pool of CPU resources. That is, the resources used to monitor the CSI-RS 1512 and transmit an uplink request in a UE-initiated CSI request procedure can be reused for receiving the A-CSI-RS 1524 and transmitting the A-CSI report 1526 in a base station-initiated CSI request procedure. In some implementations, a smaller number of CPUs can be utilized during the CPU occupation time 1510 than during the CPU occupation time 1520. For example, monitoring the CSI-RS 1512 for an uplink CSI request can use fewer resources than measuring the corresponding A-CSI-RS 1524 for a downlink CSI request. The UE 104 can trigger an uplink CSI request based on a rough estimate that fewer CPUs are used for uplink CSI request than for downlink CSI request.

[0147] In the second example 1550, the uplink CSI request in the UE-initiated CSI request procedure and the downlink CSI request in the base station-initiated CSI request procedure can use resources from separate CPU resource pools. The UE 104 can be configured with one or more CSI trigger states for uplink requests. Each activated uplink CSI trigger state can occupy a separate number of CPUs depending on the configured resources for the uplink CSI trigger state. The UE 104 can monitor the periodic CSI-RS 1562 to determine whether to transmit an uplink request on the CSI request occasion 1564. At least some of the CPU resources in the first CPU resource pool can be utilized to monitor the periodic CSI-RS 1562. Once a CPU is used to trigger a CSI request, that CPU cannot be used for another CSI operation, such as a CSI request or a CSI report. These CPU resources can be released after the CSI request occasion 1564 regardless of whether the UE transmits an uplink request. Accordingly, the CPU occupancy time 1560 can extend from the first symbol of the periodic CSI-RS 1562 to the last symbol of the CSI request occasion 1564. In the case that the UE 104 transmits an uplink request, the base station 102 can respond by transmitting a PDCCH 1572, which can correspond to the response 420, 720. The PDCCH 1572 can schedule an A-CSI-RS 1574. The UE 104 can measure the A-CSI-RS 1574 to generate an A-CSI report 1576. When the UE 104 is configured with separate resource pools for uplink CSI requests and downlink CSI requests, the UE 104 can apply different CPU resources for reporting the A-CSI report 1576 in response to the PDCCH 1572 than the CPU resources used to trigger the uplink CSI request. Accordingly, the CPU occupancy time 1570 can extend from the first symbol of the PDCCH 1572 to the last symbol of the A-CSI report 1576 and applies to the second CPU resource pool.

[0148] In some implementations, the CPU resources for uplink CSI requests in the first CPU resource pool can be reserved CPU resources of the second CPU pool. For example, when a trigger state for an uplink CSI request is activated, the CPU resources of the first pool can be reserved for the active uplink CSI request. These reserved CPU resources can be subtracted from the reported CPU capability. In some implementations, the CPU resources for uplink CSI requests in the first CPU resource pool can be dedicated CPU resources. For example, the UE 104 can separately indicate the CPU capability for uplink CSI requests in the UE-initiated CSI request procedure and the CPU capability for downlink requests in the base station-initiated CSI request procedure.

[0149] Figure 16 is a diagram 1600 illustrating an example of cumulative CPU occupancy 1650 for CSI operations requested by a UE. The cumulative CPU occupancy 1650 can be the total number of CPUs occupied at any time for concurrent CPU operations with the same resource pool. In the illustrated example, a single resource pool described above with respect to example 1500 can be utilized. A first CPU operation can be an uplink request with an occupancy time 1610 of 2 CPUs occupied. A corresponding downlink CSI request can occupy 4 CPUs during an occupancy time 1620. A second CPU operation can be an uplink request with an occupancy time 1630 of 4 CPUs occupied. A corresponding downlink CSI request can occupy 4 CPUs during an occupancy time 1640.

[0150] The cumulative CPU occupancy 1650 can be the sum of the number of CPUs occupied per active CPU occupancy time. During a period 1652, the cumulative CPU occupancy 1650 can be 2 CPUs because only the CPU occupancy time 1610 is active. During a period 1654 in which the CPU occupancy time 1610 overlaps with the CPU occupancy time 1630, the cumulative CPU occupancy 1650 can be 6 CPUs. After the CPU occupancy time 1610 ends, during a period 1656, the cumulative CPU occupancy 1650 can be 4 CPUs. During a period 1658, the cumulative CPU occupancy 1650 can be 0 CPUs. During a period 1660, the cumulative CPU occupancy 1650 can be 4 CPUs once the CPU occupancy time 1620 begins. During a period 1662, the cumulative CPU occupancy 1650 can be 8 CPUs once the CPU occupancy time 1640 begins. During a period 1664 in which the first A-CSI report is transmitted, the cumulative CPU occupancy 1650 can remain at 8 CPUs. In a period 1666, at the end of the CPU occupancy time 1630, the cumulative CPU occupancy 1650 can be 4 CPUs.

[0151] In some implementations, the base station 102 can configure the UE 104 such that the cumulative CPU occupancy 1650 does not exceed a signaled CPU capability of the UE 104. For example, the base station 102 can configure a number of uplink CSI trigger states such that the overlapping occupancy time of the configured uplink CSI trigger states does not exceed the CPU capability. If scheduling a downlink CSI request would exceed the CPU capability, the base station 102 can refrain from doing so.

[0152] Figure 17is a diagram illustrating an example of CPU occupancy for UE-requested CSI operation without a downlink response. As discussed above, the CPU occupancy time for a downlink CSI request can begin at the PDCCH scheduling the CSI report. In the case of an uplink CSI request without a response 420, 720, there can be no PDCCH corresponding to the start of the downlink CSI request, but the UE 104 can still generate a CSI report or perform another CSI operation that utilizes CPU.

[0153] In the first example 1700, the UE 104 can transmit an uplink CSI request for generation of an A-CSI report. The UE 104 can measure a periodic CSI-RS 1712 associated with the uplink CSI request. The UE 104 can determine whether to transmit the uplink CSI request on a CSI request occasion 1714 based on the measurement of the CSI-RS 1712. If the UE 104 transmits the uplink CSI request, the UE 104 can receive an A-CSI-RS 1716 associated with the uplink CSI request. The UE 104 can generate an A-CSI report 1718 based on the A-CSI-RS 1716. The CPU occupancy time 1710 can extend from the first symbol of the CSI-RS 1712 to the last symbol of the A-CSI report 1718. In particular, because there is no PDCCH scheduling the A-CSI-RS, both the UE 104 and the base station 102 can assume that CPU resources are occupied based on the configured CSI trigger for the uplink request. Additionally, it can be possible for multiple CSI request configurations to overlap during the CPU occupancy time 1710. The cumulative CPU occupancy 1650 can account for each overlapping CSI request occasion.

[0154] In the second example 1750, the UE can request a CSI-RS without a reporting quantity.

[0155] For example, the UE 104 can measure a CSI-RS for receive beam refinement in beam management. The UE 104 can not transmit a CSI report that marks the end of a CSI operation. The UE 104 can measure a periodic CSI-RS 1762 associated with an uplink CSI request. The UE 104 can determine whether to transmit an uplink CSI request on a CSI request occasion 1764 based on the measurement of the CSI-RS 1762. If the UE 104 transmits an uplink CSI request, the UE 104 can receive an A-CSI-RS 1766 associated with the uplink CSI request. Because there is no PDCCH, the time period Z3 can not apply. However, a time period Z3' 1768 can be measured from the last symbol of the A-CSI-RS. Accordingly, the CPU occupancy time 1760 can extend from the first symbol of the CSI-RS 1762 to the end of the time period Z3' 1768. Also, if there are multiple overlapping CSI request occasions during the occupancy time 1760, the cumulative CPU occupancy 1650 can account for each of the overlapping CSI request occasions.

[0156] Figure 18 FIG. 18 is a diagram illustrating example communications and components of a base station 102 and a UE 104, in accordance with some aspects. In examples described herein, an example of the base station 102 can be the BS 402 and an example of the UE 104 can be the UE 404. The UE 104 can include a UL RS request component 140. The base station 102 can include a RS request response component 120.

[0157] As discussed above with respect to Figure 1 The UL RS request component 140 can include a request transmitter 143 and a RS communication component 145. In some implementations, the RS communication component 145 can include a CSI-SR receiver 1802 configured to receive a CSI-SR. In some implementations, the RS communication component 145 can include a SRS transmitter 1804 configured to transmit a SRS. In some implementations, the UL RS request component 140 can include one or more of the configuration component 141, the activation component 142, the response receiver 144, or the reporting component 147. The UL RS request component 140 can also include a receiver component 1870 and a transmitter component 1872. The receiver component 1870 can include, for example, a radio frequency (RF) receiver for receiving signals described herein. The transmitter component 1872 can include, for example, a RF transmitter for transmitting signals described herein. In some implementations, the receiver component 1870 and the transmitter component 1872 can be collocated in a transceiver.

[0158] The RS request response component 120 can include a request reception component 122 and a RS communication component 124. In some implementations, the RS communication component 124 can include a CSI-SR transmitter 1854 configured to transmit a CSI-SR. In some implementations, the RS communication component 124 can include a SRS receiver 1856 configured to receive a SRS. In some implementations, the RS request response component 120 can also optionally include one or more of a configuration transmitter 1860, an activation transmitter 1862, a response transmitter 1864, and a report receiver 1866. The RS request response component 120 can also include a receiver component 1850 and a transmitter component 1852. The receiver component 1850 can include, for example, an RF receiver for receiving signals described herein. The transmitter component 1852 can include, for example, an RF transmitter for transmitting signals described herein. In some implementations, the receiver component 1850 and the transmitter component 1852 can be collocated in a transceiver.

[0159] The base station 102 or RS request response component 120 can transmit a trigger state configuration 1810. The trigger state configuration 1810 can correspond to, for example, the RRS signaling 1010, 1110, 1210, or 1310.

[0160] The base station 102 or RS request response component 120 can transmit an activation / deactivation command 1812. The activation / deactivation command 1812 can correspond to, for example, the MAC-CE 900, 1020, 1022, 1120, 1122, 1220, 1230, or 1320.

[0161] The UE 104 or UL RS request component 140 can transmit a RS request 1814. The RS request 1814 can correspond to, for example, the request 410, 510, 710, 860, 1030, 1032, 1130, 1132, 1134, 1136, 1240, or 1330.

[0162] The base station 102 or RS request response component 120 can optionally transmit a response 1816. The response 1816 can correspond to, for example, the response 420, 520, 720, 870, or 1340.

[0163] The base station 102 or RS request response component 120 can transmit a CSI-RS 1818. The CSI-RS 1818 can correspond to the downlink reference signal 432 or 1532 or the A-CSI-RS 734 or 882.

[0164] The UE 104 or UL RS request component 140 can transmit a SRS 1820. The SRS 1820 can correspond to the uplink reference signal 434 or 1354 or the A-SRS 534 or 884.

[0165] The UE 104 or UL RS requesting component 140 can transmit a CSI report 1822. The CSI report 1822 can correspond to, for example, the report 1360. The CSI report 1822 can include one or more of a CQI 1840, a RI 1842, or a PMI 1844.

[0166] Figure 19 is a conceptual data flow diagram 1900 illustrating the data flow between different means / components in an example base station 1902, which can be an example of a base station 102 including a RS request responding component 120, which can be a means for wireless communication of the base station. The RS request responding component 120 can be a component of the base station, such as a CU, a DU, or a RU, or other component of a distributed architecture.

[0167] The receiver component 1850 can receive, from the UE 104, uplink signals including the RS request 1814, the SRS 1820, and the CSI report 1822. In some implementations, the receiver component 1850 can receive the UE capability. The receiver component 1850 can provide the CSI report to the report receiver 1866. The receiver component 1850 can provide the SRS to the RS communication component 124. The receiver component 1850 can provide the RS request 1814 to the request receiving component 122. The receiver component 1850 can provide the UE capability to the configuration transmitter 1860 or the activation transmitter 1862.

[0168] The request receiving component 122 can receive the RS request 1814 from the receiver component 1850. The request receiving component 122 can determine the requested RS based on a mapping from the active trigger state to the uplink resource on which the RS request 1814 is received. The request receiving component 122 can provide the requested RS to the RS communication component 124 and the response transmitter 1864.

[0169] The RS communication component 124 can receive the requested RS from the request receiving component 122. The RS communication component 124 can control the receiver component 1850 and the transmitter component 1852 to communicate the requested RS. For example, the SRS receiver 1856 can control the receiver component 1850 to receive the SRS. As another example, the CSI-RS transmitter 1854 can control the transmitter component 1852 to transmit the CSI-RS.

[0170] In some implementations, the response transmitter 1864 can determine whether to transmit a grant scheduling the requested RS. For example, the response transmitter 1864 can include a scheduler configured to determine whether resources for the requested RS are available or scheduled for a different transmission. The response transmitter 1864 can transmit a response 1816 including the grant via the transmitter component 1852.

[0171] In some implementations, the configuration transmitter 1860 can generate a trigger state configuration 1810. The trigger state configuration 1810 can include one or more trigger states. For example, the trigger states can be based on UE capabilities including a number of CPUs in a resource pool for uplink requests. The configuration transmitter 1860 can transmit the trigger state configuration 1810 via the transmitter component 1852.

[0172] In some implementations, the activation transmitter 1862 can generate an activation / deactivation command 1812. The activation / deactivation command 1812 can be a MAC-CE activating a subset of one or more CSI trigger states or SRS trigger states. The MAC-CE can deactivate trigger states not included in the subset. For example, the trigger states can be activated based on UE capabilities including a number of CPUs in a resource pool for uplink requests. The activation transmitter 1862 can transmit the activation / deactivation command 1812 via the transmitter component 1852.

[0173] In some implementations, the report receiver 1866 can receive a CSI report 1822. For example, the CSI report 1822 can be in response to the CSI-RS 1818 in the case that the RS communication component 124 transmits the CSI-RS 1818.

[0174] Figure 20 FIG. 20 is a conceptual data flow diagram 2000 illustrating the data flow between different means / components in an example UE 2004, which can be an example of a UE 104 and include a UL RS request component 140. The UL RS request component 140 can be a means for wireless communication of a user equipment.

[0175] The receiver component 1870 can receive downlink signals, such as the trigger state configuration 1810, the activation / deactivation command 1812, the response 1816, and the CSI-RS 1818. The receiver component 1870 can provide the trigger state configuration 1810 to the configuration component 141. The receiver component 1870 can provide the activation / deactivation command 1812 via the activation component 142. The receiver component 1870 can provide the response 1816 to the response receiver 144. The receiver component 1870 can provide the CSI-RS 1818 to the CSI-RS receiver 1802.

[0176] Configuration component 141 can receive a trigger state configuration 1810 from receiver component 1870. Configuration component 141 can extract a list of triggers (such as SRS trigger states, CSI trigger states, or a combination thereof) from the trigger state configuration 1810. Configuration component 141 can configure request transmitter 143 with the configured trigger states. Configuration component 141 can configure activation component 142 with the trigger IDs of the configured trigger states.

[0177] Activation component 142 can receive an activation / deactivation command 1812, which can be a MAC-CE. Activation component 142 can determine a subset of configured trigger states that are activated. Activation component 142 can provide the activated trigger state subset to request transmitter 143.

[0178] Request transmitter 143 can receive configured trigger states from configuration component 141. Request transmitter 143 can receive an active trigger state subset from activation component 142. Request transmitter 143 can receive measurements from CSI-RS receiver 1802. Request transmitter 143 can determine a request reference signal based on an active trigger state on the active trigger state subset. For example, request transmitter 143 can determine that a measurement satisfies a threshold or that an event has occurred. Request transmitter 143 can determine an uplink resource mapped to the active trigger state. Request transmitter 143 can generate an uplink request indicating the active trigger state. For example, request transmitter 143 can select an uplink resource, preamble, sequence, or value for the uplink request based on a mapping between uplink resources and active trigger states. Request transmitter 143 can provide the uplink request to transmitter component 1872 for transmission. Request transmitter 143 can also provide the uplink request to RS communication component 145.

[0179] Response receiver 144 can receive a response 1816 from receiver component 1870. Response receiver 144 can determine whether the response 1816 includes a grant for a reference signal. Response receiver 144 can provide the grant to RS communication component 145.

[0180] RS communication component 145 can receive a UL request from request transmitter 143. In some implementations, RS communication component 145 can receive a grant from response receiver 144. RS communication component 145 can determine which reference signals to communicate based on the uplink request and the grant, if received. RS communication component 145 or CSI-RS receiver 1802 can receive a CSI-RS. RS communication component 145 or SRS transmitter 1804 can transmit an SRS.

[0181] The reporting component 147 can receive the measurements from the RS communication component 145. The reporting component 147 can generate a CSI report based on the measurements. The reporting component 147 can transmit the CSI report via the transmitter component 1872.

[0182] Figure 21 is a flowchart illustrating an example method 2100 for a UE requesting at least one reference signal. The method 2100 can be performed by a UE such as the UE 104, which can include the memory 360 and which can be the entire UE 104 or a component of the UE 104, such as the UL RS request component 140, the TX processor 368, the RX processor 356, or the controller / processor 359. The method 2100 can be performed by the UL RS request component 140 in communication with the RS request response component 120 of the base station 102. Optional blocks are shown with dashed lines.

[0183] At block 2110, the method 2100 can optionally include receiving a RRC configuration message indicating one or more CSI trigger states or SRS trigger states for uplink requests for at least one reference signal. In some implementations, for example, the UE 104, the RX processor 356, or the controller / processor 359 can execute the UL RS request component 140 or the configuration component 141 to receive the trigger state configuration 1810 indicating one or more CSI trigger states or SRS trigger states for uplink requests for at least one reference signal. Accordingly, the UE 104, the RX processor 356, or the controller / processor 359 executing the UL RS request component 140 or the configuration component 141 can provide means for receiving a RRC configuration message indicating one or more CSI trigger states or SRS trigger states for uplink requests for at least one reference signal.

[0184] At block 2120, the method 2100 can optionally include receiving a MAC-CE activating a subset of the one or more CSI trigger states or SRS trigger states. In some implementations, for example, the UE 104, the RX processor 356, or the controller / processor 359 can execute the UL RS request component 140 or the activation component 142 to receive the MAC-CE activating a subset of the one or more CSI trigger states or SRS trigger states. Accordingly, the UE 104, the RX processor 356, or the controller / processor 359 executing the UL RS request component 140 or the activation component 142 can provide means for receiving a MAC-CE activating a subset of the one or more CSI trigger states or SRS trigger states.

[0185] At block 2130, the method 2100 can include transmitting an uplink request for the at least one reference signal, the uplink request indicating the triggering state of the UE. In some implementations, for example, the UE 104, the Tx processor 368, or the controller / processor 359 can execute the UL RS request component 140 or the request transmitter 143 to transmit an RS request 1814 for the at least one reference signal, the RS request 1814 indicating the triggering state of the UE. In some implementations, at sub-block 2132, block 2130 can optionally include transmitting the uplink request on the uplink resource defined by the mapping 1040, 1050, 1140, or 1150 from the triggering state to the uplink resource. For example, when the uplink resource is a PRACH, the triggering state can be mapped to a PRACH preamble, a PRACH occasion, or a combination thereof. The PRACH can be one of: a contention-based PRACH, a contention-free PRACH, or a two-step PRACH. As another example, when the uplink resource is a PUCCH, the triggering state can be mapped to a UCI codepoint, a PUCCH occasion, or a combination thereof. As another example, when the uplink resource is a MAC-CE, the triggering state can be mapped to a bit field of the MAC-CE. Accordingly, the UE 104, the Tx processor 368, or the controller / processor 359 executing the UL RS request component 140 or the request transmitter 143 can provide means for transmitting an uplink request for the at least one reference signal, the uplink request indicating the triggering state of the UE.

[0186] At block 2140, the method 2100 can optionally include receiving a DCI scheduling the at least one reference signal. In some implementations, for example, the UE 104, the RX processor 356, or the controller / processor 359 can execute the UL RS request component 140 or the response receiver 144 to receive a DCI scheduling the at least one reference signal. In some implementations, the DCI includes an SRS request. In some implementations, the DCI includes a CSI request. Accordingly, the UE 104, the RX processor 356, or the controller / processor 359 executing the UL RS request component 140 or the response receiver 144 can provide means for receiving a DCI scheduling the at least one reference signal.

[0187] At block 2150, the method 2100 can include communicating at least one reference signal corresponding to the trigger state in response to the uplink request. In some implementations, for example, the UE 104, RX processor 356, TX processor 368, or controller / processor 359 can execute the UL RS request component 140 or the RS communication component 145 to communicate at least one reference signal corresponding to the trigger state in response to the uplink request. In some implementations, at sub-block 2152, block 2150 can optionally include transmitting a SRS. For example, the SRS transmitter 1804 can transmit a SRS when the uplink request indicates a SRS trigger state. In some implementations, at sub-block 2154, block 2150 or sub-block 2152 can include transmitting the SRS at a time offset after the uplink request. For example, the SRS transmitter 1804 can transmit the SRS at a time offset after the uplink request in a case that the UE 104 is not configured to receive a grant. The time offset can be associated with the trigger state. In some implementations, at sub-block 2156, block 2150 can optionally include receiving a CSI-RS. For example, the CSI-RS receiver 182 can receive a CSI-RS when the uplink request indicates a CSI trigger state. In some implementations, at sub-block 2158, block 2150 or sub-block 2156 can include receiving the CSI-RS at a time offset after the uplink request. For example, the CSI-RS receiver 1802 can receive the CSI-RS at a time offset after the uplink request in a case that the UE 104 is not configured to receive a grant. The time offset can be associated with the trigger state. Accordingly, the UE 104, RX processor 356, TX processor 368, or controller / processor 359 executing the UL RS request component 140 or the RS communication component 145 can provide means for communicating at least one reference signal corresponding to the trigger state in response to the uplink request.

[0188] At block 2160, the method 2100 can optionally include transmitting a CSI report. In some implementations, for example, the UE 104, RX processor 356, or controller / processor 359 can execute the UL RS request component 140 or the reporting component 147 to transmit a CSI report. Accordingly, the UE 104, RX processor 356, or controller / processor 359 executing the UL RS request component 140 or the reporting component 147 can provide means for transmitting a CSI report.

[0189] Figure 22is a flowchart of an example method 2200 for a base station to receive an uplink RS request. The method 2200 can be performed by a base station such as the base station 102, which can include the memory 376 and which can be the entire base station 102 or a component of the base station 102, such as the RS request response component 120, the TX processor 316, the RX processor 370, or the controller / processor 375, for example. The method 2200 can be performed by the RS request response component 120 in communication with the UL RS request component 140 of a UE 104.

[0190] At block 2210, the method 2200 can optionally include transmitting a RRC configuration message indicating one or more CSI trigger states or SRS trigger states for uplink requests for at least one reference signal. In some implementations, the base station 102, the TX processor 316, or the controller / processor 375 can execute the RS request response component 120 or the configuration transmitter 1860 to transmit a trigger state configuration 1810 indicating one or more CSI trigger states or SRS trigger states for uplink requests for at least one reference signal, for example. Accordingly, the base station 102, the TX processor 316, or the controller / processor 375 executing the RS request response component 120 or the configuration transmitter 1860 can provide means for transmitting a RRC configuration message indicating one or more CSI trigger states or SRS trigger states for uplink requests for at least one reference signal.

[0191] At block 2220, the method 2200 can optionally include transmitting a MAC-CE activating a subset of the one or more CSI trigger states or SRS trigger states. In some implementations, the base station 102, the TX processor 316, the RX processor 370, or the controller / processor 375 can execute the RS request response component 120 or the activation transmitter 1862 to transmit a MAC-CE activating a subset of the one or more CSI trigger states or SRS trigger states, for example. Thus, the base station 102, the TX processor 316, or the controller / processor 375 executing the RS request response component 120 or the activation transmitter 1862 can provide means for transmitting a MAC-CE activating a subset of the one or more CSI trigger states or SRS trigger states.

[0192] At block 2230, the method 2200 can include receiving an uplink request for the at least one reference signal, the uplink request indicating the triggering state of the UE. In some implementations, for example, the base station 102, RX processor 370, or controller / processor 375 can execute the RS request response component 120 or the request reception component 122 to receive an uplink request 1814 for the at least one reference signal, the uplink request 1814 indicating the triggering state of the UE. In some implementations, at sub-block 2232, block 2230 can optionally include receiving the uplink request on an uplink resource defined by a mapping 1040, 1050, 1140, or 1150 from the triggering state to the uplink resource. For example, when the uplink resource is a PRACH, the triggering state can be mapped to a PRACH preamble, a PRACH occasion, or a combination thereof. The PRACH can be one of: a contention-based PRACH, a contention-free PRACH, or a two-step PRACH. As another example, when the uplink resource is a PUCCH, the triggering state can be mapped to a UCI codepoint, a PUCCH occasion, or a combination thereof. As another example, when the uplink resource is a MAC-CE, the triggering state can be mapped to a bit field of the MAC-CE. Accordingly, the base station 102, RX processor 370, or controller / processor 375 executing the RS request response component 120 or the request reception component 122 can provide means for receiving an uplink request for the at least one reference signal, the uplink request indicating the triggering state of the UE.

[0193] At block 2240, the method 2200 can optionally include transmitting DCI scheduling the at least one reference signal. In some implementations, for example, the base station 102, TX processor 316, RX processor 370, or controller / processor 375 can execute the RS request response component 120 or the response transmitter 1864 to transmit DCI scheduling the at least one reference signal. In some implementations, the DCI includes a SRS request. In some implementations, the DCI includes a CSI request. Accordingly, the base station 102, TX processor 316, or controller / processor 375 executing the RS request response component 120 or the response transmitter 1864 can provide means for transmitting DCI scheduling the at least one reference signal.

[0194] At block 2250, the method 2200 can include communicating at least one reference signal corresponding to the trigger state in response to the uplink request. In some implementations, for example, the base station 102, TX processor 316, RX processor 370, or controller / processor 375 can execute the RS request response component 120 or the RS communication component 124 to communicate at least one reference signal corresponding to the trigger state in response to the uplink request. In some implementations, at sub-block 2252, block 2150 can optionally include receiving an SRS. For example, the SRS receiver 1856 can receive an SRS when the uplink request indicates an SRS trigger state. In some implementations, at sub-block 2254, block 2250 or sub-block 2252 can include receiving the SRS at a time offset after the uplink request. For example, the SRS receiver 1856 can receive the SRS at a time offset after the uplink request in a case that the UE 104 is not configured to receive a grant. The time offset can be associated with the trigger state. In some implementations, at sub-block 2256, block 2250 can optionally include transmitting a CSI-RS. For example, the CSI-RS transmitter 1854 can transmit a CSI-RS when the uplink request indicates a CSI trigger state. In some implementations, at sub-block 2258, block 2250 or sub-block 2256 can include transmitting the CSI-RS at a time offset after the uplink request. For example, the CSI-RS transmitter 1854 can transmit the CSI-RS at a time offset after the uplink request in a case that the UE 104 is not configured to receive a grant. The time offset can be associated with the trigger state. Accordingly, the base station 102, TX processor 316, RX processor 370, or controller / processor 375 executing the RS request response component 120 or the RS communication component 124 can provide means for communicating at least one reference signal corresponding to the trigger state in response to the uplink request.

[0195] At block 2260, the method 2200 can optionally include receiving a CSI report. In some implementations, for example, the base station 102, RX processor 370, or controller / processor 375 can execute the RS request response component 120 or the report component 147 to receive a CSI report. Accordingly, the base station 102, RX processor 370, or controller / processor 375 executing the RS request response component 120 or the report receiver 1866 can provide means for receiving a CSI report.

[0196] Figure 23is a flowchart illustrating an example method 2300 for a UE requesting at least one reference signal. The method 2300 can be performed by a UE such as the UE 104, which can include the memory 360 and which can be the entire UE 104 or a component of the UE 104, such as the UL RS request component 140, the TX processor 368, the RX processor 356, or the controller / processor 359. The method 2300 can be performed by the UL RS request component 140 in communication with the RS request response component 120 of the base station 102. Optional blocks are shown with dashed lines.

[0197] At block 2310, the method 2300 can include receiving a RRC configuration message indicating one or more CSI trigger states, one or more SRS trigger states, or a combination thereof. In some implementations, for example, the UE 104, the RX processor 356, or the controller / processor 359 can execute the UL RS request component 140 or the configuration component 141 to receive the trigger state configuration 1810 indicating one or more CSI trigger states, one or more SRS trigger states, or a combination thereof for UE-initiated uplink RS requests. Accordingly, the UE 104, the RX processor 356, or the controller / processor 359 executing the UL RS request component 140 or the configuration component 141 can provide means for receiving a RRC configuration message indicating one or more CSI trigger states, one or more SRS trigger states, or a combination thereof for UE-initiated uplink RS requests.

[0198] At block 2320, the method 2300 can include receiving a MAC-CE activating a subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof. In some implementations, for example, the UE 104, the RX processor 356, or the controller / processor 359 can execute the UL RS request component 140 or the activation component 142 to receive a MAC-CE (such as the activation / deactivation command 1812) activating a subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof. There can be a one-to-one mapping between the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof and one or more physical uplink resources. Thus, the UE 104, the RX processor 356, or the controller / processor 359 executing the UL RS request component 140 or the activation component 142 can provide means for receiving a MAC-CE activating a subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof.

[0199] At block 2330, the method 2300 can include selecting an activated trigger state from the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof. In some implementations, for example, the UE 104, the Tx processor 368, or the controller / processor 359 can execute the UL RS request component 140 or the request transmitter 143 to select an activated trigger state from the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof. In some implementations, the UE 104, the Tx processor 368, or the controller / processor 359 executing the UL RS request component 140 or the request transmitter 143 can provide means for selecting an activated trigger state from the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof.

[0200] At block 2340, the method 2300 can include transmitting a UE-initiated uplink RS request on a physical uplink resource of the one or more physical uplink resources corresponding to the selected activated trigger state. In some implementations, for example, the UE 104, the Tx processor 368, or the controller / processor 359 can execute the UL RS request component 140 or the transmitter component 1872 to transmit the RS request 1814 on a physical uplink resource of the one or more physical uplink resources corresponding to the selected activated trigger state. For example, when the uplink resource is a PRACH, the trigger state can be mapped to a PRACH preamble, a PRACH occasion, or a combination thereof. The PRACH can be one of a contention-based PRACH, a contention-free PRACH, or a two-step PRACH. As another example, when the uplink resource is a PUCCH, the trigger state can be mapped to a UCI codepoint, a PUCCH occasion, or a combination thereof. As another example, when the uplink resource is a MAC-CE, the trigger state can be mapped to a bit field of the MAC-CE. Accordingly, the UE 104, the Tx processor 368, or the controller / processor 359 executing the UL RS request component 140 or the transmitter component 1872 can provide means for transmitting a UE-initiated uplink RS request on a physical uplink resource of the one or more physical uplink resources corresponding to the selected activated trigger state.

[0201] At block 2350, the method 2300 can optionally include receiving DCI scheduling the at least one reference signal. In some implementations, for example, the UE 104, RX processor 356, or controller / processor 359 can execute the UL RS request component 140 or response receiver 144 to receive the DCI scheduling the at least one reference signal. In some implementations, the DCI includes a SRS request. In some implementations, the DCI includes a CSI request. Thus, a UE 104, RX processor 356, or controller / processor 359 executing the UL RS request component 140 or response receiver 144 can provide means for receiving the DCI scheduling the at least one reference signal.

[0202] At block 2360, the method 2300 can optionally include communicating the at least one reference signal corresponding to the trigger state in response to the uplink request. In some implementations, for example, the UE 104, RX processor 356, TX processor 368, or controller / processor 359 can execute the UL RS request component 140 or RS communication component 145 to communicate the at least one reference signal corresponding to the trigger state in response to the uplink request. In some implementations, at sub-block 2362, block 2360 can optionally include transmitting a SRS. For example, the SRS transmitter 1804 can transmit a SRS when the uplink request indicates a SRS trigger state. In some implementations, at sub-block 2364, block 2360 or sub-block 2362 can include transmitting the SRS at a time offset after the uplink request. For example, the SRS transmitter 1804 can transmit the SRS at a time offset after the uplink request in a case that the UE 104 is not configured to receive a grant. The time offset can be associated with the trigger state. In some implementations, at sub-block 2366, block 2360 can optionally include receiving a CSI-RS. For example, the CSI-RS receiver 182 can receive a CSI-RS when the uplink request indicates a CSI trigger state. In some implementations, at sub-block 2368, block 2360 or sub-block 2366 can include receiving the CSI-RS at a time offset after the uplink request. For example, the CSI-RS receiver 1802 can receive the CSI-RS at a time offset after the uplink request in a case that the UE 104 is not configured to receive a grant. The time offset can be associated with the trigger state. Thus, a UE 104, RX processor 356, TX processor 368, or controller / processor 359 executing the UL RS request component 140 or RS communication component 145 can provide means for communicating the at least one reference signal corresponding to the trigger state in response to the uplink request.

[0203] At block 2370, the method 2300 can optionally include transmitting the CSI report. In some implementations, for example, the UE 104, RX processor 356, or controller / processor 359 can execute the UL RS request component 140 or the reporting component 147 to transmit the CSI report. Accordingly, the UE 104, RX processor 356, or controller / processor 359 executing the UL RS request component 140 or the reporting component 147 can provide a means for transmitting the CSI report.

[0204] Figure 24 FIG. 24 is a flow diagram of an example method 2400 for a base station to receive an uplink RS request. The method 2400 can be performed by a base station such as the base station 102, which can include the memory 376 and which can be the entire base station 102 or a component of the base station 102, such as the RS request response component 120, the TX processor 316, the RX processor 370, or the controller / processor 375. The method 2400 can be performed by the RS request response component 120 in communication with the UL RS request component 140 of the UE 104.

[0205] At block 2410, the method 2400 can include transmitting a RRC configuration message indicating one or more CSI trigger states or SRS trigger states for UE-initiated uplink RS requests for uplink requests. In some implementations, for example, the base station 102, the TX processor 316, or the controller / processor 375 can execute the RS request response component 120 or the configuration transmitter 1860 to transmit the trigger state configuration 1810 indicating one or more CSI trigger states or SRS trigger states for UE-initiated uplink RS requests for uplink requests. Accordingly, the base station 102, the TX processor 316, or the controller / processor 375 executing the RS request response component 120 or the configuration transmitter 1860 can provide a means for transmitting a RRC configuration message indicating one or more CSI trigger states or SRS trigger states for UE-initiated uplink RS requests for uplink requests.

[0206] At block 2420, the method 2400 can include transmitting a MAC-CE activating the subset of the one or more CSI trigger states or SRS trigger states. In some implementations, for example, the base station 102, TX processor 316, RX processor 370, or controller / processor 375 can execute the RS request response component 120 or the activation transmitter 1862 to transmit the MAC-CE activating the subset of the one or more CSI trigger states or SRS trigger states. There can be a one-to-one mapping between the one or more activated trigger states in the subset and one or more physical uplink resources. Accordingly, the base station 102, TX processor 316, or controller / processor 375 executing the RS request response component 120 or the activation transmitter 1862 can provide means for transmitting the MAC-CE activating the subset of the one or more CSI trigger states or SRS trigger states.

[0207] At block 2430, the method 2400 can include receiving a UE-initiated uplink RS request on a physical uplink resource of the one or more physical uplink resources. In some implementations, for example, the base station 102, RX processor 370, or controller / processor 375 can execute the RS request response component 120 or the receiver component 1850 to receive the uplink request 1814 on a physical uplink resource of the one or more physical uplink resources. Accordingly, the base station 102, RX processor 370, or controller / processor 375 executing the RS request response component 120 or the receiver component 1850 can provide means for receiving an uplink request for at least one reference signal, the uplink request indicating a trigger state of the UE.

[0208] At block 2440, the method 2400 can include determining, based on the one-to-one mapping, that the UE-initiated uplink RS request corresponds to an activated trigger state from the activated subset of the one or more CSI trigger states, one or more SRS trigger states, or a combination thereof. In some implementations, for example, the base station 102, RX processor 370, or controller / processor 375 can execute the RS request response component 120 or the request reception component 122 to determine, based on the one-to-one mapping, that the UE-initiated uplink RS request corresponds to an activated trigger state from the activated subset of the one or more CSI trigger states, one or more SRS trigger states, or a combination thereof. For example, when the uplink resource is a PRACH, the trigger state can be mapped to a PRACH preamble, a PRACH occasion, or a combination thereof. The PRACH can be one of: a contention-based PRACH, a contention-free PRACH, or a two-step PRACH. As another example, when the uplink resource is a PUCCH, the trigger state can be mapped to a UCI codepoint, a PUCCH occasion, or a combination thereof. As another example, when the uplink resource is a MAC-CE, the trigger state can be mapped to a bit field of the MAC-CE. Accordingly, the base station 102, RX processor 370, or controller / processor 375 executing the RS request response component 120 or the request reception component 122 can provide means for determining, based on the one-to-one mapping, that the UE-initiated uplink RS request corresponds to an activated trigger state from the activated subset of the one or more CSI trigger states, one or more SRS trigger states, or a combination thereof.

[0209] At block 2450, the method 2400 can optionally include transmitting DCI scheduling the at least one reference signal. In some implementations, for example, the base station 102, TX processor 316, RX processor 370, or controller / processor 375 can execute the RS request response component 120 or the response transmitter 1864 to transmit DCI scheduling the at least one reference signal. In some implementations, the DCI includes an SRS request. In some implementations, the DCI includes a CSI request. Accordingly, the base station 102, TX processor 316, or controller / processor 375 executing the RS request response component 120 or the response transmitter 1864 can provide means for transmitting DCI scheduling the at least one reference signal.

[0210] At block 2460, the method 2400 can optionally include communicating at least one reference signal corresponding to the trigger state in response to the uplink request. In some implementations, for example, the base station 102, TX processor 316, RX processor 370, or controller / processor 375 can execute the RS request response component 120 or the RS communication component 124 to communicate at least one reference signal corresponding to the trigger state in response to the uplink request. In some implementations, at sub-block 2462, the block 2360 can optionally include receiving a SRS. For example, the SRS receiver 1856 can receive a SRS when the uplink request indicates a SRS trigger state. In some implementations, at sub-block 2464, the block 2460 or sub-block 2462 can include receiving the SRS at a time offset after the uplink request. For example, the SRS receiver 1856 can receive the SRS at a time offset after the uplink request in a case that the UE 104 is not configured to receive a grant. The time offset can be associated with the trigger state. In some implementations, at sub-block 2466, the block 2460 can optionally include transmitting a CSI-RS. For example, the CSI-RS transmitter 1854 can transmit a CSI-RS when the uplink request indicates a CSI trigger state. In some implementations, at sub-block 2468, the block 2460 or sub-block 2466 can include transmitting the CSI-RS at a time offset after the uplink request. For example, the CSI-RS transmitter 1854 can transmit the CSI-RS at a time offset after the uplink request in a case that the UE 104 is not configured to receive a grant. The time offset can be associated with the trigger state. Accordingly, the base station 102, TX processor 316, RX processor 370, or controller / processor 375 executing the RS request response component 120 or the RS communication component 124 can provide means for communicating at least one reference signal corresponding to the trigger state in response to the uplink request.

[0211] At block 2470, the method 2400 can optionally include receiving a CSI report. In some implementations, for example, the base station 102, RX processor 370, or controller / processor 375 can execute the RS request response component 120 or the report component 147 to receive a CSI report. Accordingly, the base station 102, RX processor 370, or controller / processor 375 executing the RS request response component 120 or the report component 147 can provide means for receiving a CSI report.

[0212] Some additional example clauses

[0213] Implementation examples are described in the following numbered clauses.

[0214] 1. A method of wireless communication at an apparatus of a user equipment (UE), comprising:

[0215] transmitting an uplink request for at least one reference signal, the uplink request indicating a trigger state of the UE; and

[0216] communicating the at least one reference signal corresponding to the trigger state in response to the uplink request.

[0217] 2. The method of clause 1, further comprising receiving a downlink control information (DCI) scheduling the at least one reference signal.

[0218] 3. The method of clause 2, wherein the DCI comprises a sounding reference signal (SRS) request.

[0219] 4. The method of clause 2, wherein the DCI comprises a channel state information (CSI) request.

[0220] 5. The method of any of clauses 1-4, wherein transmitting the uplink request comprises transmitting the uplink request on an uplink resource defined by a mapping from the trigger state to the uplink resource.

[0221] 6. The method of clause 5, wherein the uplink resource is a physical random access channel (PRACH), and the trigger state is mapped to a PRACH preamble, a PRACH occasion, or a combination thereof.

[0222] 7. The method of clause 6, wherein the PRACH is one of: a contention-based PRACH, a contention-free PRACH, or a two-step PRACH.

[0223] 8. The method of clause 5, wherein the uplink resource is a physical uplink control channel (PUCCH), and the trigger state is mapped to an uplink control information (UCI) codepoint, a PUCCH occasion, or a combination thereof.

[0224] 9. The method of clause 5, wherein the uplink resource is a medium access control (MAC) control element (CE), and the trigger state is mapped to a bit field of the MAC-CE.

[0225] 10. The method of any of clauses 1-9, wherein communicating the at least one reference signal comprises transmitting a sounding reference signal (SRS).

[0226] 11. The method of clause 10, wherein transmitting the SRS comprises transmitting the SRS at a time offset after the uplink request.

[0227] 12. The method of clause 11, wherein the time offset is associated with the trigger state.

[0228] 13. The method of any of clauses 1-12, wherein communicating the at least one reference signal comprises receiving a channel state information reference signal (CSI-RS).

[0229] 14. The method of clause 13, wherein receiving the CSI-RS comprises receiving the CSI-RS at a time offset after the uplink request.

[0230] 15. The method of clause 14, wherein the time offset is associated with the trigger state.

[0231] 16. The method of any of clauses 1-15, further comprising:

[0232] receiving a radio resource control (RRC) configuration message, the RRC message indicating one or more CSI trigger states or SRS trigger states for the uplink request for the at least one reference signal; and

[0233] receiving a medium access control (MAC) control element (CE) activating a subset of the one or more CSI trigger states or SRS trigger states,

[0234] wherein there is a one-to-one mapping between an activated trigger state and a physical uplink resource, and wherein communicating the uplink request for the at least one reference signal is on a physical uplink resource corresponding to an indicated trigger state of the UE.

[0235] 17. The method of clause 16, wherein the one or more CSI trigger states or the one or more SRS trigger states are also used for downlink scheduled reference signals.

[0236] 18. The method of clause 17, wherein the MAC-CE also activates a subset of the one or more CSI trigger states or the one or more SRS trigger states for the downlink scheduled reference signals.

[0237] 19. The method of clause 16, wherein the MAC-CE activates a subset of the one or more CSI trigger states or the one or more SRS trigger states only for uplink requests for reference signals.

[0238] 20. The method of clause 19, wherein the MAC-CE down-selects the subset of the one or more CSI trigger states or the one or more SRS trigger states only for uplink requests for reference signals from a set of one or more CSI trigger states or one or more SRS trigger states for downlink scheduled reference signals.

[0239] 21. The method of clause 16, wherein the one or more CSI trigger states are separate from CSI trigger state configurations for CSI-RS for downlink scheduling or the one or more SRS trigger states are separate from SRS trigger state configurations for SRS for downlink scheduling.

[0240] 22. The method of clause 21, wherein the MAC-CE activates the one or more CSI trigger states or the one or more SRS trigger states for different component carriers.

[0241] 23. The method of clause 22, wherein the MAC-CE includes a request identifier (ID), a serving cell ID, and a bandwidth part ID for each of the different component carriers.

[0242] 24. An apparatus of a user equipment (UE) for wireless communication, comprising:

[0243] an interface; and

[0244] a processing system coupled to the interface and configured to:

[0245] output an uplink request for at least one reference signal, the uplink request indicating a trigger state of the UE; and

[0246] communicate, via the interface, the at least one reference signal corresponding to the trigger state in response to the uplink request.

[0247] 25. The apparatus of clause 24, wherein the interface is further configured to obtain a downlink control information (DCI) scheduling the at least one reference signal.

[0248] 26. The apparatus of clause 25, wherein the DCI includes a sounding reference signal (SRS) request.

[0249] 27. The apparatus of clause 25, wherein the DCI includes a channel state information (CSI) request.

[0250] 28. The apparatus of any of clauses 24-27, wherein outputting the uplink request comprises transmitting the uplink request on an uplink resource defined by a mapping from the trigger state to the uplink resource.

[0251] 29. The apparatus of clause 28, wherein the uplink resource is a physical random access channel (PRACH) and the trigger state is mapped to a PRACH preamble, a PRACH occasion, or a combination thereof.

[0252] 30. The apparatus of clause 29, wherein the PRACH is one of: a contention-based PRACH, a contention-free PRACH, or a two-step PRACH.

[0253] 31. The apparatus of clause 28, wherein the uplink resource is a physical uplink control channel (PUCCH), and the trigger state is mapped to an uplink control information (UCI) codepoint, a PUCCH occasion, or a combination thereof.

[0254] 32. The apparatus of clause 28, wherein the uplink resource is a medium access control (MAC) control element (CE), and the trigger state is mapped to a bit field of the MAC-CE.

[0255] 33. The apparatus of any of clauses 24-32, wherein communicating the at least one reference signal comprises transmitting a sounding reference signal (SRS).

[0256] 34. The apparatus of clause 33, wherein transmitting the SRS occurs at a time offset after the uplink request.

[0257] 35. The apparatus of clause 34, wherein the time offset is associated with the trigger state.

[0258] 36. The apparatus of any of clauses 24-36, wherein communicating the at least one reference signal comprises receiving a channel state information reference signal (CSI-RS).

[0259] 37. The apparatus of clause 36, wherein receiving the CSI-RS occurs at a time offset after the uplink request.

[0260] 38. The apparatus of clause 37, wherein the time offset is associated with the trigger state.

[0261] 39. The apparatus of any of clauses 24-38, wherein the interface is further configured to:

[0262] obtain a radio resource control (RRC) configuration message indicating one or more CSI trigger states or SRS trigger states for the uplink request for the at least one reference signal; and

[0263] obtain a medium access control (MAC) control element (CE) activating a subset of the one or more CSI trigger states or SRS trigger states,

[0264] wherein there is a one-to-one mapping between an activated trigger state and a physical uplink resource, and wherein the uplink request for the at least one reference signal is made on a physical uplink resource corresponding to the indicated trigger state of the UE.

[0265] 40. The apparatus of clause 39, wherein the one or more CSI trigger states or the one or more SRS trigger states are also used for downlink scheduled reference signals.

[0266] 41. The apparatus of clause 40, wherein the MAC-CE also activates a subset of the one or more CSI trigger states or the one or more SRS trigger states for the downlink scheduled reference signals.

[0267] 42. The apparatus of clause 39, wherein the MAC-CE activates a subset of the one or more CSI trigger states or the one or more SRS trigger states only for uplink requests for reference signals.

[0268] 43. The apparatus of clause 42, wherein the MAC-CE down-selects a subset of the one or more CSI trigger states or the one or more SRS trigger states only for uplink requests for reference signals from a set of one or more CSI trigger states or one or more SRS trigger states for downlink scheduled reference signals.

[0269] 44. The apparatus of clause 39, wherein the one or more CSI trigger states are separate from CSI trigger state configurations for CSI-RS for downlink scheduling, or the one or more SRS trigger states are separate from SRS trigger state configurations for SRS for downlink scheduling.

[0270] 45. The apparatus of clause 44, wherein the MAC-CE activates the one or more CSI trigger states or the one or more SRS trigger states for different component carriers.

[0271] 46. The apparatus of clause 45, wherein the MAC-CE includes a request identifier (ID), a serving cell ID, and a bandwidth part ID for each of the different component carriers.

[0272] 47. An apparatus of a user equipment (UE) for wireless communication, comprising:

[0273] means for transmitting an uplink request for at least one reference signal, the uplink request indicating a trigger state of the UE; and

[0274] means for communicating, in response to the uplink request, the at least one reference signal corresponding to the trigger state.

[0275] 48. The apparatus of clause 47, further comprising means for receiving downlink control information (DCI) scheduling the at least one reference signal.

[0276] 49. The apparatus of clause 48, wherein the DCI comprises a sounding reference signal (SRS) request.

[0277] 50. The apparatus of clause 48, wherein the DCI comprises a channel state information (CSI) request.

[0278] 51. The apparatus of any of clauses 47-50, wherein the means for transmitting the uplink request is configured to transmit the uplink request on the uplink resource defined by a mapping from the trigger state to the uplink resource.

[0279] 52. The apparatus of clause 51, wherein the uplink resource is a physical random access channel (PRACH) and the trigger state is mapped to a PRACH preamble, a PRACH occasion, or a combination thereof.

[0280] 53. The apparatus of clause 52, wherein the PRACH is one of: a contention-based PRACH, a contention-free PRACH, or a two-step PRACH.

[0281] 54. The apparatus of clause 51, wherein the uplink resource is a physical uplink control channel (PUCCH) and the trigger state is mapped to an uplink control information (UCI) codepoint, a PUCCH occasion, or a combination thereof.

[0282] 55. The apparatus of clause 51, wherein the uplink resource is a medium access control (MAC) control element (CE) and the trigger state is mapped to a bit field of the MAC-CE.

[0283] 56. The apparatus of any of clauses 47-55, wherein the means for communicating the at least one reference signal is configured to transmit a sounding reference signal (SRS).

[0284] 57. The apparatus of clause 56, wherein communicating the at least one reference signal is configured to transmit the SRS at a time offset after the uplink request.

[0285] 58. The apparatus of clause 57, wherein the time offset is associated with the trigger state.

[0286] 59. The apparatus of any of clauses 47-36, wherein the means for communicating the at least one reference signal is configured to receive a channel state information reference signal (CSI-RS).

[0287] 60. The apparatus of clause 59, wherein the means for communicating the at least one reference signal is configured to receive the CSI-RS at a time offset after the uplink request.

[0288] 61. The apparatus of clause 60, wherein the time offset is associated with the trigger state.

[0289] 62. The apparatus of any of clauses 47-61, further comprising:

[0290] means for receiving a radio resource control (RRC) configuration message indicating one or more CSI trigger states or SRS trigger states for the uplink request for the at least one reference signal; and

[0291] means for receiving a medium access control (MAC) control element (CE) activating a subset of the one or more CSI trigger states or SRS trigger states,

[0292] wherein there is a one-to-one mapping between an activated trigger state and a physical uplink resource, and wherein the communicating the uplink request for the at least one reference signal is on a physical uplink resource corresponding to an indicated trigger state of the UE.

[0293] 63. The apparatus of clause 62, wherein the one or more CSI trigger states or the one or more SRS trigger states are also for downlink scheduled reference signals.

[0294] 64. The apparatus of clause 63, wherein the MAC-CE also activates a subset of the one or more CSI trigger states or the one or more SRS trigger states for the downlink scheduled reference signals.

[0295] 65. The apparatus of clause 62, wherein the MAC-CE activates a subset of the one or more CSI trigger states or the one or more SRS trigger states only for uplink requests for reference signals.

[0296] 66. The apparatus of clause 65, wherein the MAC-CE down-selects the subset of the one or more CSI trigger states or the one or more SRS trigger states only for uplink requests for reference signals from a set of one or more CSI trigger states or one or more SRS trigger states for downlink scheduled reference signals.

[0297] 67. The device of clause 62, wherein the one or more CSI trigger states are separate from CSI trigger state configurations for CSI-RS for downlink scheduling or the one or more SRS trigger states are separate from SRS trigger state configurations for SRS for downlink scheduling.

[0298] 68. The device of clause 67, wherein the MAC-CE activates the one or more CSI trigger states or the one or more SRS trigger states for different component carriers.

[0299] 69. The device of clause 68, wherein the MAC-CE includes a request identifier (ID), a serving cell ID, and a bandwidth part ID for each of the different component carriers.

[0300] 70. A non-transitory computer-readable medium comprising instructions stored for wireless communication at an apparatus of a user equipment (UE), the instructions executable by a processor to:

[0301] transmit an uplink request for at least one reference signal, the uplink request indicating a trigger state of the UE; and

[0302] communicate the at least one reference signal corresponding to the trigger state in response to the uplink request.

[0303] 71. The non-transitory computer-readable medium of clause 70, wherein the instructions are further executable by the processor to receive a downlink control information (DCI) scheduling the at least one reference signal.

[0304] 72. The non-transitory computer-readable medium of clause 71, wherein the DCI includes a sounding reference signal (SRS) request.

[0305] 73. The non-transitory computer-readable medium of clause 71, wherein the DCI includes a channel state information (CSI) request.

[0306] 74. The non-transitory computer-readable medium of any one of clauses 70-73, wherein transmitting the uplink request comprises transmitting the uplink request on an uplink resource defined by a mapping from the trigger state to the uplink resource.

[0307] 75. The non-transitory computer-readable medium of clause 74, wherein the uplink resource is a physical random access channel (PRACH) and the trigger state is mapped to a PRACH preamble, a PRACH occasion, or a combination thereof.

[0308] 76. The non-transitory computer-readable medium of clause 75, wherein the PRACH is one of: a contention-based PRACH, a contention-free PRACH, or a two-step PRACH.

[0309] 77. The non-transitory computer-readable medium of clause 74, wherein the uplink resource is a physical uplink control channel (PUCCH) and the trigger state is mapped to an uplink control information (UCI) codepoint, a PUCCH occasion, or a combination thereof.

[0310] 78. The non-transitory computer-readable medium of clause 74, wherein the uplink resource is a medium access control (MAC) control element (CE) and the trigger state is mapped to a bit field of the MAC-CE.

[0311] 79. The non-transitory computer-readable medium of any one of clauses 70-78, wherein communicating the at least one reference signal comprises transmitting a sounding reference signal (SRS).

[0312] 80. The non-transitory computer-readable medium of clause 79, wherein transmitting the SRS comprises transmitting the SRS at a time offset after the uplink request.

[0313] 81. The non-transitory computer-readable medium of clause 80, wherein the time offset is associated with the trigger state.

[0314] 82. The non-transitory computer-readable medium of any one of clauses 70-81, wherein communicating the at least one reference signal comprises receiving a channel state information reference signal (CSI-RS).

[0315] 83. The non-transitory computer-readable medium of clause 82, wherein receiving the CSI-RS comprises receiving the CSI-RS at a time offset after the uplink request.

[0316] 84. The non-transitory computer-readable medium of clause 83, wherein the time offset is associated with the trigger state.

[0317] 85. The non-transitory computer-readable medium of any one of claims 70-84, wherein the instructions are further executable by the processor to:

[0318] receive a radio resource control (RRC) configuration message indicating one or more CSI trigger states or SRS trigger states for the uplink request for the at least one reference signal; and

[0319] receiving a medium access control (MAC) control element (CE) that activates a subset of the one or more CSI trigger states or SRS trigger states,

[0320] wherein there is a one-to-one mapping between an activated trigger state and a physical uplink resource, and wherein the uplink request for the at least one reference signal is made on a physical uplink resource corresponding to an indicated trigger state of the UE.

[0321] 86. The non-transitory computer-readable medium of clause 85, wherein the one or more CSI trigger states or the one or more SRS trigger states are also used for downlink scheduled reference signals.

[0322] 87. The non-transitory computer-readable medium of clause 86, wherein the MAC-CE also activates a subset of the one or more CSI trigger states or the one or more SRS trigger states for the downlink scheduled reference signals.

[0323] 88. The non-transitory computer-readable medium of clause 85, wherein the MAC-CE activates a subset of the one or more CSI trigger states or the one or more SRS trigger states only for uplink requests for reference signals.

[0324] 89. The non-transitory computer-readable medium of clause 88, wherein the MAC-CE down-selects the subset of the one or more CSI trigger states or the one or more SRS trigger states only for uplink requests for reference signals from a set of one or more CSI trigger states or one or more SRS trigger states for downlink scheduled reference signals.

[0325] 90. The non-transitory computer-readable medium of clause 85, wherein the one or more CSI trigger states are separate from CSI trigger state configurations for downlink scheduled CSI-RSs, or the one or more SRS trigger states are separate from SRS trigger state configurations for downlink scheduled SRSs.

[0326] 91. The non-transitory computer-readable medium of clause 90, wherein the MAC-CE activates the one or more CSI trigger states or the one or more SRS trigger states for different component carriers.

[0327] 92. The non-transitory computer-readable medium of clause 91, wherein the MAC-CE includes, for each of the different component carriers, a request identifier (ID), a serving cell ID, and a bandwidth part ID.

[0328] 93. A method of wireless communication at an apparatus of a base station, comprising:

[0329] receiving, from a user equipment (UE), an uplink request for at least one reference signal, the uplink request indicating a trigger state of the UE; and

[0330] communicating, in response to the uplink request, the at least one reference signal corresponding to the trigger state.

[0331] 94. The method of clause 93, further comprising transmitting downlink control information (DCI) scheduling the at least one reference signal.

[0332] 95. The method of clause 94, wherein the DCI comprises a sounding reference signal (SRS) request.

[0333] 96. The method of clause 94, wherein the DCI comprises a channel state information (CSI) request.

[0334] 97. The method of any one of clauses 93-96, wherein receiving the uplink request comprises determining the trigger state based on a mapping between the trigger state and an uplink resource on which the uplink request is received.

[0335] 98. The method of clause 97, wherein the uplink resource is a physical random access channel (PRACH), and the trigger state is mapped to a PRACH preamble, a PRACH occasion, or a combination thereof.

[0336] 99. The method of clause 98, wherein the PRACH is one of: a contention-based PRACH, a contention-free PRACH, or a two-step PRACH.

[0337] 100. The method of clause 97, wherein the uplink resource is a physical uplink control channel (PUCCH), and the trigger state is mapped to an uplink control information (UCI) codepoint, a PUCCH occasion, or a combination thereof.

[0338] 101. The method of clause 97, wherein the uplink resource is a medium access control (MAC) control element (CE), and the trigger state is mapped to a bit field of the MAC-CE.

[0339] 102. The method of any one of clauses 93-101, wherein communicating the at least one reference signal comprises receiving a sounding reference signal (SRS).

[0340] 103. The method of clause 102, wherein receiving the SRS comprises receiving the SRS at a time offset after the uplink request.

[0341] 104. The method of clause 103, wherein the time offset is associated with the trigger state.

[0342] 105. The method of any of clauses 93-104, wherein communicating the at least one reference signal comprises transmitting a channel state information reference signal (CSI-RS).

[0343] 106. The method of clause 105, wherein transmitting the CSI-RS comprises transmitting the CSI-RS at a time offset after the uplink request.

[0344] 107. The method of clause 106, wherein the time offset is associated with the trigger state.

[0345] 108. The method of any of clauses 93-107, further comprising:

[0346] transmitting a radio resource control (RRC) configuration message indicating one or more CSI trigger states or SRS trigger states for the uplink request for the at least one reference signal; and

[0347] transmitting a medium access control (MAC) control element (CE) activating a subset of the one or more CSI trigger states or SRS trigger states,

[0348] wherein there is a one-to-one mapping between an activated trigger state and a physical uplink resource, and wherein receiving the uplink request for the at least one reference signal is on a physical uplink resource corresponding to an indicated trigger state of the UE.

[0349] 109. The method of clause 108, wherein the one or more CSI trigger states or the one or more SRS trigger states are also used for downlink scheduled reference signals.

[0350] 110. The method of clause 109, wherein the MAC-CE also activates a subset of the one or more CSI trigger states or the one or more SRS trigger states for the downlink scheduled reference signals.

[0351] 111. The method of clause 108, wherein the MAC-CE activates a subset of the one or more CSI trigger states or the one or more SRS trigger states only for uplink requests for reference signals.

[0352] 112. The method of clause 111, wherein the MAC-CE down-selects from a set of one or more CSI trigger states or one or more SRS trigger states for reference signals for downlink scheduling to only a subset of the one or more CSI trigger states or the one or more SRS trigger states for uplink requests for reference signals.

[0353] 113. The method of clause 108, wherein the one or more CSI trigger states are separate from CSI trigger state configuration for CSI-RS for downlink scheduling or the one or more SRS trigger states are separate from SRS trigger state configuration for SRS for downlink scheduling.

[0354] 114. The method of clause 113, wherein the MAC-CE activates the one or more CSI trigger states or the one or more SRS trigger states for different component carriers.

[0355] 115. The method of clause 114, wherein the MAC-CE includes a request identifier (ID), a serving cell ID, and a bandwidth part ID for each of the different component carriers.

[0356] 116. An apparatus for wireless communication of a base station, comprising:

[0357] an interface; and

[0358] a processing system coupled to the interface and configured to:

[0359] obtain an uplink request for at least one reference signal, the uplink request indicating a trigger state of a user equipment (UE); and

[0360] communicate the at least one reference signal corresponding to the trigger state in response to the uplink request.

[0361] 117. The apparatus of clause 116, wherein the interface is further configured to output a downlink control information (DCI) scheduling the at least one reference signal.

[0362] 118. The apparatus of clause 117, wherein the DCI includes a sounding reference signal (SRS) request.

[0363] 119. The apparatus of clause 117, wherein the DCI includes a channel state information (CSI) request.

[0364] 120. The apparatus of any of clauses 116-119, wherein obtaining the uplink request comprises determining the trigger state based on a mapping between the trigger state and an uplink resource on which the uplink request is received.

[0365] 121. The apparatus of clause 120, wherein the uplink resource is a physical random access channel (PRACH) and the trigger state is mapped to a PRACH preamble, a PRACH occasion, or a combination thereof.

[0366] 122. The apparatus of clause 121, wherein the PRACH is one of: a contention-based PRACH, a contention-free PRACH, or a two-step PRACH.

[0367] 123. The apparatus of clause 120, wherein the uplink resource is a physical uplink control channel (PUCCH) and the trigger state is mapped to an uplink control information (UCI) codepoint, a PUCCH occasion, or a combination thereof.

[0368] 124. The apparatus of clause 120, wherein the uplink resource is a medium access control (MAC) control element (CE) and the trigger state is mapped to a bit field of the MAC-CE.

[0369] 125. The apparatus of any of clauses 116-124, wherein communicating the at least one reference signal comprises receiving a sounding reference signal (SRS).

[0370] 126. The apparatus of clause 125, wherein receiving the SRS occurs at a time offset after the uplink request.

[0371] 127. The apparatus of clause 126, wherein the time offset is associated with the trigger state.

[0372] 128. The apparatus of any of clauses 116-127, wherein communicating the at least one reference signal comprises transmitting a channel state information reference signal (CSI-RS).

[0373] 129. The apparatus of clause 128, wherein transmitting the CSI-RS occurs at a time offset after the uplink request.

[0374] 130. The apparatus of clause 129, wherein the time offset is associated with the trigger state.

[0375] 131. The apparatus of any of clauses 116-130, wherein the interface is further configured to:

[0376] output a radio resource control (RRC) configuration message indicating one or more CSI trigger states or SRS trigger states for the uplink request for the at least one reference signal; and

[0377] a medium access control (MAC) control element (CE) that activates a subset of the one or more CSI trigger states or SRS trigger states,

[0378] wherein there is a one-to-one mapping between an activated trigger state and a physical uplink resource, and wherein the obtaining the uplink request for the at least one reference signal is on a physical uplink resource corresponding to the UE’s indicated trigger state.

[0379] 132. The apparatus of clause 131, wherein the one or more CSI trigger states or the one or more SRS trigger states are also used for downlink scheduled reference signals.

[0380] 133. The apparatus of clause 132, wherein the MAC-CE also activates a subset of the one or more CSI trigger states or the one or more SRS trigger states for the downlink scheduled reference signals.

[0381] 134. The apparatus of clause 131, wherein the MAC-CE activates a subset of the one or more CSI trigger states or the one or more SRS trigger states only for uplink requests for reference signals.

[0382] 135. The apparatus of clause 134, wherein the MAC-CE down-selects the subset of the one or more CSI trigger states or the one or more SRS trigger states only for uplink requests for reference signals from a set of one or more CSI trigger states or one or more SRS trigger states for downlink scheduled reference signals.

[0383] 136. The apparatus of clause 131, wherein the one or more CSI trigger states are separate from CSI trigger state configurations for downlink scheduled CSI-RSs, or the one or more SRS trigger states are separate from SRS trigger state configurations for downlink scheduled SRSs.

[0384] 137. The apparatus of clause 136, wherein the MAC-CE activates the one or more CSI trigger states or the one or more SRS trigger states for different component carriers.

[0385] 138. The apparatus of clause 137, wherein the MAC-CE includes, for each of the different component carriers, a request identifier (ID), a serving cell ID, and a bandwidth part ID.

[0386] 139. An apparatus for wireless communication at a device of a base station, comprising:

[0387] Apparatus for receiving an uplink request for at least one reference signal from a user equipment (UE), the uplink request indicating a trigger state of the UE; and

[0388] Apparatus for communicating the at least one reference signal corresponding to the trigger state in response to the uplink request.

[0389] 140. The apparatus of clause 139, further comprising means for transmitting downlink control information (DCI) scheduling the at least one reference signal.

[0390] 141. The apparatus of clause 140, wherein the DCI comprises a sounding reference signal (SRS) request.

[0391] 142. The apparatus of clause 140, wherein the DCI comprises a channel state information (CSI) request.

[0392] 143. The apparatus of any of clauses 139-142, wherein the means for receiving the uplink request is configured to determine the trigger state based on a mapping between the trigger state and an uplink resource on which the uplink request is received.

[0393] 144. The apparatus of clause 143, wherein the uplink resource is a physical random access channel (PRACH), and the trigger state is mapped to a PRACH preamble, a PRACH occasion, or a combination thereof.

[0394] 145. The apparatus of clause 144, wherein the PRACH is one of: a contention-based PRACH, a contention-free PRACH, or a two-step PRACH.

[0395] 146. The apparatus of clause 143, wherein the uplink resource is a physical uplink control channel (PUCCH), and the trigger state is mapped to an uplink control information (UCI) codepoint, a PUCCH occasion, or a combination thereof.

[0396] 147. The apparatus of clause 143, wherein the uplink resource is a medium access control (MAC) control element (CE), and the trigger state is mapped to a bit field of the MAC-CE.

[0397] 148. The apparatus of any of clauses 139-147, wherein the means for communicating the at least one reference signal is configured to receive a sounding reference signal (SRS).

[0398] 149. The apparatus of clause 148, wherein the means for communicating the at least one reference signal is configured to receive the SRS at a time offset after the uplink request.

[0399] 150. The device of clause 149, wherein the time offset is associated with the trigger state.

[0400] 151. The device of any of clauses 139-36, wherein the means for communicating the at least one reference signal is configured to transmit a channel state information reference signal (CSI-RS).

[0401] 152. The device of clause 151, wherein the means for communicating the at least one reference signal is configured to transmit the CSI-RS at a time offset after the uplink request.

[0402] 153. The device of clause 152, wherein the time offset is associated with the trigger state.

[0403] 154. The device of any of clauses 139-153, further comprising:

[0404] means for transmitting a radio resource control (RRC) configuration message indicating one or more CSI trigger states or SRS trigger states for the uplink request for the at least one reference signal; and

[0405] means for transmitting a medium access control (MAC) control element (CE) activating a subset of the one or more CSI trigger states or SRS trigger states,

[0406] wherein there is a one-to-one mapping between an activated trigger state and a physical uplink resource, and wherein receiving the uplink request for the at least one reference signal is on a physical uplink resource corresponding to an indicated trigger state of the UE.

[0407] 155. The device of clause 154, wherein the one or more CSI trigger states or the one or more SRS trigger states are also for downlink scheduled reference signals.

[0408] 156. The device of clause 155, wherein the MAC-CE also activates a subset of the one or more CSI trigger states or the one or more SRS trigger states for the downlink scheduled reference signals.

[0409] 157. The device of clause 154, wherein the MAC-CE activates a subset of the one or more CSI trigger states or the one or more SRS trigger states only for uplink requests for reference signals.

[0410] 158. The apparatus of clause 157, wherein the MAC-CE down-selects from a set of one or more CSI trigger states or one or more SRS trigger states for reference signals for downlink scheduling to only a subset of the one or more CSI trigger states or the one or more SRS trigger states for uplink requests for reference signals.

[0411] 159. The apparatus of clause 154, wherein the one or more CSI trigger states are separate from CSI trigger state configurations for CSI-RS for downlink scheduling or the one or more SRS trigger states are separate from SRS trigger state configurations for SRS for downlink scheduling.

[0412] 160. The apparatus of clause 159, wherein the MAC-CE activates the one or more CSI trigger states or the one or more SRS trigger states for different component carriers.

[0413] 161. The apparatus of clause 160, wherein the MAC-CE includes, for each of the different component carriers, a request identifier (ID), a serving cell ID, and a bandwidth part ID.

[0414] 162. A non-transitory computer-readable medium comprising instructions stored thereon to wirelessly communicate at an apparatus of a base station, the instructions executable by a processor to:

[0415] receive, from a user equipment (UE), an uplink request for at least one reference signal, the uplink request indicating a trigger state of the UE; and

[0416] communicate, in response to the uplink request, the at least one reference signal corresponding to the trigger state.

[0417] 163. The non-transitory computer-readable medium of clause 162, wherein the instructions are further executable by the processor to transmit downlink control information (DCI) scheduling the at least one reference signal.

[0418] 164. The non-transitory computer-readable medium of clause 163, wherein the DCI includes a sounding reference signal (SRS) request.

[0419] 165. The non-transitory computer-readable medium of clause 163, wherein the DCI includes a channel state information (CSI) request.

[0420] 166. The non-transitory computer-readable medium of any one of clauses 162-165, wherein receiving the uplink request comprises determining the trigger state based on a mapping between the trigger state and an uplink resource on which the uplink request is received.

[0421] 167. The non-transitory computer-readable medium of clause 166, wherein the uplink resource is a physical random access channel (PRACH) and the trigger state is mapped to a PRACH preamble, a PRACH occasion, or a combination thereof.

[0422] 168. The non-transitory computer-readable medium of clause 167, wherein the PRACH is one of: a contention-based PRACH, a contention-free PRACH, or a two-step PRACH.

[0423] 169. The non-transitory computer-readable medium of clause 166, wherein the uplink resource is a physical uplink control channel (PUCCH) and the trigger state is mapped to an uplink control information (UCI) codepoint, a PUCCH occasion, or a combination thereof.

[0424] 170. The non-transitory computer-readable medium of clause 166, wherein the uplink resource is a medium access control (MAC) control element (CE) and the trigger state is mapped to a bit field of the MAC-CE.

[0425] 171. The non-transitory computer-readable medium of any one of clauses 162-170, wherein communicating the at least one reference signal comprises receiving a sounding reference signal (SRS).

[0426] 172. The non-transitory computer-readable medium of clause 171, wherein receiving the SRS comprises receiving the SRS at a time offset after the uplink request.

[0427] 173. The non-transitory computer-readable medium of clause 172, wherein the time offset is associated with the trigger state.

[0428] 174. The non-transitory computer-readable medium of any one of clauses 162-173, wherein communicating the at least one reference signal comprises transmitting a channel state information reference signal (CSI-RS).

[0429] 175. The non-transitory computer-readable medium of clause 174, wherein transmitting the CSI-RS comprises transmitting the CSI-RS at a time offset after the uplink request.

[0430] 176. The non-transitory computer-readable medium of clause 175, wherein the time offset is associated with the trigger state.

[0431] 177. The non-transitory computer-readable medium of any one of claims 162-176, wherein the instructions are further executable by the processor to:

[0432] transmitting a radio resource control (RRC) configuration message indicating one or more CSI trigger states or SRS trigger states for the uplink request for the at least one reference signal; and

[0433] transmitting a medium access control (MAC) control element (CE) activating a subset of the one or more CSI trigger states or SRS trigger states,

[0434] wherein there is a one-to-one mapping between an activated trigger state and a physical uplink resource, and wherein the request for the at least one reference signal is made on a physical uplink resource corresponding to an indicated trigger state of the UE.

[0435] 178. The non-transitory computer-readable medium of clause 177, wherein the one or more CSI trigger states or the one or more SRS trigger states are also used for downlink scheduled reference signals.

[0436] 179. The non-transitory computer-readable medium of clause 178, wherein the MAC-CE also activates a subset of the one or more CSI trigger states or the one or more SRS trigger states for the downlink scheduled reference signals.

[0437] 180. The non-transitory computer-readable medium of clause 177, wherein the MAC-CE activates a subset of the one or more CSI trigger states or the one or more SRS trigger states only for uplink requests for reference signals.

[0438] 181. The non-transitory computer-readable medium of clause 180, wherein the MAC-CE down-selects the subset of the one or more CSI trigger states or the one or more SRS trigger states only for uplink requests for reference signals from a set of one or more CSI trigger states or one or more SRS trigger states for downlink scheduled reference signals.

[0439] 182. The non-transitory computer-readable medium of clause 177, wherein the one or more CSI trigger states are separate from CSI trigger state configurations for CSI-RS for downlink scheduling, or the one or more SRS trigger states are separate from SRS trigger state configurations for SRS for downlink scheduling.

[0440] 183. The non-transitory computer-readable medium of clause 182, wherein the MAC-CE activates the one or more CSI trigger states or the one or more SRS trigger states for different component carriers.

[0441] 184. The non-transitory computer-readable medium of clause 183, wherein the MAC-CE comprises, for each of the different component carriers, a request identifier (ID), a serving cell ID, and a bandwidth part ID.

[0442] 185. A method of wireless communication at an apparatus of a user equipment (UE), comprising:

[0443] receiving a radio resource control (RRC) configuration message indicating one or more channel state information (CSI) trigger states, one or more sounding reference signal (SRS) trigger states, or a combination thereof, for a UE-initiated uplink reference signal (RS) request;

[0444] receiving a medium access control (MAC) control element (CE) activating a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, wherein there is a one-to-one mapping between the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, and one or more physical uplink resources;

[0445] selecting an activated trigger state from the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof; and

[0446] transmitting the UE-initiated uplink RS request on a physical uplink resource of the one or more physical uplink resources corresponding to the selected activated trigger state.

[0447] 186. The method of clause 185, wherein the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, are associated with a downlink scheduled reference signal.

[0448] 187. The method of clause 186, wherein the MAC-CE activates a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, for the downlink scheduled reference signal.

[0449] 188. The method of any of clauses 185-187, wherein the MAC-CE activates a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, for an uplink RS request.

[0450] 189. The method of clause 188, wherein the MAC-CE down-selects the subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof for the uplink RS request from a set of one or more CSI trigger states, one or more SRS trigger states, or a combination thereof for reference signals used for downlink scheduling.

[0451] 190. The method of clause 185, wherein:

[0452] the one or more CSI trigger states are separate from CSI trigger state configuration of CSI-RS for downlink scheduling, or

[0453] the one or more SRS trigger states are separate from SRS trigger state configuration of SRS for downlink scheduling.

[0454] 191. The method of clause 190, wherein the MAC-CE activates the subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof for different component carriers.

[0455] 192. The method of clause 191, wherein the MAC-CE includes, for each of the different component carriers, a request identifier (ID), a serving cell ID, and a bandwidth part ID.

[0456] 193. An apparatus of a user equipment (UE) for wireless communication, comprising:

[0457] an interface configured to:

[0458] obtain a radio resource control (RRC) configuration message indicating one or more channel state information (CSI) trigger states, one or more sounding reference signal (SRS) trigger states, or a combination thereof for UE-initiated uplink reference signal (RS) requests; and

[0459] obtain a medium access control (MAC) control element (CE) activating a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, wherein there is a one-to-one mapping between the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof and one or more physical uplink resources; and

[0460] a processing system configured to:

[0461] select an activated trigger state from the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof; and

[0462] The interface is further configured to output the UE-initiated uplink RS request for transmission on a physical uplink resource of the one or more physical uplink resources corresponding to the selected activated trigger state.

[0463] 194. The apparatus of clause 193, wherein the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof are also used for downlink scheduling reference signals.

[0464] 195. The apparatus of clause 194, wherein the MAC-CE also activates a subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof for the downlink scheduling reference signals.

[0465] 196. The apparatus of clause 193, wherein the MAC-CE activates a subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof for uplink RS requests.

[0466] 197. The apparatus of clause 196, wherein the MAC-CE down-selects the subset of the one or more CSI trigger states or the one or more SRS trigger states for uplink RS requests from a set of one or more CSI trigger states or one or more SRS trigger states for downlink scheduling reference signals.

[0467] 198. The apparatus of clause 193, wherein:

[0468] the one or more CSI trigger states are separate from CSI trigger state configurations for CSI-RS for downlink scheduling, or

[0469] the one or more SRS trigger states are separate from SRS trigger state configurations for SRS for downlink scheduling.

[0470] 199. The apparatus of clause 198, wherein the MAC-CE activates a subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof for different component carriers.

[0471] 200. The apparatus of clause 199, wherein the MAC-CE includes, for each of the different component carriers, a request identifier (ID), a serving cell ID, and a bandwidth part ID.

[0472] 201. An apparatus of a user equipment (UE) for wireless communication, comprising:

[0473] An apparatus for receiving a radio resource control (RRC) configuration message indicating one or more channel state information (CSI) trigger states, one or more sounding reference signal (SRS) trigger states, or a combination thereof for a UE-initiated uplink reference signal (RS) request;

[0474] An apparatus for receiving a medium access control (MAC) control element (CE) activating a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, wherein there is a one-to-one mapping between the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof and one or more physical uplink resources;

[0475] An apparatus for selecting an activated trigger state from the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof; and

[0476] An apparatus for transmitting the UE-initiated uplink RS request on a physical uplink resource of the one or more physical uplink resources corresponding to the selected activated trigger state.

[0477] 202. The apparatus of clause 201, wherein the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof are also used for downlink scheduled reference signals.

[0478] 203. The apparatus of clause 202, wherein the MAC-CE also activates a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof for the downlink scheduled reference signals.

[0479] 204. The apparatus of clause 201, wherein the MAC-CE activates a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof for uplink RS requests.

[0480] 205. The apparatus of clause 204, wherein the MAC-CE down-selects the subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof for uplink RS requests from a set of one or more CSI trigger states or one or more SRS trigger states for downlink scheduled reference signals.

[0481] 206. The apparatus of clause 201, wherein:

[0482] the one or more CSI trigger states are separate from a CSI trigger state configuration for downlink scheduled CSI-RS, or

[0483] The one or more SRS trigger states are separate from SRS trigger state configurations for SRS for downlink scheduling.

[0484] 207. The apparatus of clause 206, wherein the MAC-CE activates a subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof for different component carriers.

[0485] 208. The apparatus of clause 207, wherein the MAC-CE includes, for each of the different component carriers, a request identifier (ID), a serving cell ID, and a bandwidth part ID.

[0486] 209. A non-transitory computer-readable medium comprising stored instructions for wireless communication at an apparatus of a user equipment (UE), the instructions executable by a processor to:

[0487] receive a radio resource control (RRC) configuration message indicating one or more channel state information (CSI) trigger states, one or more sounding reference signal (SRS) trigger states, or a combination thereof for a UE-initiated uplink reference signal (RS) request;

[0488] receive a medium access control (MAC) control element (CE) activating a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, wherein there is a one-to-one mapping between the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof and one or more physical uplink resources;

[0489] select an activated trigger state from the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof; and

[0490] transmit the UE-initiated uplink RS request on a physical uplink resource of the one or more physical uplink resources that corresponds to the selected activated trigger state based on the one-to-one mapping.

[0491] 210. The non-transitory computer-readable medium of clause 209, wherein the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof are also for reference signals for downlink scheduling.

[0492] 211. The non-transitory computer-readable medium of clause 210, wherein the MAC-CE also activates a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof for the reference signals for the downlink scheduling.

[0493] 212. The non-transitory computer-readable medium of clause 209, wherein the MAC-CE activates a subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof for an uplink RS request.

[0494] 213. The non-transitory computer-readable medium of clause 212, wherein the MAC-CE down-selects the subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof from a set of one or more CSI trigger states or one or more SRS trigger states for reference signals used for downlink scheduling.

[0495] 214. The non-transitory computer-readable medium of clause 209, wherein:

[0496] the one or more CSI trigger states are separate from CSI trigger state configurations for CSI-RS used for downlink scheduling, or

[0497] the one or more SRS trigger states are separate from SRS trigger state configurations for SRS used for downlink scheduling.

[0498] 215. The non-transitory computer-readable medium of clause 214, wherein the MAC-CE activates the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof for different component carriers.

[0499] 216. The non-transitory computer-readable medium of clause 215, wherein the MAC-CE includes, for each of the different component carriers, a request identifier (ID), a serving cell ID, and a bandwidth part ID.

[0500] 217. A method of wireless communication at an apparatus of a base station (BS), comprising:

[0501] transmitting a radio resource control (RRC) configuration message indicating one or more channel state information (CSI) trigger states, one or more sounding reference signal (SRS) trigger states, or a combination thereof for a UE-initiated uplink reference signal (RS) request;

[0502] transmitting a medium access control (MAC) control element (CE) activating a subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof, wherein there is a one-to-one mapping between the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof and one or more physical uplink resources;

[0503] receiving, on a physical uplink resource of the one or more physical uplink resources, the UE-initiated uplink RS request; and

[0504] determining, based on the one-to-one mapping, that the UE-initiated uplink RS request corresponds to an activated triggering state from an activated subset of the one or more CSI triggering states, the one or more SRS triggering states, or a combination thereof.

[0505] 218. The method of clause 217, wherein the one or more CSI triggering states or the one or more SRS triggering states are also used for downlink scheduled reference signals.

[0506] 219. The method of clause 218, wherein the MAC-CE also activates a subset of the one or more CSI triggering states or the one or more SRS triggering states for the downlink scheduled reference signals.

[0507] 220. The method of clause 217, wherein the MAC-CE activates a subset of the one or more CSI triggering states or the one or more SRS triggering states for uplink RS requests only.

[0508] 221. The method of clause 220, wherein the MAC-CE down-selects the subset of the one or more CSI triggering states or the one or more SRS triggering states for uplink RS requests only from a set of one or more CSI triggering states or one or more SRS triggering states for downlink scheduled reference signals.

[0509] 222. The method of clause 217, wherein the one or more CSI triggering states are separate from CSI triggering state configurations for CSI-RS for downlink scheduling, or the one or more SRS triggering states are separate from SRS triggering state configurations for SRS for downlink scheduling.

[0510] 223. The method of clause 222, wherein the MAC-CE activates the one or more CSI triggering states or the one or more SRS triggering states for different component carriers.

[0511] 224. The method of clause 223, wherein the MAC-CE includes, for each of the different component carriers, a request identifier (ID), a serving cell ID, and a bandwidth part ID.

[0512] 225. An apparatus of a base station (BS) for wireless communication, comprising:

[0513] at least one interface configured to:

[0514] outputting a radio resource control (RRC) configuration message indicating one or more channel state information (CSI) trigger states, one or more sounding reference signal (SRS) trigger states, or a combination thereof for a UE-initiated uplink reference signal (RS) request;

[0515] outputting a medium access control (MAC) control element (CE) activating a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, wherein there is a one-to-one mapping between the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof and one or more physical uplink resources; and

[0516] obtaining the UE-initiated uplink RS request on a physical uplink resource of the one or more physical uplink resources; and

[0517] a processing system configured to:

[0518] determine, based on the one-to-one mapping, that the UE-initiated uplink RS request corresponds to an activated trigger state from the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof.

[0519] 226. The apparatus of clause 225, wherein the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof are also used for downlink scheduled reference signals.

[0520] 227. The apparatus of clause 226, wherein the MAC-CE also activates a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof for the downlink scheduled reference signals.

[0521] 228. The apparatus of clause 225, wherein the MAC-CE activates a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof for uplink RS requests.

[0522] 229. The apparatus of clause 228, wherein the MAC-CE down-selects the subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof for uplink RS requests from a set of one or more CSI trigger states or one or more SRS trigger states for downlink scheduled reference signals.

[0523] 230. The apparatus of clause 225, wherein:

[0524] the one or more CSI trigger states are separate from CSI trigger state configurations for CSI-RS for downlink scheduling, or

[0525] the one or more SRS trigger states are separate from SRS trigger state configurations for SRS for downlink scheduling.

[0526] 231. The apparatus of clause 230, wherein the MAC-CE activates the one or more CSI trigger states or the one or more SRS trigger states for different component carriers.

[0527] 232. The apparatus of clause 231, wherein the MAC-CE includes, for each of the different component carriers, a request identifier (ID), a serving cell ID, and a bandwidth part ID.

[0528] 233. An apparatus of a base station for wireless communication, comprising:

[0529] means for transmitting a radio resource control (RRC) configuration message indicating one or more channel state information (CSI) trigger states, one or more sounding reference signal (SRS) trigger states, or a combination thereof, for a UE-initiated uplink reference signal (RS) request;

[0530] means for transmitting a medium access control (MAC) control element (CE) activating a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, wherein there is a one-to-one mapping between the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, and one or more physical uplink resources;

[0531] means for receiving the UE-initiated uplink RS request on a physical uplink resource of the one or more physical uplink resources; and

[0532] means for determining, based on the one-to-one mapping, that the UE-initiated uplink RS request corresponds to an activated trigger state from the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof.

[0533] 234. The apparatus of clause 233, wherein the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, are also for reference signals for downlink scheduling.

[0534] 235. The apparatus of clause 234, wherein the MAC-CE also activates a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, for the reference signals for the downlink scheduling.

[0535] 236. The apparatus of clause 233, wherein the MAC-CE activates a subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof for uplink RS requests.

[0536] 237. The apparatus of clause 236, wherein the MAC-CE down-selects the subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof for uplink RS requests from a set of one or more CSI trigger states or one or more SRS trigger states for downlink scheduling.

[0537] 238. The apparatus of clause 233, wherein:

[0538] the one or more CSI trigger states are separate from CSI trigger state configuration of CSI-RS for downlink scheduling, or

[0539] the one or more SRS trigger states are separate from SRS trigger state configuration of SRS for downlink scheduling.

[0540] 239. The apparatus of clause 238, wherein the MAC-CE activates the one or more CSI trigger states or the one or more SRS trigger states for different component carriers.

[0541] 240. The apparatus of clause 239, wherein the MAC-CE includes, for each of the different component carriers, a request identifier (ID), a serving cell ID, and a bandwidth part ID.

[0542] 241. A non-transitory computer-readable medium including stored instructions for wireless communication at an apparatus of a base station, the instructions executable by a processor to:

[0543] transmit a radio resource control (RRC) configuration message indicating one or more channel state information (CSI) trigger states, one or more sounding reference signal (SRS) trigger states, or a combination thereof for UE-initiated uplink reference signal (RS) requests;

[0544] transmit a medium access control (MAC) control element (CE) activating a subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof, wherein there is a one-to-one mapping between the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or a combination thereof and one or more physical uplink resources;

[0545] receiving the UE-initiated uplink RS request on a physical uplink resource of the one or more physical uplink resources; and

[0546] determining, based on the one-to-one mapping, that the UE-initiated uplink RS request corresponds to an activated triggering state from an activated subset of the one or more CSI triggering states, the one or more SRS triggering states, or a combination thereof.

[0547] 242. The non-transitory computer-readable medium of clause 241, wherein the one or more CSI triggering states, the one or more SRS triggering states, or a combination thereof are also used for downlink scheduled reference signals.

[0548] 243. The non-transitory computer-readable medium of clause 242, wherein the MAC-CE also activates a subset of the one or more CSI triggering states, the one or more SRS triggering states, or a combination thereof for the downlink scheduled reference signals.

[0549] 244. The non-transitory computer-readable medium of clause 241, wherein the MAC-CE activates a subset of the one or more CSI triggering states, the one or more SRS triggering states, or a combination thereof for uplink RS requests.

[0550] 245. The non-transitory computer-readable medium of clause 244, wherein the MAC-CE down-selects the subset of the one or more CSI triggering states, the one or more SRS triggering states, or a combination thereof for uplink RS requests from a set of one or more CSI triggering states or one or more SRS triggering states for downlink scheduled reference signals.

[0551] 246. The non-transitory computer-readable medium of clause 241, wherein:

[0552] the one or more CSI triggering states are separate from CSI triggering state configurations for CSI-RS for downlink scheduling, or

[0553] the one or more SRS triggering states are separate from SRS triggering state configurations for SRS for downlink scheduling.

[0554] 247. The non-transitory computer-readable medium of clause 246, wherein the MAC-CE activates the one or more CSI triggering states, the one or more SRS triggering states, or a combination thereof for different component carriers.

[0555] 248. The non-transitory computer-readable medium of clause 247, wherein the MAC-CE includes, for each of the different component carriers, a request identifier (ID), a serving cell ID, and a bandwidth part ID.

[0556] As used herein, “or” is used in its inclusive sense, unless otherwise expressly indicated. For example, “a or b” can include a only, b only, or a combination of a and b. As used herein, a phrase referring to “at least one of’ a list of items refers to any combination of those items, including single members. As an example, “at least one of a, b, or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c.

[0557] The various illustrative logics, logical blocks, modules, circuits and algorithm processes described in connection with the implementations disclosed herein can be implemented as electronic hardware, computer software, or combinations of both. The interchangeability of hardware and software has been described generally, in terms of their functionality, and accordingly has been described variously, depending upon the particular

[0558] The hardware and data processing apparatus used to implement the various illustrative logics, logical blocks, modules and circuits described in connection with the aspects disclosed herein can be implemented or performed with a general purpose single- or multi-chip processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor can be a microprocessor, or, any conventional processor, controller, microcontroller, or state machine. A processor also can be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some implementations, particular processes and methods can be performed by an

[0559] In one or more aspects, the functions described can be implemented in hardware, digital electronic circuitry, computer software, firmware, including the structures disclosed in this specification and their structural equivalents, or in any combination thereof. Implementations of the subject matter described in this specification also can be implemented as one or more computer programs, i.e., one or more modules of computer program instructions encoded on a computer storage media for execution by, or to control the operation of, data processing apparatus.

[0560] If implemented in software, the functions can be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media include both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. Additionally, the operations of a method or algorithm can reside in one or any combination of the aforementioned computer-readable media. The computer-readable media of a method or algorithm can also be those that can be accessed by a computer.

[0561] Various modifications to these implementations described in this disclosure can be apparent to those of ordinary skill in the art, and the generic principles defined herein can be applied to other implementations without departing from the spirit or scope of the disclosure. Thus, the claims are not intended to be limited to the implementations shown herein, but should be given the full scope consistent with the disclosure, the principles and novel features disclosed herein.

[0562] Additionally, those of ordinary skill in the art will readily recognize that the terms "above" and "below" are sometimes used herein for ease of description with respect to the orientation of the figures on the properly oriented page, and do not necessarily reflect the true orientation of any device as implemented.

[0563] Some features described in the specification in the context of separate implementations can also be implemented in combinations with each other. Conversely, various features described in the context of a single implementation can also be implemented separately or in any appropriate subcombination. Moreover, although features can be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination and the claimed combination can be directed to a subcombination or variation of a subcombination.

[0564] Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring such an order nor that all illustrated operations be performed, to accomplish desirable results. Further, the illustrated example processes can depict example operations in a particular order for purposes of illustration and discussion. Other operations can be provided in addition to, or instead of, the example operations illustrated and some operations can be performed simultaneously. In certain circumstances, multitasking and parallel processing can be advantageous. Moreover, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated in a single software product or packaged into multiple software products. Additionally, other implementations are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results.

Claims

1. A method of wireless communication at an apparatus of a user equipment (UE), the method comprising: transmitting an uplink request for at least one reference signal, the uplink request indicating a triggering state of the UE, wherein transmitting the uplink request comprises transmitting the uplink request on an uplink resource based on a mapping from the triggering state to the uplink resource; and communicating the at least one reference signal corresponding to the triggering state in response to the uplink request.

2. The method of claim 1, further comprising: receiving a downlink control information (DCI) scheduling the at least one reference signal.

3. The method of claim 1, wherein, communicating the at least one reference signal comprises transmitting a sounding reference signal (SRS).

4. The method of claim 1, wherein, communicating the at least one reference signal comprises receiving a channel state information reference signal (CSI-RS).

5. The method of claim 1, further comprising: receiving a radio resource control (RRC) configuration message indicating one or more channel state information (CSI) triggering states, one or more sounding reference signal (SRS) triggering states, or a combination thereof, for a UE-initiated uplink reference signal (RS) request; and receiving a medium access control (MAC) control element (CE) activating a subset of the one or more CSI triggering states, the one or more SRS triggering states, or the combination thereof, wherein the mapping from the triggering state to the uplink resource is a one-to-one mapping between an activated subset of the one or more CSI triggering states, the one or more SRS triggering states, or the combination thereof, and one or more physical uplink resources, and wherein transmitting the uplink request for at least one reference signal is on a physical uplink resource corresponding to the indicated triggering state of the UE.

6. The method of claim 5, further comprising: selecting an activated triggering state from the activated subset of the one or more CSI triggering states, the one or more SRS triggering states, or the combination thereof, wherein the uplink request for at least one reference signal is transmitted on a physical uplink resource corresponding to the activated triggering state.

7. The method of claim 5, wherein, the one or more CSI triggering states, the one or more SRS triggering states, or the combination thereof, are associated with downlink scheduled reference signals.

8. The method of claim 5, wherein, the MAC-CE activates a subset of the one or more CSI triggering states, the one or more SRS triggering states, or the combination thereof, for uplink RS requests.

9. The method of claim 5, wherein: the one or more CSI triggering states are separate from a CSI triggering state configuration for downlink scheduled CSI-RS, or the one or more SRS triggering states are separate from a SRS triggering state configuration for downlink scheduled SRS.

10. An apparatus of a user equipment (UE) for wireless communication, comprising: an interface; and a processing system coupled to the interface and configured to: outputting an uplink request for at least one reference signal, the uplink request indicating a trigger state of the UE, wherein outputting the uplink request comprises transmitting the uplink request on an uplink resource based on a mapping from the trigger state to the uplink resource; and communicating, via the interface, the at least one reference signal corresponding to the trigger state in response to the uplink request.

11. The apparatus of claim 10, wherein, The interface is further configured to obtain a downlink control information (DCI) scheduling the at least one reference signal.

12. The apparatus of claim 10, wherein, Communicating the at least one reference signal comprises transmitting a sounding reference signal (SRS).

13. The apparatus of claim 10, wherein, Communicating the at least one reference signal comprises receiving a channel state information reference signal (CSI-RS).

14. The apparatus of claim 10, wherein, The interface is further configured to: obtain a radio resource control (RRC) configuration message indicating one or more channel state information (CSI) trigger states, one or more sounding reference signal (SRS) trigger states, or a combination thereof, for a UE-initiated uplink reference signal (RS) request; and and obtain a medium access control (MAC) control element (CE) activating a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, wherein the mapping from the trigger state to the uplink resource is a one-to-one mapping between the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, and one or more physical uplink resources.

15. The apparatus of claim 14, wherein, The processing system is further configured to select an activated trigger state from the activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, wherein the uplink request for at least one reference signal is transmitted on a physical uplink resource corresponding to the activated trigger state.

16. The apparatus of claim 14, wherein, The one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, are associated with downlink scheduled reference signals.

17. The apparatus of claim 14, wherein, The MAC-CE activates a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, for uplink RS requests.

18. The apparatus of claim 14, wherein: the one or more CSI trigger states are separate from a CSI trigger state configuration for downlink scheduled CSI-RSs, or the one or more SRS trigger states are separate from a SRS trigger state configuration for downlink scheduled SRSs.

19. A method of wireless communication at an apparatus of a base station, comprising: receiving an uplink request for at least one reference signal, the uplink request indicating a trigger state of a user equipment (UE), wherein receiving the uplink request comprises determining the trigger state based on a mapping between the trigger state and an uplink resource on which the uplink request is received; and communicating, in response to the uplink request, the at least one reference signal corresponding to the trigger state.

20. The method of claim 19, further comprising: transmitting downlink control information (DCI) scheduling the at least one reference signal.

21. The method of claim 19, wherein, communicating the at least one reference signal includes receiving a sounding reference signal (SRS).

22. The method of claim 19, wherein, communicating the at least one reference signal includes transmitting a channel state information reference signal (CSI-RS).

23. The method of claim 19, further comprising: transmitting a radio resource control (RRC) configuration message indicating one or more channel state information (CSI) trigger states, one or more sounding reference signal (SRS) trigger states, or a combination thereof, for a UE-initiated uplink reference signal (RS) request; and transmitting a medium access control (MAC) control element (CE) activating a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, wherein the mapping from the trigger states to the uplink resources is a one-to-one mapping between activated trigger states and physical uplink resources, and wherein receiving the uplink request for at least one reference signal is on a physical uplink resource corresponding to an indicated trigger state of the UE.

24. The method of claim 23, further comprising: determining, based on the one-to-one mapping, that the UE-initiated uplink RS request corresponds to an activated trigger state from an activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof.

25. An apparatus of a base station for wireless communication, comprising: an interface; and a processing system coupled to the interface and configured to: obtain an uplink request for at least one reference signal, the uplink request indicating a trigger state of a user equipment (UE), wherein obtaining the uplink request includes determining the trigger state based on a mapping between the trigger state and an uplink resource on which the uplink request is received; and communicate the at least one reference signal corresponding to the trigger state in response to the uplink request.

26. The apparatus of claim 25, wherein, the interface is further configured to: output a radio resource control (RRC) configuration message indicating one or more channel state information (CSI) trigger states, one or more sounding reference signal (SRS) trigger states, or a combination thereof, for a UE-initiated uplink reference signal (RS) request; and output a medium access control (MAC) control element (CE) activating a subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, wherein the mapping from the trigger states to the uplink resources is a one-to-one mapping between an activated subset of the one or more CSI trigger states, the one or more SRS trigger states, or the combination thereof, and one or more physical uplink resources, and wherein obtaining the uplink request for at least one reference signal is on a physical uplink resource corresponding to an indicated trigger state of the UE.

27. The apparatus of claim 26, wherein, The processing system is configured to determine, based on the one-to-one mapping, that the UE-initiated uplink RS request corresponds to an activated triggering state from the activated subset of the one or more CSI triggering states, the one or more SRS triggering states, or a combination thereof.

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