DYNAMIC TRIGGERING AND SKIPPING OF CHANNEL STATE FEEDBACK (CSF)

Certain aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for dynamically triggering or skipping channel state feedback (CSF). A method that may be performed by a user equipment (UE) includes receiving, from a network entity, a configuration indicating CSF reporting occasions, receiving a downlink (DL) transmission, and transmitting CSF on only some CSF reporting occasions after receiving the DL transmission when one or more trigger conditions are met. According to certain aspects, when one or more trigger conditions are not met, the UE skips at least some CSF reporting occasions.

BACKGROUND

Field of the Disclosure

Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for dynamically triggering or skipping transmission(s) of channel state feedback (CSF).

Description of Related Art

In some examples, a wireless multiple-access communication system may include a number of base stations (BSs), which are each capable of simultaneously supporting communication for multiple communication devices, otherwise known as user equipments (UEs). In an LTE or LTE-A network, a set of one or more base stations may define an eNodeB (eNB). In other examples (e.g., in a next generation, a new radio (NR), or 5G network), a wireless multiple access communication system may include a number of distributed units (DUs) (e.g., edge units (EUs), edge nodes (ENs), radio heads (RHs), smart radio heads (SRHs), transmission reception points (TRPs), etc.) in communication with a number of central units (CUs) (e.g., central nodes (CNs), access node controllers (ANCs), etc.), where a set of one or more DUs, in communication with a CU, may define an access node (e.g., which may be referred to as a BS, 5G NB, next generation NodeB (gNB or gNodeB), TRP, etc. A BS or DU may communicate with a set of UEs on downlink (DL) channels (e.g., for transmissions from a BS or to a UE) and uplink (UL) channels (e.g., for transmissions from a UE to a BS or DU).

SUMMARY

One or more aspects of the subject matter described in this disclosure can be implemented in a method for wireless communications by a user equipment (UE). The method generally includes receiving, from a network entity, a configuration indicating channel state feedback (CSF) reporting occasions; receiving a downlink (DL) transmission; and transmitting CSF on only some CSF reporting occasions after receiving the DL transmission when one or more trigger conditions are met.

One or more aspects of the subject matter described in this disclosure can be implemented in a method for wireless communications by a network entity. The method generally includes transmitting, to a UE, a configuration indicating CSF reporting occasions; transmitting a DL transmission to the UE; and receiving CSF from the UE on only some CSF reporting occasions after transmitting the DL transmission when one or more trigger conditions are met.

One or more aspects of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication by a UE. The apparatus generally includes a memory and at least one processor coupled with the memory. The at least one processor coupled with the memory is generally configured to receive, from a network entity, a configuration indicating CSF reporting occasions; receive a DL transmission; and transmit CSF on only some CSF reporting occasions after receiving the DL transmission when one or more trigger conditions are met.

One or more aspects of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication by a network entity. The apparatus generally includes a memory and at least one processor coupled with the memory. The at least one processor coupled with the memory is generally configured to transmit, to a UE, a configuration indicating CSF reporting occasions; transmit a DL transmission to the UE; and receive CSF from the UE on only some CSF reporting occasions after transmitting the DL transmission when one or more trigger conditions are met.

One or more aspects of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus generally includes means for receiving signaling indicating a beam update. The apparatus generally includes means for receiving, from a network entity, a configuration indicating CSF reporting occasions; means for receiving a DL transmission; and means for transmitting CSF on only some CSF reporting occasions after receiving the DL transmission when one or more trigger conditions are met.

One or more aspects of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus generally includes means for transmitting, to a UE, a configuration indicating CSF reporting occasions; means for transmitting a DL transmission to the UE; and means for receiving CSF from the UE on only some CSF reporting occasions after transmitting the DL transmission when one or more trigger conditions are met.

One or more aspects of the subject matter described in this disclosure can be implemented in a computer readable medium having computer executable code stored thereon. The computer readable medium having computer executable code stored thereon generally includes code for receiving, from a network entity, a configuration indicating CSF reporting occasions; code for receiving a DL transmission; and code for transmitting CSF on only some CSF reporting occasions after receiving the DL transmission when one or more trigger conditions are met.

One or more aspects of the subject matter described in this disclosure can be implemented in a computer readable medium having computer executable code stored thereon. The computer readable medium having computer executable code stored thereon generally includes code for transmitting, to a UE, a configuration indicating CSF reporting occasions; code for transmitting a DL transmission to the UE; and code for receiving CSF from the UE on only some CSF reporting occasions after transmitting the DL transmission when one or more trigger conditions are met.

DETAILED DESCRIPTION

Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for dynamically triggering or skipping transmission of channel state feedback (CSF) on periodic channel state information (P-CSI) or semi-persistent CSI (SP-CSI) reporting occasions. The techniques presented herein may help conserve power and make efficient use of resources by transmitting CSF, such as channel state information (CSI) reports, only in some reporting occasions and skipping transmission in other reporting occasions where CSF is not necessary. The techniques presented herein may also help a network entity (e.g., base station (BS)/gNB) know when to expect a CSF report

The techniques described herein may be used for various wireless communication technologies, such as Long Term Evolution (LTE), code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), single-carrier frequency division multiple access (SC-FDMA), and other networks. The terms “network” and “system” are often used interchangeably. A CDMA network may implement a radio technology such as Universal Terrestrial Radio Access (UTRA), CDMA2000, etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. CDMA2000 covers IS-2000, IS-95 and IS-856 standards. A TDMA network may implement a radio technology such as Global System for Mobile Communications (GSM). An OFDMA network may implement a radio technology such as New Radio (NR) (e.g. 5G RA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunication System (UMTS).

NR is an emerging wireless communications technology under development in conjunction with the 5G Technology Forum (5GTF). 3GPP LTE and LTE-Advanced (LTE-A) are releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A and GSM are described in documents from an organization named “3rd Generation Partnership Project” (3GPP). CDMA2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2). The techniques described herein may be used for the wireless networks and radio technologies mentioned above as well as other wireless networks and radio technologies. For clarity, while aspects may be described herein using terminology commonly associated with 3G and/or 4G wireless technologies, aspects of the present disclosure can be applied in other generation-based communication systems, such as 5G and later, including NR technologies.

Example Wireless Communications System

FIG. 1illustrates an example wireless communication network100(e.g., a New Radio (NR)/5G network), in which aspects of the present disclosure may be performed. For example, wireless communication network100may include a user equipment (UE)120configured to perform operations400ofFIG. 4to transmit channel state feedback (CSF) to a network entity (e.g., such as a base station (BS)110a) (performing operations500ofFIG. 5). For example, UE120aincludes a CSF Manager122and BS110aincludes a CSF Manager112. CSF Manager122may be configured for transmitting CSF on only some CSF reporting occasions, after receiving a downlink (DL) transmission, when one or more trigger conditions are met, in accordance with certain aspects of the present disclosure. Further, CSF112may be configured for receiving CSF on only some CSF reporting occasions, after transmitting a DL transmission, when one or more trigger conditions are met, in accordance with certain aspects of the present disclosure.

As illustrated inFIG. 1, wireless communication network100may include a number of BSs110and other network entities. ABS may be a station that communicates with UEs. Each BS110may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to a coverage area of a NodeB (NB) and/or a NodeB subsystem serving this coverage area, depending on the context in which the term is used. In NR systems, the term “cell” and next generation NodeB (gNB), NR BS, 5G NB, access point (AP), or transmission reception point (TRP) may be interchangeable. In some examples, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a mobile BS. In some examples, the base stations may be interconnected to one another and/or to one or more other base stations or network nodes (not shown) in wireless communication network100through various types of backhaul interfaces, such as a direct physical connection, a wireless connection, a virtual network, or the like using any suitable transport network.

A network controller130may couple to a set of BSs and provide coordination and control for these BSs. Network controller130may communicate with BSs110via a backhaul. BSs110may also communicate with one another (e.g., directly or indirectly) via wireless or wireline backhaul.

UEs120(e.g.,120x,120y, etc.) may be dispersed throughout wireless communication network100, and each UE120may be stationary or mobile. A UE may also be referred to as a mobile station, a terminal, an access terminal, a subscriber unit, a station, a Customer Premises Equipment (CPE), a cellular phone, a smart phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet computer, a camera, a gaming device, a netbook, a smartbook, an ultrabook, an appliance, a medical device or medical equipment, a biometric sensor/device, a wearable device such as a smart watch, smart clothing, smart glasses, a smart wrist band, smart jewelry (e.g., a smart ring, a smart bracelet, etc.), an entertainment device (e.g., a music device, a video device, a satellite radio, etc.), a vehicular component or sensor, a smart meter/sensor, industrial manufacturing equipment, a global positioning system device, gaming device, reality augmentation device (augmented reality (AR), extended reality (XR), or virtual reality (VR)), or any other suitable device that is configured to communicate via a wireless or wired medium.

Some UEs may be considered machine-type communication (MTC) devices or evolved MTC (eMTC) devices. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., that may communicate with a BS, another device (e.g., remote device), or some other entity. A wireless node may provide, for example, connectivity for or to a network (e.g., a wide area network such as Internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered Internet-of-Things (IoT) devices, which may be narrowband IoT (NB-IoT) devices.

While aspects of the examples described herein may be associated with LTE technologies, aspects of the present disclosure may be applicable with other wireless communications systems, such as NR. NR may utilize OFDM with a cyclic prefix (CP) on the UL and DL and include support for half-duplex operation using time division duplex (TDD). Beamforming may be supported and beam direction may be dynamically configured. Multiple-input multiple-output (MIMO) transmissions with precoding may also be supported. MIMO configurations in the DL may support up to 8 transmit antennas with multi-layer DL transmissions up to 8 streams and up to 2 streams per UE. Multi-layer transmissions with up to 2 streams per UE may be supported. Aggregation of multiple cells may be supported with up to 8 serving cells.

In some scenarios, air interface access may be scheduled. For example, a scheduling entity (e.g., a BS, Node B, eNB, gNB, or the like) can allocate resources for communication among some or all devices and equipment within its service area or cell. The scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communication, subordinate entities can utilize resources allocated by one or more scheduling entities.

BSs are not the only entities that may function as a scheduling entity. In some examples, a UE may function as a scheduling entity and may schedule resources for one or more subordinate entities (e.g., one or more other UEs), and the other UEs may utilize the resources scheduled by the UE for wireless communication. In some examples, a UE may function as a scheduling entity in a peer-to-peer (P2P) network, and/or in a mesh network. In a mesh network example, UEs may communicate directly with one another in addition to communicating with a scheduling entity.

Turning back toFIG. 1, this figure illustrates a variety of potential deployments for various deployment scenarios. For example, inFIG. 1, a solid line with double arrows indicates desired transmissions between a UE and a serving BS, which is a BS designated to serve the UE on the downlink (DL) and/or uplink (UL). A finely dashed line with double arrows indicates interfering transmissions between a UE and a BS. Other lines show component to component (e.g., UE to UE) communication options.

FIG. 2illustrates example components of BS110and UE120(as depicted inFIG. 1) which may be used to implement aspects of the present disclosure. For example, antennas252, processors266,258,264, and/or controller/processor280, which includes CSF Manager122, of UE120may be used to perform operations400ofFIG. 4, while antennas234, processors220,230,238, and/or controller/processor240, which includes CSF Manager112, of BS110may be used to perform operations500ofFIG. 5.

At BS110, a transmit processor220may receive data from a data source212and control information from a controller/processor240. The control information may be for the physical broadcast channel (PBCH), physical control format indicator channel (PCFICH), physical hybrid ARQ indicator channel (PHICH), physical downlink control channel (PDCCH), group common PDCCH (GC PDCCH), etc. The data may be for the physical downlink shared channel (PDSCH), etc. Processor220may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. Processor220may also generate reference symbols, e.g., for the primary synchronization signal (PSS), secondary synchronization signal (SSS), and cell-specific reference signal (CRS). A transmit (TX) MIMO processor230may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to the modulators (MODs) in transceivers232a-232t. Each modulator in transceivers232a-232tmay process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a DL signal. DL signals from modulators in transceivers232a-232tmay be transmitted via the antennas234a-234t, respectively.

At UE120, antennas252a-252rmay receive DL signals from BS110and may provide received signals to demodulators (DEMODs) in transceivers254a-254r, respectively. Each demodulator in transceivers254a-254rmay condition (e.g., filter, amplify, down convert, and digitize) a respective received signal to obtain input samples. Each demodulator may further process input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector256may obtain received symbols from all demodulators in transceivers254a-254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor258may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE120to a data sink260, and provide decoded control information to a controller/processor280.

Controllers/processors240and280may direct operations at BS110and UE120, respectively. Processor240and/or other processors and modules at BS110may perform or direct execution of processes for techniques described herein. Memories242and282may store data and program codes for BS110and UE120, respectively. A scheduler244may schedule UEs for data transmission on the DL and/or UL.

FIG. 3illustrates an example of a frame format300for a new radio (NR) system, in accordance with certain aspects of the present disclosure. The transmission timeline for each of the DL and UL may be partitioned into units of radio frames. Each radio frame may have a predetermined duration (e.g., 10 ms) and may be partitioned into 10 subframes, each of 1 ms, with indices of 0 through 9. Each subframe may include a variable number of slots depending on the subcarrier spacing (SCS). Each slot may include a variable number of symbol periods (e.g., 7 or 14 symbols) depending on the subcarrier spacing. The symbol periods in each slot may be assigned indices. A mini-slot is a subslot structure (e.g., 2, 3, or 4 symbols).

In NR, a synchronization signal block (SSB) is transmitted. In certain aspects, SSBs may be transmitted in a burst where each SSB in the burst corresponds to a different beam direction for UE-side beam management (e.g., including beam selection and/or beam refinement). The SSB includes a PSS, a SSS, and a two symbol PBCH. The SSB can be transmitted in a fixed slot location, such as the symbols 0-3 as shown inFIG. 3. The PSS and SSS may be used by UEs for cell search and acquisition. The PSS may provide half-frame timing, and the SS may provide the CP length and frame timing. The PSS and SSS may provide the cell identity. The PBCH carries some basic system information, such as DL system bandwidth, timing information within radio frame, synchronization signal (SS) burst set periodicity, system frame number, etc. The SSBs may be organized into SS bursts to support beam sweeping. Further system information such as, remaining minimum system information (RMSI), system information blocks (SIBs), other system information (OSI) can be transmitted on a PDSCH in certain subframes. The SSB can be transmitted up to sixty-four times, for example, with up to sixty-four different beam directions for mmWave. The multiple transmissions of the SSB are referred to as a SS burst set. SSBs in an SS burst set may be transmitted in the same frequency region, while SSBs in different SS bursts sets can be transmitted at different frequency regions.

A control resource set (CORESET) for systems, such as an NR and LTE systems, may comprise one or more control resource (e.g., time and frequency resources) sets, configured for conveying PDCCH, within the system bandwidth. Within each CORESET, one or more search spaces (e.g., common search space (CSS), UE-specific search space (USS), etc.) may be defined for a given UE. According to aspects of the present disclosure, a CORESET is a set of time and frequency domain resources, defined in units of resource element groups (REGs). Each REG may comprise a fixed number (e.g., twelve) tones in one symbol period (e.g., a symbol period of a slot), where one tone in one symbol period is referred to as a resource element (RE). A fixed number of REGs may be included in a control channel element (CCE). Sets of CCEs may be used to transmit new radio PDCCHs (NR-PDCCHs), with different numbers of CCEs in the sets used to transmit NR-PDCCHs using differing aggregation levels. Multiple sets of CCEs may be defined as search spaces for UEs, and thus a NodeB or other base station may transmit an NR-PDCCH to a UE by transmitting the NR-PDCCH in a set of CCEs that is defined as a decoding candidate within a search space for the UE, and the UE may receive the NR-PDCCH by searching in search spaces for the UE and decoding the NR-PDCCH transmitted by the NodeB.

Example Dynamic Triggering and Skipping of Channel State Feedback (CSF)

Certain aspects of the present disclosure provide techniques for dynamically triggering or skipping channel state feedback (CSF). These techniques may help conserve resources by transmitting channel state information (CSI) reports only in some reporting occasions, and skipping transmission in other reporting occasions (e.g., when the CSF may be “stale” in scenarios with rapidly changing channel conditions).

New Radio (NR) 3GPP Release 15 and 16 support two CSI reporting mechanisms: periodic CSI (P-CSI) reports transmitted on the physical uplink control channel (PUCCH) and semi-persistent CSI (SP-CSI) reports transmitted on the PUCCH. P-CSI reporting is used to periodically report channel quality of a downlink (DL) channel at the UE. Parameters such as periodicity and subframe offset are configured by a serving cell using higher layer signaling (e.g., radio resource control (RRC) signaling). Similar to P-CSI reporting, SP-CSI reporting has a periodicity and subframe offset which may be configured by the serving cell. However, a dynamic trigger may be used to signal a UE to begin periodically reporting CSI. In some cases, a dynamic trigger may also be used to signal the UE to stop the SP transmission of CSI reports. For example, a medium access control (MAC) control element (CE) may be used as a dynamic trigger to activate/deactivate SP-CSI reporting occasions.

NR 3GPP Release 17 supports various wireless communication services, such as ultra-reliable low-latency communications (URLLC). URLLC generally refers to a set of features that provide low latency and ultra-high reliability for mission critical applications such as industrial internet, smart grids, remote surgery and intelligent transportation systems. Thus, given the low latency and reliability requirements of URLLC, aperiodic CSI (A-CSI) reporting has been considered for NR 3GPP Release 17. This type of CSI reporting involves a one-time CSI report by the UE which is dynamically triggered by a network entity, e.g. by downlink control information (DCI) in the physical downlink control channel (PDCCH). Some of the parameters related to the configuration of the aperiodic CSI report are semi-statically configured from the network entity to the UL but the triggering is dynamic. While A-CSI reporting is advantageous in that it has low latency (e.g., is faster), and it only needs to be triggered when there is DL data/communication, A-CSI reporting also has its drawbacks. For example, A-CSI reporting may increase overhead due to DCI (i.e., a DL grant is required to trigger A-CSI reports on PUCCH), and in some cases, require complicated procedures be defined on top of the existing CSI reporting.

Aspects of the present disclosure provide techniques that may help clarify triggering and skipping of CSI-reporting when CSF reporting occasions comprise P-CSI or SP-CSI reporting occasions. As such, the techniques may help a UE conserve power and make efficient use of resources. The techniques may also help a BS (e.g., a gNB) know when to expect a CSF report.

According to certain aspects, when using P/SP-CSI report resources, the UE may only transmit the P/SP-CSI report when the UE receives a DL grant via a PDCCH or DL data via a semi-persistent scheduled (SPS) physical downlink shared channel (PDSCH) without PDCCH. Accordingly, because P/SP-CSI report resources may not always be transmitted in configured P-CSI or SP-CSI reporting occasions, a network entity may configure the CSI report to be transmitted with relatively small periodicity (e.g., as compared to conventional P/SP-CSI reports). Thus, the techniques presented herein provide a good tradeoff between CSI reporting latency and triggering overhead.

FIG. 4is a flow diagram illustrating example operations400for wireless communication by a UE, in accordance with certain aspects of the present disclosure. Operations400may be performed, for example, by UE120ain wireless communication network100. Operations400may be implemented as software components that are executed and run on one or more processors (e.g., controller/processor280ofFIG. 2). Further, the transmission and reception of signals by the UE in operations400may be enabled, for example, by one or more antennas (e.g., antennas252ofFIG. 2). In certain aspects, the transmission and/or reception of signals by the UE may be implemented via a bus interface of one or more processors (e.g., controller/processor280) obtaining and/or outputting signals.

Operations400begin, at405, by the UE receiving, from a network entity, a configuration indicating CSF reporting occasions. For example, the UE may receive a configuration for the UE to provide CSI reports via P-CSI or SP-CSI reporting schemes.

At410, the UE receives a DL transmission. For example, the UE may receive a DCI triggering a report. At415, the UE transmits CSF on only some CSF reporting occasions after receiving the DL transmission when one or more trigger conditions are met. According to certain aspects, when one or more trigger conditions are not met, the UE skips at least some CSF reporting occasions (e.g., does not transmit CSF in at least some CSF reporting occasions). As will be described in greater detail below, the DCI may trigger a report based on certain channel state information-reference signal (CSI-RS), and the UE may or may not send the report in a subsequent reporting occasion (e.g., configured via the configuration received at block405).

FIG. 5is a flow diagram illustrating example operations500for wireless communication by a network entity, in accordance with certain aspects of the present disclosure. Operations500may be performed, for example, by BS110ain wireless communication network100. Operations500may be complementary operations by the network entity to operations400performed by the UE. Operations500may be implemented as software components that are executed and run on one or more processors (e.g., controller/processor240ofFIG. 2). Further, the transmission and reception of signals by the network entity in operations500may be enabled, for example, by one or more antennas (e.g., antennas234ofFIG. 2). In certain aspects, the transmission and/or reception of signals by the network entity may be implemented via a bus interface of one or more processors (e.g., controller/processor240) obtaining and/or outputting signals.

Operations500begin, at505, by the network entity transmitting, to a UE, a configuration indicating CSF reporting occasions. At510, the network entity transmits a DL transmission to the UE. At515, the network entity receives CSF from the UE on only some CSF reporting occasions after transmitting the DL transmission when one or more trigger conditions are met.

Operations400and500ofFIGS. 4 and 5may be understood with reference to diagrams600,700,800,900, and1000ofFIGS. 6, 7, 8, 9, and 10, respectively, that show example dynamic triggering and skipping of CSF, in accordance with certain aspects of the present disclosure.

FIG. 6illustrates example dynamic triggering of CSF, in accordance with certain aspects of the present disclosure. As shown inFIG. 6, where higher layer signaling (e.g., RRC signaling) configures one or more occasions as SP-CSI report occasions, a dynamic trigger may be needed to enable a UE to periodically report CSI. However, after receiving such a trigger (e.g., a MAC-CE activating SP-CSI reporting), a UE may skip transmission of CSF in activated slots where no DL data is received. Rather, one or more SP-CSI reports may be triggered in activated slots where a DL transmission is received from a network entity. According to certain aspects, the DL transmission may be a DL grant (e.g., a DL grant associated with a high priority) or a semi-persistent scheduled (SPS) PDSCH (e.g., an SPS PDSCH without PDCCH associated with a high priority). As shown inFIG. 6, following receipt of the DL assignment (e.g., associated with a high priority), a UE may be triggered to transmit CSF (e.g., CSI report(s)) in both a first SP-CSI reporting occasion (N=1) and a second SP-CSI reporting occasion (N=2) (e.g., where N is an integer greater than 0 and Nmax=2).

WhileFIG. 6illustrates dynamic triggering of CSF when CSF reporting occasions comprise SP-CSI reporting occasions activated via MAC-CE signaling, other embodiments may include dynamic triggering of CSF when CSF reporting occasions comprise P-CSI reporting occasions. In such embodiments, CSI reporting occasions may be activated without the need for MAC-CE. However, P-CSI reporting may not be triggered in a P-CSI reporting occasion unless a DL transmission (e.g., a DL grant or a SPS PDSCH) is received in a slot.

Various options, as shown in diagrams700,800,900, and1000ofFIGS. 7, 8, 9, and 10, respectively, may be considered for determining a slot for transmission of a CSI report when reporting is triggered by the receipt of a DL transmission. More specifically, one or more trigger conditions may involve relative timing between a CSF reporting occasion on which CSF is transmitted and a timing of the DL grant or SPS PDSCH, a measurement resource on which the transmitted CSF is based, or both.

FIG. 7illustrates an example timeline700for transmitting CSF on only some CSF reporting occasions after receipt of a downlink (DL) transmission by a UE, in accordance with certain aspects of the present disclosure.

According to a first option, a UE may perform channel and/or interference measurement using a first P/SP-CSI reference signal (P/SP-CSI-RS)/interference measurement (IM) resource that is at least a first threshold time, T1, after receiving the DL grant or SPS PDSCH (shown as CSI-RS 2 inFIG. 7). In some examples, as also shown in the example ofFIG. 7, the UE may be triggered to transmit a P/SP-CSI report, based on CSI-RS 2, on a first P/SP-CSI report occasion (N) that occurs at a time t that occurs at least a threshold time, T2, after receiving the DL grant/SPS PDSCH (e.g., t>T2) and at least a threshold time, T3, after the measurement resource, CSI-RS 2 (e.g., t>T3). In other words, the UE may be triggered to transmit a P/SP-CSI report, based on CSI-RS 2, on a first P/SP-CSI report occasion (N) that has a time t>T2and T3.

In some examples not shown inFIG. 7, the UE may be triggered to transmit a P/SP-CSI report, based on CSI-RS 2, on a first P/SP-CSI report occasion (N) that occurs at least a time t that only satisfies T2(e.g., t>T2) (irrespective of time t relative to T3). In some other examples not shown inFIG. 7, the UE may be triggered to transmit a P/SP-CSI report, based on CSI-RS 2, on a first P/SP-CSI report occasion (N) that occurs at least a time t that only satisfies T3(e.g., t>T3) (irrespective of time t relative to T2).

FIGS. 8A and 8Billustrate other example timelines800A and800B, respectively, for transmitting CSF on only some CSF reporting occasions after receipt of a DL transmission by a UE, in accordance with certain aspects of the present disclosure. According to a second option, a UE may generate CSF (i.e., perform channel and/or interference measurement) based on a most recent measurement resource satisfying a processing time constraint. In other words, as shown inFIGS. 8A and 8B, the UE may generate CSF based on a CSI-RS/IM occurring after receipt of the DL grant/SPS PDSCH (e.g., CSI-RS 2 inFIG. 8A) or on a CSI-RS/IM occurring prior to receiving the DL grant/SPS PDSCH (e.g., CSI-RS 1 inFIG. 8B).

Generating CSF based on CSI-RS/IM resource occurring before the DL grant/SPS PDSCH essentially requires the UE to always monitor for the measurement resource. Following generation of the P/SP-CSI report, the UE may be triggered to transmit the report, based on the most recent measurement resource, on a first P/SP-CSI report occasion (N) that occurs (at time t) at least the threshold time, T2, after receiving the DL grant/SPS PDSCH (e.g., t>T2).

FIG. 9illustrates another example timeline900for transmitting CSF on only some CSF reporting occasions after receipt of a DL transmission by a UE, in accordance with certain aspects of the present disclosure. According to a third option, a UE may be configured to transmit CSF only when a time t of the first reporting occasion after the DL grant or SPS PDSCH occurs at least the threshold time, T2, after the DL grant or SPS PDSCH. In the illustrated example timeline900, a first P/SP-CSI reporting occasion (N) occurring at a time t does not satisfy the threshold time T2measured from the DL grant/SPS PDSCH (e.g., t<T2). Accordingly, a UE may skip transmitting a P/SP-CSI report on the first P/SP-CSI report occasion (N). Further, the UE may also not transmit the P/SP-CSI report in a subsequent reporting occasion (N+1) that satisfies the threshold time T2. In other words, where the first reporting occasion (N) does not satisfy the T2threshold, then the UE may skip transmission in the first reporting occasion (N) and any subsequent reporting occasion (e.g., N+1) as the CSI report may be considered too late (e.g., due to a high mobility or other scenario with rapidly changing channel conditions).

According to certain aspects, when a UE may receive multiple DL grants or SPS PDSCHs triggering CSF in a same slot, the UE may only send one report.FIG. 10illustrates an example timeline1000for transmitting CSF on only some CSF reporting occasions after receipt of multiple DL transmission by a UE, in accordance with certain aspects of the present disclosure. With respect to the first, second, and third option described herein, where a UE receives multiple DL grants or SPS PDSCHS triggering CSI reporting in a same slot, the UE may transmit only one P/SP-CSI report in that slot.

As shown inFIG. 10, with respect to the second option, the UE may receive a first DL transmission (e.g., DL grant/SPS PDSCH 1) and a second DL transmission (e.g., DL grant/SPS PDSCH 2) triggering CSF in a same slot. In response, the UE may transmit one P/SP-CSI report, based on CSI-RS 1 in this example, in the indicated slot (e.g., the P/SP-CSI reporting occasion that satisfies T2). Multiple DL transmission triggers may be satisfied by the transmission of a single P/SP-CSI report.

According to certain aspects, a UE may receive multiple DL grants or SPS PDSCHs triggering CSI reporting in different slots. For example, the UE may receive a first DL transmission triggering a first CSF in a first slot and subsequently receive a second DL transmission triggering a second CSF in a second slot. Where the first slot for the CSF transmission occurs before the second slot for CSF transmission but after the second DL transmission, the UE may transmit the first CSF and determine not to transmit the second CSF because the first CSF is transmitted after the second DL transmission and may be considered to be up to date.

According to a fourth option, instead of using configured P/SP-CSI report occasions, a UE may be triggered to transmit CSF on a CSF reporting occasion that occurs a fixed offset after the DL grant or SPS PDSCH (e.g., in a slot occurring a fixed offset after the DL grant or SPS PDSCH may be considered a configured report occasion).

According to certain aspects, transmitting CSF on only some CSF reporting occasions after receiving the DL transmission may occur only when the DL transmission (e.g., DL grant or SPS PDSCH) is of a given priority. For example, transmitting the (enhanced) P/SP-CSI may only be triggered by a DL grant or SPS PDSCH associated with a high priority. As such, this P/SP-CSI report may be treated as a high priority CSI report. In certain aspects, transmitting CSF on only some CSF reporting occasions after receiving the DL transmission may occur only when the DL transmission (e.g., DL grant or SPS PDSCH) is of a priority higher than or equal to a priority threshold. For example, transmitting CSF on only some CSF reporting occasions after receiving the DL transmission may occur when the DL transmission is of a priority of four where the priority threshold is a priority of three.

According to certain aspects, a UE may receive signaling indicating whether the UE can skip CSF reporting occasions when the one or more trigger conditions are not met. In some cases where the CSF reporting occasions are P-CSI reporting occasions, RRC signaling may indicate whether the UE can skip CSF reporting occasions when the one or more trigger conditions are not met. In some cases where the CSF reporting occasions are SP-CSI reporting occasions activated via MAC-CE, the MAC-CE may indicate whether the UE can skip CSF reporting occasions when the one or more trigger conditions are not met. For example, the MAC-CE may be an enhanced MAC-CE indicating that SP-CSI occasions may be skipped when no data is received by the UE.

According to certain aspects, transmitting CSF on only some CSF reporting occasions after receiving the DL transmission may occur only when the DL transmission is a PDCCH associated with a particular control resource set (CORESET)/search space or has a particular downlink control information (DCI) format (e.g., DCI 1_2).

According to certain aspects, transmitting CSF on only some CSF reporting occasions after receiving the DL transmission may occur only when one or more fields of the DL transmission indicate a particular code point. For example, one or more other fields beyond the priority field in DCI, including a field with a hybrid automatic repeat request (HARM) process number, a field with a modulation and coding scheme (MCS), and a field with a physical uplink control channel (PUCCH) resource indicator, may be used to trigger the CSF.

Example Wireless Communications Devices

FIG. 11illustrates a communications device1100that may include various components (e.g., corresponding to means-plus-function components) configured to perform operations for the techniques disclosed herein, such as operations400illustrated inFIG. 4. In some examples, communications device1100may be a user equipment (UE), such as UE120as described, for example with respect toFIGS. 1 and 2.

Communications device1100includes a processing system1102coupled to a transceiver1108(e.g., a transmitter and/or a receiver). Transceiver1108is configured to transmit and receive signals for communications device1100via an antenna1110, such as the various signals as described herein. Processing system1102may be configured to perform processing functions for communications device1100, including processing signals received and/or to be transmitted by communications device1100.

Processing system1102includes a processor1104coupled to a computer-readable medium/memory1112via a bus1106. In certain aspects, computer-readable medium/memory1112is configured to store instructions (e.g., computer-executable code) that when executed by processor1104, cause processor1104to perform operations400illustrated inFIG. 4, or other operations for performing the various techniques discussed herein for dynamically triggering or skipping channel state information (CSI) reporting. In certain aspects, computer-readable medium/memory1112stores code1114for receiving (e.g., for receiving, from a network entity, a configuration indicating channel state feedback (CSF) reporting occasions and/or for receiving a downlink (DL) transmission); code1116for generating (e.g., for generating the CSF based on a most recent measurement resource satisfying a processing time constraint); code1118for transmitting (e.g., for transmitting CSF on only some CSF reporting occasions after receiving the DL transmission when one or more trigger conditions are met); and code1120for skipping (e.g., for skipping at least some CSF reporting occasions when one or more trigger conditions are not met); etc.

Examples of a computer-readable medium/memory1112include random access memory (RAM), read-only memory (ROM), solid state memory, a hard drive, a hard disk drive, etc. In some examples, computer-readable medium/memory1112is used to store computer-readable, computer-executable software including instructions that, when executed, cause a processor to perform various functions described herein. In some cases, the memory contains, among other things, a basic input/output system (BIOS) which controls basic hardware or software operation such as the interaction with peripheral components or devices. In some cases, a memory controller operates memory cells. For example, the memory controller can include a row decoder, column decoder, or both. In some cases, memory cells within a memory store information in the form of a logical state.

In certain aspects, processor1104has circuitry configured to implement the code stored in computer-readable medium/memory1112. Processor1104includes circuitry1124for receiving (e.g., for receiving, from a network entity, a configuration indicating CSF reporting occasions and/or for receiving a DL transmission); circuitry1126for generating (e.g., for generating the CSF based on a most recent measurement resource satisfying a processing time constraint); circuitry1128for transmitting (e.g., for transmitting CSF on only some CSF reporting occasions after receiving the DL transmission when one or more trigger conditions are met); circuitry1130for skipping (e.g., for skipping at least some CSF reporting occasions when one or more trigger conditions are not met); etc.

Various components of communications device1100may provide means for performing the methods described herein, including with respect toFIG. 4.

In some examples, means for generating and means for skipping may include various processing system1102components, such as: the one or more processors1104inFIG. 11, or aspects of UE120depicted inFIG. 2, including receive processor258, transmit processor264, TX MIMO processor266, and/or controller/processor280.

Notably,FIG. 11is just one use example, and many other examples and configurations of communications device1100are possible.

FIG. 12illustrates a communications device1200that may include various components (e.g., corresponding to means-plus-function components) configured to perform operations for the techniques disclosed herein, such as operations500illustrated inFIG. 5. In some examples, communications device1200may be a network entity, such as base station (BS)110as described, for example with respect toFIGS. 1 and 2.

Communications device1200includes a processing system1202coupled to a transceiver1208(e.g., a transmitter and/or a receiver). Transceiver1208is configured to transmit and receive signals for communications device1200via an antenna1210, such as the various signals as described herein. Processing system1202may be configured to perform processing functions for communications device1200, including processing signals received and/or to be transmitted by communications device1200.

Processing system1202includes a processor1204coupled to a computer-readable medium/memory1212via a bus1206. In certain aspects, computer-readable medium/memory1212is configured to store instructions (e.g., computer-executable code) that when executed by processor1204, cause processor1204to perform the operations illustrated inFIG. 5, or other operations for performing the various techniques discussed herein for dynamically triggering or skipping CSI reporting.

In certain aspects, computer-readable medium/memory1212stores code1214for transmitting (e.g., for transmitting, to a UE, a configuration indicating CSF reporting occasions and/or for transmitting a DL transmission to the UE); code1216for receiving (e.g., for receiving CSF from the UE on only some CSF reporting occasions after transmitting the DL transmission when one or more trigger conditions are met); etc.

Examples of a computer-readable medium/memory1212include RAM, ROM, solid state memory, a hard drive, a hard disk drive, etc. In some examples, computer-readable medium/memory1212is used to store computer-readable, computer-executable software including instructions that, when executed, cause a processor to perform various functions described herein. In some cases, the memory contains, among other things, a BIOS which controls basic hardware or software operation such as the interaction with peripheral components or devices. In some cases, a memory controller operates memory cells. For example, the memory controller can include a row decoder, column decoder, or both. In some cases, memory cells within a memory store information in the form of a logical state.

In certain aspects, processor1204has circuitry configured to implement the code stored in the computer-readable medium/memory1212. Processor1204includes circuitry1224for transmitting (e.g., for transmitting, to a UE, a configuration indicating CSF reporting occasions and/or for transmitting a DL transmission to the UE); circuitry1226for receiving (e.g., for receiving CSF from the UE on only some CSF reporting occasions after transmitting the DL transmission when one or more trigger conditions are met); etc.

Various components of communications device1200may provide means for performing the methods described herein, including with respect toFIG. 5.

Notably,FIG. 12is just one use example, and many other examples and configurations of communications device1200are possible.

EXAMPLE ASPECTS

Aspect 1: A method for wireless communication by a user equipment (UE), comprising: receiving, from a network entity, a configuration indicating channel state feedback (CSF) reporting occasions; receiving a downlink (DL) transmission; and transmitting CSF on only some CSF reporting occasions after receiving the DL transmission when one or more trigger conditions are met.

Aspect 2: The method of Aspect 1, further comprising skipping at least some CSF reporting occasions when one or more trigger conditions are not met.

Aspect 3: The method of Aspect 1 or 2, wherein the CSF reporting occasions comprise periodic channel state information (P-CSI) reporting occasions.

Aspect 4: The method of any of Aspects 1-3, wherein the CSF reporting occasions comprise semi-persistent channel state information (SP-CSI) reporting occasions activated via medium access control (MAC) control element (CE) signaling.

Aspect 5: The method of any of Aspects 1-4, wherein the DL transmission comprises at least one of a DL grant or semi-persistent scheduled (SPS) physical downlink shared channel (PDSCH).

Aspect 6: The method of any of Aspects 1-5, wherein the one or more trigger conditions involve relative timing between a CSF reporting occasion on which CSF is transmitted and at least one of: a DL grant or semi-persistent scheduled (SPS) physical downlink shared channel (PDSCH); or a measurement resource on which the transmitted CSF is based.

Aspect 7: The method of Aspect 6, wherein: the measurement resource occurs at least a first threshold after the grant or SPS PDSCH; and the CSF reporting occasion on which CSF is transmitted occurs at least at least one of a second threshold after the grant or SPS PDSCH; or a third threshold after the measurement resource.

Aspect 8: The method of Aspect 6 or 7, wherein the CSF reporting occasion on which CSF is transmitted occurs at least a threshold after the grant or SPS PDSCH.

Aspect 9: The method of Aspect 8, wherein the UE generates the CSF based on a most recent measurement resource satisfying a processing time constraint.

Aspect 10: The method of Aspect 8 or 9, wherein the UE is configured to transmit CSF only when a first reporting occasion after the grant or SPS PDSCH occurs at least the threshold after the grant or SPS PDSCH.

Aspect 11: The method of any of Aspects 5-10, wherein the UE transmits CSF on a CSF reporting occasion that occurs a fixed offset after the grant or SPS PDSCH when the one or more trigger conditions are met.

Aspect 12: The method of any of Aspects 1-11, wherein, if the UE receives multiple DL transmissions triggering CSF reporting in a same slot, the UE transmits only one CSF report in that slot.

Aspect 13: The method of any of Aspects 1-12, wherein: if the UE receives a first DL transmission triggering a first CSF in a first slot and a second DL transmission triggering a second CSF in a second slot, wherein the first slot occurs before the second slot and after the second DL transmission, the UE transmits the first CSF but not the second CSF.

Aspect 14: The method of any of Aspects 1-13, wherein the one or more trigger conditions are met only when the DL transmission is of a priority higher than or equal to a priority threshold.

Aspect 15: The method of any of Aspects 1-14, further comprising receiving signaling indicating whether the UE can skip CSF reporting occasions when the one or more trigger conditions are not met.

Aspect 16: The method of Aspect 15, wherein: the CSF reporting occasions comprise periodic channel state information (P-CSI) reporting occasions; and the signaling comprises radio resource control (RRC) signaling.

Aspect 17: The method of Aspect 15 or 16, wherein: the CSF reporting occasions comprise semi-persistent channel state information (SP-CSI) reporting occasions activated via a medium access control (MAC) control element (CE); and the MAC CE indicates whether the UE can skip CSF reporting occasions when the one or more trigger conditions are not met.

Aspect 18: The method of any of Aspects 1-17, wherein the one or more trigger conditions are met only when the DL transmission comprises a physical downlink control channel (PDCCH) associated with a particular control resource set (CORESET) or has a particular downlink control information (DCI) format.

Aspect 19: The method of any of Aspects 1-18, wherein the one or more trigger conditions are met only when one or more fields of the DL transmission indicate a particular code point.

Aspect 20: A method for wireless communication by a network entity, comprising: transmitting, to a user equipment (UE), a configuration indicating channel state feedback (CSF) reporting occasions; transmitting a downlink (DL) transmission to the UE; and receiving CSF from the UE on only some CSF reporting occasions after transmitting the DL transmission when one or more trigger conditions are met.

Aspect 21: The method of Aspect 20, wherein the CSF reporting occasions comprise periodic channel state information (P-CSI) reporting occasions.

Aspect 22: The method of Aspect 20 or 21, wherein the CSF reporting occasions comprise semi-persistent channel state information (SP-CSI) reporting occasions activated via medium access control (MAC) control element (CE) signaling.

Aspect 23: The method of any of Aspects 20-22, wherein the DL transmission comprises at least one of a DL grant or semi-persistent scheduled (SPS) physical downlink shared channel (PDSCH).

Aspect 24: The method of any of Aspects 20-23, wherein the one or more trigger conditions involve relative timing between a CSF reporting occasion on which CSF is transmitted and at least one of: a DL grant or semi-persistent scheduled (SPS) physical downlink shared channel (PDSCH); or a measurement resource on which the transmitted CSF is based.

Aspect 25: The method of Aspect 24, wherein: the measurement resource occurs at least a first threshold after the grant or SPS PDSCH; and the CSF reporting occasion on which CSF is transmitted occurs at least at least one of: a second threshold after the grant or SPS PDSCH; or a third threshold after the measurement resource.

Aspect 26: The method of Aspect 24 or 25, wherein the CSF reporting occasion on which CSF is transmitted occurs at least a threshold after the grant or SPS PDSCH.

Aspect 27: The method of Aspect 26, wherein the UE generates the CSF based on a most recent measurement resource satisfying a processing time constraint.

Aspect 28: The method of Aspect 26 or 27, wherein the UE is configured to transmit CSF only when a first reporting occasion after the grant or SPS PDSCH occurs at least the threshold after the grant or SPS PDSCH.

Aspect 29: The method of any of Aspects 23-28, wherein the UE transmits CSF on a CSF reporting occasion that occurs a fixed offset after the grant or SPS PDSCH.

Aspect 30: The method of any of Aspects 20-29, wherein, if the network entity transmits multiple DL transmissions triggering CSF reporting in a same slot, the network entity receives only one CSF report in that slot from the UE.

Aspect 31: The method of any of Aspects 20-30, wherein, if the network entity transmits a first DL transmission triggering a first CSF in a first slot and a second DL transmission triggering a second CSF in a second slot, wherein the first slot occurs before the second slot and after the second DL transmission, the network entity receives only the first CSF but not the second CSF.

Aspect 32: The method of any of Aspects 20-31, wherein the one or more trigger conditions are met only when the DL transmission is of a given priority.

Aspect 33: The method of any of Aspects 20-32, further comprising transmitting to the UE signaling indicating whether the UE can skip CSF reporting occasions when the one or more trigger conditions are not met.

Aspect 34: The method of Aspect 33, wherein: the CSF reporting occasions comprise periodic channel state information (P-CSI) reporting occasions; and the signaling comprises radio resource control (RRC) signaling.

Aspect 35: The method of Aspect 33 or 34, wherein: the CSF reporting occasions comprise semi-persistent channel state information (SP-CSI) reporting occasions activated via a medium access control (MAC) control element (CE); and the MAC CE indicates whether the UE can skip CSF reporting occasions when the one or more trigger conditions are not met.

Aspect 36: The method of any of Aspects 20-35, wherein the one or more trigger conditions are met only when the DL transmission comprises a physical downlink control channel (PDCCH) associated with a particular control resource set (CORESET) or has a particular downlink control information (DCI) format.

Aspect 37: The method of any of Aspects 20-36, wherein the one or more trigger conditions are met only when one or more fields of the DL transmission indicate a particular code point.

Aspect 38: An apparatus, comprising a memory comprising computer-executable instructions and one or more processors configured to execute the computer-executable instructions and cause the one or more processors to perform a method in accordance with any one of Aspects 1-19.

Aspect 39: An apparatus, comprising means for performing a method in accordance with any one of Aspects 1-19.

Aspect 40: A non-transitory computer-readable medium comprising computer-executable instructions that, when executed by one or more processors, cause the one or more processors to perform a method in accordance with any one of Aspects 1-19.

Aspect 41: A computer program product embodied on a computer-readable storage medium comprising code for performing a method in accordance with any one of Aspects 1-19.

Aspect 42: An apparatus, comprising a memory comprising computer-executable instructions and one or more processors configured to execute the computer-executable instructions and cause the one or more processors to perform a method in accordance with any one of Aspects 20-37.

Aspect 43: An apparatus, comprising means for performing a method in accordance with any one of Aspects 20-37.

Aspect 44: A non-transitory computer-readable medium comprising computer-executable instructions that, when executed by one or more processors, cause the one or more processors to perform a method in accordance with any one of Aspects 20-37.

ADDITIONAL CONSIDERATIONS