Channel state information (CSI) for unlicensed spectrum

Abstract

This disclosure provides systems, methods, and apparatus for identifying channel state information reference signal (CSI-RS) resources. In some aspects, a UE receiving a CSI-RS may determine CSI feedback based at least in part on the CSI-RS after detecting a CSI-RS resource including the CSI-RS. Signaling or techniques are also provided for when no CSI-RS is detected (e.g., when a channel access operation of a base station on all available CSI-RS resources fails). Further, a method for rate matching of a shared channel surrounding CSI-RS resources or for CSI interference management (CSI-IM) resources, and a CSI reporting method, such as triggered or re-triggered CSI reporting, for cases when the UE fails to transmit CSI feedback due to failed channel access operations are provided.

Description

[0001] This application is a divisional application of the following invention patent application: Application number: 202080049811.4, Application date: July 8, 2020, Invention name: Channel State Information (CSI) for unlicensed spectrum.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This patent application claims priority to Indian Provisional Patent Application No. 201941027431 filed on July 9, 2019, Indian Provisional Patent Application No. 201941032560 filed on August 12, 2019, Indian Provisional Patent Application No. 201941033077 filed on August 16, 2019, all of which are titled “CHANNEL STATE INFORMATION FOR UNLICENSED SPECTRUM” and U.S. Non-Provisional Patent Application No. 16 / 922,916 filed on July 7, 2020, titled “CHANNEL STATE INFORMATION (CSI) FOR UNLICENSED SPECTRUM,” which are hereby expressly incorporated herein by reference. Technical Field

[0004] Aspects of the present disclosure relate generally to wireless communications and techniques for channel state information (CSI) feedback in unlicensed spectrum. Background Art

[0005] Wireless communication systems are widely deployed to provide a variety of telecommunication services, such as telephony, video, data, messaging, and broadcasting. Typical wireless communication systems may employ multiple access technologies that can support communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). 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, time division synchronous code division multiple access (TD-SCDMA) systems, and long term evolution (LTE). LTE / LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP).

[0006] A wireless communication network may include multiple base stations that can support communication of multiple user equipments. A user equipment (UE) may communicate with a base station (BS) via a downlink (DL) and an uplink (UL). DL (or forward link) refers to a communication link from a BS to a UE, and UL (or reverse link) refers to a communication link from a UE to a BS. As will be described in more detail herein, a BS may be referred to as a NodeB, an LTE evolved NodeB (eNB), a gNB, an access point (AP), a radio head, a transmit receive point (TRP), a new radio (NR) BS, a 5G NodeB, etc.

[0007] The above-mentioned multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different UEs to communicate at municipal, national, regional and even global levels. NR, also known as 5G, is a set of enhancements to the LTE mobile standard promulgated by the Third Generation Partnership Project (3GPP). NR is designed to better support mobile broadband Internet access by improving spectrum efficiency, reducing costs, improving services, utilizing new spectrum, and using orthogonal frequency division multiplexing (OFDM) (CP-OFDM) with cyclic prefix (CP) on DL and CP-OFDM or SC-FDM (e.g., also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on UL (or a combination thereof) to better integrate with other open standards, and support beamforming, multiple-input multiple-output (MIMO) antenna technology and carrier aggregation. Summary of the invention

[0008] The systems, methods and devices of the present disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.

[0009] One innovative aspect of the subject matter described in the present disclosure includes a method of wireless communication performed by a network entity, comprising: sending configuration information for a channel state information reference signal CSI-RS, wherein the configuration information indicates a plurality of CSI-RS resources; selectively sending the CSI-RS on a selected CSI-RS resource among the plurality of CSI-RS resources, wherein the selected CSI-RS resource is based on a measurement-based method and the configuration information, wherein the measurement-based method includes measurement of one or more CSI-RS resources among the plurality of CSI-RS resources; and selectively receiving a CSI report based on the CSI-RS.

[0010] One innovative aspect of the subject matter described in the present disclosure includes an apparatus for wireless communication, comprising: a first interface configured to output configuration information for a channel state information reference signal CSI-RS, wherein the configuration information indicates a plurality of CSI-RS resources; and selectively outputting the CSI-RS on a selected CSI-RS resource among the plurality of CSI-RS resources, wherein the selected CSI-RS resource is based on a measurement-based method and the configuration information, wherein the measurement-based method includes measurement of one or more CSI-RS resources among the plurality of CSI-RS resources; and a second interface configured to selectively obtain a CSI report based on whether the CSI-RS is received.

[0011] One innovative aspect of the subject matter described in the present disclosure can be implemented in a wireless communication method performed by a user equipment (UE). The method may include receiving configuration information of a channel state information reference signal (CSI-RS), wherein the configuration information indicates a plurality of CSI-RS resources; determining whether the CSI-RS is received on the plurality of CSI-RS resources based on the configuration information; and selectively sending a CSI report based on whether the CSI-RS is received.

[0012] In some implementations, determining whether the CSI-RS is received further comprises identifying a CSI-RS resource from among the plurality of CSI-RS resources at which the CSI-RS is received based on measurements of the plurality of CSI-RS resources.

[0013] In some implementations, determining whether a CSI-RS is received further comprises identifying a CSI-RS resource from among the plurality of CSI-RS resources at which the CSI-RS is received based on the CSI-RS resource associated with the measurement value satisfying the threshold.

[0014] In some implementations, the CSI-RS resource is an earliest CSI-RS resource among the plurality of CSI-RS resources that is associated with a measurement value that satisfies a threshold.

[0015] In some implementations, whether the CSI-RS is received is determined based on decoded information indicating that a CSI-RS resource among a plurality of CSI-RS resources is included in a transmit opportunity (TXOP).

[0016] In some implementations, the method may include determining whether the CSI-RS is received based on information indicating a CSI-RS resource.

[0017] In some implementations, multiple CSI-RS resources are associated with a tracking reference signal (TRS) burst, wherein the TRS burst is received when all CSI-RS resources in the multiple CSI-RS resources are included in a transmit opportunity of a base station that transmits the TRS burst.

[0018] In some implementations, when the CSI-RS is not received, selectively sending the CSI report further includes skipping the sending of the CSI report.

[0019] In some implementations, when no CSI-RS is received, the CSI report relates to CSI-RS received before a time associated with the plurality of CSI-RS resources.

[0020] In some implementations, when the CSI-RS is not received, the CSI report indicates that the CSI-RS is not received.

[0021] In some implementations, a CSI report is sent including information identifying at least one of: an indication of which CSI-RS resource is associated with the CSI report, an indication of a CSI period associated with the CSI report, or an indication of whether the CSI report is valid.

[0022] In some implementations, the method may include receiving a grant for a shared channel that overlaps at least one CSI-RS resource of the plurality of CSI-RS resources, and rate matching the shared channel around the at least one CSI-RS resource.

[0023] In some embodiments, at least one CSI-RS resource is used for zero-power CSI-RS, and rate matching the shared channel around the at least one CSI-RS resource further includes rate matching the shared channel around one or more CSI-RS resources overlapping with the shared channel.

[0024] In some embodiments, at least one CSI-RS resource is used for zero-power CSI-RS, and rate matching a shared channel around the at least one CSI-RS resource also includes rate matching a shared channel in a first CSI-RS resource including around at least one CSI-RS resource in a transmit opportunity.

[0025] In some implementations, the grant includes an indication of whether to rate match the shared channel around at least one CSI-RS resource.

[0026] In some embodiments, the method may include receiving a trigger for retransmission of a CSI report, wherein the trigger identifies the CSI report, and wherein the CSI report is a periodic CSI report or a semi-persistent CSI report. The method may include performing the retransmission of the CSI report according to the trigger.

[0027] In some embodiments, the trigger includes an indication that the trigger is an aperiodic retransmission trigger for CSI reporting.

[0028] In some embodiments, the trigger includes an indication of at least one of an index of a CSI report configuration or an index of a CSI-RS resource configuration for which retransmission of the CSI report is to be triggered.

[0029] In some embodiments, the trigger includes an indication of at least one of a slot index of a CSI report or a slot index of a CSI-RS resource in which a CSI-RS is received among a plurality of CSI-RS resources.

[0030] In some embodiments, the trigger includes an indication of at least one of: uplink resources for retransmission of the CSI report, coding information for retransmission of the CSI report, or a channel access type for retransmission of the CSI report.

[0031] In some embodiments, the trigger includes an indication of whether the CSI report for which retransmission is triggered is an aperiodic CSI report, a periodic CSI report, or a semi-persistent CSI report.

[0032] In some implementations, the trigger identification is the CSI report that triggers the retransmission.

[0033] In some implementations, performing retransmission of the CSI report based on a trigger further includes performing retransmission based on a maximum time limit between the trigger and a previous trigger of the CSI report.

[0034] In some embodiments, determining whether a CSI-RS is received includes identifying a CSI-RS resource from among a plurality of CSI-RS resources where the CSI-RS is received based at least in part on a CSI-RS resource having a signal strength value that satisfies a threshold. In some embodiments, the signal strength value may be a maximum signal strength value. In some embodiments, when the signal strength value satisfies the threshold, out-of-sync and in-sync metrics may be determined.

[0035] Another innovative aspect of the subject matter described in the present disclosure may be implemented in a UE for wireless communication. The UE may include a memory and one or more processors operably coupled to the memory. The memory and the one or more processors may be configured to receive configuration information indicating multiple CSI-RS resources for CSI-RS, determine whether to receive CSI-RS on the multiple CSI-RS resources, and selectively send a CSI report based at least in part on the CSI-RS.

[0036] Another innovative aspect of the subject matter described in the present disclosure can be implemented in an apparatus for wireless communication. The apparatus may include: a first interface configured to obtain configuration information of a CSI-RS, wherein the configuration information indicates a plurality of CSI-RS resources; a processing system configured to determine whether a CSI-RS is received on the plurality of CSI-RS resources based on the configuration information; and a second interface configured to selectively output a CSI report based on whether the CSI-RS is received.

[0037] Another innovative aspect of the subject matter described in the present disclosure can be implemented in a non-transitory computer-readable medium. The non-transitory computer-readable medium can store one or more instructions for wireless communication. When executed by one or more processors of a UE, the one or more instructions can cause the one or more processors to receive configuration information for a CSI-RS, wherein the configuration information indicates a plurality of CSI-RS resources; determine whether a CSI-RS is received on the plurality of CSI-RS resources based on the configuration information; and selectively send a CSI report based on whether the CSI-RS is received.

[0038] Another innovative aspect of the subject matter described in the present disclosure can be implemented in an apparatus for wireless communication. The apparatus may include a component for receiving configuration information for a CSI-RS, wherein the configuration information indicates a plurality of CSI-RS resources; a component for determining whether a CSI-RS is received on the plurality of CSI-RS resources based on the configuration information; and a component for selectively sending a CSI report based on whether the CSI-RS is received.

[0039] Another innovative aspect of the subject matter described in the present disclosure can be implemented in a wireless communication method performed by a base station (BS). The method may include sending configuration information for a CSI-RS, wherein the configuration information indicates a plurality of CSI-RS resources; selectively sending a CSI-RS on a selected CSI-RS resource among the plurality of CSI-RS resources, wherein the selected CSI-RS resource is based on a channel access operation and the configuration information; and selectively receiving a CSI report based on the CSI-RS.

[0040] In some embodiments, the method may include transmitting information indicating that a selected CSI-RS resource of the CSI-RS is included in the transmission opportunity based on success of the channel access operation.

[0041] In some implementations, the method may include sending information indicating the selected CSI-RS resource.

[0042] In some implementations, multiple CSI-RS resources are associated with a tracking reference signal (TRS) burst, and the TRS burst is transmitted only when all CSI-RS resources in the multiple CSI-RS resources are included in a TXOP of the base station.

[0043] In some implementations, when the CSI-RS is not transmitted based on a failure of a channel access operation, a CSI report is not received.

[0044] In some implementations, when CSI-RS is not transmitted, the CSI report relates to CSI-RS transmitted before a plurality of CSI-RS resources.

[0045] In some implementations, when the CSI-RS is not transmitted, the CSI report indicates that the CSI-RS is not received by the user equipment.

[0046] In some implementations, a CSI report is received that includes information identifying at least one of: an indication of which CSI-RS resource is associated with the CSI report, an indication of a CSI period associated with the CSI report, or an indication of whether the CSI report is valid.

[0047] In some implementations, the method may include sending a grant for a shared channel that overlaps at least one CSI-RS resource of the plurality of CSI-RS resources, and rate matching the shared channel around the at least one CSI-RS resource.

[0048] In some implementations, at least one CSI-RS resource is used for zero-power CSI-RS.Rate matching the shared channel around at least one CSI-RS resource may also include rate matching the shared channel around one or more CSI-RS resources overlapping with the shared channel.

[0049] In some embodiments, at least one CSI-RS resource is used for zero-power CSI-RS. In some aspects, rate matching the shared channel around at least one CSI-RS resource may also include rate matching the shared channel around a first CSI-RS resource including around at least one CSI-RS resource in a transmit opportunity.

[0050] In some implementations, the grant includes an indication of whether to rate match the shared channel around at least one CSI-RS resource.

[0051] In some embodiments, the method may include sending a trigger for a retransmission of a CSI report, wherein the trigger identifies the CSI report, and wherein the CSI report is a periodic CSI report or a semi-persistent CSI report. The method may include receiving a retransmission of the CSI report based on the trigger.

[0052] In some embodiments, the trigger includes an indication that the trigger is an aperiodic retransmission trigger for CSI reporting.

[0053] In some embodiments, the trigger includes an indication of at least one of an index of a CSI report configuration or an index of a CSI-RS resource configuration for which retransmission of the CSI report is to be triggered.

[0054] In some embodiments, the trigger includes an indication of at least one of a slot index of a CSI report or a slot index of a CSI-RS resource of a plurality of CSI-RS resources in which the CSI-RS is received.

[0055] In some embodiments, the trigger includes an indication of at least one of: uplink resources for retransmission of the CSI report, coding information for retransmission of the CSI report, or a channel access type for retransmission of the CSI report.

[0056] In some embodiments, the trigger includes an indication of whether the CSI report for which retransmission is triggered is an aperiodic CSI report, a periodic CSI report, or a semi-persistent CSI report.

[0057] In some implementations, the trigger identification is the CSI report that triggers the retransmission.

[0058] In some implementations, a trigger is sent based on a maximum time limit between the trigger and a previous trigger of a CSI report.

[0059] Another innovative aspect of the subject matter described in the present disclosure may be implemented in a BS for wireless communication. The BS may include a memory and one or more processors operably coupled to the memory. The memory and the one or more processors may be configured to send configuration information indicating a plurality of CSI-RS resources for CSI-RS; selectively send CSI-RS on a selected CSI-RS resource among the plurality of CSI-RS resources, wherein the selected CSI-RS resource is based at least in part on a channel access operation; and selectively receive a CSI report based at least in part on whether the CSI-RS is received.

[0060] Another innovative aspect of the subject matter described in the present disclosure can be implemented in an apparatus for wireless communication. The apparatus may include a first interface configured to output configuration information for a CSI-RS, wherein the configuration information indicates a plurality of CSI-RS resources; and selectively output the CSI-RS on a selected CSI-RS resource among the plurality of CSI-RS resources, wherein the selected CSI-RS resource is based on a channel access operation and the configuration information. The apparatus may include a second interface configured to selectively obtain a CSI report based on whether the CSI-RS is received.

[0061] Another innovative aspect of the subject matter described in the present disclosure can be implemented in a non-transitory computer-readable medium. The non-transitory computer-readable medium can store one or more instructions for wireless communication. When executed by one or more processors of a BS, the one or more instructions can cause the one or more processors to send configuration information for a CSI-RS, wherein the configuration information indicates a plurality of CSI-RS resources; selectively send a CSI-RS on a selected CSI-RS resource among the plurality of CSI-RS resources, wherein the selected CSI-RS resource is based on a channel access operation and the configuration information, and selectively receive a CSI report based on the CSI-RS.

[0062] Another innovative aspect of the subject matter described in the present disclosure can be implemented in an apparatus for wireless communication. The apparatus may include a component for sending configuration information for a CSI-RS, wherein the configuration information indicates a plurality of CSI-RS resources; a component for selectively outputting a CSI-RS on a selected CSI-RS resource among the plurality of CSI-RS resources, wherein the selected CSI-RS resource is based on a channel access operation and the configuration information; and a component for selectively obtaining a CSI report based on whether the CSI-RS is received.

[0063] Aspects generally include methods, apparatuses, systems, computer program products, non-transitory computer-readable media, user equipment, base stations, wireless communication devices, or processing systems substantially as described with reference to and illustrated by the accompanying drawings.

[0064] The details of one or more embodiments of the subject matter described in this disclosure are set forth in the accompanying drawings and the following description. Other features, aspects, and advantages will become apparent from the description, drawings, and claims. Please note that the relative dimensions of the following figures may not be drawn to scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 is a block diagram conceptually illustrating an example of a wireless network.

[0066] Figure 2 is a block diagram conceptually illustrating an example of communication between a base station (BS) and a user equipment (UE) in a wireless network.

[0067] Figure 3 is a diagram illustrating an example of channel state information (CSI) reporting in an unlicensed spectrum.

[0068] Figure 4 is a diagram showing an example of triggering CSI report retransmission in unlicensed spectrum.

[0069] Figure 5is a diagram showing an example of triggering CSI report retransmission in unlicensed spectrum.

[0070] Figure 6 is a diagram showing an example of a Tracking Reference Signal (TRS) configuration using a CSI reference signal resource.

[0071] Figure 7 is a diagram showing an example of TRS transmission based on a transmission opportunity of a TRS transmitter.

[0072] Figure 8 is a diagram showing an example of a rate matching configuration of a zero-power CSI reference signal.

[0073] Fig. 9 is a diagram illustrating an example process performed, for example, by a UE.

[0074] Fig.10 is a diagram illustrating an example process performed, for example, by a BS.

[0075] Like reference numbers and designations in the various drawings indicate like elements. DETAILED DESCRIPTION

[0076] The following description is directed to certain embodiments for the purpose of describing the innovative aspects of the present disclosure. However, one of ordinary skill in the art will readily recognize that the teachings herein can be applied in a variety of different ways. Some examples in the present disclosure are based on wireless and wired local area network (LAN) communications in accordance with the Institute of Electrical and Electronics Engineers (IEEE) 802.11 wireless standard, the IEEE 802.3 Ethernet standard, and the IEEE 1901 Power Line Communication (PLC) standard. However, the described embodiments can be implemented in any device, system, or network capable of sending and receiving radio frequency signals in accordance with any wireless communication standard, including any IEEE 802.11 standard, 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 (W-CDMA), Evolution Data Optimized (EV-DO), 1xEV-DO, EV-DO Rev A, EV-DO Rev B, High Speed ​​Packet Access (HSPA), High Speed ​​Downlink Packet Access (HSDPA), High Speed ​​Uplink Packet Access (HSUPA), Evolved High Speed ​​Packet Access (HSPA+), Long Term Evolution (LTE), AMPS or other known signals for communication within a wireless, cellular or Internet of Things (IoT) network, such as systems utilizing 3G, 4G or 5G, or further implementations of their technologies.

[0077] Some radio access technologies, such as NR, may allow operation in unlicensed spectrum. NR RAT for unlicensed spectrum may be referred to as NR-Unlicensed (NR-U). Not all subbands in the unlicensed spectrum may be used at any time. For example, some subbands may be occupied by other UEs, base stations, or wireless nodes. A base station or UE may perform a channel access operation to determine whether one or more subbands are available for communication. In the channel access operation, the base station or UE may monitor a channel or subband for a period of time, and then if no other reservations for the channel or subband are received while monitoring, or if the interference on the channel or subband meets a threshold, an indication may be sent that the base station or UE has reserved the channel or subband for a time window. Therefore, coexistence between devices on non-centrally scheduled channels, such as sidelink channels on unlicensed spectrum, is allowed.

[0078] The base station may use channel state information (CSI) feedback to determine the channel conditions of the channel between the base station and the UE. For example, the base station may send a CSI-RS to one or more UEs having certain characteristics that are available to or determinable by the UE. Using the CSI-RS, the UE may determine appropriate CSI feedback, such as a CSI report, which may indicate the channel conditions between the base station and the UE. In some embodiments, the term "CSI report" may be used interchangeably with "CSI feedback". However, in the case of unlicensed spectrum, one or both of the CSI-RS transmission or the CSI report transmission may fail due to a failed channel access operation. For unpredictable unlicensed spectrum, a single CSI-RS or CSI feedback method may not be robust enough. In addition, certain operations, such as rate matching around certain types of CSI-RS, may be hindered by this uncertainty.

[0079] The techniques and devices described herein provide identification of CSI-RS resources of multiple CSI-RS resources in which CSI-RS has been sent. For example, the UE can use the various techniques described herein to identify the CSI-RS resources in which the CSI-RS is sent, or can determine whether the CSI-RS has been sent on the CSI-RS resources. If the CSI-RS is detected on the CSI-RS resource, the UE can determine a specific CSI feedback (which may include a CSI report). Some of the techniques and devices described herein provide signaling or techniques for when no CSI-RS is detected (for example, when the channel access operation of the base station to all available CSI-RS resources fails). Some of the techniques and devices described herein provide methods for rate matching around CSI-RS resources or CSI interference management (CSI-IM) resources. Some of the techniques and devices described herein provide CSI reporting methods for situations when the UE fails to send CSI feedback due to a failed channel access operation, such as a triggered or re-triggered CSI reporting method. In addition, some of the techniques and devices described herein provide tracking reference signal (TRS) configurations for shared spectrum scenarios.

[0080] Specific embodiments of the subject matter described in this disclosure may be implemented to achieve one or more of the following potential advantages. By providing more robust CSI-RS transmissions and CSI reporting, throughput and channel access performance in unlicensed spectrum can be improved, particularly in more densely populated unlicensed spectrum scenarios. Therefore, by configuring multiple opportunities over a period of time to mitigate channel access-related failures, communications between the BS and the UE can be made more robust when the medium is shared. In addition, in the case of opportunistic channel access in the unlicensed spectrum, efficient and robust utilization of the medium is possible. In addition, the techniques described herein can mitigate performance degradation caused by slow channel adaptation associated with channel access-related delays in channel state feedback. By providing a more robust tracking reference signal (TRS) in a shared spectrum scenario, communication and synchronization performance between the BS and the UE can be improved.

[0081] Figure 11 is a block diagram conceptually illustrating an example of a wireless network. The wireless network 100 may be an LTE network or some other wireless network, such as a 5G or NR network. The wireless network 100 may include a plurality of BSs 110 (shown as BSs 110a, BSs 110b, BSs 110c, and BSs 110d) and other network entities. A BS is an entity that communicates with a user equipment (UE) and may also be referred to as a base station, NR BS, Node B, gNB, 5G Node B (NB), access point, transmit receive point (TRP), etc. Each BS may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" may refer to a coverage area of ​​a BS, a BS subsystem serving the coverage area, or a combination thereof, depending on the context in which the term is used.

[0082] A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, another type of cell, or a combination thereof. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access to UEs with service subscriptions. A pico cell may cover a relatively small geographic area and may allow unrestricted access to UEs with service subscriptions. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access to UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG)). A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In Figure 1 In the example shown, BS 110a may be a macro BS for macro cell 102a, BS 110b may be a pico BS for pico cell 102b, and BS 110c may be a femto BS for femto cell 102c. A BS may support one or more (e.g., three) cells. The terms "eNB", "base station", "NR BS", "gNB", "TRP", "AP", "nodeB", "5G NB", and "cell" may be used interchangeably herein.

[0083] In some examples, the cells may not necessarily be fixed, and the geographic area of ​​the cells may move according to the location of the mobile BS. In some examples, the BSs may be interconnected to each other and to one or more other BSs or network nodes (not shown) in the wireless network 100 via various types of backhaul interfaces, such as direct physical connections using any suitable transport network, virtual networks, or combinations thereof.

[0084] The wireless network 100 may also include a relay station. A relay station is an entity that can receive data transmissions from an upstream station (e.g., a BS or a UE) and send data transmissions to a downstream station (e.g., a UE or a BS). A relay station may also be a UE that can relay transmissions for other UEs. Figure 1 In the example shown, a relay station 110d may communicate with the macro BS 110a and the UE 120d to facilitate communication between the BS 110a and the UE 120d. A relay station may also be referred to as a relay BS, a relay base station, a relay, or the like.

[0085] The wireless network 100 may be a heterogeneous network including different types of BSs, such as macro base stations, pico base stations, femto base stations, relay BSs, etc. These different types of BSs may have different transmit power levels, different coverage areas, and different effects on interference in the wireless network 100. For example, a macro BS may have a higher transmit power level (e.g., 5 to 40 watts), while a pico BS, a femto BS, and a relay BS may have a lower transmit power level (e.g., 0.1 to 2 watts).

[0086] A network controller 130 may be coupled to a set of BSs and may provide coordination and control for these BSs. The network controller 130 may communicate with the BSs via a backhaul. The BSs may also communicate with each other directly or indirectly, for example, via a wireless or wired backhaul.

[0087] UE 120 (e.g., 120a, 120b, 120c) may be dispersed throughout the wireless network 100, and each UE may be fixed or mobile. UE may also be referred to as an access terminal, terminal, mobile station, subscriber unit, station, etc., and UE may be a cellular phone (e.g., 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, a medical device or equipment, a biometric sensor / device, a wearable device (smart watch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart bracelet)), an entertainment device (e.g., a music or video device, or a satellite radio), a vehicle component or sensor, a smart meter / sensor, industrial manufacturing equipment, a global positioning system device, or any other suitable device configured to communicate via a wireless or wired medium.

[0088] Some UEs may be considered machine type communication (MTC) or evolved or enhanced machine type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., which may communicate with a base station, another device (e.g., a remote device), or some other entity. A wireless node may provide, for example, a connection for or to a network (e.g., a wide area network such as the Internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered Internet of Things (IoT) devices, or may be implemented as NB-IoT (narrowband Internet of Things) devices. Some UEs may be considered customer premises equipment (CPE). UE 120 may be included in a housing that houses components of UE 120 (e.g., a processor component, a memory component, a similar component, or a combination thereof).

[0089] Generally, any number of wireless networks can be deployed in a given geographic area. Each wireless network can support a specific RAT and can operate on one or more frequencies. RAT can also be referred to as radio technology, air interface, etc. Frequency can also be referred to as carrier, frequency channel, etc. Each frequency can support a single RAT in a given geographic area to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks can be deployed.

[0090] In some examples, access to the air interface may be scheduled, wherein a scheduling entity (e.g., a base station) allocates resources for communications between some or all devices and equipment within a service area or cell of the scheduling entity. In the present disclosure, as discussed further below, a scheduling entity may be responsible for scheduling, allocating, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communications, the subordinate entities utilize resources allocated by the scheduling entity.

[0091] The base station is not the only entity that can function as a scheduling entity. That is, in some examples, the UE can function as a scheduling entity, scheduling resources for one or more subordinate entities (e.g., one or more other UEs). In this example, the UE acts as a scheduling entity, and other UEs wirelessly communicate using resources scheduled by the UE. The UE can act as a scheduling entity in a peer-to-peer (P2P) network, a mesh network, or another type of network. In the mesh network example, the UEs can optionally communicate directly with each other in addition to communicating with the scheduling entity.

[0092] Thus, in a wireless communication network having scheduled access to time-frequency resources and having a cellular configuration, a P2P configuration, and a mesh configuration, a scheduling entity and one or more slave entities may communicate using the scheduled resources.

[0093] In some aspects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly (e.g., without using base station 110 as an intermediary to communicate with each other) using one or more bypass channels. For example, UE 120 may communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) protocol (which may include vehicle-to-vehicle (V2V) protocol, vehicle-to-infrastructure (V2I) protocol, or similar protocol), mesh network, or similar network, or a combination thereof. In this case, UE 120 may perform scheduling operations, resource selection operations, and other operations performed by base station 110 as described elsewhere herein.

[0094] Figure 2 2 is a block diagram conceptually illustrating an example 200 of a base station (BS) 110 communicating with a user equipment (UE) 120. In some aspects, the base station 110 and the UE 120 may be Figure 1 One of the base stations and one of the UEs in the wireless network 100. The base station 110 may be equipped with T antennas 234a through 234T, and the UE 120 may be equipped with R antennas 252a through 252R, where in general T≥1 and R≥1.

[0095] At the base station 110, the transmit processor 220 may receive data for one or more UEs from the data source 212, select one or more modulation and coding schemes (MCS) for each UE based on the channel quality indicator received from the UE, process (e.g., encode and modulate) the data for each UE based on the MCS selected for the UE, and provide data symbols for all UEs. The transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI), etc.) and control information (e.g., CQI request, grant, upper layer signaling, etc.), and provide overhead symbols and control symbols. The transmit processor 220 may also generate reference symbols for reference signals (e.g., cell-specific reference signals (CRS)) and synchronization signals (e.g., primary synchronization signals (PSS) and secondary synchronization signals (SSS)). The transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, overhead symbols, or reference symbols (if applicable), and may provide T output symbol streams to T modulators 232a to 232t. Each modulator 232 can process a corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 can further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. T downlink signals from modulators 232a to 232T can be transmitted via T antennas 234a to 234T, respectively. According to various aspects described in more detail below, position coding can be used to generate synchronization signals to convey additional information.

[0096] At the UE 120, antennas 252a to 252r may receive downlink signals from the base station 110 or other base stations, and may provide received signals to demodulators (DEMODs) 254a to 254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) the received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. The MIMO detector 256 may obtain received symbols from all R demodulators 254a to 254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. The receive processor 258 may process (e.g., demodulate and decode) the detected symbols, provide decoded data for the UE 120 to the data sink 260, and provide decoded control information and system information to the controller or processor (controller / processor) 280. The channel processor may determine reference signal received power (RSRP), received signal strength indicator (RSSI), reference signal received quality (RSRQ), channel quality indicator (CQI), etc. In some aspects, one or more components of UE 120 may be included in a housing.

[0097] On the uplink, at the UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information from a controller / processor 280 (e.g., for reports including RSRP, RSSI, RSRQ, CQI, etc.). The transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from the transmit processor 264 may be pre-coded and decoded by a TX MIMO processor 266, if applicable, further processed by modulators 254a through 254r (e.g., for DFT-s-OFDM, CP-OFDM, etc.), and transmitted to the base station 110. At the base station 110, uplink signals from the UE 120 and other UEs may be received by the antenna 234, processed by the demodulator 232, detected by the MIMO detector 236, if applicable, and further processed by the receive processor 238 to obtain decoded data and control information transmitted by the UE 120. The receive processor 238 may provide decoded data to a data sink 239 and provide decoded control information to a controller or processor (i.e., controller / processor) 240. The base station 110 may include a communication unit 244 and communicate with the network controller 130 via the communication unit 244. The network controller 130 may include a communication unit 294, a controller or processor (i.e., controller / processor) 290, and a memory 292.

[0098] In some embodiments, the controller / processor 280 may be a component of a processing system. A processing system generally refers to a system or series of machines or components that receives input and processes the input to produce a set of outputs that may be delivered to other systems or components, such as the UE 120. For example, the processing system of the UE 120 may refer to a system that includes various other components or subcomponents of the UE 120.

[0099] The processing system of UE 120 may interface with other components of UE 120, and may process information (e.g., input or signal) received from other components, output information to other components, etc. For example, a chip or modem of UE 120 may include a processing system, a first interface configured to receive or obtain information, and a second interface configured to output, send, or provide information. In some cases, the first interface may refer to an interface between a processing system of a chip or modem and a receiver, so that UE 120 may receive information or signal input, and the information may be passed to the processing system. In some cases, the second interface may refer to an interface between a processing system of a chip or modem and a transmitter, so that UE 120 may send information output from the chip or modem. One of ordinary skill in the art will readily recognize that the second interface may also obtain or receive information or signal input, and the first interface may also output, send, or provide information.

[0100] In some embodiments, controller / processor 240 may be a component of a processing system. A processing system generally refers to a system or series of machines or components that receives inputs and processes the inputs to produce a set of outputs that may be passed to other systems or components, such as BS 110. For example, a processing system of BS 110 may refer to a system that includes various other components or subcomponents of BS 110.

[0101] The processing system of BS110 may interface with other components of BS110, and may process information (e.g., input or signal) received from other components, output information to other components, etc. For example, a chip or modem of BS110 may include a processing system, a first interface configured to receive or obtain information, and a second interface configured to output, send or provide information. In some cases, the first interface may refer to an interface between the processing system of the chip or modem and a receiver, so that BS110 may receive information or signal input, and the information may be passed to the processing system. In some cases, the second interface may refer to an interface between the processing system of the chip or modem and a transmitter, so that BS110 may send information output from the chip or modem. Those of ordinary skill in the art will readily recognize that the second interface may also obtain or receive information or signal input, and the first interface may also output, send or provide information.

[0102] The controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, or Figure 2 Any other component of the controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, or the like may perform one or more techniques associated with CSI feedback in unlicensed spectrum, as described in more detail elsewhere herein. Figure 2 Any other component (or combination of components) may perform or direct, for example Fig. 9 The process of 900 Fig.10 The operations of process 1000 or other processes as described herein. Memories 242 and 282 may store data and program codes for base station 110 and UE 120, respectively. Scheduler 246 may schedule UEs for data transmission on the downlink, uplink, or a combination thereof.

[0103] When executed by the controller / processor 280 or other processors and modules at the UE 120, the stored program code may cause the UE 120 to perform operations related to Fig. 9 The stored program code, when executed by the controller / processor 240 or other processors and modules at the base station 110, may cause the base station 110 to perform operations related to Fig.10The operations described by process 1000 or other processes as described herein. The scheduler 246 may schedule UEs for data transmission on the downlink, uplink, or a combination thereof.

[0104] The UE 120 may include components for performing one or more operations described herein, such as Fig. 9 900 or other processes described herein. In some aspects, such components may include combining Figure 2 One or more components of the UE 120 described herein. The base station 110 may include components for performing one or more operations described herein, such as Fig.10 1000 or other processes described herein. In some aspects, such components may include combining Figure 2 One or more components of base station 110 are described.

[0105] Although Figure 2 The blocks in the 200 and 210 are shown as distinct components, but the functionality described above with respect to these blocks may be implemented in a single hardware, software, or combined component or in various combinations of components. For example, the functionality described with respect to the transmit processor 264, the receive processor 258, the TX MIMO processor 266, or another processor may be performed by or under the control of the controller / processor 280.

[0106] Figure 3 3 is a diagram illustrating an example of channel state information (CSI) reporting in an unlicensed spectrum. As shown, example 300 includes UE 120 and BS 110.

[0107] As indicated by reference numeral 310, BS 110 may send configuration information for the CSI-RS to UE 120. The configuration information for the CSI-RS may identify a plurality of CSI-RS resources on which the CSI-RS may be transmitted, a CSI-RS periodicity, one or more time slot offsets for resource allocation of the plurality of CSI-RS resources, whether the CSI-RS is periodic, aperiodic, or semi-persistent, or other information. In some aspects, the configuration information may identify CSI reporting information, such as a periodicity for CSI reporting, a time slot offset for CSI reporting, an uplink frequency resource for CSI reporting, whether the CSI reporting is periodic, aperiodic, or semi-persistent, or other information.

[0108] As shown in reference numeral 320, BS110 may perform a channel access operation to identify a transmission opportunity for CSI-RS. "Transmission opportunity" is sometimes abbreviated as "TXOP" in the accompanying drawings. BS110 may perform a channel access operation to identify which CSI-RS resource among multiple configured CSI-RS resources can be used for the transmission of CSI-RS. If the channel access operation is successful, BS110 may send CSI-RS on the first available CSI-RS resource in the transmission opportunity identified by the channel access operation, and may cancel subsequent CSI-RS resources. If the channel access operation is unsuccessful, BS110 may perform subsequent channel access operations to identify another configured CSI-RS resource on which CSI-RS can be sent. In some cases, no CSI-RS resources are available (or, in other words, all channel access operations performed by BS110 may fail). In this case, BS110 may not send CSI-RS in the CSI-RS period.

[0109] BS110 may configure multiple CSI-RS resources, and the slot offsets of the multiple CSI-RS resources may be based on the CSI-RS periodicity of the CSI-RS. For example, a longer period may be associated with more CSI-RS resources (indicating a larger number of slot offsets, where each CSI-RS resource is associated with a corresponding slot offset). In some aspects, each CSI-RS resource may be associated with a corresponding CSI report configuration, such as a corresponding physical uplink control channel. For example, a CSI resource configuration radio resource control value may identify multiple slot offsets associated with a corresponding CSI-RS resource for each CSI-RS period. In some cases, the number of slot offsets in a period may depend on the period. For example, a longer period may be associated with a larger number of slot offsets. In some aspects, multiple P / SP CSI-RS resource sets may be provided in the CSI-RS resource configuration. In such an embodiment, the resources for which the first channel access is successful may be used within a period, and other P / SP CSI-RS resource sets in multiple P / SP CSI-RS resource sets may be ignored. The first transmitted CSI-RS may be within or outside the channel occupancy time (COT) of BS 110 .

[0110] As indicated by reference numeral 330, BS 110 may transmit CSI-RS on a first available CSI-RS resource among the plurality of CSI-RS resources identified by the configuration information (indicated by reference numeral 340). For example, once a channel access operation is successful (e.g., on a first CSI-RS resource associated with a successful channel access result), BS 110 may transmit CSI-RS.

[0111] As indicated by reference numeral 350, the UE 120 may determine whether a CSI-RS is received or may determine which CSI-RS resource among a plurality of configured CSI-RS resources is used for the CSI-RS.

[0112] In some aspects, the UE 120 may identify a periodic CSI-RS (P-CSI-RS) by measuring multiple P-CSI-RS resources in a CSI-RS period and selecting a resource with the best measurement value (e.g., best signal-to-noise ratio (SNR), best reference signal received power, best reference signal received quality, or similar measurement). In some aspects, the UE 120 may select a first P-CSI-RS resource with a measurement value that satisfies a threshold (e.g., a measured SNR ratio greater than a threshold). In some aspects, if no CSI-RS satisfies the threshold, the UE 120 may determine that no valid CSI-RS is received. In addition, if a valid CSI-RS is detected in a given CSI-RS resource, the UE 120 may report a slot offset or index of the given CSI-RS resource. In this case, if the BS 110 determines that the CSI-RS resource used by the UE 120 is invalid (or, in other words, the CSI-RS is not transmitted on the CSI-RS resource), the BS 110 may ignore the CSI report.

[0113] In some aspects, the UE 120 may use information indicating a transmission opportunity of the CSI-RS (e.g., a channel occupancy time (COT) structure indicator (SI), a physical downlink control channel (PDCCH), a synchronization signal block (SSB), or a similar indication of a transmission opportunity) to identify the resource on which the CSI-RS is received. For example, the CSI-RS may be transmitted within the COT of the BS 110 (including SSB or demodulation reference DMRS signal transmission). The slot format indicator or COT-SI received by the UE 120 may be used to determine whether the CSI-RS resource is within the COT and in the downlink symbol of the COT. For example, if the CSI-RS resource is outside the COT, the BS 110 may not use the CSI-RS resource to transmit the CSI-RS, and therefore the UE 120 may determine that the CSI-RS is not received on the CSI-RS resource. If UE 120 does not detect a COT or a transmission opportunity, UE 120 may determine that CSI-RS is not transmitted on the CSI-RS resource, or may use a measurement threshold based method to determine whether CSI-RS is transmitted on the CSI-RS resource.

[0114] In some embodiments, BS 110 may trigger aperiodic CSI-RS transmission via downlink control information (DCI) within a COT. In such embodiments, aperiodic CSI-RS transmission may be triggered if the CSI-RS may be transmitted within the same COT. In some embodiments, UE 120 may determine that an aperiodic CSI-RS is received if the aperiodic CSI-RS falls within the same COT as the downlink control information (DCI) that triggered it, and additionally or alternatively, if it falls within a downlink symbol of the COT.

[0115] In some aspects, the UE 120 may receive a physical downlink control channel (PDCCH), such as a common PDCCH or a UE-specific PDCCH, that explicitly indicates the presence or absence of a CSI-RS. For example, the UE 120 may receive a downlink grant or COT-SI that includes an indication (such as a bit or a bitmap) indicating the presence or absence of a CSI-RS transmission.

[0116] In some aspects, BS 110 may provide an indication of which CSI-RS resource is used to transmit the CSI-RS. For example, BS 110 may provide an explicit indication, such as a common PDCCH or a downlink with a bitmap indicating one or more CSI-RS transmitted in a CSI-RS period. In some aspects, similar to the case of an aperiodic CSI report request (e.g., for a P / SP CSI-RS that has already been transmitted), BS 110 may transmit a bitmap indicating the CSI-RS.

[0117] In some aspects, the UE 120 may perform any combination of the techniques described herein to determine whether a CSI-RS is received. For example, the UE 120 may first determine whether an explicit indication of a CSI-RS resource is received, and if no explicit indication is received, the UE 120 may use a measurement-based approach to determine whether the CSI-RS is received. In some aspects, the UE 120 may perform radio link monitoring based on the CSI-RS. For example, the radio link monitoring measurements of the UE 120 may use valid CSI-RS opportunities identified using the techniques described above.

[0118] For example, the UE 120 may be configured with multiple CSI-RS resources in a time period corresponding to the radio link monitoring of the downlink beam. In some embodiments, the UE 120 may measure one or more CSI-RS resources in the multiple CSI-RS resources in the time period and select the CSI-RS resource with a specific signal strength value. For example, in some embodiments based on the receiver design, the specific signal strength value may be a maximum signal strength value, such as the highest signal strength value of one or more signal strength values ​​associated with one or more measured CSI-RS resources. In some embodiments, the UE 120 may use the signal strength of the selected CSI-RS resource for radio link monitoring and evaluation of the downlink beam. In such an embodiment, the UE 120 may use the signal strength of the selected CSI-RS resource to determine the out-of-sync or in-sync metric. In some other embodiments, the UE 120 may perform a measurement process of one or more CSI-RS resources in the multiple CSI-RS resources in the time period, and once it is determined that the CSI-RS resource has a signal strength value greater than a threshold, the measurement process may be stopped. In other words, the UE 120 may be implemented to not perform measurements of the remaining CSI-RS resources in the time period. In some implementations, the threshold may be based on a signal strength threshold for synchronization metric evaluation.

[0119] Once the CSI-RS resource is determined, the UE 120 may use the signal strength for radio link monitoring and evaluation of the downlink beam to determine the out-of-sync or in-sync metric. Alternatively, if the UE 120 cannot determine a CSI-RS resource with a signal strength greater than a threshold, the UE 120 may select the CSI-RS resource with the maximum signal strength value. In such a scenario, the UE 120 may use the signal strength of the selected CSI-RS resource for radio link monitoring and evaluation of the downlink beam to determine the out-of-sync or in-sync metric. In addition, the UE 120 may perform a similar process for performing radio link monitoring using a synchronization signal block (SSB) resource that occurs within a discovery reference signal measurement timing configuration (DMTC) and corresponds to a downlink beam.

[0120] In some aspects, the UE 120 may determine that no valid periodic or semi-persistent (P / SP) CSI-RS was detected in a previous CSI-RS cycle. This may occur when the channel access operation of the BS 110 is not successful, when the UE 120 does not detect a CSI-RS that meets a measurement threshold, and the like. In this case, in some aspects, the UE 120 may not send a CSI report. For example, if the CSI report is provided in a physical uplink control channel (PUCCH), the UE 120 may skip the PUCCH. If the CSI report is provided in a physical uplink shared channel (PUSCH), the UE 120 may not include CSI report information in the PUSCH. In some aspects, the UE 120 may send a CSI report on a CSI-RS measured in a previous CSI-RS cycle. In this case, the CSI report may indicate at least one of a CSI cycle for which the CSI report is being provided or a CSI-RS resource or a transmission opportunity associated with the CSI-RS within the CSI cycle. In some aspects, UE 120 may provide an indication in a CSI report that UE 120 did not receive a valid CSI-RS.

[0121] In some aspects, including optional implementations, UE 120 may rate match a shared channel around one or more CSI-RS resources, as indicated by reference numeral 360. For example, BS 110 may send a grant of a shared channel, such as a physical downlink shared channel (PDSCH), to UE 120. UE 120 and BS 110 may rate match the shared channel around one or more CSI-RS resources to prevent collisions between the CSI-RS resources and the shared channel and maintain throughput of the shared channel.

[0122] In some aspects, UE 120 may rate match around zero power (ZP) CSI-RS. ZP-CSI-RS may be used to force rate matching around non-ZP (NZP) CSI-RS resources available for CSI reporting. For example, BS 110 may configure multiple ZP-CSI-RS resources in a period so that the shared channel is rate matched around NZP-CSI-RS resources available for CSI reporting. Not all configured ZP-CSI-RS resources are valid for all UEs because multiple CSI-RS resources are configured for robustness against channel access failures. Various rate matching techniques for multiple ZP-CSI-RS resources are described in turn below.

[0123] In a first option (referred to herein as Option 1), UE 120 may rate match around all configured ZP-CSI-RS resources within a CSI-RS period, regardless of which CSI-RS resources are actually valid. This may save processing or signaling power that would otherwise be used to determine or signal which CSI-RS resources to rate match around.

[0124] In a second option (referred to herein as Option 2), UE 120 may rate match only around the first ZP-CSI-RS resource configured in a CSI-RS period that is in a valid transmit opportunity (e.g., when UE 120 detects a downlink burst of a CSI-RS period). As used herein, detecting a downlink burst may refer to detecting a grant that includes a CSI-RS period or detecting a COT-SI that identifies a CSI-RS period as a transmit opportunity. In this case, if UE 120 does not detect a downlink burst, UE 120 may rate match the shared channel around the next CSI-RS opportunity in the CSI-RS period.

[0125] In a third option (referred to herein as option 3), the grant for the shared channel may include an explicit indication of whether UE 120 is to perform rate matching around the ZP-CSI-RS resource. This may save resources that would otherwise be used by UE 120 to determine whether UE 120 is to perform rate matching, and may provide increased flexibility and higher throughput relative to an approach that performs rate matching on all ZP-CSI-RS resources or the first valid ZP-CSI-RS resource in a transmit opportunity.

[0126] As indicated by reference numeral 370, UE 120 may send a CSI report based on the CSI-RS received from the BS. The CSI report may include CSI determined using the CSI-RS or other information associated with the CSI.

[0127] In some aspects, similar to when multiple CSI-RS resources are configured, the CSI report may include an indication of which CSI-RS resource is used to determine the CSI report. In some aspects, the CSI report may include an indication of the CSI-RS period for receiving the CSI-RS used to determine the CSI report. For example, the first value may indicate the current period, the second value may indicate the previous period (e.g., when no CSI-RS is detected in the current period), and so on. In some aspects, the CSI report may include an indication of whether the CSI-RS is detected or whether the CSI report is valid. For example, if no CSI-RS is detected, the CSI report may be invalid.

[0128] In some aspects, UE 120 may be configured with multiple CSI report transmission opportunities. For example, each of multiple CSI-RS resources may be associated with one or more CSI report transmission opportunities. As another example, each CSI-RS resource (on the downlink) may be associated with one or more PUCCH opportunities (on the uplink). In each direction (uplink and downlink), BS 110 and UE 120 may use the first resource or opportunity associated with a successful channel access operation. If UE 120 misses a PUCCH opportunity, UE 120 may use the next PUCCH opportunity. UE 120 may indicate in the CSI report which CSI-RS is associated with the CSI report. In some aspects, the configuration information for the CSI report may indicate one or more offsets of the CSI report relative to the CSI-RS resource.

[0129] Figure 4 4 is a diagram illustrating an example of triggering CSI report retransmission in an unlicensed spectrum. As shown, example 400 includes UE 120 and BS 110.

[0130] As shown at 410, BS 110 may send CSI-RS to UE 120, which will be combined with Figure 3 Detailed description. As shown in reference numeral 420, UE 120 may fail to identify a transmission opportunity for a CSI report about a CSI-RS. For example, UE 120 may fail a channel access operation associated with multiple CSI reporting opportunities. In some aspects, UE 120 may fail a channel access operation for all CSI reporting opportunities for UE 120. Therefore, UE 120 may not send a CSI report. In some aspects, UE 120 may send a CSI report, and BS 110 may not receive the CSI report (e.g., due to interference, higher priority traffic preempting the CSI report, or another reason).

[0131] As shown by reference numeral 430, BS 110 may provide a trigger to UE 120 to trigger UE 120 to resend the CSI report. For example, BS 110 may provide the trigger based on determining that the CSI-RS is not received. Some possible implementations of the trigger are shown by reference numerals 440 and 450.

[0132] As indicated by reference numeral 440, in some aspects, the trigger may relate to periodic or semi-persistent (P / SP) CSI reporting. For example, the trigger may be an aperiodic trigger for P / SP CSI reporting. In this case, the UE 120 may continue to send P / SP CSI reports without receiving the trigger and may send triggered CSI reports related to the trigger. In certain aspects, the trigger may include an indication that the trigger is an aperiodic re-trigger for an unreceived CSI report, an indication of a P / SP CSI reporting configuration index or a CSI-RS resource configuration index that triggers the CSI report, an indication of a time slot index for the P / SP CSI report or a time slot index for the CSI-RS resource, an indication of whether the P / SP CSI-RS resource or P / SP CSI reporting opportunity occurs in a current period or a previous period, or an index of a period in which the P / SP CSI-RS resource or P / SP CSI reporting opportunity occurs. In some aspects, the trigger may be associated with a most recent past CSI reporting opportunity or a most recent past CSI reporting opportunity in a current CSI-RS cycle.

[0133] In some aspects, the trigger may include an indication of uplink resources for sending the CSI report (e.g., a time slot offset, a frequency / time resource, or an indication of whether to use PUCCH or PUSCH). In some aspects, the trigger may include an indication of coding information, such as a PUSCH modulation and coding scheme, a PUCCH format, or the like. In some aspects, the trigger may include an indication of a channel access type for CSI report transmission (e.g., Category 2 or Category 4). In some aspects, if the UE 120 does not detect a CSI-RS in the time slot indicated by the trigger, the UE 120 may provide an indication that the UE 120 did not detect a CSI-RS, may provide a CSI report from a previous time period, or may not provide a CSI report.

[0134] As shown in reference numeral 450, in some aspects, the trigger may be an aperiodic second trigger (sometimes referred to as a re-trigger) for retransmitting an aperiodic CSI report. This may be used in the event that the BS 110 does not receive a previously triggered CSI report (e.g., due to a channel access failure of the UE 120). In some aspects, the trigger may include an indication that the trigger is a second trigger (e.g., the trigger is a second trigger for a previous AP-CSI-RS). In this case, the CSI-RS associated with the second trigger may not be transmitted at the same time slot offset as the previous AP-CSI-RS in the future. In some aspects, the trigger may include an indication of whether the CSI report for which retransmission is triggered is an aperiodic CSI report, a periodic CSI report, or a semi-persistent CSI report. In some aspects, the trigger may include an indication of an aperiodic CSI report configuration or an aperiodic CSI-RS resource configuration that triggered the CSI report. In some aspects, the trigger may include an indication of a time slot index of the CSI report that triggered the retransmission, or an indication of a time slot index of the CSI-RS to which the CSI report relates. In some aspects, the trigger may implicitly correspond to the most recent AP CSI reporting trigger sent. In some aspects, the trigger may indicate a channel access type for retransmission.

[0135] In some aspects, BS 110 may send a trigger based on a time constraint. For example, the time constraint may identify a maximum time limit between an original AP CSI report trigger and the trigger, or identify a maximum time limit between an original CSI report (such as a P, SP, or AP CSI report) time slot that failed to transmit due to channel access and the trigger. If UE 120 receives a second trigger after the time constraint has passed, UE 120 may not perform a retransmission. This may reduce resource consumption at UE 120 that would otherwise occur if UE 120 stored CSI report information for an excessive amount of time.

[0136] As indicated by reference numeral 460, UE 120 may retransmit the CSI report based on the trigger. For example, in other examples, UE 120 may retransmit the CSI report using the resources indicated by the trigger or the next available transmission opportunity for the CSI report.

[0137] Figure 5 is a diagram showing an example of triggering CSI report retransmission in unlicensed spectrum. Figure 5 The top row in shows the operations performed by BS 110, Figure 5The bottom row in FIG. 1 shows operations performed by UE 120. As shown in reference numeral 510, BS 110 may send CSI-RS to UE 120. As shown in reference numeral 520, UE 120 may fail a channel access operation for CSI feedback associated with the CSI-RS and may not send CSI feedback. Therefore, as shown in reference numeral 530, BS 110 may use a combination of Figure 4 10. The UE 120 may trigger a retransmission of the CSI feedback based at least in part on a determination that the CSI feedback was not received at the time when the CSI feedback was expected to arrive at the BS 110, as shown by reference numeral 540. The UE 120 may transmit the CSI feedback on the PUCCH. In some cases, the trigger indicates a PUSCH shared channel resource (e.g., using an uplink grant) for channel state feedback (CSF) retransmission, and the UE 120 may retransmit the CSI feedback on the PUSCH associated with the shared channel resource based on receiving the trigger.

[0138] Figure 6 600 is a diagram showing an example of a tracking reference signal (TRS) configuration using CSI-RS resources. The TRS can be sent in a burst 610 having a length of X slots (here, X=2), where the length of a slot is shown by L. CSI-RS resource elements (which can be used to send TRS) are shown using black fill, and the slot boundaries of the slots are shown using diagonal fill. As shown, a burst can have a TRS period 620 of Y slots (Y is an integer). Figure 6 The illustrated TRS configuration may be configured as a CSI resource set with multiple CSI-RS resources. For example, example 600 includes 4 CSI-RS resources 630, 640, 650, 660 in a burst 610. As shown by reference numeral 670, a TRS burst may include CSI-RS resources 630, 640, 650, 660 configured in 4 symbols of two consecutive time slots.

[0139] Figure 7 705 and 710. The CSI-RS resources that can be used to transmit the TRS are generally shown by black fill.

[0140] In example 700, a TRS burst is transmitted only if all CSI-RS resources of the TRS burst are included in the transmit opportunity. In other words, if any CSI-RS resource of a 2-slot TRS burst is outside the transmit opportunity, for example due to channel access failure or maximum channel occupancy time (MCOT) regulation, the TRS burst will not be transmitted. If BS 110 triggers aperiodic TRS transmission, BS 110 may trigger the transmission such that all resources in the TRS burst fall within the transmit opportunity.

[0141] As shown by reference numeral 715, BS 110 performs a first channel access operation based on first time slot offset 720 and fails. Therefore, BS 110 performs a second channel access operation shown by reference numeral 725 and secures a transmit opportunity shown by reference numeral 730. As shown by reference numeral 735, BS 110 then transmits a TRS burst during the transmit opportunity and according to second time slot offset 740. In the second part of this example, a first channel access operation 745 associated with first time slot offset 750 succeeds, and BS 110 transmits a TRS burst 755 after first time slot offset 750.

[0142] Figure 8 800 is a diagram showing an example of a rate matching configuration for a zero power CSI reference signal. The P / SP CSI-RS resource configuration is shown by reference numeral 805. The first and second slot offsets of the ZP CSI-RS are shown by reference numerals 810 and 815. The configured CSI-RS resources for periodic ZP CSI-RS are shown by reference numerals 820 and 825. As shown in example 800, CSI-RS is transmitted on the configured CSI-RS resources shown by reference numeral 820, and CSI-RS is not transmitted on the configured CSI-RS resources shown by reference numeral 825. The configured CSI resources shown by the dashed fill are aligned with the BS / UE timeline shown by reference numerals 830 and 840.

[0143] Combination Figure 3 Option 1 described by reference numeral 360 in FIG. 1 is denoted by reference numeral 830. In option 1, UE 120 and BS 110 rate match around all ZP-CSI-RS resources, regardless of whether the ZP-CSI-RS resources carry CSI-RS. This is shown by reference numeral 835. As shown in option 1, UE 120 and BS 110 rate match around the configured CSI-RS resources shown by reference numerals 820 and 825, even if CSI-RS is not transmitted on the configured CSI-RS resources shown by reference numeral 825.

[0144] Combination Figure 3Option 2, described by reference numeral 360 in FIG. 1 , is denoted by reference numeral 840. In option 2, UE 120 and BS 110 perform rate matching only around the first ZP-CSI-RS resource in the transmission opportunity. The rate matching resources of option 2 are shown by reference numerals 845 and 850. Note that in option 2, UE 120 and BS 110 do not perform rate matching around resource 855 corresponding to CSI-RS resource 825 in the first CSI-RS period because no CSI-RS is transmitted on CSI-RS resource 825 in the first CSI-RS period. Figure 3 Option 3, described by reference numeral 360 , is not shown in example 800 .

[0145] Fig. 9 is a diagram illustrating an example process performed, for example, by a UE.Example process 900 illustrates where a UE, such as UE 120, performs operations associated with CSI reporting for unlicensed spectrum.

[0146] like Fig. 9 As shown, in some aspects, process 900 may include receiving configuration information for a channel state information reference signal (CSI-RS), wherein the configuration information indicates a plurality of CSI-RS resources (block 910). For example, a UE or an interface of a UE (e.g., using antenna 252, DEMOD 254, MIMO detector 256, receive processor 258, or controller / processor 280) may receive the configuration information for the CSI-RS. As described above, the configuration information may indicate a plurality of CSI-RS resources.

[0147] like Fig. 9 As further shown, in some aspects, process 900 may include determining whether to receive CSI-RS on multiple CSI-RS resources based on the configuration information (block 920). For example, the UE or an interface of the UE (e.g., using the controller / processor 280) may determine whether to receive CSI-RS on multiple CSI-RS resources based on the configuration information, as described above.

[0148] like Fig. 9 As further shown, in some aspects, process 900 may include selectively sending a CSI report based on whether a CSI-RS is received (block 930). For example, the UE or an interface of the UE (e.g., using controller / processor 280, transmit processor 264, TX MIMO processor 266, MOD 254, or antenna 252) may selectively send a CSI report based on whether a CSI-RS is received, as described above.

[0149] Process 900 may include additional aspects, such as any single aspect or any combination of aspects described below, or in conjunction with one or more other processes described elsewhere herein.

[0150] In the first aspect, determining whether the CSI-RS is received further comprises identifying a CSI-RS resource from among the plurality of CSI-RS resources at which the CSI-RS is received based on measurement of the plurality of CSI-RS resources.

[0151] In a second aspect, alone or in combination with the first aspect, determining whether a CSI-RS is received further comprises identifying a CSI-RS resource in which the CSI-RS is received among multiple CSI-RS resources based on the CSI-RS resource associated with a measurement value that satisfies a threshold.

[0152] In a third aspect, alone or in combination with one or more of the first and second aspects, the CSI-RS resource is an earliest CSI-RS resource among the plurality of CSI-RS resources associated with a measurement value satisfying a threshold.

[0153] In a fourth aspect, alone or in combination with one or more of the first to third aspects, it is determined whether a CSI-RS is received based on decoded information indicating that a CSI-RS resource among a plurality of CSI-RS resources is included in a TXOP.

[0154] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, a UE may determine whether a CSI-RS is received based on information indicating a CSI-RS resource.

[0155] In a sixth aspect, alone or in combination with one or more of the first to fifth aspects, multiple CSI-RS resources are associated with a tracking reference signal (TRS) burst, wherein the TRS burst is received when all CSI-RS resources among the multiple CSI-RS resources are included in a transmission opportunity of a base station that sends the TRS burst.

[0156] In a seventh aspect, alone or in combination with one or more of the first to sixth aspects, when a CSI-RS is not received, selectively sending a CSI report further comprises skipping the sending of the CSI report.

[0157] In an eighth aspect, alone or in combination with one or more of the first to seventh aspects, when no CSI-RS is received, the CSI report relates to CSI-RS received before a time associated with the plurality of CSI-RS resources.

[0158] In a ninth aspect, alone or in combination with one or more of the first to eighth aspects, when the CSI-RS is not received, the CSI report indicates that the CSI-RS is not received.

[0159] In the tenth aspect, alone or in combination with one or more of the first to ninth aspects, a CSI report is sent, comprising information identifying at least one of: an indication of which CSI-RS resource is associated with the CSI report, an indication of a CSI period associated with the CSI report, or an indication of whether the CSI report is valid.

[0160] In the eleventh aspect, alone or in combination with one or more of the first to tenth aspects, the UE may receive an authorization for a shared channel that overlaps with at least one CSI-RS resource among a plurality of CSI-RS resources, and rate match the shared channel around the at least one CSI-RS resource.

[0161] In the twelfth aspect, alone or in combination with one or more of the first to eleventh aspects, at least one CSI-RS resource is used for zero-power CSI-RS, and rate matching the shared channel around the at least one CSI-RS resource also includes rate matching the shared channel around one or more CSI-RS resources overlapping with the shared channel.

[0162] In the thirteenth aspect, alone or in combination with one or more of the first to twelfth aspects, at least one CSI-RS resource is used for zero-power CSI-RS, and rate matching a shared channel around at least one CSI-RS resource also includes rate matching a shared channel in a first CSI-RS resource including around at least one CSI-RS resource in a transmission opportunity.

[0163] In a fourteenth aspect, alone or in combination with one or more of the first to thirteenth aspects, the grant includes an indication of whether to rate match a shared channel around at least one CSI-RS resource.

[0164] In a fifteenth aspect, alone or in combination with one or more of the first to fourteenth aspects, the UE may receive a trigger for retransmitting a CSI report, wherein the trigger identifies the CSI report, and wherein the CSI report is a periodic CSI report or a semi-persistent CSI report. The UE may perform retransmission of the CSI report according to the trigger.

[0165] In a sixteenth aspect, alone or in combination with one or more of the first to fifteenth aspects, the trigger comprises an indication that the trigger is a non-periodic retransmission trigger for CSI reporting.

[0166] In the seventeenth aspect, alone or in combination with one or more of the first to sixteenth aspects, the trigger includes an indication of at least one of an index of a CSI report configuration or an index of a CSI-RS resource configuration, for which retransmission of the CSI report will be triggered.

[0167] In an eighteenth aspect, alone or in combination with one or more of the first to seventeenth aspects, the trigger comprises an indication of at least one of a time slot index of a CSI report or a time slot index of a CSI-RS resource in which a CSI-RS is received among a plurality of CSI-RS resources.

[0168] In the nineteenth aspect, alone or in combination with one or more of the first to eighteenth aspects, the trigger includes an indication of at least one of: uplink resources for retransmission of the CSI report, coding information for retransmission of the CSI report, or a channel access type for retransmission of the CSI report.

[0169] In a twentieth aspect, alone or in combination with one or more of the first to nineteenth aspects, the trigger includes an indication of whether the CSI report triggered for retransmission is an aperiodic CSI report, a periodic CSI report, or a semi-persistent CSI report.

[0170] In a twenty-first aspect, alone or in combination with one or more of the first to twentieth aspects, the trigger identification is a CSI report that triggers retransmission.

[0171] In a twenty-second aspect, alone or in combination with one or more of aspects one to twenty-one, performing retransmission of a CSI report based on a trigger further comprises performing retransmission based on a maximum time limit between the trigger and a previous trigger of the CSI report.

[0172] In the twenty-third aspect, alone or in combination with one or more of the first to twenty-second aspects, determining whether the CSI-RS is received also includes identifying a CSI-RS resource in which the CSI-RS is received among multiple CSI-RS resources based on a CSI-RS resource having a signal strength value that satisfies a threshold.

[0173] In a twenty-fourth aspect, alone or in combination with one or more of the first to twenty-third aspects, the signal strength value is a maximum signal strength value.

[0174] In a twenty-fourth aspect, alone or in combination with one or more of the first to twenty-third aspects, process 900 includes determining an out-of-sync or in-sync metric when a signal strength value satisfies a threshold.

[0175] although Fig. 9 Example blocks of process 900 are shown, but in some aspects process 900 may include Fig. 9 The blocks described in the process 900 may be more blocks, fewer blocks, different blocks, or blocks in a different arrangement. Additionally or alternatively, two or more blocks of process 900 may be executed in parallel.

[0176] Fig.10is a diagram illustrating an example process 1000, performed, for example, by a BS. Example process 1000 illustrates where a base station, such as base station 110, performs operations associated with CSI configuration and reporting for unlicensed spectrum.

[0177] like Fig.10 As shown, in some aspects, process 1000 may include sending configuration information for a channel state information reference signal (CSI-RS), where the configuration information indicates a plurality of CSI-RS resources (block 1010). For example, a base station or an interface of a base station (e.g., using controller / processor 240, transmit processor 220, TX MIMO processor 230, MOD 232, or antenna 234) may send configuration information for CSI-RS, as described above. The configuration information may indicate a plurality of CSI resources.

[0178] like Fig.10 As further shown in FIG. 1 , in some aspects, process 1000 may include selectively transmitting a CSI-RS on a selected CSI-RS resource among a plurality of CSI-RS resources, wherein the selected CSI-RS resource is based on a channel access operation and configuration information (block 1020). For example, as described above, a base station or an interface of a base station (e.g., using controller / processor 240, transmit processor 220, TX MIMO processor 230, MOD 232, or antenna 234) may selectively transmit a CSI-RS on a selected CSI-RS resource among a plurality of CSI-RS resources. In some aspects, the selected CSI-RS resource is based on the channel access operation and configuration information. For example, the selected CSI resource may be selected from a plurality of CSI resources identified by the configuration information.

[0179] like Fig.10 As further shown in FIG. 10 , in some aspects, process 1000 may include selectively receiving a CSI report based on the CSI-RS (block 1030). For example, as described above, a base station or an interface of a base station (e.g., using antenna 234, DEMOD 232, MIMO detector 236, receive processor 238, or controller / processor 240) may selectively receive a CSI report based on the CSI-RS. In some aspects, as described above, a base station may selectively receive a CSI report based on whether a UE receives the CSI-RS.

[0180] Process 1000 may include additional aspects, such as any single aspect or any combination of aspects described below, or in conjunction with one or more other processes described elsewhere herein.

[0181] In the first aspect, the base station may transmit information indicating that a selected CSI-RS resource of a CSI-RS is included in a transmission opportunity based on success of a channel access operation.

[0182] In a second aspect, alone or in combination with the first aspect, the base station may send information indicating the selected CSI-RS resource.

[0183] In a third aspect, alone or in combination with one or more of the first and second aspects, multiple CSI-RS resources are associated with a TRS burst, and the TRS burst is transmitted when all CSI-RS resources in the multiple CSI-RS resources are included in a transmission opportunity of the base station.

[0184] In a fourth aspect, alone or in combination with one or more of the first to third aspects, when a CSI-RS is not transmitted based on a failure of a channel access operation, a CSI report is not received.

[0185] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, when the CSI-RS is not transmitted, the CSI report relates to the CSI-RS transmitted before the plurality of CSI-RS resources.

[0186] In a sixth aspect, alone or in combination with one or more of the first to fifth aspects, when the CSI-RS is not transmitted, the CSI report indicates that the CSI-RS is not received by the user equipment.

[0187] In a seventh aspect, alone or in combination with one or more of the first to sixth aspects, a CSI report is received, comprising information identifying at least one of: an indication of which CSI-RS resource is associated with the CSI report, an indication of a CSI period associated with the CSI report, or an indication of whether the CSI report is valid.

[0188] In the eighth aspect, alone or in combination with one or more of the first to eleventh aspects, the base station may send an authorization for a shared channel that overlaps with at least one CSI-RS resource among multiple CSI-RS resources, and rate match the shared channel around at least one CSI-RS resource.

[0189] In the ninth aspect, alone or in combination with one or more of the first to eighth aspects, at least one CSI-RS resource is used for zero-power CSI-RS. Rate matching the shared channel around at least one CSI-RS resource may also include rate matching the shared channel around one or more CSI-RS resources overlapping with the shared channel.

[0190] In the tenth aspect, alone or in combination with one or more of the first to ninth aspects, at least one CSI-RS resource is used for zero-power CSI-RS. In some aspects, rate matching a shared channel around at least one CSI-RS resource may also include rate matching a shared channel around a first CSI-RS resource of at least one CSI-RS resource included in a TXOP.

[0191] In an eleventh aspect, alone or in combination with one or more of the first to tenth aspects, the grant includes an indication of whether to rate match a shared channel around at least one CSI-RS resource.

[0192] In a twelfth aspect, alone or in combination with one or more of the first to eleventh aspects, a base station may send a trigger for retransmitting a CSI report, wherein the trigger identifies the CSI report, and wherein the CSI report is a periodic CSI report or a semi-persistent CSI report. The base station may receive a retransmission of the CSI report based on the trigger.

[0193] In a thirteenth aspect, alone or in combination with one or more of the first to twelfth aspects, the trigger comprises an indication that the trigger is an aperiodic retransmission trigger for CSI reporting.

[0194] In the fourteenth aspect, alone or in combination with one or more of the first to thirteenth aspects, the trigger includes an indication of at least one of an index of a CSI report configuration or an index of a CSI-RS resource configuration, for which retransmission of the CSI report will be triggered.

[0195] In a fifteenth aspect, alone or in combination with one or more of the first to fourteenth aspects, the trigger comprises an indication of at least one of a time slot index of a CSI report or a time slot index of a CSI-RS resource in which a CSI-RS is received among a plurality of CSI-RS resources.

[0196] In the sixteenth aspect, alone or in combination with one or more of the first to fifteenth aspects, the trigger includes an indication of at least one of: uplink resources for retransmission of the CSI report, coding information for retransmission of the CSI report, or a channel access type for retransmission of the CSI report.

[0197] In a seventeenth aspect, alone or in combination with one or more of the first to sixteenth aspects, the trigger includes an indication of whether the CSI report triggered for retransmission is an aperiodic CSI report, a periodic CSI report, or a semi-persistent CSI report.

[0198] In an eighteenth aspect, alone or in combination with one or more of the first to seventeenth aspects, the trigger identification is a CSI report for which retransmission is triggered.

[0199] In a nineteenth aspect, alone or in combination with one or more of the first to eighteenth aspects, a trigger is sent based on a maximum time limit between the trigger and a previous trigger for CSI reporting.

[0200] although Fig.10 Example blocks of process 1000 are shown, but in some aspects process 1000 may include more Fig.10 The blocks depicted in the process 1000 may be more blocks, fewer blocks, different blocks, or blocks in a different arrangement. Additionally or alternatively, two or more blocks of the process 1000 may be executed in parallel.

[0201] The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations are possible in light of the above disclosure or may be acquired from practice of these aspects.

[0202] As used herein, the term "component" is intended to be broadly interpreted as hardware, firmware, or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, or a combination of hardware and software. As used herein, the phrase "based on" is intended to be broadly interpreted as meaning "based at least in part on."

[0203] Some aspects are described herein in conjunction with thresholds. As used herein, satisfying a threshold may refer to a value greater than a threshold, greater than or equal to a threshold, less than a threshold, less than or equal to a threshold, equal to a threshold, not equal to a threshold, etc.

[0204] As used herein, a phrase referring to "at least one" of a list of items refers to any combination of those items, including single members. For example, "at least one of a, b, or c" is intended to cover: a, b, c, ab, ac, bc, and abc.

[0205] The various illustrative logics, logic blocks, modules, circuits, and algorithmic processes described in conjunction with the aspects disclosed herein may be implemented as electronic hardware, computer software, or a combination of both. The interchangeability of hardware and software has been generally described in terms of functionality and illustrated in the various illustrative components, blocks, modules, circuits, and processes described above. Whether such functionality is implemented in hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0206] The hardware and data processing apparatus for implementing the various illustrative logics, logic blocks, modules, and circuits described in conjunction with the aspects disclosed herein may be implemented or executed with a general purpose single-chip 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 may be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, for example, a DSP and a microprocessor, a plurality of microprocessors, a combination of one or more microprocessors combined with a DSP core, or any other such configuration. In some aspects, specific processes and methods may be performed by circuits specific to a given function.

[0207] In one or more aspects, the functions described may be implemented in hardware, digital electronic circuitry, computer software, firmware (including the structures disclosed in this specification and their equivalents), or any combination thereof. Aspects of the subject matter described in this specification may also be implemented as one or more computer programs, i.e., one or more modules of computer program instructions, encoded on a computer storage medium for execution by a data processing apparatus or for controlling the operation of the data processing apparatus.

[0208] If implemented in software, these functions can be stored as one or more instructions or codes on a computer-readable medium or transmitted on a computer-readable medium. The process of the method or algorithm disclosed herein can be implemented in a processor executable software module that can reside on a computer-readable medium. Computer-readable media include computer storage media and communication media, and communication media include any medium that can transfer a computer program from one place to another. The storage medium can be any available medium that a computer can access. As an example and not a limitation, such a computer-readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, disk storage or other magnetic storage device, or any other medium that can be used to store the required program code in the form of an instruction or data structure and can be accessed by a computer. In addition, any connection can be properly referred to as a computer-readable medium. Disks and optical disks as used herein include compact disks (CDs), laser disks, optical disks, digital versatile disks (DVDs), floppy disks and blue-ray disks, wherein disks are generally used to reproduce data magnetically, and optical disks are used to reproduce data optically with lasers. The above combination should also be included in the scope of computer-readable media. Additionally, the operations of a method or algorithm may reside as one or any combination or set of codes and instructions on a machine-readable medium and a computer-readable medium, which may be incorporated into a computer program product.

[0209] Various modifications to the aspects described in this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the spirit or scope of this disclosure. Therefore, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the broadest scope consistent with this disclosure, the principles, and the novel features disclosed herein.

[0210] In addition, one of ordinary skill in the art will readily appreciate that the terms "upper" and "lower" are sometimes used to facilitate description of the drawings and indicate relative positions corresponding to the orientation of the drawings on a correctly oriented page and may not reflect the correct orientation of any device implemented.

[0211] Certain features described in this specification in the context of separate aspects may also be implemented in combination in a single aspect. Conversely, various features described in the context of a single aspect may also be implemented in multiple aspects individually or in any suitable subcombination. Furthermore, while the features described above may be described as functioning in certain combinations, or even initially claimed as such, in some cases one or more features from a claimed combination may be deleted from that combination, and a claimed combination may be directed to a subcombination or a variation of a subcombination.

[0212] Similarly, although operations are depicted in a particular order in the accompanying drawings, this should not be understood as requiring such operations to be performed in the particular order or sequence shown, or performing all the operations shown to obtain the desired result. In addition, the accompanying drawings may schematically depict more than one example process in the form of a flow chart. However, other operations not described may be combined in the schematically illustrated example process. For example, one or more additional operations may be performed before, after, simultaneously, or between any of the illustrated operations. In some cases, multitasking and parallel processing may be advantageous. In addition, the separation of various system components in the above aspects should not be understood as requiring such separation in all aspects, 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. In addition, other aspects are within the scope of the following claims. In some cases, the actions described in the claims may be performed in different orders, and still obtain desirable results.

Claims

1. A method of wireless communication performed by a network entity, comprising: Sending configuration information for a channel state information reference signal CSI-RS, wherein the configuration information indicates a plurality of CSI-RS resources; selectively transmitting the CSI-RS on a selected CSI-RS resource among the plurality of CSI-RS resources, wherein the selected CSI-RS resource is based on a measurement-based method and the configuration information, wherein the measurement-based method includes measurement of one or more CSI-RS resources among the plurality of CSI-RS resources; as well as A CSI report is selectively received based on the CSI-RS.

2. The method according to claim 1, further comprising: Information indicating that the selected CSI-RS resource of the CSI-RS is included in a transmission opportunity is transmitted based on the success of the channel access operation.

3. The method according to claim 1, further comprising: Information indicating the selected CSI-RS resource is sent.

4. The method of claim 1 , wherein the plurality of CSI-RS resources are associated with a tracking reference signal (TRS) burst, and wherein the TRS burst is transmitted when all CSI-RS resources of the plurality of CSI-RS resources are included in a transmit opportunity (TXOP) of the network entity.

5. The method according to claim 1, wherein: When the CSI-RS is not transmitted based on the failure of the channel access operation, the CSI report is not received.

6. The method according to claim 1, wherein: When the CSI-RS is not transmitted, the CSI report relates to a CSI-RS transmitted before the plurality of CSI-RS resources.

7. The method according to claim 1, wherein: When the CSI-RS is not transmitted, the CSI report indicates that the CSI-RS is not received by the user equipment.

8. The method according to claim 1, wherein: Receiving a CSI report having information identifying at least one of: an indication of which CSI-RS resource is associated with the CSI report, an indication of the CSI periodicity associated with the CSI report, or An indication of whether the CSI report is valid.

9. The method according to claim 1, further comprising: sending a grant for a shared channel overlapping at least one CSI-RS resource of the plurality of CSI-RS resources; as well as The shared channel is rate matched around the at least one CSI-RS resource.

10. The method of claim 9, wherein the at least one CSI-RS resource is for a zero-power CSI-RS, and wherein rate matching the shared channel around the at least one CSI-RS resource further comprises: The shared channel is rate matched around one or more CSI-RS resources overlapping with the shared channel.

11. The method of claim 9, wherein the at least one CSI-RS resource is for a zero-power CSI-RS, and wherein rate matching the shared channel around the at least one CSI-RS resource further comprises: The shared channel is rate matched around a first CSI-RS resource of the at least one CSI-RS resource included in a transmission opportunity.

12. The method of claim 9, wherein the grant includes an indication of whether to rate match the shared channel around the at least one CSI-RS resource.

13. The method according to claim 1, further comprising: sending a trigger for retransmission of the CSI report, wherein the trigger identifies the CSI report, and wherein the CSI report is a periodic CSI report or a semi-persistent CSI report; as well as The retransmission of the CSI report is received based on the trigger.

14. The method of claim 13, wherein the trigger comprises an indication that the trigger is an aperiodic retransmission trigger for the CSI report.

15. The method of claim 13, wherein the trigger comprises an indication of at least one of an index of a CSI report configuration or an index of a CSI-RS resource configuration, for which the retransmission of the CSI report is to be triggered.

16. The method of claim 13, wherein the trigger comprises an indication of at least one of a time slot index of the CSI report or a time slot index of a CSI-RS resource in which the CSI-RS is received among the plurality of CSI-RS resources.

17. The method of claim 13, wherein the trigger comprises an indication of at least one of: uplink resources for retransmission of said CSI report, encoding information for retransmission of said CSI report, or The channel access type used for retransmission of the CSI report.

18. The method of claim 13, wherein the trigger comprises an indication of whether the CSI report that triggers the retransmission is an aperiodic CSI report, a periodic CSI report, or a semi-persistent CSI report.

19. The method of claim 18, wherein the trigger identifies the CSI report for which the retransmission is triggered.

20. The method of claim 13, wherein the trigger is sent based on a maximum time limit between the trigger and a previous trigger for the CSI report.

21. An apparatus for wireless communication, comprising: A first interface is configured to output configuration information for a channel state information reference signal CSI-RS, wherein the configuration information indicates a plurality of CSI-RS resources; as well as selectively outputting the CSI-RS on a selected CSI-RS resource among the plurality of CSI-RS resources, wherein the selected CSI-RS resource is based on a measurement-based method and the configuration information, wherein the measurement-based method includes measurement of one or more CSI-RS resources among the plurality of CSI-RS resources; as well as The second interface is configured to selectively obtain a CSI report based on whether the CSI-RS is received.

22. The apparatus of claim 21, wherein the first interface is configured to output information indicating that the selected CSI-RS resource of the CSI-RS is included in a transmission opportunity based on success of the channel access operation.

23. The apparatus of claim 21, wherein the first interface is configured to output information indicative of a selected CSI-RS resource.

24. The apparatus of claim 21, wherein the plurality of CSI-RS resources are associated with a Tracking Reference Signal (TRS) burst, and wherein the TRS burst is output when all CSI-RS resources of the plurality of CSI-RS resources are included in a transmit opportunity (TXOP) of the network entity.

25. The device according to claim 21, wherein Receiving a CSI report having information identifying at least one of: an indication of which CSI-RS resource is associated with the CSI report, an indication of the CSI periodicity associated with the CSI report, or An indication of whether the CSI report is valid.

26. The apparatus of claim 21, wherein the first interface is configured to: outputting a grant for a shared channel overlapping at least one CSI-RS resource of the plurality of CSI-RS resources; and The shared channel is rate matched around the at least one CSI-RS resource.

27. The apparatus of claim 26, wherein the at least one CSI-RS resource is for a zero-power CSI-RS, and wherein when rate matching the shared channel around the at least one CSI-RS resource, the first interface is further configured to: The shared channel is rate matched around one or more CSI-RS resources overlapping with the shared channel.

28. The apparatus of claim 26, wherein the at least one CSI-RS resource is for a zero-power CSI-RS, and wherein when rate matching the shared channel around the at least one CSI-RS resource, the first interface is further configured to: The shared channel is rate matched around a first CSI-RS resource of the at least one CSI-RS resource included in a transmission opportunity.

29. The apparatus of claim 26, wherein the grant comprises an indication of whether to rate match the shared channel around the at least one CSI-RS resource.

30. The apparatus of claim 21, wherein the first interface is further configured to: outputting a trigger for retransmission of the CSI report, wherein the trigger identifies the CSI report, and wherein the CSI report is a periodic CSI report or a semi-persistent CSI report; and in, The second interface is configured to obtain the retransmission of the CSI report based on the trigger.

31. The apparatus of claim 30, wherein the trigger comprises an indication that the trigger is an aperiodic retransmission trigger for the CSI report.

Images