Channel state information reference signals for wideband operation.

Abstract

To provide a method in user equipment (UE) for receiving a channel state information reference signal (CSI-RS) by means of wideband sub-bands and transmitting channel state information (CSI) feedback.SOLUTION: In a wideband CSI-RS configuration 400 for an aperiodic CSI-RS, UE 120 is configured for: receiving, from a BS 110, configuration information for a channel state information reference signal (CSI-RS), where the configuration information indicates that the CSI-RS is configured on a plurality of sub-bands of a wideband structure; selectively receiving the CSI-RS, on the basis of the configuration information and a sub-band valid indication associated with the plurality of sub-bands; and, if the CSI-RS is received, transmitting channel state information (CSI) feedback on the basis of the configuration information.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This patent application is expressly incorporated herein by reference. Indian Patent Application No. 201941028335 filed on July 15, 2019, entitled "STATE INFORMATION REFERENCE SIGNAL FOR WIDEBAND OPERATION" and "CHANNEL STATE INFORMATION REFERENCE SIGNAL FOR WIDEBAND This application claims priority to U.S. Nonprovisional Patent Application No. 16 / 946,901, filed July 10, 2020, entitled "A METHOD FOR IMPROVING PERFORMANCE OF A HIGH-FREQUENCY PERFORMANCE SYSTEM AND METHODS OF PERFORMING THE ...."

[0002]

[0002] Aspects of the present disclosure generally relate to wireless communications and to techniques for channel state information (CSI) reference signals (RS) for wideband operation in unlicensed spectrum. [Background technology]

[0003] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasting. Typical wireless communication systems may employ multiple access technologies capable of supporting 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 extensions to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the 3rd Generation Partnership Project (3GPP).

[0004] A wireless communication network may include several base stations (BSs) that can support communication for several user equipments (UEs). The user equipments (UEs) may communicate with the base stations (BSs) via a downlink (DL) and an uplink (UL). The DL (or forward link) refers to the communication link from the BS to the UE, and the UL (or reverse link) refers to the communication link from the UE to the BS. As described in more detail herein, a BS may be referred to as a Node B, an LTE evolved Node B (eNB), a gNB, an access point (AP), a radio head, a transmit receive point (TRP), a new radio (NR) BS, a 5G Node B, or as further examples.

[0005]

[0005] The above multiple access technologies have been adopted in various telecommunications standards to provide common protocols that enable different UEs to communicate on a city, national, regional, or even global scale. NR, sometimes referred to as 5G, is a set of extensions to the LTE mobile standard promulgated by the Third Generation Partnership Project (3GPP). NR is designed to improve spectral efficiency, lower costs, improve services, utilize new spectrum, and better support mobile broadband Internet access by using orthogonal frequency division multiplexing (OFDM) with cyclic prefix (CP) (CP-OFDM) on the DL and CP-OFDM or SC-FDM (e.g., also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on the UL (or a combination thereof), better integrating with other open standards, as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation. Summary of the Invention

[0006]

[0006] The systems, methods, and devices of the present disclosure each have several inventive aspects, no single aspect of which may be solely responsible for the desirable attributes disclosed herein.

[0007] One inventive aspect of the subject matter described in this disclosure may be implemented in a method of wireless communications performed by a user equipment (UE). The method may include receiving configuration information for a channel state information reference signal (CSI-RS), where the configuration information indicates that the CSI-RS is configured on a plurality of sub-bands of a wideband structure, selectively receiving the CSI-RS based on the configuration information and based on sub-band valid indications associated with the plurality of sub-bands, and transmitting channel state information (CSI) feedback based on the configuration information if the CSI-RS is received.

[0008]

[0008] In some implementations, the method may include receiving downlink control information indicating a subband availability indication.

[0009]

[0009] In some implementations, CSI-RS is received when all sub-bands of multiple sub-bands are available for CSI-RS, and CSI-RS is not received when at least one sub-band of the multiple sub-bands is not available for CSI-RS.

[0010]

[0010] In some implementations, the method may include rate matching a shared channel around a resource of the CSI-RS regardless of whether the CSI-RS is received.

[0011]

[0011] In some implementations, the method may include performing processing operations related to the CSI-RS for multiple subbands regardless of whether the CSI-RS is received.

[0012]

[0012] In some implementations, the method may include determining that the CSI-RS is to be received based on sub-band usage information received before a resource associated with the CSI-RS, and performing processing operations related to the CSI-RS for a plurality of sub-bands based on determining that the CSI-RS is to be received.

[0013] In some implementations, the CSI-RS is received on a subset of subbands of the plurality of subbands based on the subset of subbands available for the CSI-RS.

[0014] In some implementations, a sequence for CSI-RS for multiple subbands is punctured to generate CSI-RS for a subset of the subbands.

[0015]

[0015] In some implementations, the CSI-RS for a subset of subbands is generated based on a shortened sequence relative to a sequence for the CSI-RS for multiple subbands.

[0016]

[0016] In some implementations, the method may include receiving a trigger for CSI feedback based on all subbands of a plurality of subbands available for CSI-RS.

[0017]

[0017] In some implementations, when the CSI-RS is received on a subset of subbands among multiple subbands, the CSI-RS is received on a resource element on the subset of subbands that corresponds to the widest bandwidth of the wideband structure.

[0018] In some implementations, the CSI-RS is generated based on the same sequence for the widest bandwidth and for a subset of the subbands.

[0019] In some implementations, the CSI-RS spans 48 resource blocks in the subbands of the subset of subbands.

[0020] In some implementations, the resource elements intersect with the resource elements of the wideband structure.

[0021]

[0021] In some implementations, the method may include receiving a trigger for CSI feedback after a COT-SI indicating a subset of subbands among a plurality of subbands that are available for CSI-RS.

[0022] In some implementations, the CSI-RS is for periodic or semi-persistent CSI feedback.

[0023] In some implementations, the CSI-RS is for aperiodic CSI feedback.

[0024]

[0024] In some implementations, the method may include rate-matching a shared channel around resources of the CSI-RS based on a plurality of subbands available for the CSI-RS.

[0025]

[0025] In some implementations, the method may include selectively receiving the CSI-RS based on at least one of a COT-SI received before the resources of the CSI-RS, a signal-to-noise ratio associated with the resources of the CSI-RS, or a value associated with a grant for a shared channel.

[0026]

[0026] In some implementations, the method may include performing processing operations related to the CSI-RS for multiple subbands based on the COT-SI received after the CSI-RS is received.

[0027]

[0027] In some implementations, the method may include performing a per-sub-band processing operation associated with the CSI-RS to determine per-sub-band CSI feedback; and identifying a subset of subbands among a plurality of subbands on which the CSI-RS is received, wherein the CSI feedback is based on the per-sub-band CSI feedback associated with the subset of subbands.

[0028]

[0028] In some implementations, the method may include receiving a grant for a subset of subbands among a plurality of subbands, and rate-matching a shared channel associated with the grant around resources associated with the CSI-RS on the subset of subbands.

[0029]

[0029] In some implementations, the method may include receiving a grant for a subset of subbands among a plurality of subbands, and rate-matching a shared channel associated with the grant around resources associated with the CSI-RS on the subset of subbands based on a COT-SI received before the CSI-RS, where the COT-SI indicates that the subset of subbands is available.

[0030] In some implementations, the CSI-RS is received on a subset of the subbands.

[0031]

[0031] In some implementations, the configuration information includes configurations for multiple different subsets of subbands of the multiple subbands.

[0032]

[0032] In some implementations, the method may include receiving a trigger related to a configuration for a particular subset of subbands of a plurality of different subsets of subbands based on a particular subset of subbands that are available for CSI-RS.

[0033]

[0033] In some implementations, the method may include receiving a trigger indicating a particular subset of subbands of a plurality of different subsets of subbands based on the particular subset of subbands that are available for CSI-RS.

[0034]

[0034] In some implementations, the power level of the CSI-RS per resource element or per sub-band is independent of the number of sub-bands on which the CSI-RS is transmitted.

[0035] In some implementations, the power level of the CSI-RS per resource element or per subband is based on the number or configuration of subbands on which the CSI-RS is transmitted.

[0036]

[0036] In some implementations, the power level of the CSI-RS is based on whether the CSI-RS is aperiodic, periodic, or semi-persistent.

[0037]

[0037] In some implementations, the method may include determining a power level of the CSI-RS based on at least one of information indicating the number or configuration of subbands on which the CSI-RS is transmitted, or information indicating the power level of the CSI-RS.

[0038] Another inventive aspect of the subject matter described in this disclosure may be implemented in an apparatus of a UE for wireless communication. The apparatus may include: a first interface; the first interface configured to acquire configuration information for a CSI-RS, where the configuration information indicates that the CSI-RS is configured on multiple subbands of a wideband structure; and selectively acquire the CSI-RS based on the configuration information and on subband enablement indications associated with the multiple subbands; and a second interface configured to transmit CSI feedback based on the configuration information when the CSI-RS is acquired.

[0039] Another inventive aspect of the subject matter described in this disclosure may be implemented in a non-transitory computer-readable medium. The non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a UE, may cause the one or more processors to: receive configuration information for a CSI-RS, where the configuration information indicates that the CSI-RS is configured on multiple subbands of a wideband structure; selectively transmit the CSI-RS based on the configuration information and based on subband enable indications associated with the multiple subbands; and, if the CSI-RS is received, transmit CSI feedback based on the configuration information.

[0040] Another inventive aspect of the subject matter described in this disclosure may be implemented in an apparatus for wireless communication. The apparatus may include means for transmitting configuration information for a CSI-RS, where the configuration information indicates that the CSI-RS is configured on multiple subbands of a wideband structure, means for selectively transmitting the CSI-RS based on the configuration information and based on subband enablement indications associated with the multiple subbands, and means for transmitting CSI feedback based on the configuration information when the CSI-RS is received.

[0041] Another inventive aspect of the subject matter described in this disclosure may be implemented in a method of wireless communication performed by a base station (BS) apparatus. The method may include transmitting configuration information for a CSI-RS, where the configuration information indicates a plurality of subbands of a wideband structure for the CSI-RS, performing a listen-before-talk (LBT) operation to identify a subset of subbands among the plurality of subbands available for the CSI-RS, and selectively transmitting the CSI-RS based on a result of the LBT operation, where the subset of subbands includes up to all subbands among the plurality of subbands.

[0042]

[0042] In some implementations, when all subbands of the multiple subbands are available for CSI-RS, CSI-RS is transmitted, and when at least one subband of the multiple subbands is not available for CSI-RS, CSI-RS is not transmitted.

[0043]

[0043] In some implementations, the method may include rate-matching the shared channel around resources of the CSI-RS regardless of whether the CSI-RS is transmitted or not.

[0044]

[0044] In some implementations, the subset of subbands includes less than all subbands of the plurality of subbands.

[0045] In some implementations, a sequence for CSI-RS for multiple subbands is punctured to generate CSI-RS for a subset of the subbands.

[0046] In some implementations, the CSI-RS for a subset of subbands is generated based on a shortened sequence relative to a sequence for the CSI-RS for multiple subbands.

[0047]

[0047] In some implementations, the method may include transmitting a trigger for CSI feedback related to the CSI-RS based on all subbands among a plurality of subbands available for the CSI-RS.

[0048]

[0048] In some implementations, when CSI-RS is transmitted on a subset of subbands among multiple subbands, the CSI-RS is transmitted on resource elements on the subset of subbands that corresponds to the widest bandwidth of the wideband structure.

[0049] In some implementations, the CSI-RS is based on the same sequence for the widest bandwidth and for a subset of subbands.

[0050] In some implementations, the CSI-RS spans 48 resource blocks in the subbands of the subset of subbands.

[0051]

[0051] In some implementations, resource elements intersect with resource elements of a wideband structure.

[0052] In some implementations, the CSI-RS is for periodic or semi-persistent CSI feedback.

[0053] In some implementations, the CSI-RS is for aperiodic CSI feedback.

[0054]

[0054] In some implementations, the method may include rate-matching a shared channel around resources of the CSI-RS based on a plurality of subbands available for the CSI-RS.

[0055]

[0055] In some implementations, the method may include transmitting subband usage information that identifies a subset of subbands, where the subband usage information that identifies the subset of subbands is associated with at least one of COT-SI transmitted before resources of the CSI-RS, a value related to a grant for a shared channel, or downlink control information that indicates the subset of subbands.

[0056]

[0056] In some implementations, the method may include transmitting a grant for a subset of subbands and rate-matching a shared channel associated with the grant around resources associated with CSI-RS on the subset of subbands.

[0057]

[0057] In some implementations, the method may include transmitting a grant for a subset of subbands, transmitting a COT-SI before the CSI-RS, and rate-matching a shared channel associated with the grant around resources associated with the CSI-RS on the subset of subbands based on the COT-SI being transmitted before the CSI-RS.

[0058]

[0058] In some implementations, the method may include transmitting a trigger for CSI feedback related to the CSI-RS after a COT-SI indicating a subset of subbands among a plurality of subbands available for the CSI-RS.

[0059]

[0059] In some implementations, the configuration information includes configurations for multiple different subsets of subbands of the multiple subbands.

[0060]

[0060] In some implementations, the method may include transmitting a trigger related to a configuration for a particular subset of subbands of a plurality of different subsets of subbands based on the particular subset of subbands that are available for CSI-RS.

[0061]

[0061] In some implementations, the method may include transmitting a trigger indicating a particular subset of subbands of a plurality of different subsets of subbands based on the particular subset of subbands that are available for CSI-RS.

[0062] In some implementations, the power level of the CSI-RS per resource element or per subband is independent of the number of subbands on which the CSI-RS is transmitted.

[0063] In some implementations, the power level of the CSI-RS per resource element or per subband is based on the number or configuration of subbands on which the CSI-RS is transmitted.

[0064]

[0064] In some implementations, the power level of the CSI-RS per resource element or per subband is based on whether the CSI-RS is aperiodic, periodic, or semi-persistent.

[0065]

[0065] In some implementations, the method may include determining a power level of the CSI-RS based on at least one of the number or configuration of subbands on which the CSI-RS is transmitted, or information indicating a power level of the CSI-RS.

[0066]

[0066] In some implementations, the CSI-RS is transmitted when the COT-SI associated with the CSI-RS may be transmitted before the CSI-RS, and the CSI-RS is not transmitted when the COT-SI associated with the CSI-RS may not be transmitted before the CSI-RS.

[0067] Another inventive aspect of the subject matter described in this disclosure may be implemented in an apparatus of a BS for wireless communication. The apparatus may include a first interface and a processing system configured to output configuration information for a CSI-RS, where the configuration information indicates a plurality of subbands of a wideband structure for the CSI-RS, and the processing system configured to perform a listen-before-talk (LBT) operation to identify a subset of subbands among the plurality of subbands available for the CSI-RS, where the subset of subbands includes up to all subbands among the plurality of subbands, where the first interface is further configured to selectively output the CSI-RS based on a result of the LBT operation.

[0068] Another inventive aspect of the subject matter described in this disclosure may be implemented in a non-transitory computer-readable medium. The non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a BS, may cause the one or more processors to: transmit configuration information for a CSI-RS, where the configuration information indicates a plurality of subbands of a wideband structure for the CSI-RS; perform a listen-before-talk (LBT) operation to identify a subset of subbands among the plurality of subbands available for the CSI-RS; and selectively transmit the CSI-RS based on a result of the LBT operation, where the subset of subbands includes up to all subbands among the plurality of subbands.

[0069] Another inventive aspect of the subject matter described in this disclosure may be implemented in an apparatus for wireless communication. The apparatus may include means for transmitting configuration information for a CSI-RS, where the configuration information indicates a plurality of subbands of a wideband structure for the CSI-RS, means for performing a listen-before-talk (LBT) operation to identify a subset of subbands among a plurality of subbands available for the CSI-RS, and means for selectively transmitting the CSI-RS based on a result of the LBT operation, where the subset of subbands includes up to all subbands among the plurality of subbands.

[0070]

[0070] Aspects generally include a method, apparatus, system, computer program product, non-transitory computer-readable medium, user equipment, base station, wireless communication device, or processing system substantially as described with reference to and as illustrated in the drawings.

[0071]

[0071] Details of one or more implementations 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 explanation of the drawings]

[0072] [Figure 1]

[0072] FIG. 1 is a block diagram conceptually illustrating an example of a wireless network. [Figure 2]

[0073] 1 is a block diagram conceptually illustrating an example of a base station (BS) in communication with user equipment (UE) in a wireless network. [Figure 3]

[0074] FIG. 1 illustrates an example of a wideband channel state information reference signal (CSI-RS) configuration for periodic or semi-persistent CSI-RS. [Figure 4]

[0075] FIG. 10 illustrates an example of a wideband CSI-RS configuration for aperiodic CSI-RS. [Figure 5]

[0076] 1 illustrates an example of a CSI-RS configuration in which CSI-RS is transmitted on available subbands and not transmitted on unavailable subbands. [Figure 6]

[0077] FIG. 10 illustrates an example of a CSI-RS configuration in which CSI-RS is not transmitted when a subband is unavailable. [Figure 7]

[0078] FIG. 10 illustrates an example of resource element selection for broadband CSI-RS. [Figure 8]

[0079] FIG. 10 illustrates an exemplary process performed, for example, by a UE. [Figure 9]

[0080] FIG. 1 illustrates an exemplary process performed, for example, by a BS. DETAILED DESCRIPTION OF THE INVENTION

[0073]

[0081] Like reference numbers and designations in the various drawings indicate like elements.

[0074]

[0082] The following description is directed to several implementations for the purposes of illustrating the inventive aspects of the present disclosure. However, those skilled in the art will readily recognize that the teachings herein can be applied in many different ways. Some of the examples in this disclosure are based on wireless and wired local area network (LAN) communications according to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 wireless standard, the IEEE 802.3 Ethernet standard, and the IEEE 1901 Power Line Communications (PLC) standard.However, the described implementations may be used to communicate within wireless, cellular, or Internet of Things (IoT) networks, such as systems utilizing 3G, 4G, or 5G, or further implementations thereof, including the IEEE 802.11 standard, Bluetooth® 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 RevA, EV-DO RevB, High Speed Packet Access (HSPA), High Speed Downlink Packet Access (HSDPA), and other standards. The present invention may be implemented in any device, system, or network capable of transmitting and receiving radio frequency signals in accordance with any of the wireless communications standards, including LTE, AMPS, LTE Downlink Packet Access, High Speed Uplink Packet Access (HSUPA), Evolved High Speed Packet Access (HSPA+), Long Term Evolution (LTE), AMPS, or any other known signal.

[0075]

[0083] Some radio access technologies (RATs), such as NR, may allow operation in unlicensed spectrum. The RAT may be referred to as NR-Unlicensed (NR-U or NRU). Some RATs may support different bandwidths for subbands or combinations of subbands, such as 20 MHz, 40 MHz, 60 MHz, 80 MHz, or further examples. For example, multiple subbands of 20 MHz may be combined to form a larger bandwidth referred to as a wideband. In this specification, a combination of multiple subbands may be referred to as a wideband structure. A wideband structure may be a bandwidth portion of a UE (i.e., a configured bandwidth of a UE in which the UE may communicate on one or more subbands).

[0076]

[0084] When a UE is configured with multiple subbands in an unlicensed spectrum, not all subbands may be available at all times. For example, some subbands may be occupied by other UEs, base stations, wireless nodes, or further examples. A base station or UE may perform a listen-before-talk (LBT) operation to determine whether one or more subbands are available for communication. In an LBT operation, the base station or UE may listen to a channel or subband for a length of time and then transmit an indication that the base station or UE has reserved the channel or subband for a time window if no other reservations for the channel or subband are received while the base station or UE is listening, or if interference to the channel or subband meets a threshold. Thus, coexistence between devices on non-centrally scheduled channels, such as sidelink channels on unlicensed spectrum, is possible.

[0077]

[0085] A base station may use channel state information (CSI) feedback to determine channel conditions for a channel between the base station and a UE. For example, a base station may transmit a CSI-RS to one or more UEs along with certain characteristics that may be available to or determinable by the UE. Using the CSI-RS, the UE may determine CSI feedback, such as a CSI report, that indicates the channel conditions between the base station and the UE. However, in the case of unlicensed spectrum with a wideband structure, not all subbands configured for the CSI-RS may be available when the CSI-RS is to be transmitted. Furthermore, the UE may or may not have received information indicating which subbands are available when the CSI-RS is to be transmitted (since this information may sometimes come after the CSI-RS). Some operations, such as rate-matching around the CSI-RS and transmitting or processing the CSI-RS itself, may be hindered by this uncertainty.

[0078]

[0086] The techniques and apparatuses described herein provide a determination of whether a CSI-RS is to be transmitted and a configuration for transmitting the CSI-RS on a wideband structure based on the results of an LBT operation for subbands of the wideband structure. For example, some techniques and apparatuses described herein provide signaling of subband usage information indicating which subbands are available before the CSI-RS is transmitted, thus enabling a UE to determine whether the CSI-RS is to be transmitted and, if so, on which subbands. Furthermore, some techniques and apparatuses described herein provide a rate matching configuration based on whether subband usage is received, which subbands are available, or further examples. Still further, some techniques and apparatuses described herein provide power configurations and resource element selection criteria for the wideband CSI-RS and CSI feedback.

[0079]

[0087] Particular implementations of the subject matter described in this disclosure may be implemented to achieve one or more of the following potential advantages: Utilization of CSI-RS over a wideband may be improved by determining which subbands will contain CSI-RS and by determining the power configuration of the CSI-RS. Some implementations may improve resource utilization by providing a rate-matching configuration that is specific to a subband rather than an “all-or-nothing” approach where the CSI-RS is either rate-matched across the entire wideband or not at all. Some implementations may reduce complexity by providing an all-or-nothing approach to rate-matching the CSI-RS. Furthermore, some implementations may improve resource utilization by ensuring that subband usage information is provided to the UE before the CSI-RS, which may reduce uncertainty in unlicensed bands and save UE resources that would otherwise be used to process a non-existent CSI-RS. This may ensure that the UE estimates and reports accurate channel estimation / channel quality indication to the base station, so that the base station can configure DL / UL communication parameters and resources (such as modulation scheme, coding rate, spatial multiplexing / diversity, etc.) For example, if the UE incorrectly assumes the presence of CSI-RS in a subband, the UE may transmit erroneous CSI feedback / report, which may lead the BS to configure communication parameters that are suboptimal and result in degraded performance.

[0080]

[0088] 1 is a block diagram conceptually illustrating an example of a wireless network 100. 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 several BSs 110 (shown as BS 110a, BS 110b, BS 110c, and BS 110d) and other network entities. A BS is an entity that communicates with user equipment (UE) and may also be referred to as a base station, an NR BS, a Node B, a gNB, a 5G Node B (NB), an access point, a transmit / receive point (TRP), or further examples. Each BS may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" can refer to the coverage area of a BS, a BS subsystem serving this coverage area, or a combination thereof, depending on the context in which the term is used.

[0081]

[0089] A BS may provide communication coverage for a macrocell, a picocell, a femtocell, another type of cell, or a combination thereof. A macrocell may cover a relatively large geographic area (e.g., a few kilometers in radius) and may allow unrestricted access by UEs with service subscriptions. A picocell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscriptions. A femtocell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs that have an association with the femtocell (e.g., UEs in a Closed Subscriber Group (CSG)). A BS for a macrocell may be referred to as a macroBS. A BS for a picocell may be referred to as a picoBS. A BS for a femtocell may be referred to as a femtoBS or a home BS. 1, 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,” “Node B,” “5G NB,” and “cell” may be used interchangeably herein.

[0082]

[0090] 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 wireless network 100 through various types of backhaul interfaces, such as direct physical connections, virtual networks, or combinations thereof, using any suitable transport network.

[0083]

[0091] Wireless network 100 may also include relay stations. A relay station is an entity that can receive a data transmission from an upstream station (e.g., a BS or a UE) and send the data transmission 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. In the example shown in FIG. 1, relay station 110d may communicate with macro BS 110a and UE 120d to facilitate communication between BS 110a and UE 120d. A relay station may also be called a relay BS, a relay base station, a relay, etc.

[0084]

[0092] Wireless network 100 may be a heterogeneous network including different types of BSs, e.g., macro BSs, pico BSs, femto BSs, relay BSs, etc. These different types of BSs may have different transmit power levels, different coverage areas, and different impacts on interference in wireless network 100. For example, macro BSs may have high transmit power levels (e.g., 5-40 watts), while pico BSs, femto BSs, and relay BSs may have lower transmit power levels (e.g., 0.1-2 watts).

[0085]

[0093] A network controller 130 may couple to a set of BSs and 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 wireless or wireline backhaul.

[0086]

[0094] The UEs 120 (e.g., 120a, 120b, 120c) may be dispersed throughout the wireless network 100, and each UE may be fixed or mobile. A UE may also be referred to as an access terminal, terminal, mobile station, subscriber unit, station, etc. A UE may be a cellular phone (e.g., a smartphone), 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, 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 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 over a wireless or wired medium.

[0087]

[0095] Some UEs may be considered machine type communication (MTC) UEs or evolved or enhanced machine type communication (eMTC) UEs. MTC UEs and eMTC UEs include, for example, a robot, a drone, a remote device, a sensor, a meter, a monitor, a location tag, etc. that may communicate with a base station, another device (e.g., a remote device), or some other entity. A wireless node may provide, for example, connectivity for or to a network (e.g., a wide area network such as 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). The UE 120 may be included within a housing that houses components of the UE 120, such as a processor component, a memory component, similar components, or a combination thereof.

[0088]

[0096] Generally, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a particular RAT and may operate on one or more frequencies. A RAT may also be referred to as a radio technology, air interface, etc. A frequency may also be referred to as a carrier, frequency channel, etc. Each frequency may support a single RAT within a given geographic area to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.

[0089]

[0097] In some examples, access to the air interface may be scheduled, with a scheduling entity (e.g., a base station) allocating resources for communication among some or all devices and equipment within the scheduling entity's service area or cell. Within this disclosure, as described further below, the scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communication, the subordinate entities utilize resources allocated by the scheduling entity.

[0090]

[0098] A base station is not the only entity that can function as a scheduling entity. That is, in some examples, a UE may function as a scheduling entity that schedules resources for one or more subordinate entities (e.g., one or more other UEs). In this example, the UE is functioning as the scheduling entity, and the other UEs utilize the resources scheduled by the UE for wireless communication. A UE may function as a scheduling entity in a peer-to-peer (P2P) network, a mesh network, or another type of network. In the example of a mesh network, the UEs may communicate directly with each other in some cases in addition to communicating with the scheduling entity.

[0091]

[0099] Thus, in a wireless communication network with scheduled access to time-frequency resources and having a cellular, P2P, and mesh configuration, a scheduling entity and one or more subordinate entities may communicate utilizing the scheduled resources.

[0092]

[0100] In some aspects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly (e.g., without using a base station 110 as an intermediary for communicating with each other) using one or more sidelink channels. For example, the UEs 120 may communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, a vehicle-to-everything (V2X) protocol (which may include, e.g., a vehicle-to-vehicle (V2V) protocol, a vehicle-to-infrastructure (V2I) protocol, or a similar protocol), a mesh network, or a similar network, or a combination thereof. In this case, the UEs 120 may perform scheduling operations, resource selection operations, and other operations described elsewhere herein as being performed by the base station 110.

[0093]

[0101] 2 is a block diagram conceptually illustrating an example base station (BS) 200 in communication with user equipment (UE) 120 in a wireless network. In some aspects, base station 110 and UE 120 may be one of the base stations and one of the UEs, respectively, in wireless network 100 of FIG. 1. Base station 110 may be equipped with T antennas 234a through 234t, and UE 120 may be equipped with R antennas 252a through 252r, where in general T≧1 and R≧1.

[0094]

[0102] At the base station 110, a transmit processor 220 may receive data from a data source 212 for one or more UEs, select one or more modulation and coding schemes (MCSs) for each UE based on a channel quality indicator (CQI) received from the UE, process (e.g., encode and modulate) the data for each UE based on the selected MCS(es) for that UE, and provide data symbols for all UEs. The transmit processor 220 may also process system information and control information (e.g., for semi-static resource partitioning information (SRPI), etc.) and provide overhead and control symbols. The transmit processor 220 may also generate reference symbols for reference signals (e.g., a cell-specific reference signal (CRS)) and synchronization signals (e.g., a primary synchronization signal (PSS) and a secondary synchronization signal (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 (MODs) 232a through 232t. Each modulator 232 may process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. The T downlink signals from modulators 232a through 232t may be transmitted via T antennas 234a through 234t, respectively. According to various aspects described in more detail below, synchronization signals may be generated using location coding to convey additional information.

[0095]

[0103] At UE 120, antennas 252a through 252r may receive downlink signals from base station 110 or other base stations and may provide received signals to demodulators (DEMODs) 254a through 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. A MIMO detector 256 may obtain received symbols from all R demodulators 254a through 254r, perform MIMO detection on the received symbols, if applicable, and provide detected symbols. A receive processor 258 may process (e.g., demodulate and decode) the detected symbols and provide decoded data for UE 120 to a data sink 260 and decoded control and system information to a controller or processor (controller / processor) 280. The channel processor may determine a reference signal received power (RSRP), a received signal strength indicator (RSSI), a reference signal received quality (RSRQ), a channel quality indicator (CQI), etc. In some aspects, one or more components of the UE 120 may be included in a housing.

[0096]

[0104] On the uplink, at 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 comprising 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 are transmitted to a TX The base station 110 may include a communication unit 244 and may communicate with the network controller 130 via the communication unit 244. The network controller 130 may include a communication unit 244, a controller or processor (i.e., controller / processor) 290, and a memory 292. The base station 110 may include a communication unit 244 and may 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. The base station 110 may include a communication unit 24 ... communication unit 244, a communication unit 244, a communication unit 244, a communication unit 244, a communication unit 244, a communication unit 244, a communication unit 244, a communication unit 24

[0097]

[0105] In some implementations, the controller / processor 280 may be a component of a processing system. A processing system may generally refer to a system or series of machines or components that receive inputs and process the inputs to generate a set of outputs (e.g., that may be passed to other systems or components of 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.

[0098]

[0106] The processing system of the UE 120 may interface with other components of the UE 120 and may process information received from other components (such as inputs or signals), output information to other components, etc. For example, a chip or modem of the UE 120 may include a processing system, a first interface for receiving or acquiring information, and a second interface for outputting, transmitting, or providing information. In some cases, the first interface may refer to an interface between the processing system of the chip or modem and a receiver, such that the 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 the processing system of the chip or modem and a transmitter, such that the UE 120 may transmit information output from the chip or modem. Those skilled in the art will readily recognize that the second interface may also acquire or receive information or signal input and the first interface may also output, transmit, or provide information.

[0099]

[0107] In some implementations, the controller / processor 240 may be a component of a processing system. A processing system may generally refer to a system or series of machines or components that receive and process inputs to generate a set of outputs (e.g., that may be passed to other systems or components of the BS 110). For example, the processing system of the BS 110 may refer to a system that includes various other components or subcomponents of the BS 110.

[0100]

[0108] The processing system of the BS 110 may interface with other components of the BS 110, process information received from other components (such as inputs or signals), output information to other components, etc. For example, a chip or modem of the BS 110 may include a processing system, a first interface for receiving or acquiring information, and a second interface for outputting, transmitting, or providing information. In some cases, the first interface may refer to an interface between the processing system of the chip or modem and a receiver, such that the BS 110 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, such that the BS 110 may transmit information output from the chip or modem. Those skilled in the art will readily recognize that the second interface may also acquire or receive information or signal input, and the first interface may also output, transmit, or provide information.

[0101]

[0109] Controller / processor 240 of base station 110, controller / processor 280 of UE 120, or any other component of FIG. 2 may perform one or more techniques associated with CSI-RS for wideband operation, as described in more detail elsewhere herein. For example, controller / processor 240 of base station 110, controller / processor 280 of UE 120, or any other component (or combination of components) of FIG. 2 may perform or direct the operation of, for example, process 800 of FIG. 8, process 900 of FIG. 9, or other processes 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.

[0102]

[0110] The stored program code, when executed by controller / processor 280 or other processors and modules of UE 120, may cause UE 120 to perform operations described with reference to process 800 of FIG. 8 or other processes described herein. The stored program code, when executed by controller / processor 240 or other processors and modules of base station 110, may cause base station 110 to perform operations described with reference to process 900 of FIG. 9 or other processes described herein. Scheduler 246 may schedule UEs for data transmission on the downlink, uplink, or a combination thereof.

[0103]

[0111] The UE 120 may include means for performing one or more operations described herein, such as process 800 of FIG. 8 or other processes described herein. In some aspects, such means may include one or more components of the UE 120 described with respect to FIG. 2. The base station 110 may include means for performing one or more operations described herein, such as process 900 of FIG. 9 or other processes described herein. In some aspects, such means may include one or more components of the base station 110 described with respect to FIG. 2.

[0104]

[0112] 2 are shown as separate components, the functionality described above with respect to those blocks may be implemented in a single hardware, software, or combined component, or in various combinations of components. For example, functionality described with respect to transmit processor 264, receive processor 258, TX MIMO processor 266, or another processor may be performed by or under the control of controller / processor 280.

[0105]

[0113] 3 is a diagram illustrating an example wideband channel state information (CSI) reference signal (RS) configuration 300 for periodic or semi-persistent CSI-RS. Although FIG. 3 includes a single UE 120 and a single BS 110, the operations described with respect to FIG. 3 may be performed by any two or more wireless nodes. Furthermore, the BS 110 may perform the operations described herein for a group of UEs 120, such as UEs 120 that are in communication with the BS 110.

[0106]

[0114] As indicated by reference numeral 310, the BS 110 may transmit configuration information. For example, the configuration information may identify a CSI-RS configuration for periodic CSI-RS (P-CSI-RS) or semi-persistent CSI-RS (SP-CSI-RS), etc. In some aspects, the CSI-RS may be aperiodic CSI-RS (A-CSI-RS), which will be described in more detail with respect to FIG. 4. In some aspects, the configuration information may include, for example, information indicating a resource allocation for the CSI-RS, information indicating a sequence used to generate the CSI-RS, or further examples. For example, the configuration information may identify a group of subbands on which the CSI-RS may be transmitted and on which the UE 120 is to process the CSI-RS. In some aspects, the UE 120 may determine the group of subbands based on a configuration of the UE 120, such as a bandwidth portion configuration of the UE 120. In some aspects, the configuration information may include information indicating a power scaling configuration for the CSI-RS, which will be described in more detail below.

[0107]

[0115] In some aspects, UE 120 may receive a grant for a shared channel, such as a physical downlink shared channel (PDSCH). Because BS 110 cannot grant resources on unavailable subbands, the grant may be received on one or more subbands that are available for CSI-RS. Thus, UE 120 may determine which subbands are available subbands based on the grant. UE 120 may rate-match the shared channel around the CSI-RS resources, as described in more detail below.

[0108]

[0116] As indicated by reference numeral 320, the BS 110 may perform an LBT operation on a group of subbands. For example, the BS 110 may perform an LBT operation on subbands on which the CSI-RS is configured before transmitting the CSI-RS. The BS 110 may determine an LBT result for each subband in the group of subbands. The LBT result may indicate whether the corresponding subband is available for CSI-RS or other communications by the BS 110. The subbands on which LBT is performed may also be referred to as an RB set or LBT bandwidth. For example, the LBT result for a subband may indicate that the subband is associated with an interference level that meets (i.e., is lower than) a threshold or that the subband is not associated with another reservation during a time window associated with the CSI-RS. As an example, the threshold for the interference level may be approximately −82 decibel milliwatts (dBm) at the antenna of the BS 110. The time window of the LBT operation may be referred to as a transmission opportunity. The BS 110 may provide a subband validity indication to the UE 120 indicating the LBT result. For example, the BS 110 may provide a subband validity indication via DCI, medium access control signaling, etc. The subband validity indication may include information indicating one or more subbands that are valid (or not valid) for communication. For example, the subband validity indication may include a bitmap that indicates subbands, LBT bandwidths, or RB sets that are valid for communication based at least in part on a channel access operation (e.g., based at least in part on an LBT result associated with the channel access operation).

[0109]

[0117] In some cases, not all subbands in a group of subbands may be available for CSI-RS, as indicated by reference numeral 330. In this case, BS 110 may drop or not transmit CSI-RS, or may perform CSI-RS transmission on available subbands.

[0110]

[0118] In some aspects, BS 110 may not transmit CSI-RS when at least one subband in a group of subbands is unavailable for CSI-RS. This may be referred to herein as an “all-or-nothing” approach. In the all-or-nothing approach, BS 110 may transmit CSI-RS when all subbands in a group of subbands are available for CSI-RS. This may save signaling resources that would otherwise be used to configure or transmit partial CSI-RS using less than all subbands in the group of subbands and may reduce the complexity of a particular design implementation. Second, in the all-or-nothing approach, if CSI-RS is not transmitted in a valid subband (because another subband is unavailable), the CSI-RS resource may be used for data; therefore, data does not need to be rate-matched around the CSI-RS resource.

[0111]

[0119] In some aspects, the BS 110 may transmit the CSI-RS on available subbands of a group of subbands. For example, when one subband is unavailable for the CSI-RS and three subbands are available, the BS 110 may transmit the CSI-RS on the three subbands instead of the one unavailable subband. This may enable provision of the CSI-RS on partially available resources, which may improve network utilization efficiency relative to an all-or-nothing approach.

[0112]

[0120] In some aspects, the BS 110 may use a sequence to generate the CSI-RS. In some aspects, the BS 110 may modify the sequence when the CSI-RS is transmitted on a subset of subbands of a group of bands. As a first example, the BS 110 may puncture a sequence for a group of subbands to generate a sequence for the subset of subbands. In this case, if subbands 0, 2, and 3 are available for CSI-RS and subband 1 is unavailable, the BS 110 may puncture the sequence for subbands 0, 1, 2, and 3 at a location in the sequence corresponding to subband 1 and generate the CSI-RS using the punctured sequence. As used herein, puncturing a sequence may refer to dropping one or more values of the sequence that correspond to unavailable subbands. For example, if a sequence includes 80 values and the second subband of the four subbands associated with the sequence is unavailable, the BS 110 may drop values 21 through 24 of the sequence and may use zero or default values for these values, or use further examples. As a second example, the BS 110 may use a shortened sequence based on the number of resource elements of the CSI-RS. In this example, if the sequence includes 80 values and the second of the four subbands associated with the sequence is unavailable, the BS 110 may generate the CSI-RS using a sequence of 60 symbols. In the case of a shortened sequence, the UE 120 may determine subband usage information (using a channel occupancy time (COT) structure indicator (SI), a grant-based indication, or further examples) prior to the CSI-RS so that the UE 120 can determine the length of the shortened sequence.In some aspects, UE 120 may determine the punctured sequence without determining or receiving subband usage information (e.g., by performing per-subband processing of CSI-RS to determine which subbands are used for CSI-RS), which may simplify processing at UE 120.

[0113]

[0121] As indicated by reference numeral 340, the BS 110 may transmit subband usage information, denoted here as a channel occupation time (COT) structure indicator (SI). In some aspects, the subband usage information may be transmitted in another form, such as downlink control information (DCI) indicating subband usage, an aperiodic CSI-RS trigger, a PDSCH grant, a physical uplink shared channel grant, or further examples. The COT-SI may indicate which subbands of a group of subbands are available for CSI-RS. For example, the COT-SI may indicate an LBT result for the group of subbands. In some aspects, the UE 120 may receive the COT-SI in a control channel, such as a physical downlink control channel (PDCCH).

[0114]

[0122] In some cases, COT-SI may be transmitted before CSI-RS. In such a case, UE 120 may determine which subband will be used for CSI-RS or whether CSI-RS will be transmitted before the transmission time of CSI-RS. In some aspects, UE 120 may determine that CSI-RS is present during a transmission opportunity if COT-SI is received before the transmission time of CSI-RS. If UE 120 does not receive COT-SI before the transmission time of CSI-RS, UE 120 may determine that CSI-RS is not expected during the transmission opportunity. In this case, if BS 110 cannot transmit COT-SI before the transmission time of CSI-RS, BS 110 may not transmit CSI-RS. This may save UE resources that would otherwise be used to store CSI-RS while waiting for COT-SI.

[0115]

[0123] In some aspects, the COT-SI may be transmitted after the CSI-RS. In this case, the UE 120 cannot know which subbands will be used for the CSI-RS until after the CSI-RS is received. In some aspects, the UE 120 may store the CSI-RS and process the CSI-RS after receiving the COT-SI. For example, the UE 120 may delay processing the CSI-RS until after the COT-SI is received. In this case, the UE 120 may process the latest CSI-RS even if the COT-SI is not available (e.g., based on the COT-SI that comes after the CSI-RS).

[0116]

[0124] As indicated by reference numeral 350, the BS 110 may transmit the CSI-RS. For example, the BS 110 may transmit the CSI-RS using available subbands of the group of subbands. In some aspects, the BS 110 may transmit the CSI-RS in a downlink (DL) burst, such as a synchronization signal burst. As indicated by reference numeral 360, the UE 120 may selectively process the CSI-RS. For example, in some aspects, the UE 120 may process the CSI-RS based on determining that the CSI-RS is to be transmitted. The UE 120 may generate CSI feedback based on processing the CSI-RS.

[0117]

[0125] In some aspects, UE 120 may process CSI-RS based on detecting a DL burst (e.g., before COT-SI is received). For example, UE 120 may process CSI-RS on each subband of a group of subbands individually and examine the CSI feedback to form combined CSI feedback for the available subbands after COT-SI is received. Processing CSI-RS on each subband individually may be referred to as a per-subband processing operation. Thus, UE 120 may process CSI-RS before COT-SI is received and then generate CSI feedback for the available subbands. This may be more reliable than attempting to identify the subband in which CSI-RS resides using measurements on the subbands.

[0118]

[0126] In some aspects, UE 120 may determine whether CSI-RS is present on a subband based on measurements performed by UE 120. For example, the measurements may relate to a signal-to-noise ratio (SNR) or another threshold. UE 120 may identify which subbands include CSI-RS and process the CSI-RS on the subbands that include CSI-RS. This may be less resource intensive than processing CSI-RS on each subband individually and may not use COT-SI.

[0119]

[0127] In some aspects, the UE 120 or the BS 110 may determine a power level for the CSI-RS. The power level may be based, for example, on a power spectral density (PSD) or similar value. In some aspects, the power level may depend on the number of subbands available for the CSI-RS. For example, the power level may be static over time, which may save resources that would otherwise be used to dynamically determine the power level. In some aspects, the power level may be based on the number of subbands available for the CSI-RS. For example, the power level may vary over time, which may provide improved CSI-RS performance across different numbers of subbands. In some aspects, the power level may be independent or dependent on the number of subbands based on whether the CSI is periodic, semi-persistent, or aperiodic.

[0120]

[0128] In some aspects, the power level may be determined based on the subbands available for the CSI-RS. In some aspects, the power level may be explicitly signaled (such as by using a transmit power reduction (TPR) value relative to a nominal power level). In some aspects, the signaling may be included in the COT-SI or may be included in an aperiodic CSI-RS trigger. In some aspects, the BS 110 may be operating on many more subbands than the UE 120, and the COT-SI signaling may be limited to a smaller set of subbands. In this case, explicit signaling of the power level may be beneficial to the BS 110 because the power level of the CSI-RS can be adapted to the smaller set of subbands.

[0121]

[0129] As indicated by reference numeral 370, in some aspects, UE 120 may rate-match the shared channel around CSI-RS. For example, if UE 120 receives a PDSCH grant on a given subband, the subband may be considered available for CSI-RS because BS 110 does not grant a PDSCH on an unavailable subband. In some aspects, UE 120 may rate-match the shared channel around the configured resources of CSI-RS regardless of whether CSI-RS is to be received, which may save resources that would otherwise be used to determine whether CSI-RS is to be received. In some aspects, when CSI-RS is transmitted only when all subbands are available, UE 120 may rate-match around CSI-RS when all subbands are available for CSI-RS. In such cases, if subband usage information is not received before CSI-RS, UE 120 may not decode the PDSCH or may assume that CSI-RS is not present. In some aspects, UE 120 may determine whether UE 120 has received CSI-RS based on a measurement (such as an SNR measurement or further examples) and, if UE 120 has received CSI-RS, may rate-match around the CSI-RS. In some aspects, the PDSCH grant may include an indicator of whether UE 120 is to rate-match around the shared channel. For example, the indicator may include a bit indicating whether UE 120 is to rate-match around the CSI-RS, which may save resources in UE 120 that would otherwise be used to determine whether to rate-match around the shared channel.

[0122]

[0130] As indicated by reference numeral 380, UE 120 may selectively transmit CSI feedback to BS 110. For example, UE 120 may transmit CSI feedback when UE 120 determines CSI feedback based on receiving CSI-RS from BS 110. If CSI-RS is not received or UE 120 determines that CSI-RS is not to be received, UE 120 may not determine or transmit CSI feedback.

[0123]

[0131] 4 is a diagram illustrating an example wideband CSI-RS configuration 400 for aperiodic CSI-RS. Although FIG. 4 includes a single UE 120 and a single BS 110, the operations described with respect to FIG. 4 may be performed by any two or more wireless nodes. Furthermore, the BS 110 may perform the operations described herein for a group of UEs 120, such as several UEs 120 that are in communication with the BS 110.

[0124]

[0132] As indicated by reference numeral 410, the BS 110 may transmit configuration information for aperiodic CSI-RS (sometimes abbreviated as A-CSI-RS). The configuration information is described in more detail above with respect to FIG. 3. The aperiodic CSI-RS may be associated with aperiodic CSI. The BS 110 may configure the UE 120 with one or more aperiodic CSI-RS opportunities and may indicate when the UE 120 will determine and transmit CSI feedback using triggers described below. The UE 120 may not process the CSI-RS or transmit CSI feedback for the CSI-RS resources unless the UE 120 receives a trigger from the BS 110.

[0125]

[0133] In some aspects, UE 120 may receive multiple different CSI-RS configurations. For example, UE 120 may receive respective CSI-RS configurations for multiple different subband combinations selected from a group of subbands. In this case, the trigger described below may correspond to the CSI-RS configuration to be used (e.g., the CSI-RS configuration corresponding to the set of available subbands for CSI-RS). As an example, for four subbands, there may be 15 CSI-RS configurations.

[0126]

[0134] As indicated by reference numeral 420, the BS 110 may perform an LBT operation on a group of subbands. This is described in more detail with respect to FIG. 3. As indicated by reference numeral 430, in some cases, not all subbands in a group of subbands may be available for CSI-RS. In this case, the BS 110 may drop or not transmit the CSI-RS, or may perform CSI-RS transmission on available subbands. When the BS 110 determines that CSI-RS transmission is to be performed on available subbands, the BS 110 may send a trigger for the CSI-RS, as indicated by reference numeral 440.

[0127]

[0135] In some aspects, the BS 110 may transmit a trigger based on an LBT result that indicates that all subbands of a group of subbands are available for use, which may save resources that would otherwise be used to provide the UE 120 with subband usage information, because the UE 120 will not receive the trigger unless all subbands are available for CSI-RS.

[0128]

[0136] In some aspects, the BS 110 may transmit a trigger when a subset of subbands in a group of subbands are available. For example, the BS 110 may transmit a trigger when fewer than all subbands in a group of subbands are available for CSI-RS. In some aspects, the BS 110 may transmit the trigger after transmitting the subband usage information denoted by reference numeral 450, and the UE 120 may use the subband usage information to determine which subbands contain CSI-RS. In this case, the BS 110 may provide a gap between the trigger and the subband usage information sufficient for the UE 120 to decode the subband usage information. This may be based on UE capabilities or other information regarding the UE 120.

[0129]

[0137] In some aspects, the trigger may include information indicating which subbands are available for CSI-RS. For example, the configuration information denoted by reference numeral 410 may configure some CSI-RS parameters, and the trigger may indicate the bandwidth of the CSI-RS, the set of subbands to be used for the CSI-RS, or further examples. Thus, the BS 110 may use the trigger to indicate which subbands are to be used for the CSI-RS, which saves resources that would otherwise be used to transmit COT-SI.

[0130]

[0138] The BS 110 may transmit the CSI-RS as indicated by reference numeral 460. In some aspects, the BS 110 may generate the CSI-RS based on a sequence, as described in more detail with respect to FIG. 3. For example, the sequence may be punctured for unavailable subbands or shortened for unavailable subbands, as also described in more detail with respect to FIG. 3.

[0131]

[0139] As indicated by reference numeral 470, UE 120 may selectively process the CSI-RS, as described in more detail above with respect to FIG. 3. As indicated by reference numeral 480, UE 120 may rate-match the shared channel around the CSI-RS. As indicated by reference numeral 490, UE 120 may selectively transmit CSI feedback to BS 110. These operations are also described in more detail with respect to FIG. 3.

[0132]

[0140] FIG. 5 illustrates an example CSI-RS configuration 500 in which CSI-RS is transmitted on available subbands and not on unavailable subbands. As shown, example 500 includes subbands 0 through 3. As further shown, subbands 0, 2, and 3 are available, and subband 1 is unavailable. A COT-SI, e.g., 500, is indicated by reference numeral 510. The COT-SI may indicate that subbands 0, 2, and 3 are available, and subband 1 is unavailable. In some aspects, the COT-SI may be configured to be transmitted before the CSI-RS, as described elsewhere herein. For example, the CSI-RS may not be transmitted unless the CSI-RS is preceded by the COT-SI, thereby allowing the UE 120 to determine which subbands are available for CSI-RS. As indicated by reference numeral 520, the BS 110 may not transmit the CSI-RS in subband 1. Additionally, BS 110 may transmit CSI-RS in subbands 0, 2, and 3.

[0133]

[0141] FIG. 6 illustrates an example CSI-RS configuration 600 in which CSI-RS is not transmitted when a subband is unavailable. As shown in FIG. 6, CSI-RS is not transmitted on any subband based on the unavailability of subband 1. For example, reference numeral 610 indicates that the LBT operation failed in subband 1, and reference numerals 620, 630, and 640 indicate that the LBT operation was successful in subbands 0, 2, and 3, respectively. Because the LBT operation failed in at least one of the subbands illustrated in example 600, CSI-RS is not transmitted on any of the four subbands, as indicated by reference numeral 650. This implementation is referred to as an all-or-nothing approach.

[0134]

[0142] FIG. 7 illustrates an example 700 of resource element selection for wideband CSI-RS. The transmitter enforces guard bands for bandwidths, which may mean that resource elements at the edges of the bandwidth are not usable by the transmitter based on regulatory rules. This may reduce interference and help manage the power spectral density (PSD) of the air interface. The width of the guard bands may be based on the bandwidth of the channel. For example, wider bandwidths may be associated with wider guard bands. In example 700, each rectangle generally corresponds to a subband or a wideband structure composed of multiple subbands. The guard bands are indicated by dashed lines, where the area between the dashed lines and the edges of the subband is the guard band. For example, the guard band for subband 3 is between the dashed lines indicated by reference numerals 705 and 710 and the respective edges of subband 3, and the guard band for a 40 MHz wideband structure formed from subbands 2 and 3 is between the dashed lines indicated by reference numerals 715 and 720 and the respective outer edges of subbands 2 and 3. It can be seen that the guard band for the 40 MHz wideband structure is wider than that for the 20 MHz wideband structure.

[0135]

[0143] The CSI-RS described with respect to Figures 3-6 may be based on a sequence associated with an 80 MHz wideband structure, indicated by reference numeral 725. More generally, the CSI-RS for a group of subbands may be based on a sequence associated with the widest bandwidth structure that can be formed using the group of subbands. However, the guard bands for smaller bandwidths, such as those indicated by 705 through 720, may be smaller than those for the wideband structure 725. This may mean that some resource elements of smaller or intermediate bandwidths (such as 40 MHz and 60 MHz) fall outside the usable area of the wideband structure, which may reduce flexibility and lead to non-compliant transmissions when such resource elements are used for CSI-RS on the wideband structure.

[0136]

[0144] The BS 110 may use resource elements usable for the wideband structure, denoted by reference numeral 725, regardless of which set of subbands is actually used for CSI-RS. In other words, the BS 110 may use resource elements of the set of subbands that intersect with resource elements of the wideband structure 725 and discard resource elements that do not intersect with resource elements of the wideband structure. Referring now to FIG. 7, the guard bands of the wideband structure 725 are denoted by reference numerals 730 and 735. Thus, the smaller bandwidth sets of subbands, denoted by reference numerals 740, 745, 750, 755, 760, 765, and 770, do not use resource elements in the guard bands of the wideband structure. The bandwidth of usable resource elements for subband 0 740 of the 20 MHz bandwidth in this configuration is denoted by reference numeral 775. It can be seen that the left side of the bandwidth of subband 0 740 ends at guard band 730 of the wideband structure, not at the guard band for the 20 MHz bandwidth. In some examples, such as for a 30 kHz subcarrier spacing, the number of usable resource elements for subband 0 may be 48×12 resource elements or 48 resource blocks. In some other examples, the number of usable resource elements for a subband may be 48×12 resource elements or 48 resource blocks to make each of the subbands the same. Similar diagrams of bandwidth for 40 MHz and 60 MHz bandwidths are shown by reference numerals 780 and 785, respectively. Thus, by limiting the resource elements of the smaller bandwidth to those that intersect with resource elements within the usable bandwidth of wideband structure 725, the CSI-RS sequence may be more simply mapped to the smaller bandwidth, as the same sequence may be used for a given resource element in the subband case and in the wideband structure case.

[0137]

[0145] 8 illustrates an example process 800 performed, for example, by a UE. The process 800 illustrates a process by which a UE (such as UE 120) performs operations related to CSI feedback for wideband operation.

[0138]

[0146] 8, in some aspects, process 800 may include receiving configuration information for a channel state information reference signal (CSI-RS), where the configuration information indicates that the CSI-RS is configured on multiple subbands of a wideband structure (block 810). For example, a UE or an interface of the UE (using antenna 252, DEMOD 254, MIMO detector 256, receive processor 258, controller / processor 280) may receive the configuration information for the CSI-RS. The configuration information may indicate that the CSI-RS is configured on multiple subbands of a wideband structure.

[0139]

[0147] 8, in some aspects, process 800 may include selectively receiving a CSI-RS based on the configuration information and based on a subband enable indication associated with the plurality of subbands (block 820). For example, the UE or an interface of the UE (e.g., using antenna 252, DEMOD 254, MIMO detector 256, receive processor 258, or controller / processor 280) may selectively receive a CSI-RS based on the configuration information and based on a subband enable indication associated with the plurality of subbands.

[0140]

[0148] 8, in some aspects, process 800 may include transmitting channel state information (CSI) feedback based on the configuration information when CSI-RS is received (block 830). For example, when CSI-RS is received, the UE or an interface of the UE (using antennas 252, DEMOD 254, MIMO detector 256, receive processor 258, controller / processor 280) may transmit channel state information (CSI) feedback based on the configuration information.

[0141]

[0149] Process 800 may include additional aspects, such as any single aspect or any combination of aspects, with respect to one or more other processes described below or elsewhere herein.

[0142]

[0150] In a first aspect, process 800 may include receiving downlink control information indicating a subband availability indication.

[0143]

[0151] In a second aspect, either alone or in combination with the first aspect, when all subbands of the plurality of subbands are available for CSI-RS, CSI-RS is received, and when at least one subband of the plurality of subbands is not available for CSI-RS, CSI-RS is not received.

[0144]

[0152] In a third aspect, alone or in combination with one or more of the first and second aspects, the process 800 may include rate-matching the shared channel around resources of the CSI-RS regardless of whether the CSI-RS is received.

[0145]

[0153] In a fourth aspect, alone or in combination with one or more of the first through third aspects, the process 800 may include performing processing operations related to the CSI-RS for multiple subbands regardless of whether the CSI-RS is received.

[0146]

[0154] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, the process 800 may include determining that the CSI-RS is to be received based on subband usage information received before a resource associated with the CSI-RS, and performing processing operations related to the CSI-RS for a plurality of subbands based on determining that the CSI-RS is to be received.

[0147]

[0155] In a sixth aspect, alone or in combination with one or more of the first to fifth aspects, the CSI-RS is received on a subset of subbands of the plurality of subbands based on a subset of subbands that are available for the CSI-RS.

[0148]

[0156] In a seventh aspect, alone or in combination with one or more of the first to sixth aspects, a sequence for CSI-RS for a plurality of subbands is punctured to generate CSI-RS for a subset of the subbands.

[0149]

[0157] In an eighth aspect, alone or in combination with one or more of the first to seventh aspects, in some implementations, the CSI-RS for a subset of subbands is generated based on a shortened sequence relative to a sequence for the CSI-RS for the multiple subbands.

[0150]

[0158] In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the process 800 may include receiving a trigger for CSI feedback based on all subbands of a plurality of subbands that are available for the CSI-RS.

[0151]

[0159] In a tenth aspect, alone or in combination with one or more of the first to ninth aspects, when the CSI-RS is received on a subset of subbands of a plurality of subbands, the CSI-RS is received on resource elements on the subset of subbands corresponding to the widest bandwidth of the wideband structure.

[0152]

[0160] In an eleventh aspect, alone or in combination with one or more of the first to tenth aspects, the CSI-RS is generated based on the same sequence for the widest bandwidth and for a subset of subbands.

[0153]

[0161] In a twelfth aspect, alone or in combination with one or more of the first to eleventh aspects, the CSI-RS spans 48 resource blocks in subbands of a subset of subbands.

[0154]

[0162] In a thirteenth aspect, alone or in combination with one or more of the first to twelfth aspects, the resource elements intersect with resource elements of the wideband structure.

[0155]

[0163] In a fourteenth aspect, alone or in combination with one or more of the first through thirteenth aspects, the process 800 may include receiving a trigger for CSI feedback after a COT-SI indicating a subset of subbands among a plurality of subbands that are available for the CSI-RS.

[0156]

[0164] In a fifteenth aspect, alone or in combination with one or more of the first to fourteenth aspects, the CSI-RS is for periodic or semi-persistent CSI feedback.

[0157]

[0165] In a sixteenth aspect, alone or in combination with one or more of the first to fifteenth aspects, the CSI-RS is for aperiodic CSI feedback.

[0158]

[0166] In a seventeenth aspect, alone or in combination with one or more of the first through sixteenth aspects, the process 800 may include rate-matching a shared channel around resources of the CSI-RS based on a plurality of subbands available for the CSI-RS.

[0159]

[0167] In an eighteenth aspect, alone or in combination with one or more of the first through seventeenth aspects, the process 800 may include selectively receiving the CSI-RS based on at least one of a COT-SI received before the resource of the CSI-RS, a signal-to-noise ratio associated with the resource of the CSI-RS, or a value associated with a grant for the shared channel.

[0160]

[0168] In a nineteenth aspect, alone or in combination with one or more of the first to eighteenth aspects, the process 800 may include performing processing operations related to the CSI-RS for a plurality of subbands based on the COT-SI received after the CSI-RS is received.

[0161]

[0169] In a twentieth aspect, alone or in combination with one or more of the first to nineteenth aspects, the process 800 may include: performing a processing operation for each subband associated with the CSI-RS to determine CSI feedback for each subband; and identifying a subset of subbands among the plurality of subbands on which the CSI-RS is received; wherein the CSI feedback is based on the CSI feedback for each subband associated with the subset of subbands.

[0162]

[0170] In a twenty-first aspect, alone or in combination with one or more of the first through twentieth aspects, the process 800 may include receiving a grant for a subset of subbands among a plurality of subbands, and rate-matching a shared channel associated with the grant around resources associated with the CSI-RS on the subset of subbands.

[0163]

[0171] In a 22nd aspect, alone or in combination with one or more of the 1st to 21st aspects, the process 800 may include receiving a grant for a subset of subbands among a plurality of subbands, and rate-matching a shared channel associated with the grant around resources associated with the CSI-RS on the subset of subbands based on a COT-SI received prior to the CSI-RS, where the COT-SI indicates that the subset of subbands is available.

[0164]

[0172] In a twenty-third aspect, alone or in combination with one or more of the first to twenty-second aspects, CSI-RS is received on a subset of subbands.

[0165]

[0173] In a twenty-fourth aspect, alone or in combination with one or more of the first to twenty-third aspects, the configuration information includes configurations for a plurality of different subsets of subbands of the plurality of subbands.

[0166]

[0174] In a twenty-fifth aspect, alone or in combination with one or more of the first through twenty-fourth aspects, the process 800 may include receiving a trigger related to a configuration for a particular subset of subbands of a plurality of different subsets of subbands based on the particular subset of subbands that are available for CSI-RS.

[0167]

[0175] In a twenty-sixth aspect, alone or in combination with one or more of the first through twenty-fifth aspects, the process 800 may include receiving a trigger indicating a particular subset of subbands of a plurality of different subsets of subbands based on the particular subset of subbands that are available for CSI-RS.

[0168]

[0176] In a 27th aspect, alone or in combination with one or more of the first to 26th aspects, the power level of the CSI-RS per resource element or per subband is independent of the number of subbands on which the CSI-RS is transmitted.

[0169]

[0177] In a 28th aspect, alone or in combination with one or more of the first to 27th aspects, the power level of the CSI-RS per resource element or per subband is based on the number or configuration of subbands on which the CSI-RS is transmitted.

[0170]

[0178] In a 29th aspect, alone or in combination with one or more of the first to 28th aspects, the power level of the CSI-RS is based on whether the CSI-RS is aperiodic, periodic, or semi-persistent.

[0171]

[0179] In a thirtieth aspect, alone or in combination with one or more of the first to twenty-ninth aspects, the process 800 may include determining a power level of the CSI-RS based on at least one of information indicating the number or configuration of subbands on which the CSI-RS is transmitted, or the power level of the CSI-RS.

[0172]

[0180] 8 illustrates example blocks of process 800, in some aspects process 800 may include additional blocks, fewer blocks, different blocks, or blocks configured differently than those illustrated in FIGURE 8. Additionally or alternatively, two or more of the blocks of process 800 may be performed in parallel.

[0173]

[0181] 9 illustrates an example process 900, performed by, for example, a BS, by a base station, such as base station 110, to perform operations related to CSI-RS transmission over a wideband structure.

[0174]

[0182] 9, in some aspects, process 900 may include transmitting configuration information for CSI-RS, where the configuration information indicates a plurality of subbands of a wideband structure for the CSI-RS (block 910). For example, a base station or an interface of the base station (using controller / processor 240, transmit processor 220, TX MIMO processor 230, MOD 232, antenna 234) may transmit the configuration information for the CSI-RS. In some aspects, the configuration information indicates a plurality of subbands of a wideband structure for the CSI-RS.

[0175]

[0183] 9, in some aspects, process 900 may include performing a listen-before-talk (LBT) operation to identify a subset of subbands among a plurality of subbands available for CSI-RS, where the subset of subbands includes up to all subbands among the plurality of subbands (block 920). For example, a base station or an interface of the base station (using antenna 234, DEMOD 232, MIMO detector 236, receive processor 238, controller / processor 240) may perform an LBT operation to identify a subset of subbands among a plurality of subbands available for CSI-RS. The subset of subbands includes up to all subbands among the plurality of subbands.

[0176]

[0184] 9, in some aspects, process 900 may include selectively transmitting the CSI-RS based on the result of the LBT operation (block 930). For example, the base station or an interface of the base station (using controller / processor 240, transmit processor 220, TX MIMO processor 230, MOD 232, antennas 234) may selectively transmit the CSI-RS based on the result of the LBT operation, as described above.

[0177]

[0185] Process 900 may include additional aspects, such as any single aspect or any combination of aspects, related to one or more other processes described below or elsewhere herein.

[0178]

[0186] In a first aspect, when all subbands of the plurality of subbands are available for CSI-RS, CSI-RS is transmitted, and when at least one subband of the plurality of subbands is not available for CSI-RS, CSI-RS is not transmitted.

[0179]

[0187] In a second aspect, alone or in combination with the first aspect, the process 900 may include rate-matching the shared channel around the resources of the CSI-RS regardless of whether the CSI-RS is transmitted or not.

[0180]

[0188] In a third aspect, alone or in combination with one or more of the first and second aspects, the subset of subbands includes less than all subbands of the plurality of subbands.

[0181]

[0189] In a fourth aspect, alone or in combination with one or more of the first to third aspects, a sequence for CSI-RS for multiple subbands is punctured to generate CSI-RS for a subset of the subbands.

[0182]

[0190] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, the CSI-RS for a subset of subbands is generated based on a shortened sequence relative to a sequence for the CSI-RS for the plurality of subbands.

[0183]

[0191] In a sixth aspect, alone or in combination with one or more of the first to fifth aspects, the process 900 may include transmitting a trigger for CSI feedback related to the CSI-RS based on all subbands of a plurality of subbands that are available for the CSI-RS.

[0184]

[0192] In a seventh aspect, alone or in combination with one or more of the first to sixth aspects, when the CSI-RS is transmitted on a subset of subbands of a plurality of subbands, the CSI-RS is transmitted on resource elements on the subset of subbands corresponding to the widest bandwidth of the wideband structure.

[0185]

[0193] In an eighth aspect, alone or in combination with one or more of the first to seventh aspects, the CSI-RS is based on the same sequence for the widest bandwidth and for a subset of subbands.

[0186]

[0194] In a ninth aspect, alone or in combination with one or more of the first to eighth aspects, the CSI-RS spans 48 resource blocks in subbands of a subset of subbands.

[0187]

[0195] In a tenth aspect, alone or in combination with one or more of the first to ninth aspects, the resource elements intersect with resource elements of the wideband structure.

[0188]

[0196] In an eleventh aspect, alone or in combination with one or more of the first to tenth aspects, the CSI-RS is for periodic or semi-persistent CSI feedback.

[0189]

[0197] In a twelfth aspect, alone or in combination with one or more of the first to eleventh aspects, the CSI-RS is for aperiodic CSI feedback.

[0190]

[0198] In a thirteenth aspect, alone or in combination with one or more of the first through twelfth aspects, the process 900 may include rate-matching a shared channel around resources of the CSI-RS based on a plurality of subbands available for the CSI-RS.

[0191]

[0199] In a fourteenth aspect, alone or in combination with one or more of the first to thirteenth aspects, the process 900 may include transmitting subband usage information that identifies a subset of subbands, where the subband usage information that identifies the subset of subbands is associated with at least one of COT-SI transmitted before resources of the CSI-RS, a value related to a grant for the shared channel, or downlink control information indicating the subset of subbands.

[0192]

[0200] In a fifteenth aspect, alone or in combination with one or more of the first through fourteenth aspects, the process 900 may include transmitting a grant for a subset of subbands and rate-matching a shared channel associated with the grant around resources associated with the CSI-RS on the subset of subbands.

[0193]

[0201] In a sixteenth aspect, alone or in combination with one or more of the first through fifteenth aspects, the process 900 may include transmitting a grant for a subset of subbands, transmitting the COT-SI before the CSI-RS, and rate-matching a shared channel associated with the grant around resources associated with the CSI-RS on the subset of subbands based on the COT-SI being transmitted before the CSI-RS.

[0194]

[0202] In a seventeenth aspect, alone or in combination with one or more of the first to sixteenth aspects, the process 900 may include transmitting a trigger for CSI feedback related to the CSI-RS after a COT-SI indicating a subset of subbands among a plurality of subbands available for the CSI-RS.

[0195]

[0203] In an eighteenth aspect, alone or in combination with one or more of the first to seventeenth aspects, the configuration information includes configurations for a plurality of different subsets of subbands of the plurality of subbands.

[0196]

[0204] In a nineteenth aspect, alone or in combination with one or more of the first through eighteenth aspects, the process 900 may include transmitting a trigger related to a configuration for a particular subset of subbands of a plurality of different subsets of subbands based on the particular subset of subbands that are available for CSI-RS.

[0197]

[0205] In a twentieth aspect, alone or in combination with one or more of the first through nineteenth aspects, the process 900 may include transmitting a trigger indicating a particular subset of subbands of a plurality of different subsets of subbands based on the particular subset of subbands that are available for CSI-RS.

[0198]

[0206] In a 21st aspect, alone or in combination with one or more of the 1st to 20th aspects, the power level of the CSI-RS per resource element or per subband is independent of the number of subbands on which the CSI-RS is transmitted.

[0199]

[0207] In a 22nd aspect, alone or in combination with one or more of the 1st to 21st aspects, the power level of the CSI-RS per resource element or per subband is based on the number or configuration of subbands on which the CSI-RS is transmitted.

[0200]

[0208] In a 23rd aspect, alone or in combination with one or more of the 1st to 22nd aspects, the power level of the CSI-RS per resource element or per subband is based on whether the CSI-RS is aperiodic, periodic, or semi-persistent.

[0201]

[0209] In a 24th aspect, alone or in combination with one or more of the 1st to 23rd aspects, the process 900 may include determining a power level of the CSI-RS based on at least one of information indicating the number or configuration of subbands on which the CSI-RS is transmitted or the power level of the CSI-RS.

[0202]

[0210] In a 25th aspect, alone or in combination with one or more of the first to 24th aspects, a CSI-RS is transmitted when a COT-SI associated with the CSI-RS may be transmitted before the CSI-RS, and wherein the CSI-RS is not transmitted when a COT-SI associated with the CSI-RS may not be transmitted before the CSI-RS.

[0203]

[0211] 9 illustrates example blocks of process 900, in some aspects process 900 may include additional blocks, fewer blocks, different blocks, or blocks configured differently than those shown in FIGURE 9. Additionally or alternatively, two or more of the blocks of process 900 may be performed in parallel.

[0204]

[0212] The above disclosure provides illustration and description, and is not intended to be exhaustive or to limit the embodiments to the precise form disclosed. Modifications and variations may be made in light of the above disclosure or acquired from practice of the embodiments.

[0205]

[0213] The term "component" as used herein shall be broadly interpreted as hardware, firmware, or a combination of hardware and software. A processor as used herein is implemented in hardware, firmware, or a combination of hardware and software. The phrase "based on" as used herein shall be broadly interpreted to mean "based on."

[0206]

[0214] As used herein, satisfying a threshold can refer to a value being greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, etc., depending on the context.

[0207]

[0215] As used in the specification, a phrase referring to "at least one of" a list of items refers to any combination of those items, including single members. As an example, "at least one of a, b, or c" is intended to encompass a, b, c, ab, ac, bc, and abc.

[0208]

[0216] The various example logic, logic blocks, modules, circuits, and algorithmic processes described in connection with the aspects disclosed herein may be implemented as electronic hardware, computer software, or a combination of both. Interchangeability between hardware and software has been described generally in terms of functionality and is illustrated in the various example components, blocks, modules, circuits, and processes described above. Whether such functionality is implemented in hardware or software depends on the particular application and design constraints imposed on the overall system.

[0209]

[0217] The hardware and data processing devices used to implement the various example logic, logic blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed using general-purpose single-chip or multi-chip processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, 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. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a group of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some aspects, particular processes and methods may be performed by circuitry that is specific to a given function.

[0210]

[0218] In one or more aspects, the functions described may be implemented in hardware, digital electronic circuitry, computer software, firmware, including the structures disclosed herein, and structural equivalents of those structures, or any combination thereof. Aspects of the subject matter described herein may also be implemented as one or more computer programs, i.e., as one or more modules of computer program instructions encoded on a computer storage medium for execution by, or for controlling the operation of, a data processing apparatus.

[0211]

[0219] If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. The processes of a method or algorithm disclosed herein may be implemented in a processor-executable software module, which may reside on a computer-readable medium. Computer-readable media includes both computer storage media and computer communication media, including any medium that may enable transfer of a computer program from one place to another. A storage medium may be any available medium that can be accessed by a computer. By way of example, and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection may be properly referred to as a computer-readable medium. As used herein, disk and disc include compact discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), floppy discs, and Blu-ray discs, where disks typically reproduce data magnetically and discs reproduce data optically with a laser. Combinations of the above should also be included within the scope of computer-readable media. Furthermore, the operations of a method or algorithm may reside as one or any combination of code and instructions on a machine-readable medium and a computer-readable medium, which may be incorporated into a computer program product.

[0212]

[0220] Various modifications to the embodiments described in this disclosure will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Accordingly, the claims are not intended to be limited to the embodiments shown herein, but are to be accorded the widest scope consistent with this disclosure and the principles and novel features disclosed herein.

[0213]

[0221] Additionally, those skilled in the art will readily appreciate that the terms "upper" and "lower" are sometimes used to simplify the description of the figures and refer to relative positions that correspond to the orientation of the figure on a properly oriented page, and may not reflect the proper orientation of any device when implemented.

[0214]

[0222] Also, certain features described herein in the context of separate aspects may be implemented in combination in a single aspect. Conversely, various features described in the context of a single aspect may be implemented in multiple aspects separately or in any suitable subcombination. Furthermore, while features may be described above as acting in a particular combination and initially claimed as such, one or more features of a claimed combination may, in some cases, be separated from that combination, and the claimed combination may be directed to a subcombination or a variation of the subcombination.

[0215]

[0223] Similarly, while operations are illustrated in the figures in a particular order, this should not be understood as requiring such operations to be performed in the particular order or sequence shown, or that all of the illustrated operations be performed, to achieve desirable results. Additionally, the figures may generally depict another exemplary process in the form of a flow chart. However, other operations not shown may be incorporated into the generally depicted exemplary process. For example, one or more additional operations may be performed before, after, simultaneously with, or between any of the illustrated operations. In some situations, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the above-described aspects should not be understood as requiring such separation in all aspects, and it should be understood that the described program components and systems may generally be integrated together in a single software product or packaged in multiple software products. Furthermore, other aspects are within the scope of the following claims. In some cases, the actions recited in the claims may be performed in a different order and still achieve desirable results. The inventions described in the claims of the present application as originally filed are set forth below. [C1] 1. A method of wireless communication performed by a user equipment (UE) device, comprising: receiving configuration information for a channel state information reference signal (CSI-RS), wherein the configuration information indicates that the CSI-RS is configured on a plurality of subbands of a wideband structure; selectively receiving the CSI-RS based on the configuration information and based on subband validity indications associated with the plurality of subbands; If the CSI-RS is received, transmitting channel state information (CSI) feedback based on the configuration information. A method comprising: [C2] receiving downlink control information indicating the subband availability indication; The method of C1, further comprising: [C3] The method of claim 1, wherein the CSI-RS is received when all subbands of the plurality of subbands are available for the CSI-RS, and the CSI-RS is not received when at least one subband of the plurality of subbands is not available for the CSI-RS. [C4] rate-matching a shared channel around resources of the CSI-RS regardless of whether the CSI-RS is received; The method of C1, further comprising: [C5] performing processing operations related to the CSI-RS on the plurality of subbands regardless of whether the CSI-RS is received. The method of C1, further comprising: [C6] determining that the CSI-RS is to be received based on subband usage information received prior to a resource associated with the CSI-RS; and performing processing operations related to the CSI-RS on the plurality of subbands based on determining that the CSI-RS is to be received; and The method of C1, further comprising: [C7] The method of C1, wherein the CSI-RS is received on a subset of subbands of the plurality of subbands based on the subset of subbands available for the CSI-RS. [C8] The method of C7, wherein a sequence for the CSI-RS for the plurality of subbands is punctured to generate the CSI-RS for the subset of subbands. [C9] The method of C7, wherein the CSI-RS for the subset of subbands is generated based on a shortened sequence relative to a sequence for the CSI-RS for the plurality of subbands. [C10] receiving a trigger for the CSI feedback based on all subbands among the plurality of subbands available for the CSI-RS; The method of C1, further comprising: [C11] The method of claim 1, wherein when the CSI-RS is received on a subset of subbands among the plurality of subbands, the CSI-RS is received on resource elements on the subset of subbands corresponding to a widest bandwidth of the wideband structure. [C12] The method of C11, wherein the CSI-RS is generated based on the same sequence for the widest bandwidth and for the subset of subbands. [C13] The method of C11, wherein the CSI-RS spans 48 resource blocks in subbands of the subset of subbands. [C14] The method of C11, wherein the resource elements intersect with resource elements of the wideband structure. [C15] receiving a trigger for the CSI feedback after a channel occupancy time structure indicator (COT-SI) indicating a subset of subbands among the plurality of subbands that are available for the CSI-RS; The method of C1, further comprising: [C16] The method of C1, wherein the CSI-RS is for periodic or semi-persistent CSI feedback. [C17] The method according to C1, wherein the CSI-RS is for aperiodic CSI feedback. [C18] rate-matching a shared channel around resources of the CSI-RS based on the plurality of subbands available for the CSI-RS; The method of C1, further comprising: [C19] Selectively receiving the CSI-RS includes: a channel occupancy time structure indicator (COT-SI) received before the resource of the CSI-RS; a signal-to-noise ratio associated with said CSI-RS resource; or Values related to permissions for shared channels selectively receiving the CSI-RS based on at least one of The method of C1, further comprising: [C20] performing processing operations related to the CSI-RS for the plurality of subbands based on a channel occupancy time structure indicator (COT-SI) received after the CSI-RS is received. The method of C1, further comprising: [C21] performing a per-subband processing operation associated with the CSI-RS to determine per-subband CSI feedback; identifying a subset of subbands among the plurality of subbands on which the CSI-RS is received, wherein the CSI feedback is based on the per-subband CSI feedback associated with the subset of subbands; The method of C1, further comprising: [C22] receiving a grant for a subset of subbands of the plurality of subbands; rate matching a shared channel associated with the grant around resources associated with the CSI-RS on the subset of subbands; and The method of C1, further comprising: [C23] receiving a grant for a subset of subbands of the plurality of subbands; rate-matching a shared channel associated with the grant around resources associated with the CSI-RS on the subset of subbands based on a channel occupancy time structure indicator (COT-SI) received prior to the CSI-RS, wherein the COT-SI indicates that the subset of subbands is available for use. The method of C1, further comprising: [C24] The method of C23, wherein the CSI-RS is received on a subset of subbands. [C25] The method of C1, wherein the configuration information includes configurations for different subsets of subbands of the plurality of subbands. [C26] receiving a trigger related to a configuration for the particular subset of subbands of the plurality of different subsets of subbands based on the particular subset of subbands that are available for the CSI-RS; The method of C25, further comprising: [C27] receiving a trigger indicating a particular subset of subbands of the plurality of different subsets of subbands based on the particular subset of subbands that are available for the CSI-RS; The method of C25, further comprising: [C28] The method of C1, wherein the power level of the CSI-RS per resource element or per subband is independent of the number of subbands on which the CSI-RS is transmitted. [C29] The method of C1, wherein the power level of the CSI-RS per resource element or per subband is based on the number or configuration of subbands on which the CSI-RS is transmitted. [C30] The method of C1, wherein the power level of the CSI-RS is based on whether the CSI-RS is aperiodic, periodic, or semi-persistent. [C31] the number or configuration of subbands on which the CSI-RS is transmitted; or Information indicating the power level of the CSI-RS determining the power level of the CSI-RS based on at least one of The method of C1, further comprising: [C32] 1. A method of wireless communication performed by a base station device, comprising: transmitting configuration information for a channel state information reference signal (CSI-RS), wherein the configuration information indicates a plurality of subbands of a wideband structure for the CSI-RS; performing a listen-before-talk (LBT) operation to identify a subset of subbands of the plurality of subbands that are available for the CSI-RS, wherein the subset of subbands includes up to all subbands of the plurality of subbands; selectively transmitting the CSI-RS based on a result of the LBT operation; A method comprising: [C33] The method of claim 32, wherein the CSI-RS is transmitted when all subbands of the plurality of subbands are available for the CSI-RS, and the CSI-RS is not transmitted when at least one subband of the plurality of subbands is not available for the CSI-RS. [C34] rate-matching a shared channel around resources of the CSI-RS regardless of whether the CSI-RS is transmitted; The method of C32, further comprising: [C35] The method of C32, wherein the subset of subbands includes less than all subbands of the plurality of subbands. [C36] The method of C35, wherein a sequence for the CSI-RS for the plurality of subbands is punctured to generate the CSI-RS for the subset of subbands. [C37] The method of C35, wherein the CSI-RS for the subset of subbands is generated based on a shortened sequence relative to a sequence for the CSI-RS for the plurality of subbands. [C38] transmitting a trigger for CSI feedback related to the CSI-RS based on all subbands among the plurality of subbands available for the CSI-RS. The method of C32, further comprising: [C39] 3. The method of claim 2, wherein when the CSI-RS is transmitted on the subset of subbands of the plurality of subbands, the CSI-RS is transmitted on resource elements on the subset of subbands corresponding to a widest bandwidth of the wideband structure. [C40] The method of C39, wherein the CSI-RS is based on the same sequence for the widest bandwidth and for the subset of subbands. [C41] 30. The method of claim 39, wherein the CSI-RS spans 48 resource blocks in subbands of the subset of subbands. [C42] The method of C39, wherein the resource elements intersect with resource elements of the wideband structure. [C43] The method of C32, wherein the CSI-RS is for periodic or semi-persistent CSI feedback. [C44] The method of C32, wherein the CSI-RS is for aperiodic CSI feedback. [C45] rate-matching a shared channel around resources of the CSI-RS based on the plurality of subbands available for the CSI-RS; The method of C32, further comprising: [C46] transmitting subband usage information identifying the subset of subbands, wherein the subband usage information identifying the subset of subbands comprises: a channel occupancy time structure indicator (COT-SI) transmitted before the resource of said CSI-RS; A value related to the permissions for the shared channel, or downlink control information indicating said subset of subbands associated with at least one of The method of C32, further comprising: [C47] transmitting a grant for the subset of subbands; rate matching a shared channel associated with the grant around resources associated with the CSI-RS on the subset of subbands; and The method of C32, further comprising: [C48] transmitting a grant for the subset of subbands; transmitting a channel occupancy time structure indicator (COT-SI) before the CSI-RS; rate matching the grant-related shared channel around resources related to the CSI-RS on the subset of subbands based on the COT-SI being transmitted before the CSI-RS; The method of C32, further comprising: [C49] transmitting a trigger for CSI feedback associated with the CSI-RS after a channel occupancy time structure indicator (COT-SI) indicating the subset of subbands among the plurality of subbands that are available for the CSI-RS; The method of C32, further comprising: [C50] The method of C32, wherein the configuration information includes configurations for different subsets of subbands of the plurality of subbands. [C51] transmitting a trigger related to a configuration for the particular subset of subbands of the plurality of different subsets of subbands based on the particular subset of subbands that are available for the CSI-RS. The method of C50, further comprising: [C52] transmitting a trigger indicating the particular subset of subbands of the plurality of different subsets of subbands based on the particular subset of subbands that are available for the CSI-RS. The method of C50, further comprising: [C53] The method of C32, wherein the power level of the CSI-RS per resource element or per subband is independent of the number of subbands on which the CSI-RS is transmitted. [C54] The method of C32, wherein the power level of the CSI-RS per resource element or per subband is based on the number or configuration of subbands on which the CSI-RS is transmitted. [C55] The method of claim 32, wherein the power level of the CSI-RS per resource element or per subband is based on whether the CSI-RS is aperiodic, periodic, or semi-persistent. [C56] the number or configuration of subbands on which the CSI-RS is transmitted; or Information indicating the power level of the CSI-RS determining the power level of the CSI-RS based on at least one of The method of C32, further comprising: [C57] The method of C32, wherein the CSI-RS is transmitted when a channel occupancy time structure indicator (COT-SI) associated with the CSI-RS may be transmitted before the CSI-RS, and wherein the CSI-RS is not transmitted when the COT-SI associated with the CSI-RS may not be transmitted before the CSI-RS. [C58] 1. A user equipment (UE) apparatus for wireless communications, comprising: a first interface; and obtaining configuration information for a channel state information reference signal (CSI-RS), wherein the configuration information indicates that the CSI-RS is configured on a plurality of subbands of a wideband structure; selectively acquiring the CSI-RS based on the configuration information and based on subband validity indications associated with the plurality of subbands; configured to: a second interface configured to transmit channel state information (CSI) feedback based on the configuration information if the CSI-RS is acquired; and An apparatus comprising: [C59] The first interface includes: obtaining downlink control information indicative of the subband availability indication; The apparatus of C58, further configured to: [C60] The apparatus of C58, wherein the CSI-RS is acquired when all subbands of the plurality of subbands are available for the CSI-RS, and the CSI-RS is not acquired when at least one subband of the plurality of subbands is not available for the CSI-RS. [C61] determining that the CSI-RS is to be received based on subband usage information received prior to a resource associated with the CSI-RS; and performing processing operations related to the CSI-RS with respect to the plurality of subbands based on determining that the CSI-RS is to be acquired; and The apparatus of C58, further comprising a processing system configured to perform [C62] The apparatus of C58, wherein the CSI-RS is obtained on the subset of subbands of the plurality of subbands based on the subset of subbands available for the CSI-RS. [C63] The apparatus of C62, wherein a sequence for the CSI-RS for the plurality of subbands is punctured to generate the CSI-RS for the subset of subbands. [C64] The apparatus of C62, wherein the CSI-RS for the subset of subbands is generated based on a shortened sequence relative to a sequence for the CSI-RS for the plurality of subbands. [C65] The first interface includes: deriving the trigger for CSI feedback based on all subbands among the plurality of subbands available for the CSI-RS; The apparatus of C58, further configured to: [C66] 5. The apparatus of claim 4, wherein when the CSI-RS is obtained on a subset of subbands among the plurality of subbands, the CSI-RS is obtained on resource elements on the subset of subbands corresponding to a widest bandwidth of the wideband structure. [C67] The apparatus of C66, wherein the CSI-RS is generated based on the same sequence for the widest bandwidth and for the subset of subbands. [C68] The apparatus of C66, wherein the CSI-RS spans 48 resource blocks in subbands of the subset of subbands. [C69] The apparatus of C66, wherein the resource elements intersect with resource elements of the wideband structure. [C70] 1. An apparatus of a base station for wireless communication, comprising: a first interface; and outputting configuration information for a channel state information reference signal (CSI-RS), wherein the configuration information indicates a plurality of subbands of a wideband structure for the CSI-RS; configured to: a processing system, performing a listen-before-talk (LBT) operation to identify a subset of subbands of the plurality of subbands that are available for the CSI-RS, wherein the subset of subbands includes up to all subbands of the plurality of subbands; configured to: Equipped with wherein the first interface is Selectively outputting the CSI-RS based on a result of the LBT operation. The apparatus is further configured to: [C71] The apparatus of C70, wherein the CSI-RS is output when all subbands of the plurality of subbands are available for the CSI-RS, and the CSI-RS is not output when at least one subband of the plurality of subbands is not available for the CSI-RS. [C72] The first interface includes: rate-matching a shared channel around the resources of the CSI-RS regardless of whether the CSI-RS is output; The apparatus of C70, further configured to: [C73] The apparatus of C70, wherein the subset of subbands includes less than all subbands of the plurality of subbands. [C74] The apparatus of C73, wherein a sequence for the CSI-RS for the plurality of subbands is punctured to generate the CSI-RS for the subset of subbands. [C75] The apparatus of C73, wherein the CSI-RS for the subset of subbands is generated based on a shortened sequence relative to a sequence for the CSI-RS for the plurality of subbands. [C76] The first interface includes: outputting a trigger for CSI feedback related to the CSI-RS based on all subbands among the plurality of subbands available for the CSI-RS; The apparatus of C70, further configured to: [C77] 4. The apparatus of claim 3, wherein when the CSI-RS is output on the subset of subbands of the plurality of subbands, the CSI-RS is output on resource elements on the subset of subbands corresponding to a widest bandwidth of the wideband structure. [C78] The apparatus of C77, wherein the CSI-RS is based on the same sequence for the widest bandwidth and for the subset of subbands. [C79] The apparatus of C77, wherein the CSI-RS spans 48 resource blocks in subbands of the subset of subbands. [C80] The apparatus of C77, wherein the resource elements intersect with resource elements of the wideband structure. [C81] 1. A non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions comprising: When executed by one or more processors of a user equipment (UE), the one or more processors: receiving configuration information for a channel state information reference signal (CSI-RS), wherein the configuration information indicates that the CSI-RS is configured on a plurality of subbands of a wideband structure; selectively transmitting the CSI-RS based on the configuration information and based on subband availability indications associated with the plurality of subbands; If the CSI-RS is received, transmitting channel state information (CSI) feedback based on the configuration information. One or more instructions that cause 1. A non-transitory computer-readable medium comprising: [C82] The one or more instructions, when executed by the one or more processors, cause the one or more processors to: receiving downlink control information indicating the subband availability indication; A non-transitory computer-readable medium as described in C81, which causes [C83] The non-transitory computer-readable medium of C81, wherein the CSI-RS is received when all subbands of the plurality of subbands are available for the CSI-RS, and the CSI-RS is not received when at least one subband of the plurality of subbands is not available for the CSI-RS. [C84] The one or more instructions, when executed by the one or more processors, cause the one or more processors to: determining that the CSI-RS is to be received based on subband usage information received prior to a resource associated with the CSI-RS; and performing processing operations related to the CSI-RS on the plurality of subbands based on determining that the CSI-RS is to be received; and A non-transitory computer-readable medium as described in C81, which causes [C85] The non-transitory computer-readable medium of C81, wherein the CSI-RS is received on a subset of subbands of the plurality of subbands based on the subset of subbands available for the CSI-RS. [C86] 8. The non-transitory computer-readable medium of claim 7, wherein a sequence for the CSI-RS for the plurality of subbands is punctured to generate the CSI-RS for the subset of subbands. [C87] The non-transitory computer-readable medium of C85, wherein the CSI-RS for the subset of subbands is generated based on a shortened sequence relative to a sequence for the CSI-RS for the plurality of subbands. [C88] The one or more instructions, when executed by the one or more processors, cause the one or more processors to: receiving a trigger for the CSI feedback based on all subbands among the plurality of subbands available for the CSI-RS; A non-transitory computer-readable medium as described in C81, which causes [C89] 8. The non-transitory computer-readable medium of claim 7, wherein when the CSI-RS is received on a subset of subbands among the plurality of subbands, the CSI-RS is received on resource elements on the subset of subbands corresponding to a widest bandwidth of the wideband structure. [C90] The non-transitory computer-readable medium of C89, wherein the CSI-RS is generated based on the same sequence for the widest bandwidth and for the subset of subbands. [C91] 89. The non-transitory computer-readable medium of claim 89, wherein the CSI-RS spans 48 resource blocks in subbands of the subset of subbands. [C92] The non-transitory computer-readable medium of C89, wherein the resource elements intersect with resource elements of the wideband structure. [C93] 1. A non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions comprising: When executed by one or more processors of a base station, the one or more processors: transmitting configuration information for a channel state information reference signal (CSI-RS), wherein the configuration information indicates a plurality of subbands of a wideband structure for the CSI-RS; performing a listen-before-talk (LBT) operation to identify a subset of subbands of the plurality of subbands that are available for the CSI-RS, wherein the subset of subbands includes up to all subbands of the plurality of subbands; selectively transmitting the CSI-RS based on a result of the LBT operation; One or more instructions that cause 1. A non-transitory computer-readable medium comprising: [C94] 9. The non-transitory computer-readable medium of claim 8, wherein the CSI-RS is transmitted when all subbands of the plurality of subbands are available for the CSI-RS, and the CSI-RS is not transmitted when at least one subband of the plurality of subbands is not available for the CSI-RS. [C95] The one or more instructions, when executed by the one or more processors, cause the one or more processors to: rate-matching a shared channel around resources of the CSI-RS regardless of whether the CSI-RS is transmitted; A non-transitory computer-readable medium as described in C93 that causes [C96] The non-transitory computer-readable medium of C93, wherein the subset of subbands includes less than all subbands of the plurality of subbands. [C97] 93. The non-transitory computer-readable medium of claim 93, wherein a sequence for the CSI-RS for the plurality of subbands is punctured to generate the CSI-RS for the subset of subbands. [C98] 93. The non-transitory computer-readable medium of claim 93, wherein the CSI-RS for the subset of subbands is generated based on a shortened sequence relative to a sequence for the CSI-RS for the plurality of subbands. [C99] The one or more instructions, when executed by the one or more processors, cause the one or more processors to: transmitting a trigger for CSI feedback related to the CSI-RS based on all subbands among the plurality of subbands available for the CSI-RS. A non-transitory computer-readable medium as described in C93 that causes [C100] 9. The non-transitory computer-readable medium of claim 8, wherein when the CSI-RS is transmitted on the subset of subbands of the plurality of subbands, the CSI-RS is transmitted on resource elements on the subset of subbands corresponding to a widest bandwidth of the wideband structure. [C101] The non-transitory computer-readable medium of C100, wherein the CSI-RS is based on the same sequence for the widest bandwidth and for the subset of subbands. [C102] The non-transitory computer-readable medium of C100, wherein the CSI-RS spans 48 resource blocks in subbands of the subset of subbands. [C103] The non-transitory computer-readable medium of C100, wherein the resource elements intersect with resource elements of the wideband structure. [C104] 1. An apparatus for wireless communication, comprising: means for transmitting configuration information for a channel state information reference signal (CSI-RS), wherein the configuration information indicates that the CSI-RS is configured on a plurality of subbands of a wideband structure. means for selectively transmitting the CSI-RS based on the configuration information and based on a subband validity indication associated with the plurality of subbands; means for transmitting channel state information (CSI) feedback based on the configuration information if the CSI-RS is received; An apparatus comprising: [C105] means for receiving downlink control information indicative of said subband availability indication; The apparatus of C104, further comprising: [C106] The apparatus of C104, wherein the CSI-RS is received when all subbands of the plurality of subbands are available for the CSI-RS, and the CSI-RS is not received when at least one subband of the plurality of subbands is not available for the CSI-RS. [C107] means for determining that the CSI-RS is to be received based on subband usage information received before a resource associated with the CSI-RS; means for performing processing operations related to the CSI-RS on the plurality of subbands based on determining that the CSI-RS is to be received; The apparatus of C104, further comprising: [C108] The apparatus of C104, wherein the CSI-RS is received on a subset of subbands of the plurality of subbands based on the subset of subbands available for the CSI-RS. [C109] 108. The apparatus of claim 108, wherein a sequence for the CSI-RS for the plurality of subbands is punctured to generate the CSI-RS for the subset of subbands. [C110] The apparatus of C108, wherein the CSI-RS for the subset of subbands is generated based on a shortened sequence relative to a sequence for the CSI-RS for the plurality of subbands. [C111] means for receiving a trigger for the CSI feedback based on all subbands of the plurality of subbands available for the CSI-RS; The apparatus of C104, further comprising: [C112] 10. The apparatus of claim 104, wherein when the CSI-RS is received on a subset of subbands among the plurality of subbands, the CSI-RS is received on resource elements on the subset of subbands corresponding to a widest bandwidth of the wideband structure. [C113] The apparatus of C112, wherein the CSI-RS is generated based on the same sequence for the widest bandwidth and for the subset of subbands. [C114] The apparatus of C112, wherein the CSI-RS spans 48 resource blocks in subbands of the subset of subbands. [C115] The apparatus of C112, wherein the resource elements intersect with resource elements of the wideband structure. [C116] 1. An apparatus for wireless communication, comprising: means for transmitting configuration information for a channel state information reference signal (CSI-RS), wherein the configuration information indicates a plurality of subbands of a wideband structure for the CSI-RS; means for performing a listen-before-talk (LBT) operation to identify a subset of subbands of the plurality of subbands that are available for the CSI-RS, wherein the subset of subbands includes up to all subbands of the plurality of subbands. means for selectively transmitting the CSI-RS based on a result of the LBT operation; An apparatus comprising: [C117] 117. The apparatus of claim 116, wherein the CSI-RS is transmitted when all subbands of the plurality of subbands are available for the CSI-RS, and the CSI-RS is not transmitted when at least one subband of the plurality of subbands is not available for the CSI-RS. [C118] means for rate-matching a shared channel around resources of the CSI-RS regardless of whether the CSI-RS is transmitted; The apparatus of C116, further comprising: [C119] The apparatus of C116, wherein the subset of subbands includes less than all subbands of the plurality of subbands. [C120] 13. The apparatus of claim 119, wherein a sequence for the CSI-RS for the plurality of subbands is punctured to generate the CSI-RS for the subset of subbands. [C121] The apparatus of C119, wherein the CSI-RS for the subset of subbands is generated based on a shortened sequence relative to a sequence for the CSI-RS for the plurality of subbands. [C122] means for transmitting a trigger for CSI feedback related to the CSI-RS based on all subbands of the plurality of subbands available for the CSI-RS; The apparatus of C119, further comprising: [C123] 119. The apparatus of claim 119, wherein when the CSI-RS is transmitted on the subset of subbands among the plurality of subbands, the CSI-RS is transmitted on resource elements on the subset of subbands corresponding to a widest bandwidth of the wideband structure. [C124] The apparatus of C123, wherein the CSI-RS is based on the same sequence for the widest bandwidth and for the subset of subbands. [C125] The apparatus of C123, wherein the CSI-RS spans 48 resource blocks in subbands of the subset of subbands. [C126] The apparatus of C123, wherein the resource elements intersect with resource elements of the wideband structure.

Claims

1. 1. A method of wireless communication performed by a user equipment (UE) device, comprising: receiving configuration information for a channel state information reference signal (CSI-RS), wherein the configuration information indicates that the CSI-RS is configured on a plurality of subbands; receiving information indicating availability of the plurality of subbands for the CSI-RS; selectively receiving the CSI-RS based on the configuration information and based on the availability of the plurality of subbands for the CSI-RS, wherein the CSI-RS is received when all subbands of the plurality of subbands are available for the CSI-RS, and the CSI-RS is not received when at least one subband of the plurality of subbands is not available for the CSI-RS. If the CSI-RS is received, transmitting channel state information (CSI) feedback based on the configuration information; A method comprising:

2. The method described in claim 1, wherein the information indicates the availability of the plurality of subbands for the CSI-RS when the CSI-RS is supposed to be received.

3. The method of claim 2, wherein the receiving information indicates the availability of the plurality of subbands for the CSI-RS. receiving a channel occupation time (COT) structure indicator (SI) indicating the availability of the plurality of subbands for the CSI-RS; The method of claim 1 , comprising:

4. The method of claim 3, wherein receiving the information indicating the availability of the plurality of subbands for the CSI-RS comprises: receiving downlink control information (DCI) indicating the availability of the plurality of subbands for the CSI-RS; The method of claim 1 , comprising:

5. The method of claim 4, wherein receiving the information indicating the availability of the plurality of subbands for the CSI-RS comprises: receiving a channel occupation time (COT) structure indicator (SI) prior to a transmission time of the CSI-RS, the SI indicating the availability of the plurality of subbands for the CSI-RS; The method of claim 1 , comprising:

6. The method of claim 1, wherein the plurality of subbands are associated with a wideband structure.

7. The method of claim 1, wherein the CSI-RS is received on resource elements associated with the plurality of subbands.

8. The method of claim 1, wherein the information indicating the availability of the plurality of subbands for the CSI-RS includes a bitmap indicating one or more resource block (RB) sets.

9. A user equipment (UE) apparatus for wireless communications, comprising: obtaining configuration information for a channel state information reference signal (CSI-RS), wherein the configuration information indicates that the CSI-RS is configured on a plurality of subbands; obtaining information indicating availability of the plurality of subbands for the CSI-RS; selectively acquiring the CSI-RS based on the configuration information and based on the availability of the plurality of subbands for the CSI-RS, wherein the CSI-RS is received when all subbands of the plurality of subbands are available for the CSI-RS, and the CSI-RS is not received when at least one subband of the plurality of subbands is not available for the CSI-RS. a first interface configured to: the first interface or the second interface configured to output channel state information (CSI) feedback based on the configuration information when the CSI-RS is acquired; and An apparatus comprising:

10. The apparatus of claim 9, wherein the information indicates the availability of the plurality of subbands for the CSI-RS when the CSI-RS is to be received.

11. The first interface for obtaining the information indicating the availability of the plurality of subbands for the CSI-RS, comprising:

10. The apparatus of claim 9, configured to obtain a channel occupation time (COT) structure indicator (SI) indicating the availability of the plurality of subbands for the CSI-RS.

12. The first interface for obtaining the information indicating the availability of the plurality of subbands for the CSI-RS, comprising:

10. The apparatus of claim 9, configured to obtain downlink control information (DCI) indicating the availability of the plurality of subbands for the CSI-RS.

13. The first interface for obtaining the information indicating the availability of the plurality of subbands for the CSI-RS, comprising:

10. The apparatus of claim 9, configured to obtain, prior to a transmission time of the CSI-RS, a channel occupation time (COT) structure indicator (SI) indicating the availability of the plurality of subbands for the CSI-RS.

14. The device of claim 9, wherein the plurality of subbands are associated with a wideband structure.

15. The device of claim 9, wherein the CSI-RS is received on resource elements associated with the plurality of subbands.

16. The device of claim 9, wherein the information indicating the availability of the plurality of subbands for the CSI-RS includes a bitmap indicating one or more resource block (RB) sets.

17. A method of wireless communication performed by a device of a network entity, comprising: transmitting configuration information for a channel state information reference signal (CSI-RS), wherein the configuration information indicates that the CSI-RS is configured on a plurality of subbands; transmitting information indicating availability of the plurality of subbands for the CSI-RS; selectively transmitting the CSI-RS based on the configuration information and based on the availability of the plurality of subbands for the CSI-RS, wherein the CSI-RS is transmitted when all subbands among the plurality of subbands are available for the CSI-RS, and the CSI-RS is not transmitted when at least one subband among the plurality of subbands is not available for the CSI-RS. If the CSI-RS is transmitted, receiving channel state information (CSI) feedback based on the configuration information. A method comprising:

18. The method of claim 17, wherein the information indicates the availability of the plurality of subbands for the CSI-RS when the CSI-RS is to be transmitted.

19. The method of claim 18, wherein the transmitting the information indicating the availability of the plurality of subbands for the CSI-RS comprises: transmitting a channel occupation time (COT) structure indicator (SI) indicating the availability of the plurality of subbands for the CSI-RS; 20. The method of claim 17, comprising:

20. The method of claim 20, wherein the transmitting the information indicating the availability of the plurality of subbands for the CSI-RS comprises: transmitting a channel occupation time (COT) structure indicator (SI) indicating the availability of the plurality of subbands for the CSI-RS prior to a transmission time of the CSI-RS.

20. The method of claim 17, comprising:

21. The method of claim 17, wherein the plurality of subbands are associated with a wideband structure.

22. The method of claim 17, wherein the information indicating the availability of the plurality of subbands for the CSI-RS includes a bitmap indicating one or more resource block (RB) sets.

23. An apparatus of a network entity for wireless communication, comprising: outputting configuration information for a channel state information reference signal (CSI-RS), wherein the configuration information indicates that the CSI-RS is configured on a plurality of subbands; outputting information indicating availability of the plurality of subbands for the CSI-RS; selectively outputting the CSI-RS based on the configuration information and based on the availability of the plurality of subbands for the CSI-RS, wherein the CSI-RS is output when all subbands among the plurality of subbands are available for the CSI-RS, and the CSI-RS is not output when at least one subband among the plurality of subbands is not available for the CSI-RS. a first interface configured to: When the CSI-RS is output, the first interface or the second interface is configured to obtain channel state information (CSI) feedback based on the configuration information; and An apparatus comprising:

24. The apparatus of claim 23, wherein the information indicates the availability of the plurality of subbands for the CSI-RS when the CSI-RS is to be output.

25. The first interface for outputting the information indicating the availability of the plurality of subbands for the CSI-RS, comprising:

24. The apparatus of claim 23, configured to output a channel occupation time (COT) structure indicator (SI) indicating the availability of the plurality of subbands for the CSI-RS.

26. The first interface for outputting the information indicating the availability of the plurality of subbands for the CSI-RS, comprising:

24. The apparatus of claim 23, configured to output downlink control information (DCI) indicating the availability of the plurality of subbands for the CSI-RS.

27. The first interface for outputting the information indicating the availability of the plurality of subbands for the CSI-RS, comprising:

24. The apparatus of claim 23, configured to output a channel occupation time (COT) structure indicator (SI) prior to a transmission time of the CSI-RS, the CSI-RS indicating the availability of the plurality of subbands for the CSI-RS.

28. The device of claim 23, wherein the plurality of subbands are associated with a wideband structure.

29. The device of claim 23, wherein the CSI-RS is output on resource elements associated with the plurality of subbands.

30. The device of claim 23, wherein the information indicating the availability of the plurality of subbands for the CSI-RS includes a bitmap indicating one or more resource block (RB) sets.

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