Floating Band CSI-RS

Abstract

Certain aspects of the present disclosure provide techniques for floating band channel state information (CSI) reference signals (RS). A method that may be performed by an apparatus includes: determining a floating band for sending one or more CSI-RS to a wireless device based on data transmission previously scheduled by the apparatus. The apparatus sends one or more CSI-RS to the wireless device on the floating band. In some aspects, the wireless device receives one or more floating band CSI-RS from the apparatus. The wireless device generates one or more CSI reports based on the one or more CSI-RS and sends the one or more CSI reports.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Application No. 17 / 031,555, filed on September 24, 2020, which claims priority to U.S. Provisional Application No. 62 / 905,944, filed on September 25, 2019, both of which are hereby assigned to the assignee of this application and are hereby expressly incorporated by reference in their entirety, as fully set forth below, and for all applicable purposes. Technical Field

[0003] Various aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for channel state information (CSI) reference signals that may be used between user equipments (UEs) via a sidelink channel. Various aspects relate to floating band CSI-RS. Background Art

[0004] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcast, etc. These 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 systems include 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single Carrier Frequency Division Multiple Access (SC-FDMA) systems, and Time Division Synchronous Code Division Multiple Access (TD-SCDMA) systems, to name a few.

[0005] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at a city, country, region, and even global level. New radio (e.g., 5G NR) is an example of an emerging telecommunication standard. NR is an enhancement set to the Long Term Evolution (LTE) mobile standard released by 3GPP. NR is designed to better support mobile broadband Internet access by improving spectrum efficiency, reducing costs, improving services, utilizing new spectrum, and using OFDMA with cyclic prefix (CP) on the downlink (DL) and on the uplink (UL) to better integrate with other open standards. To this end, NR supports beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.

[0006] However, as the demand for mobile broadband access continues to grow, there is a need for further improvements to NR and LTE technologies. Preferably, these improvements should be applicable to other multiple access technologies and the telecommunication standards that employ them. Summary of the invention

[0007] The systems, methods, and devices of the present disclosure each have several aspects, no single one of which is solely responsible for its desirable attributes. Without limiting the scope of the present disclosure as expressed by the appended claims, some features will now be briefly discussed. After considering this discussion, and particularly after reading the section entitled "Detailed Description of the Invention," one will understand how the features of the present disclosure provide advantages including improved channel state information (CSI) reporting for sidelink communications.

[0008] One or more aspects of the subject matter described in the present disclosure may be implemented in a method for wireless communication by an apparatus. The method generally includes: determining a floating frequency band for transmitting one or more channel state information reference signals (CSI-RS) to a wireless device based on data transmission previously scheduled by the apparatus. The method generally includes: transmitting one or more CSI-RS to the wireless device on the floating frequency band.

[0009] One or more aspects of the subject matter described in the present disclosure may be implemented in a method for wireless communication by a wireless device. The method generally includes: receiving one or more floating band CSI-RS from the device. The method generally includes: generating one or more CSI reports based on the one or more CSI-RS, and sending the one or more CSI reports.

[0010] To achieve the aforementioned and related purposes, one or more aspects include the features fully described below and particularly pointed out in the claims. The following description and the accompanying drawings set forth in detail certain illustrative features of one or more aspects. However, these features are indicative of a few of the various ways in which the principles of the various aspects can be employed. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to be able to understand in detail the manner in which the above features of the present disclosure are achieved, the above brief overview may be described in more detail by reference to various aspects (some of which are illustrated in the accompanying drawings). However, it should be noted that the accompanying drawings only illustrate certain typical aspects of the present disclosure and are therefore not to be considered as limiting its scope, as the description may allow for other equally effective aspects.

[0012] Figure 1 is a block diagram conceptually illustrating an example telecommunications system in accordance with certain aspects of the present disclosure.

[0013] Figure 2is a block diagram conceptually illustrating designs of example base stations (BSs) and user equipment (UEs) in accordance with certain aspects of the present disclosure.

[0014] Figure 3 is an example frame format for certain wireless communication systems (e.g., New Radio (NR)) in accordance with certain aspects of the present disclosure.

[0015] Figure 4 An example vehicle-to-everything (V2X) communication system in accordance with certain aspects of the present disclosure is illustrated.

[0016] Figure 5 Another example V2X communication system in accordance with certain aspects of the present disclosure is illustrated.

[0017] Figure 6 is a flow diagram illustrating example operations of channel state information (CSI) processing by a sidelink UE transmitting a CSI reference signal (CSI-RS), in accordance with certain aspects of the present disclosure.

[0018] Figure 7 is a flow diagram illustrating example operations for CSI processing by a sidelink UE reporting CSI in accordance with certain aspects of the present disclosure.

[0019] Figure 8 is a diagram illustrating an example multicast CSI-RS via a sidelink channel in accordance with certain aspects of the present disclosure.

[0020] Fig. 9 is a call flow illustrating example floating-band CSI-RS transmission and CSI reporting between UEs via a sidelink channel in accordance with certain aspects of the present disclosure.

[0021] Fig.10 Illustrated are communications devices that may include various components configured to perform operations for the techniques disclosed herein in accordance with aspects of the present disclosure.

[0022] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized on other aspects without specific recitation. DETAILED DESCRIPTION

[0023] Aspects of the present disclosure provide apparatus, methods, processing systems, and computer-readable media for managing reporting of channel state information (CSI) via a sidelink channel between user equipment (UE). As will be described, the techniques presented herein provide floating band CSI reference signal (CSI-RS) transmissions and CSI reporting based on floating band CSI-RS in sidelink communications. The floating band CSI-RS may be based on previous data transmissions scheduled for the device that transmits the CSI-RS.

[0024] The following description provides an example of a floating band CSI-RS that can be used for a side link in a communication system, and does not limit the scope, applicability, or examples set forth in the claims. Without departing from the scope of the present disclosure, the functions and arrangements of the elements discussed may be changed. Various examples may appropriately omit, replace, or add various processes or components. For example, the described method may be performed in a different order than described, and various steps may be added, omitted, or combined. In addition, the features described for some examples may be combined in some other examples. For example, any number of aspects set forth herein may be used to implement a device or implement a method. In addition, the scope of the present disclosure is intended to cover such a device or method that is practiced using other structures, functions, or structures and functions other than or different from the various aspects of the present disclosure set forth herein. It should be understood that any aspect of the present disclosure disclosed herein may be embodied by one or more elements of the claims. The word "exemplary" is used herein to mean "used as an example, instance, or illustration". Any aspect described as "exemplary" herein is not necessarily to be interpreted as being preferred or superior to other aspects.

[0025] Generally, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a specific radio access technology (RAT) and may operate on one or more frequencies. RAT may also be referred to as a radio technology, air interface, etc. Frequency may also be referred to as a carrier, subcarrier, frequency channel, tone, subband, etc. Each frequency may support a single RAT in a given geographic area to avoid interference between wireless networks of different RATs.

[0026] The techniques described herein can be used for various wireless networks and radio technologies. For clarity, although various aspects may be described herein using terms commonly associated with 3G, 4G, and / or new radio (e.g., 5G NR) wireless technologies, various aspects of the present disclosure may be applied to other generation-based communication systems.

[0027] NR access can support various wireless communication services, such as enhanced mobile broadband (eMBB) for wide bandwidth (e.g., 80MHz or higher), millimeter wave (mmW) for high carrier frequency (e.g., 25GHz or higher), massive machine type communication MTC (mMTC) for non-backward compatible MTC technology, and / or mission critical ultra-reliable low latency communication (URLLC). These services may include latency and reliability requirements. These services may also have different transmission time intervals (TTIs) to meet corresponding quality of service (QoS) requirements. In addition, these services can coexist in the same subframe. NR supports beamforming and can dynamically configure beam directions. MIMO transmission with precoding can also be supported. MIMO configuration in DL can support up to 8 transmit antennas, multi-layer DL transmission of up to 8 streams, and up to 2 streams per UE. Multi-layer transmission of up to 2 streams per UE can be supported. Multi-cell aggregation of up to 8 serving cells can be supported.

[0028] Figure 1 An example wireless communication network 100 is illustrated in which aspects of the present disclosure may be performed. For example, the wireless communication network 100 may be a NR system (e.g., a 5G NR network). Figure 1 As shown in , the wireless communication network 100 may communicate with a core network 132. The core network 132 may communicate with one or more base stations (BSs) 110a-z (each also individually referred to herein as BS 110 or collectively referred to herein as BS 110) and / or user equipments (UEs) 120a-y (each also individually referred to herein as UE 120 or collectively referred to herein as UE 120) in the wireless communication network 100 via one or more interfaces.

[0029] BS 110 may provide communication coverage for a particular geographic area (sometimes referred to as a "cell"), which may be stationary or may move depending on the location of mobile BS 110. In some examples, BS 110 may be interconnected with each other and / or connected to one or more other BSs or network nodes (not shown) in wireless communication network 100 through various types of backhaul interfaces (e.g., direct physical connections, wireless connections, virtual networks, etc.) using any suitable transmission network. Figure 1In the example shown, BSs 110a, 110b, and 110c may be macro BSs for macro cells 102a, 102b, and 102c, respectively. BS 110x may be a pico BS for pico cell 102x. BSs 110y and 110z may be femto BSs for femto cells 102y and 102z, respectively. A BS may support one or more cells. BS 110 communicates with user equipment (UE) 120a-y (each also individually referred to herein as UE 120 or collectively referred to as UE 120) in wireless communication network 100. UE 120 (e.g., 120x, 120y, etc.) may be dispersed throughout wireless communication network 100, and each UE 120 may be stationary or mobile.

[0030] According to certain aspects, UE 120 may be configured for sidelink communications. Figure 1 As shown in , UE 110a includes a sidelink CSI manager 122a and UE 120b includes a floating band CSI-RS manager 122b. According to aspects of the present disclosure, floating band CSI-RS manager 122a and / or floating band CSI-RS manager 122b may be configured to determine a floating band CSI-RS, transmit a floating band CSI-RS, receive a floating band CSI-RS, generate a CSI report based on the floating band CSI-RS, send a CSI report, and / or receive a CSI report.

[0031] The wireless communication network 100 may also include a relay station (e.g., relay station 110r), also known as a relay, etc., which receives data and / or other information from an upstream station (e.g., BS 110a or UE 120r) and transmits data and / or other information to a downstream station (e.g., UE 120 or BS 110), or relays transmissions between UEs 120 to facilitate communication between devices.

[0032] The network controller 130 may be coupled to a set of BSs 110 and provide coordination and control for these BSs 110. The network controller 130 may communicate with the BSs 110 via a backhaul. In various aspects, the network controller 130 may communicate with a core network 132 (e.g., a 5G core network (5GC)), which provides various network functions such as access and mobility management, session management, user plane functions, policy control functions, authentication server functions, unified data management, application functions, network exposure functions, network repository functions, network slice selection functions, etc.

[0033] Figure 2 Example components of BS 110a and UE 120a are shown (eg, in Figure 1In the wireless communication network 100 of the present invention, they may be similar components in the UE 120b), which may be used to implement various aspects of the present disclosure.

[0034] At BS 110a, a transmit processor 220 may receive data from a data source 212 and control information from a controller / processor 240. The control information may be for a physical broadcast channel (PBCH), a physical control format indicator channel (PCFICH), a physical hybrid ARQ indicator channel (PHICH), a physical downlink control channel (PDCCH), a group common PDCCH (GC PDCCH), etc. The data may be for a physical downlink shared channel (PDSCH), etc. A medium access control (MAC)-control element (MAC-CE) is a MAC layer communication structure that may be used for the exchange of control commands between wireless nodes. For example, a base station may send a MAC CE to a UE to put the UE into a discontinuous reception (DRX) mode to reduce the power consumption of the UE. The MAC-CE may be carried in a shared channel such as a PDSCH, a physical uplink shared channel (PUSCH), or a physical sidelink shared channel. The MAC-CE may also be used to communicate information that facilitates communication, such as information about buffer status and available power headroom.

[0035] The processor 220 may process (e.g., encode and symbol map) data and control information to obtain data symbols and control symbols, respectively. The transmit processor 220 may also generate reference symbols (such as for a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a channel state information reference signal (CSI-RS)). The transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, and / or reference symbols (if applicable), and may provide an output symbol stream to a modulator (MOD) in a transceiver 232a-232t. Each modulator may process a corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator may further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The downlink signals from the modulators in the transceivers 232a-232t may be transmitted via antennas 234a-234t, respectively.

[0036] At UE 120a, antennas 252a-252r may receive downlink signals from BS 110a (or sidelink signals from sidelink devices such as UE 120b) and may provide received signals to demodulators (DEMODs) in transceivers 254a-254r, respectively. Each demodulator may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. MIMO detector 256 may obtain received symbols from all demodulators in transceivers 254a-254r, perform MIMO detection on the received symbols (if applicable), and provide detected symbols. Receive processor 258 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for UE 120a to data sink 260, and provide decoded control information to controller / processor 280.

[0037] On the uplink or sidelink, at the UE 120a, a transmit processor 264 may receive and process data from a data source 262 (e.g., for a PUSCH or a physical sidelink shared channel (PSSCH)) and control information from a controller / processor 280 (e.g., for a physical uplink control channel (PUCCH) or a physical sidelink control channel (PSCCH)). The transmit processor 264 may also generate reference symbols for reference signals (e.g., for a sounding reference signal (SRS) or a CSI-RS). The symbols from the transmit processor 264 may be precoded by a TX MIMO processor 266 (if applicable), further processed by a modulator in a transceiver 254a-254r (e.g., for SC-FDM, etc.), and transmitted to the BS 110a or the sidelink UE 120b. At BS 110a (or a receiving sidelink UE), the uplink (or sidelink) signal from UE 120a may be received by antenna 234, processed by a demodulator, detected by MIMO detector 236 (if applicable), and further processed by receive processor 238 to obtain decoded data and control information sent by UE 120a. Receive processor 238 may provide decoded data to data sink 239 and decoded control information to controller / processor 240.

[0038] Memories 242 and 282 may store data and program codes for BS 110a and UE 120a, respectively.A scheduler 244 may schedule UEs for data transmission on the downlink and / or uplink.

[0039] The antennas 252, processors 266, 258, 264, and / or controller / processor 280 of the UE 120a may be used to perform the various techniques and methods described herein. Figure 2 As shown in the figure, according to various aspects of the present disclosure, the controller / processor 280 of the UE 120a has a floating band CSI-RS manager 222, which can be configured to determine a floating band CSI-RS, transmit a floating band CSI-RS, receive a floating band CSI-RS, generate a CSI report based on the floating band CSI-RS, transmit a CSI report and / or receive a CSI report.

[0040] NR can utilize orthogonal frequency division multiplexing (OFDM) with cyclic prefix (CP) on uplink and downlink. NR can support half-duplex operation using time division duplex (TDD). OFDM and single carrier frequency division multiplexing (SC-FDM) divide the system bandwidth into multiple orthogonal subcarriers, which are also commonly referred to as tones, bins, etc. Each subcarrier can be modulated with data. Modulation symbols can be transmitted in the frequency domain using OFDM and in the time domain using SC-FDM. The spacing between adjacent subcarriers can be fixed, and the total number of subcarriers can depend on the system bandwidth. The minimum resource allocation called a resource block (RB) can be 12 consecutive subcarriers. The system bandwidth can also be divided into subbands. For example, a subband can cover multiple RBs. NR can support a basic subcarrier spacing (SCS) of 15KHz, and other SCSs (e.g., 30kHz, 60kHz, 120kHz, 240kHz, etc.) can be defined relative to the basic SCS.

[0041] Figure 3 300 is a diagram showing an example of a frame format for NR. The transmission timeline for each of the downlink and uplink can be divided into units of radio frames. Each radio frame can have a predetermined duration (e.g., 10ms) and can be divided into 10 subframes with indexes 0 to 9, each subframe being 1ms. Depending on the SCS, each subframe can include a variable number of slots (e.g., 1, 2, 4, 8, 16, ... slots). Each slot can include a variable number of symbol periods (e.g., 7, 12, or 14 symbols) depending on the SCS. The symbol period in each slot can be assigned an index. The subslot structure can refer to a transmission time interval having a duration less than a slot (e.g., 2, 3, or 4 symbols). Each symbol in a slot can be configured for a link direction (e.g., DL, UL, or flexible) for data transmission, and the link direction for each subframe can be dynamically switched. The link direction can be based on the slot format. Each slot can include DL / UL data and DL / UL control information.

[0042] In NR, synchronization signal blocks (SSBs) are transmitted. In certain aspects, SSBs may be transmitted in bursts, where each SSB in a burst corresponds to a different beam direction for UE-side beam management (e.g., including beam selection and / or beam refinement). SSBs include PSS, SSS, and dual-symbol PBCH. SSBs may be transmitted at fixed timeslot locations, such as Figure 3 Symbols 0-3 shown in . The UE can use PSS and SSS for cell search and acquisition. PSS can provide half-frame timing, and SS can provide CP length and frame timing. PSS and SSS can provide cell identification. PBCH carries some basic system information, such as downlink system bandwidth, timing information within radio frames, SS burst set periodicity, system frame number, etc. SSB can be organized into SS bursts to support beam scanning. Additional system information (such as remaining minimum system information (RMSI), system information block (SIB), other system information (OSI)) can be sent on the physical downlink shared channel (PDSCH) in certain subframes. SSB can be sent up to sixty-four times, for example, for millimeter waves (mmWave), there can be up to sixty-four different beam directions. Multiple transmissions of SSB are called SS burst sets. SSBs in an SS burst set can be sent in the same frequency domain, while SSBs in different SS burst sets can be sent in different frequency domains.

[0043] In some examples, access to the air interface can be scheduled. A scheduling entity (e.g., BS 110) allocates resources for communications between some or all devices and equipment within its service area or cell. The scheduling entity may be responsible for scheduling, allocating, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communications, subordinate entities utilize resources allocated by the scheduling entity. BS 110 is not the only entity that can act as a scheduling entity. In some examples, UE 120 may act as a scheduling entity and may schedule resources for one or more subordinate entities (e.g., one or more other UEs 120), and other UEs 120 may use resources scheduled by UE 120 for wireless communications. In some examples, UE 120 may act as a scheduling entity in a peer-to-peer (P2P) network and / or a mesh network. In a mesh network example, in addition to communicating with a scheduling entity, UE 120 may also communicate directly with each other.

[0044] In some examples, the communication between UE 120 and BS 110 is referred to as an access link. The access link may be provided via a Uu interface. The communication between devices may be referred to as a side link.

[0045] In some examples, two or more slave entities (e.g., UE 120) can communicate with each other using side link signals. Practical applications of such side link communications can include public safety, proximity services, UE to network relay, vehicle to vehicle (V2V) communications, V2X, Internet of Everything (IoE) communications, Internet of Things (IoT) communications, mission critical grids, and / or various other suitable applications. Typically, a side link signal can refer to a signal that is communicated from one slave entity (e.g., UE 120a) to another slave entity (e.g., another UE 120) without relaying the communication through a scheduling entity (e.g., UE 120 or BS 110), even if the scheduling entity can be used for scheduling and / or control purposes. In some examples, licensed spectrum (unlike wireless local area networks that typically use unlicensed spectrum) can be used to communicate side link signals. An example of side link communication is PC5, for example, as used in V2V, LTE, and / or NR.

[0046] Various sidelink channels may be used for sidelink communications, including a physical sidelink discovery channel (PSCCH), a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), and a physical sidelink feedback channel (PSFCH). The PSSCH may carry discovery expressions that enable near-end devices to discover each other. The PSCCH may carry control signaling such as sidelink resource configuration and other parameters for data transmission, and the PSSCH may carry data transmission. The PSFCH may carry feedback such as CSI related to sidelink channel quality.

[0047] Figure 4 and Figure 5 A diagrammatic representation of an example vehicle-to-everything (V2X) system according to some aspects of the present disclosure is shown. For example, Figure 4 and Figure 5 The vehicles shown in can communicate via a sidelink channel and can perform sidelink CSI reporting as described herein.

[0048] Figure 4 and Figure 5 The V2X system provided in provides two complementary transmission modes. Figure 4 The first transmission mode shown by way of example in relates to direct communication (eg also referred to as sidelink communication) between nearby participants in a local area. Figure 5 The second transmission mode illustrated by way of example in FIG. 8 involves network communication through a network, which may be implemented through a Uu interface (eg, a wireless communication interface between a radio access network (RAN) and a UE).

[0049] Reference Figure 4, a V2X system 400 (e.g., including V2V communications) is illustrated as having two vehicles 402, 404. A first transmission mode allows direct communication between different participants in a given geographic location. As illustrated, the vehicle may have a wireless communication link 406 with a person (e.g., in V2P, and may be via a UE) via a PC5 interface. Communication between vehicle 402 and vehicle 404 may also occur via a PC5 interface 408. In a similar manner, communication may occur from vehicle 402 to other highway components (e.g., highway component 410), such as traffic signals or signs (e.g., in V2I), via a PC5 interface 412. With respect to Figure 4 Each communication link illustrated in the figure can communicate bidirectionally between elements, so each element can be a sender and receiver of information. The V2X system 400 can be a self-managed system implemented without the help of a network entity. Since no network service interruption occurs during the switching operation of the moving vehicle, the self-managed system can achieve improved spectrum efficiency, reduced costs and increased reliability. The V2X system can be configured to operate in a licensed or unlicensed spectrum, so any vehicle equipped with the system can access common frequencies and share information. This coordinated / common spectrum operation allows safe and reliable operation.

[0050] Figure 5 A V2X system 500 is shown for communicating between a vehicle 552 and a vehicle 554 via a network entity 556. These network communications may occur via discrete nodes such as base stations (e.g., eNBs or gNBs) that send and receive information to and from the vehicles 552, 554 (e.g., relay information between the vehicles 552, 554). Network communications via vehicle-to-network (V2N) links 558 and 510 may be used, for example, for long-range communications between vehicles, such as for communicating the presence of a vehicle incident some distance ahead along a road or highway. Other types of communications may be sent by the nodes to the vehicles, such as traffic flow conditions, road hazard warnings, environmental / weather reports, and service station availability, etc. Such data may be obtained from a cloud-based sharing service.

[0051] As noted above, aspects of the present disclosure are related to sidelink CSI.

[0052] The CSI in New Radio (NR) includes various channel quality indicators. For example, NR channel quality indicators may include channel quality indicator (CQI), precoding matrix indicator (PMI), CSI-RS resource indicator (CRI), strongest layer indication (SLI), rank indication (RI), and layer 1 reference signal received power (L1-RSRP). One or more of the NR channel quality indicators may be used for beam management.

[0053] For V2X deployment, such as reference Figure 4 and / or Figure 5 As described, CSI reporting can be turned on and off by configuration. For flexibility, a device can be configured to report a subset of metrics for CSI reporting.

[0054] CSI reporting configuration and scheduling in NR may depend on the type of CSI report. The type of channel carrying the CSI report may depend on the type of CSI report. For example, periodic CSI reporting may be performed on short PUCCH or long PUCCH, while semi-persistent (SP) CSI reporting may be performed on long PUCCH or PUSCH. Resources and transmission parameters (e.g., modulation and coding scheme (MCS)) for SP-CSI on PUSCH may be semi-permanently allocated using downlink control information (DCI). SP-CSI may support type II CSI reporting with a minimum periodicity of 5ms. Aperiodic CSI-RS may not support SP-CSI reporting (although this lack of support does not preclude one CSI report carried by multiple uplink reporting instances). In NR, A-CSI reporting may be performed on PUSCH multiplexed with or without uplink data. Periodic and semi-persistent CSI reporting in NR may support the following periodicities: {5, 10, 20, 40, 80, 160, 320} time slots.

[0055] In some systems, the sidelink CSI-RS may support CQI / RI measurements for no more than two ports. The sidelink CSI-RS may be restricted to PSSCH transmissions. However, more detailed CSI may be required, such as for beam management and MIMO. These various use cases for the sidelink may involve different CSI reporting procedures (e.g., depending on the amount of feedback and available resources).

[0056] In conventional systems, on Uu (access link), scheduling of data transmission for both uplink and downlink is done by the BS (e.g., gNB). However, in the sidelink scenario, the relationship between the two UEs is more symmetrical. For example, in LTE sidelink and NR sidelink V2X, the UE sending data generally performs scheduling. The UE sending data can select resources for data transmission from a configured resource pool (e.g., a set of resources configured by the gNB).

[0057] Sidelink communications may be limited to when a UE transmits data on a frequency allocation (e.g., within its transmit pool), then the UE transmits on a different frequency allocation (e.g., within its transmit pool) the next time. The selection of the next frequency allocation may not be known at the current transmit time (e.g., it may depend on other expected or measured transmissions / receptions at that time).

[0058] Therefore, techniques and apparatus for CSI-RS transmission and reception, CSI reporting that can be used even when the frequency allocation may be unknown are desirable.

[0059] Example floating band CSI-RS

[0060] Various aspects of the present disclosure provide a floating band channel state information reference signal (CSI-RS). In some examples, the floating band CSI-RS is used for CSI reporting between user equipment (UE) via a sidelink channel. The bandwidth and / or frequency range of the floating band CSI-RS can be based on previously scheduled data transmissions of the device transmitting the floating band CSI-RS.

[0061] Figure 6 6 is a flow diagram illustrating example operations 600 for wireless communication in accordance with certain aspects of the present disclosure. Operations 600 may be performed, for example, by an apparatus that transmits a CSI-RS for a CSI process. In some examples, the apparatus may be an access node (e.g., a base station (BS), such as BS 110a in wireless communication network 100). In some examples, the apparatus may be a wireless sidelink device, such as a sidelink user equipment (UE) (e.g., such as UE 120a and / or 120b in wireless communication network 100).

[0062] Operation 600 may begin at 610 by determining a floating frequency band for transmitting one or more CSI-RS to a wireless device based on a data transmission previously scheduled by the device. In some examples, the wireless device is a UE, which may be a served UE when the device is an access node, or may be another side link UE when the device is a wireless side link device. When the device is a side link UE, the one or more CSI-RS may be a side link RS. In some examples, the previously scheduled data transmission is a transmission via a previous physical side link shared channel (PSSCH) of the device. The previously scheduled data transmission may be an immediately preceding transmission or a data transmission by the device.

[0063] According to certain aspects, the bandwidth and / or frequency range of the floating frequency band used for the CSI-RS is different from the bandwidth and / or frequency range of the previously scheduled data transmission. For example, the floating frequency band can be wider, can include, can deviate from, and / or can be adjusted relative to the bandwidth and / or frequency range of the previously scheduled data transmission. In some examples, the floating frequency band includes the frequency range of the previously scheduled data transmission and additionally includes adjacent frequency resources around the frequency range of the previously scheduled data transmission.

[0064] According to certain aspects, a floating frequency band may be determined based on a configuration. As shown, optionally, at 605, the device may receive information from a BS for determining the floating frequency band. In some examples, the device may receive downlink control information (DCI) or radio resource control (RRC) signaling from a BS (e.g., a gNB) that configures the floating frequency band or indicates adjacent resources for the floating frequency band. In some examples, the device may receive sidelink RRC signaling or sidelink control information (SCI) from a sidelink wireless device that configures the floating frequency band or indicates adjacent resources for the floating frequency band. The frequency resources may be indicated as the number of adjacent resource blocks (RBs) or the number of adjacent frequency subbands.

[0065] As shown, optionally, at 615, the apparatus sends information indicating a floating frequency band to the wireless device. According to certain aspects, the apparatus dynamically indicates to the wireless device the floating frequency band (e.g., frequency range) of the determined CSI-RS. For example, the apparatus may indicate the determined floating frequency band via sidelink control information (SCI). In some examples, the SCI may be carried in a physical sidelink control channel (PSCCH). In some examples, the SCI may be carried in a PSCCH that schedules previously scheduled data transmissions.

[0066] According to certain aspects, other parameters of the CSI-RS (e.g., in addition to bandwidth and frequency range) can be based on (e.g., implicitly dependent on) previously scheduled data transmissions. For example, the density of the floating band CSI-RS in frequency, time, or both can be based on one or more parameters of previously scheduled data transmissions (e.g., based on the bandwidth and / or rank of the previously scheduled data transmissions). The association of the parameters of the previously scheduled data transmissions with the parameters of the floating band CSI-RS can be configured by the BS (e.g., gNB), configured by the sidelink device via the sidelink RRC, and / or specified in the IEEE standard.

[0067] According to certain aspects, the floating frequency band may include the entirety of the currently activated bandwidth part (BWP).In some examples, the floating frequency band is a wide frequency band.

[0068] At 620, the apparatus transmits one or more CSI-RS to the wireless device on the floating frequency band. In some examples, the apparatus transmits the one or more CSI-RS to the wireless device via a sidelink channel. In some examples, the apparatus transmits (e.g., groupcasts) the floating frequency band CSI-RS to a group of wireless devices. Figure 8 An example multicast CSI-RS is shown. Figure 8As shown in , UE A transmits (e.g., multicasts) a sidelink CSI-RS to UE B1, UE B2, UE B3, and UE B4. In some examples, the device selects UEs to report CSI for the multicast CSI-RS, for example, to better utilize system resources and make sidelink CSI reporting only available to certain UEs of interest, or to stagger CSI reports from multiple UEs. Figure 8 As shown in , only UE B2 transmits CSI reports to UE A.

[0069] According to certain aspects, the apparatus may configure the wireless device with a CSI report setting. For example, the apparatus may configure the wireless device with the CSI report setting via the SCI and / or the sidelink RRC. In some examples, the apparatus determines the parameters of the CSI report setting based on the parameters of the previously scheduled data transmission. The apparatus may receive a CSI report from the wireless device based on (e.g., according to) the CSI report setting. In some examples, the CSI report setting configures different CSI reports for the CSI-RS. For example, the CSI report setting may configure the wireless device to send a first CSI report to the apparatus and a second CSI report to the BS (e.g., gNB). In some examples, the CSI report setting configures different parameters for different reports. For example, the CSI report setting may configure the wireless device to send CSI reports to the apparatus more frequently than sending CSI reports to the BS. In another example, the CSI report setting may configure the CSI report only for estimating the sidelink interference power.

[0070] Figure 7 700 may be performed, for example, by a wireless device for CSI processing via CSI reporting. The wireless device may be a sidelink UE (e.g., such as UE 120a or 120b in wireless communication network 100). Operation 700 may be a supplemental operation to operation 600 by the UE. Operation 700 may be implemented as a processor (e.g., Figure 2 In addition, the sending and receiving of signals by the UE in operation 700 may be performed, for example, via one or more antennas (e.g., Figure 2 In some aspects, the transmission and / or reception of signals by the UE may be implemented via a bus interface of one or more processors (eg, controller / processor 280) that acquire and / or output signals.

[0071] Operations 700 may begin at 710 by receiving (e.g., via an access link or a sidelink) one or more floating band CSI-RS (e.g., an access link CSI-RS or a sidelink CSI-RS) from a device (e.g., a gNB or a sidelink UE).

[0072] According to certain aspects, the floating frequency band is based on a data transmission (e.g., PSSCH) previously scheduled by the device (e.g., the frequency range of the CSI-RS may be different from the frequency range of the previously scheduled data transmission). The frequency range of the CSI-RS may include the frequency range of the previously scheduled data transmission and one or more adjacent frequency resources around the frequency range of the previously scheduled data transmission. In some examples, the floating frequency band includes all of the currently activated bandwidth portion. In some examples, the floating frequency band is a wide frequency band.

[0073] In some cases, optionally, at 705, the wireless device may receive information indicating a floating frequency band for one or more CSI-RS from an apparatus (e.g., a BS or another sidelink UE). According to certain aspects, other parameters such as the density of the sidelink CSI-RS in frequency, time, or both are based on one or more parameters of previously scheduled data (e.g., bandwidth and / or rank of previously scheduled data transmissions). The wireless device may receive an indication of the association of the density of the sidelink CSI-RS with the parameters of previously scheduled data from the BS (e.g., via DCI or RCE), or receive the indication from the sidelink wireless device (e.g., via sidelink RRC signaling), as specified in a wireless standard specification, or a combination thereof.

[0074] According to certain aspects, a wireless device receives a configuration indicating a floating frequency band from a BS (e.g., via DCI or RRC) or from an apparatus (e.g., via sidelink RRC or SCI). The wireless device may monitor the floating frequency band for one or more CSI-RS based on the received configuration. The SCI may be carried in a PSCCH (e.g., a PSCCH that scheduled a previously scheduled data transmission). The received configuration may indicate additional adjacent frequency resources (adjacent to a frequency range of a data transmission previously scheduled by the apparatus), for example, in terms of the number of RBs or frequency subbands.

[0075] At 715, the wireless device generates one or more CSI reports based on the one or more CSI-RS. According to certain aspects, the wireless device may be configured with a CSI report setting. For example, the CSI report setting may be configured by the BS (e.g., via DCI or RRC), by the sidelink (e.g., via SCI or sidelink RRC). The CSI report setting may configure the wireless device to send different CSI reports to the BS and to the sidelink UE. In some examples, the CSI report setting configures the wireless device to transmit CSI reports to the BS less frequently than to the sidelink UE. In some examples, the CSI report setting configures the wireless device to transmit CSI reports only for interference estimation. In some examples, the CSI report setting configures the wireless device to transmit CSI reports for partial subband reporting.

[0076] At 720, the wireless device sends one or more CSI reports (eg, to a sidelink UE and / or to a BS).

[0077] Fig. 9 900 is an example call flow illustrating example floating band sidelink CSI-RS and CSI reporting between UEs via a sidelink channel in accordance with certain aspects of the present disclosure. Figure 7 As shown in , UE A sends a PSCCH to UE B which is scheduled by UE A for data transmission to UE B. UE A then sends a PSSCH with the scheduled data to UE B. Fig. 9 As shown in , UE A determines the floating frequency band for CSI-RS based on data transmission scheduled by PSCCH. Fig. 9 As described above, UE A may receive information indicating information for determining the floating frequency band from a BS (not shown) or from UE B. Fig. 9 Not shown in the figure, as described above, UE A or a BS (not shown) may provide an indication of the floating frequency band to UE B, so that UE B may monitor the floating frequency band for CSI-RS.

[0078] As shown, UE A sends a floating band sidelink CSI-RS to UE B. UE B measures the CSI-RS and generates a CSI report. UE B transmits the CSI report (and possibly data) to UE A in a PSSCH transmission. Fig. 9 Not shown, but as described above, UE A or a BS (not shown) may configure UE B with a CSI reporting setting (with which UE B generates and / or transmits a CSI report).

[0079] Fig.10 The diagram may include a method configured to perform operations for the techniques disclosed herein (such as Figure 6 and / or Figure 7 1000 includes various components (e.g., corresponding to means plus function components) of the communication device 1000 and the operations illustrated in the figure. The communication device 1000 includes a processing system 1002 coupled to a transceiver 1008 (e.g., a transmitter and / or a receiver). The transceiver 1008 is configured to send and receive signals, such as the various signals described herein, for the communication device 1000 via an antenna 1010. The processing system 1002 can be configured to perform processing functions for the communication device 1000, including processing signals received and / or to be transmitted by the communication device 1000.

[0080] The processing system 1002 includes a processor 1004 coupled to a computer readable medium / memory 1012 via a bus 1006. In some aspects, the computer readable medium / memory 1012 is configured to store instructions (e.g., computer executable code) that, when executed by the processor 1004, cause the processor 1004 to perform Figure 6 and / or Figure 7 , or other operations for performing the various techniques discussed herein for floating band CSI-RS for a sidelink. According to aspects of the present disclosure, in some aspects, the computer-readable medium / memory 1012 stores code 1014 for determining a floating band for a CSI-RS; code 1016 for sending a floating band CSI-RS; code 1018 for receiving a floating band CSI-RS; code 1020 for generating a CSI report; code 1022 for sending a CSI report; code 1024 for receiving information for determining a floating band; and / or code 1026 for transmitting and / or receiving an indication of a floating band. In some aspects, the processor 1004 has circuitry configured to implement the code stored in the computer-readable medium / memory 1012. According to various aspects of the present disclosure, processor 1004 includes circuitry 1028 for determining a floating band for a CSI-RS; circuitry 1030 for sending a floating band CSI-RS; circuitry 1032 for receiving a floating band CSI-RS; circuitry 1034 for generating a CSI report; circuitry 1036 for sending a CSI report; circuitry 1038 for receiving information for determining a floating band; and / or circuitry 1040 for transmitting and / or receiving an indication of a floating band.

[0081] The techniques described herein can be used for various wireless communication technologies, such as NR (e.g., 5G NR), 3GPP Long Term Evolution (LTE), LTE-Advanced (LTE-A), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), Time Division Synchronous Code Division Multiple Access (TD-SCDMA), and other networks. The terms "network" and "system" are often used interchangeably. A CDMA network can implement radio technologies such as Universal Terrestrial Radio Access (UTRA), cdma2000, and the like. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. cdma2000 covers IS-2000, IS-95, and IS-856 standards. A TDMA network can implement radio technologies such as Global System for Mobile Communications (GSM). OFDMA networks can implement radio technologies such as NR (e.g. 5G RA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, etc. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). LTE and LTE-A are versions of UMTS that use EUTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization named "3rd Generation Partnership Project" (3GPP). cdma2000 and UMB are described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). NR is an emerging wireless communication technology under development.

[0082] In 3GPP, the term "cell" can refer to the coverage area of ​​a Node B (NB) and / or a NB subsystem serving the coverage area, depending on the context in which the term is used. In NR systems, the terms "cell" and BS, next-generation Node B (gNB or gNodeB), access point (AP), distributed unit (DU), carrier or transmit receive point (TRP) can be used interchangeably. The BS can provide communication coverage for macro cells, pico cells, femto cells and / or other types of cells. A macro cell can cover a relatively large geographic area (e.g., a radius of several kilometers) and can allow unrestricted access by UEs with service subscriptions. A pico cell can cover a relatively small geographic area and can allow unrestricted access by UEs with service subscriptions. A femto cell can cover a relatively small geographic area (e.g., a home) and can allow restricted access by UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs for users in the home, etc.). A BS for a macro cell can be referred to as a macro BS. A BS for a pico cell can be referred to as a pico BS. A BS for a femto cell may be called a femto BS or a home BS.

[0083] UE may also be referred to as a mobile station, a terminal, an access terminal, a subscriber unit, a station, customer premises equipment (CPE), a cellular phone, a smart phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet computer, a camera, a gaming device, a netbook, a smartbook, an ultrabook, an appliance, a medical device or medical equipment, a biosensor / device, a wearable device (such as a smart watch, smart clothing, smart glasses, a smart wristband, smart jewelry (e.g., a smart ring, a smart bracelet, etc.)), an entertainment device (e.g., a music device, a video device, a satellite radio, etc.), a vehicle component or sensor, a smart meter / sensor, an industrial manufacturing equipment, a global positioning system device, or any other suitable device configured to communicate via a wireless or wired medium. Some UEs may be considered machine type communication (MTC devices or evolved MTC (eMTC) devices. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc. that may communicate with a BS, another device (e.g., a remote device), or some other entity. For example, a wireless node may provide 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, which may be narrowband IoT (NB-IoT) devices.

[0084] The methods disclosed herein include one or more steps or actions for implementing these methods. Without departing from the scope of the claims, the method steps and / or actions may be interchangeable with each other. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions may be modified without departing from the scope of the claims.

[0085] As used herein, a phrase referring to "at least one" of a list of items refers to any combination of those items, including single members. As an example, "at least one of a, b, or c" is intended to cover a, b, c, ab, ac, bc, and abc, as well as any combination with multiple of the same elements (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc or any other order of a, b, and c).

[0086] As used herein, the term "determining" includes a wide variety of actions. For example, "determining" may include calculating, computing, processing, deriving, investigating, searching (e.g., searching in a table, a database, or another data structure), ascertaining, etc. In addition, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), etc. In addition, "determining" may include resolving, selecting, choosing, establishing, etc.

[0087] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Therefore, the claims are not intended to be limited to the various aspects shown herein, but to conform to the full scope consistent with the language of the claims, wherein, unless otherwise specified, the elements mentioned in the singular are not intended to mean "one and only one", but "one or more". Unless otherwise explicitly stated, the term "some" refers to one or more. All structural and functional equivalents of the elements of the various aspects described throughout this disclosure are known or will be known to those of ordinary skill in the art, and are expressly incorporated herein by reference and are intended to be covered by the claims. In addition, nothing disclosed herein is intended to be dedicated to the public, regardless of whether such disclosure is explicitly stated in the claims. Any claim element shall not be interpreted according to the provisions of Section 112 (f) of Section 35 of the United States Code, unless the element is explicitly stated using the phrase "parts for...", or in the case of a method claim, the element is stated using the phrase "step for...".

[0088] The various operations of the method described above can be performed by any suitable component capable of performing the corresponding functions. These components may include various hardware and / or (multiple) software components and / or (multiple) modules, including but not limited to circuits, application specific integrated circuits (ASICs) or processors. Typically, where there are operations shown in the figure, these operations may have corresponding counterparts with similar numbering plus function (means-plus-function) components.

[0089] The various illustrative logic blocks, modules, and circuits described in conjunction with the present disclosure may be implemented or executed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The general purpose processor may be a microprocessor, but as an alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration.

[0090] If implemented in hardware, an example hardware configuration may include a processing system in a wireless node. The processing system may be implemented using a bus architecture. Depending on the specific application and overall design constraints of the processing system, the bus may include any number of interconnecting buses and bridges. The bus may link together various circuits including a processor, a machine-readable medium, and a bus interface. Among other things, the bus interface may be used to connect a network adapter to the processing system via the bus. The network adapter may be used to implement signal processing functions at the PHY layer. In the user terminal 120 (see Figure 1 ), a user interface (e.g., a keypad, display, mouse, joystick, etc.) may also be connected to the bus. The bus may also link various other circuits such as timing sources, peripherals, voltage regulators, power management circuits, etc., which are well known in the art and therefore will not be described further. The processor may be implemented using one or more general purpose and / or special purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuits that can execute software. Those skilled in the art will recognize how to best implement the functionality described for the processing system depending on the specific application and the overall design constraints imposed on the entire system.

[0091] If implemented in software, these functions can be stored on or sent through a computer-readable medium as one or more instructions or codes. Whether it is referred to as software, firmware, middleware, microcode, hardware description language or other, software should be broadly interpreted as meaning instructions, data or any combination thereof. Computer-readable media include both computer storage media and communication media, and communication media include any media that helps to deliver a computer program from one place to another. The processor can be responsible for managing the bus and general processing, including the execution of software modules stored on a machine-readable storage medium. The computer-readable storage medium can be coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. As an alternative, the storage medium can be integrated into the processor. For example, the machine-readable medium can include a transmission line, a carrier modulated by data, and / or a computer-readable storage medium on which instructions separated from a wireless node are stored, all of which can be accessed by the processor through a bus interface. Alternatively or additionally, the machine-readable medium or any part thereof can be integrated into the processor, such as the case of a cache and / or a general register file. By way of example, examples of machine-readable storage media may include, for example, RAM (random access memory), flash memory, ROM (read only memory), PROM (programmable read only memory), EPROM (erasable programmable read only memory), EEPROM (electrically erasable programmable read only memory), registers, magnetic disks, optical disks, hard drives, or any other suitable storage media, or any combination thereof. The machine-readable medium may be embodied in a computer program product.

[0092] A software module may include a single instruction or many instructions, and may be distributed over several different code segments, between different programs, and across multiple storage media. A computer-readable medium may include multiple software modules. A software module includes instructions that, when executed by a device such as a processor, cause a processing system to perform various functions. A software module may include a sending module and a receiving module. Each software module may reside in a single storage device, or may be distributed across multiple storage devices. By way of example, when a triggering event occurs, a software module may be loaded from a hard drive into a RAM. During the execution of a software module, a processor may load some of the instructions into a cache to increase access speed. Subsequently, one or more cache lines may be loaded into a general register file to be executed by a processor. When the function of a software module is mentioned below, it should be understood that this function is implemented by a processor when executing instructions from the software module.

[0093] In addition, any connection is appropriately defined as a computer-readable medium. For example, if the software is transmitted from a website, server or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technology (such as infrared (IR), radio and microwave), then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technology (such as infrared, radio, microwave) are all included in the definition of medium. As used herein, disk and disc include compact disk (CD), laser disk, optical disk, digital versatile disk (DVD), floppy disk and Disks, where magnetic disks typically reproduce data magnetically, and optical disks reproduce data optically. Thus, in some aspects, computer-readable media may include non-transitory computer-readable media (e.g., tangible media). Additionally, for other aspects, computer-readable media may include transient computer-readable media (e.g., signals). Combinations of the above should also be included within the scope of computer-readable media.

[0094] Thus, certain aspects may include a computer program product for performing the operations presented herein. For example, such a computer program product may include a computer-readable medium having instructions stored (and / or encoded) thereon, which instructions may be executed by one or more processors to perform the operations described herein, for example, for performing the operations described herein and in Figure 6 and / or Figure 7 The operations shown in the instructions.

[0095] In addition, it should be understood that, if applicable, the modules and / or other suitable components for performing the methods and techniques described herein can be downloaded and / or otherwise obtained by the user terminal and / or base station. For example, such a device can be coupled to a server to facilitate the delivery of the components for performing the methods described herein. Alternatively, the various methods described herein can be provided via a storage component (e.g., RAM, ROM, a physical storage medium such as a compact disk (CD) or a floppy disk), so that the user terminal and / or base station can obtain the various methods when the storage component is coupled to or provided to the device. In addition, any other suitable technology for providing the methods and techniques described herein to the device can be utilized.

[0096] It is to be understood that the claims are not limited to the precise configuration and components illustrated above. Various modifications, changes and variations may be made in the arrangement, operation and details of the methods and apparatus described above without departing from the scope of the claims.

Claims

1. A method for wireless communication by a device, the method comprising: determining, based on a data transmission previously scheduled by the apparatus, a floating frequency band for transmitting one or more sidelink channel state information reference signals (CSI-RS) to a wireless device, wherein the floating frequency band includes a frequency range of the previously scheduled data transmission and one or more additional adjacent frequency resources around the frequency range of the previously scheduled data transmission; as well as The one or more CSI-RS are transmitted to the wireless device on the floating frequency band.

2. The method according to claim 1, wherein: Transmitting the one or more CSI-RS to the wireless device includes transmitting the one or more CSI-RS to one or more other UEs via a sidelink channel.

3. The method according to claim 1, wherein: The previously scheduled data transmission includes a physical sidelink shared channel (PSSCH) transmission by the apparatus.

4. The method of claim 1, further comprising receiving a configuration from a base station (BS) or another wireless device via downlink control information (DCI) or sidelink radio resource control (RRC) signaling indicating the additional adjacent frequency resources.

5. The method according to claim 4, wherein: The additional adjacent frequency resources are indicated as the number of adjacent resource blocks (RBs) or the number of adjacent frequency subbands.

6. The method of claim 1, further comprising indicating the determined frequency range of the one or more CSI-RSs to the wireless device via sidelink control information (SCI).

7. The method according to claim 6, wherein: The SCI is carried in a Physical Sidelink Control Channel (PSCCH) that scheduled the previously scheduled data transmission.

8. The method according to claim 1, further comprising: Based on one or more parameters of the previously scheduled data, a density of the one or more sidelink CSI-RS in frequency, time, or both is determined.

9. The method according to claim 8, wherein: The one or more parameters include at least one of a bandwidth or a rank of the previously scheduled data.

10. The method according to claim 8, wherein: The association of the density of the one or more sidelink CSI-RSs with parameters of the previously scheduled data is configured by a base station (BS), configured by sidelink radio resource control (RRC) signaling from another wireless device, specified in a wireless standard specification, or a combination thereof.

11. The method according to claim 1, wherein: The floating frequency band includes the entirety of the currently activated bandwidth portion.

12. The method according to claim 1, wherein: The floating frequency band includes a wide frequency band.

13. The method according to claim 1, further comprising: determining CSI reporting parameters based on the previously scheduled data transmission; as well as The wireless device is configured with a CSI reporting setting via sidelink control information (SCI).

14. The method according to claim 13, wherein: The CSI reporting settings configure the wireless device to send a first CSI report to the apparatus and a second CSI report to a base station (BS).

15. The method according to claim 14, wherein: The CSI reporting setting configures the wireless device to send the first CSI report more frequently than sending the second CSI report.

16. A method for wireless communication by a wireless device, the method comprising: receiving one or more floating frequency band channel state information (CSI) reference signals (RS) from a device via a sidelink channel, wherein the floating frequency band includes a frequency range for a previously scheduled data transmission by the device and one or more additional adjacent frequency resources around the frequency range for the previously scheduled data transmission by the device; generating one or more CSI reports based on the CSI-RS; as well as Send the CSI report.

17. The method of claim 16, wherein receiving the one or more floating band CSI-RS comprises: The one or more floating band CSI-RS are received from a sidelink user equipment (UE).

18. The method according to claim 16, further comprising: receiving transmissions from said device; as well as The floating frequency band is determined based on the received transmission.

19. The method according to claim 18, further comprising: receiving signaling indicating the floating frequency band from a base station (BS) via at least one of downlink control information (DCI), sidelink radio resource control (RRC) signaling, or receiving signaling indicating the floating frequency band from the device via sidelink control information (SCI); as well as The floating frequency band is determined based on the signaling.

20. The method according to claim 19, wherein: The SCI is carried in a Physical Sidelink Control Channel (PSCCH) that scheduled the previously scheduled data transmission.

21. The method according to claim 19, wherein: The signaling indicates frequency resources for the one or more floating band CSI-RSs that are adjacent to frequency resources of the previously scheduled data transmission.

22. The method according to claim 16, wherein: The floating frequency band includes the entire or wide frequency band of the currently activated bandwidth portion.

23. The method of claim 16, further comprising: receiving signaling from the apparatus or a base station (BS) to configure the wireless device with a CSI reporting setting via sidelink radio resource control (RRC) signaling, sidelink control information (SCI), downlink control information (DCI), or a combination thereof, wherein Sending the one or more CSI reports includes sending the one or more CSI reports according to the CSI report setting.

24. The method according to claim 23, wherein: The CSI reporting settings configure the wireless device to send a first CSI report to the apparatus and a second CSI report to the BS.

25. An apparatus comprising: at least one processor; as well as a memory coupled to the at least one processor, the memory comprising code, the code being executed by the at least one processor to cause the apparatus to: determining, based on a data transmission previously scheduled by the apparatus, a floating frequency band for transmitting one or more sidelink channel state information reference signals (CSI-RS) to a wireless device, wherein the floating frequency band includes a frequency range of the previously scheduled data transmission and one or more additional adjacent frequency resources around the frequency range of the previously scheduled data transmission; as well as The one or more CSI-RS are transmitted to the wireless device on the floating frequency band.

26. A wireless device comprising: at least one processor; as well as a memory coupled to the at least one processor, the memory comprising code, the code being executed by the at least one processor to cause the wireless device to: receiving one or more floating band channel state information (CSI) reference signals (RS) from a device via a sidelink channel; generating one or more CSI reports based on the one or more floating frequency band CSI-RSs, wherein the floating frequency band includes a frequency range for previously scheduled data transmissions by the apparatus and one or more additional adjacent frequency resources around the frequency range for previously scheduled data transmissions by the apparatus; as well as The one or more CSI reports are sent.

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