WO2024137063A1

WO2024137063A1 - Frequency dependent residual side band reference signals

Info

Publication number: WO2024137063A1
Application number: PCT/US2023/079092
Authority: WO
Inventors: Ronen Shaked; Aviv Regev; Assaf Touboul
Original assignee: Qualcomm Inc
Current assignee: Qualcomm Inc
Priority date: 2022-12-21
Filing date: 2023-11-08
Publication date: 2024-06-27
Anticipated expiration: 2025-06-21
Also published as: CN120345206A; IL299318A; EP4639828A1

Abstract

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may transmit an indication of a requested signal length of a frequency dependent residual side band (FDRSB) reference signal. The UE may receive the FDRSB reference signal based at least in part on the requested signal length. Numerous other aspects are described.

Description

FREQUENCY DEPENDENT RESIDUAL SIDE BAND REFERENCE SIGNALS

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This Patent Application claims priority to Israel Nonprovisional Patent Application No. 299318, filed on December 21, 2022, entitled “FREQUENCY DEPENDENT RESIDUAL SIDE BAND REFERENCE SIGNALS,” which is hereby expressly incorporated by reference herein.

FIELD OF THE DISCLOSURE

[0002] Aspects of the present disclosure generally relate to wireless communication and to techniques and apparatuses for frequency dependent residual side band reference signals.

BACKGROUND

[0003] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. 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, or the like). Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC- FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and Long Term Evolution (LTE). LTE/LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3 GPP).

[0004] A wireless network may include one or more network nodes that support communication for wireless communication devices, such as a user equipment (UE) or multiple UEs. A UE may communicate with a network node via downlink communications and uplink communications. “Downlink” (or “DL”) refers to a communication link from the network node to the UE, and “uplink” (or “UL”) refers to a communication link from the UE to the network node. Some wireless networks may support device-to-device communication, such as via a local link (e.g., a sidelink (SL), a wireless local area network (WLAN) link, and/or a wireless personal area network (WPAN) link, among other examples). [0005] The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different UEs to communicate on a municipal, national, regional, and/or global level. New Radio (NR), which may be referred to as 5G, is a set of enhancements to the LTE mobile standard promulgated by the 3GPP. NR is designed to better support mobile broadband internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) (CP-OFDM) on the downlink, using CP-OFDM and/or single-carrier frequency division multiplexing (SC-FDM) (also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on the uplink, as well as supporting beamforming, multiple-input multiple -output (MIMO) antenna technology, and carrier aggregation. As the demand for mobile broadband access continues to increase, further improvements in LTE, NR, and other radio access technologies remain useful.

SUMMARY

[0006] Some aspects described herein relate to a method of wireless communication performed by a user equipment (UE). The method may include transmitting an indication of a requested signal length of a frequency dependent residual side band (FDRSB) reference signal. The method may include receiving the FDRSB reference signal based at least in part on the requested signal length.

[0007] Some aspects described herein relate to a method of wireless communication performed by a network node. The method may include receiving an indication of a requested signal length of an FDRSB reference signal. The method may include transmitting the FDRSB reference signal based at least in part on the requested signal length.

[0008] Some aspects described herein relate to a UE for wireless communication. The user equipment may include a memory and one or more processors coupled to the memory. The one or more processors may be configured to transmit an indication of a requested signal length of an FDRSB reference signal. The one or more processors may be configured to receive the FDRSB reference signal based at least in part on the requested signal length.

[0009] Some aspects described herein relate to a network node for wireless communication. The network node may include a memory and one or more processors coupled to the memory. The one or more processors may be configured to receive an indication of a requested signal length of an FDRSB reference signal. The one or more processors may be configured to transmit the FDRSB reference signal based at least in part on the requested signal length.

[0010] Some aspects described herein relate to a non-transitory computer-readable medium that stores a set of instructions for wireless communication by a UE. The set of instructions, when executed by one or more processors of the UE, may cause the UE to transmit an indication of a requested signal length of an FDRSB reference signal. The set of instructions, when executed by one or more processors of the UE, may cause the UE to receive the FDRSB reference signal based at least in part on the requested signal length.

[0011] Some aspects described herein relate to a non-transitory computer-readable medium that stores a set of instructions for wireless communication by a network node. The set of instructions, when executed by one or more processors of the network node, may cause the network node to receive an indication of a requested signal length of an FDRSB reference signal. The set of instructions, when executed by one or more processors of the network node, may cause the network node to transmit the FDRSB reference signal based at least in part on the requested signal length.

[0012] Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include means for transmitting an indication of a requested signal length of an FDRSB reference signal. The apparatus may include means for receiving the FDRSB reference signal based at least in part on the requested signal length.

[0013] Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include means for receiving an indication of a requested signal length of an FDRSB reference signal. The apparatus may include means for transmitting the FDRSB reference signal based at least in part on the requested signal length.

[0014] Aspects generally include a method, apparatus, system, computer program product, non-transitory computer-readable medium, user equipment, base station, network entity, network node, wireless communication device, and/or processing system as substantially described herein with reference to and as illustrated by the drawings and specification.

[0015] The foregoing has outlined rather broadly the features and technical advantages of examples according to the disclosure in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter. The conception and specific examples disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. Characteristics of the concepts disclosed herein, both their organization and method of operation, together with associated advantages, will be better understood from the following description when considered in connection with the accompanying figures. Each of the figures is provided for the purposes of illustration and description, and not as a definition of the limits of the claims.

[0016] While aspects are described in the present disclosure by illustration to some examples, those skilled in the art will understand that such aspects may be implemented in many different arrangements and scenarios. Techniques described herein may be implemented using different platform types, devices, systems, shapes, sizes, and/or packaging arrangements. For example, some aspects may be implemented via integrated chip embodiments or other non-modulecomponent based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, and/or artificial intelligence devices). Aspects may be implemented in chip-level components, modular components, non-modular components, non-chip-level components, device-level components, and/or system-level components. Devices incorporating described aspects and features may include additional components and features for implementation and practice of claimed and described aspects. For example, transmission and reception of wireless signals may include one or more components for analog and digital purposes (e.g., hardware components including antennas, radio frequency (RF) chains, power amplifiers, modulators, buffers, processors, interleavers, adders, and/or summers). It is intended that aspects described herein may be practiced in a wide variety of devices, components, systems, distributed arrangements, and/or end-user devices of varying size, shape, and constitution.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] So that the above-recited features of the present disclosure can be understood in detail, a more particular description, briefly summarized above, may be had by reference to aspects, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only certain typical aspects of this disclosure and are therefore not to be considered limiting of its scope, for the description may admit to other equally effective aspects. The same reference numbers in different drawings may identify the same or similar elements.

[0018] Fig. 1 is a diagram illustrating an example of a wireless network, in accordance with the present disclosure.

[0019] Fig. 2 is a diagram illustrating an example of a network node in communication with a user equipment (UE) in a wireless network, in accordance with the present disclosure.

[0020] Fig. 3 is a diagram illustrating an example disaggregated base station architecture, in accordance with the present disclosure.

[0021] Fig. 4 is a diagram illustrating an example of a communication having frequency dependent residual side band (FDRSB), in accordance with the present disclosure.

[0022] Fig. 5 is a diagram of an example associated with FDRSB reference signals, in accordance with the present disclosure.

[0023] Fig. 6 is a diagram illustrating an example of a communication having FDRSB, in accordance with the present disclosure. [0024] Fig. 7 is a diagram illustrating an example process performed, for example, by a UE, in accordance with the present disclosure.

[0025] Fig. 8 is a diagram illustrating an example process performed, for example, by a network node, in accordance with the present disclosure.

[0026] Fig. 9 is a diagram of an example apparatus for wireless communication, in accordance with the present disclosure.

[0027] Fig. 10 is a diagram of an example apparatus for wireless communication, in accordance with the present disclosure.

DETAILED DESCRIPTION

[0028] Various aspects of the disclosure are described more fully hereinafter with reference to the accompanying drawings. This disclosure may, however, be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. One skilled in the art should appreciate that the scope of the disclosure is intended to cover any aspect of the disclosure disclosed herein, whether implemented independently of or combined with any other aspect of the disclosure. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method which is practiced using other structure, functionality, or structure and functionality in addition to or other than the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim. [0029] Several aspects of telecommunication systems will now be presented with reference to various apparatuses and techniques. These apparatuses and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, or the like (collectively referred to as “elements”). These elements may be implemented using hardware, software, or combinations thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. [0030] While aspects may be described herein using terminology commonly associated with a 5G or New Radio (NR) radio access technology (RAT), aspects of the present disclosure can be applied to other RATs, such as a 3G RAT, a 4G RAT, and/or a RAT subsequent to 5G (e.g., 6G).

[0031] Fig. 1 is a diagram illustrating an example of a wireless network 100, in accordance with the present disclosure. The wireless network 100 may be or may include elements of a 5G (e.g., NR) network and/or a 4G (e.g., Long Term Evolution (LTE)) network, among other examples. The wireless network 100 may include one or more network nodes 110 (shown as a network node 110a, a network node 110b, a network node 110c, and a network node 1 lOd), a user equipment (UE) 120 or multiple UEs 120 (shown as a UE 120a, a UE 120b, a UE 120c, a UE 120d, and a UE 120e), and/or other entities. A network node 110 is a network node that communicates with UEs 120. As shown, a network node 110 may include one or more network nodes. For example, a network node 110 may be an aggregated network node, meaning that the aggregated network node is configured to utilize a radio protocol stack that is physically or logically integrated within a single radio access network (RAN) node (e.g., within a single device or unit). As another example, a network node 110 may be a disaggregated network node (sometimes referred to as a disaggregated base station), meaning that the network node 110 is configured to utilize a protocol stack that is physically or logically distributed among two or more nodes (such as one or more central units (CUs), one or more distributed units (DUs), or one or more radio units (RUs)).

[0032] In some examples, a network node 110 is or includes a network node that communicates with UEs 120 via a radio access link, such as an RU. In some examples, a network node 110 is or includes a network node that communicates with other network nodes 110 via a fronthaul link or a midhaul link, such as a DU. In some examples, a network node 110 is or includes a network node that communicates with other network nodes 110 via a midhaul link or a core network via a backhaul link, such as a CU. In some examples, a network node 110 (such as an aggregated network node 110 or a disaggregated network node 110) may include multiple network nodes, such as one or more RUs, one or more CUs, and/or one or more DUs. A network node 110 may include, for example, an NR base station, an LTE base station, a Node B, an eNB (e.g., in 4G), a gNB (e.g., in 5G), an access point, a transmission reception point (TRP), a DU, an RU, a CU, a mobility element of a network, a core network node, a network element, a network equipment, a RAN node, or a combination thereof. In some examples, the network nodes 110 may be interconnected to one another or to one or more other network nodes 110 in the wireless network 100 through various types of fronthaul, midhaul, and/or backhaul interfaces, such as a direct physical connection, an air interface, or a virtual network, using any suitable transport network.

[0033] In some examples, a network node 110 may provide communication coverage for a particular geographic area. In the Third Generation Partnership Project (3GPP), the term “cell” can refer to a coverage area of a network node 110 and/or a network node subsystem serving this coverage area, depending on the context in which the term is used. A network node 110 may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or another type of cell. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs 120 with service subscriptions. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs 120 with service subscriptions. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs 120 having association with the femto cell (e.g., UEs 120 in a closed subscriber group (CSG)). A network node 110 for a macro cell may be referred to as a macro network node. A network node 110 for a pico cell may be referred to as a pico network node. A network node 110 for a femto cell may be referred to as a femto network node or an in-home network node. In the example shown in Fig. 1, the network node 110a may be a macro network node for a macro cell 102a, the network node 110b may be a pico network node for a pico cell 102b, and the network node 110c may be a femto network node for a femto cell 102c. A network node may support one or multiple (e.g., three) cells. In some examples, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a network node 110 that is mobile (e.g., a mobile network node).

[0034] In some aspects, the terms “base station” or “network node” may refer to an aggregated base station, a disaggregated base station, an integrated access and backhaul (IAB) node, a relay node, or one or more components thereof. For example, in some aspects, “base station” or “network node” may refer to a CU, a DU, an RU, a Near-Real Time (Near-RT) RAN Intelligent Controller (RIC), or a Non-Real Time (Non-RT) RIC, or a combination thereof. In some aspects, the terms “base station” or “network node” may refer to one device configured to perform one or more functions, such as those described herein in connection with the network node 110. In some aspects, the terms “base station” or “network node” may refer to a plurality of devices configured to perform the one or more functions. For example, in some distributed systems, each of a quantity of different devices (which may be located in the same geographic location or in different geographic locations) may be configured to perform at least a portion of a function, or to duplicate performance of at least a portion of the function, and the terms “base station” or “network node” may refer to any one or more of those different devices. In some aspects, the terms “base station” or “network node” may refer to one or more virtual base stations or one or more virtual base station functions. For example, in some aspects, two or more base station functions may be instantiated on a single device. In some aspects, the terms “base station” or “network node” may refer to one of the base station functions and not another. In this way, a single device may include more than one base station.

[0035] The wireless network 100 may include one or more relay stations. A relay station is a network node that can receive a transmission of data from an upstream node (e.g., a network node 110 or a UE 120) and send a transmission of the data to a downstream node (e.g., a UE 120 or a network node 110). A relay station may be a UE 120 that can relay transmissions for other UEs 120. In the example shown in Fig. 1, the network node 1 lOd (e.g., a relay network node) may communicate with the network node 110a (e.g., a macro network node) and the UE 120d in order to facilitate communication between the network node 110a and the UE 120d. A network node 110 that relays communications may be referred to as a relay station, a relay base station, a relay network node, a relay node, a relay, or the like.

[0036] The wireless network 100 may be a heterogeneous network that includes network nodes 110 of different types, such as macro network nodes, pico network nodes, femto network nodes, relay network nodes, or the like. These different types of network nodes 110 may have different transmit power levels, different coverage areas, and/or different impacts on interference in the wireless network 100. For example, macro network nodes may have a high transmit power level (e.g., 5 to 40 watts) whereas pico network nodes, femto network nodes, and relay network nodes may have lower transmit power levels (e.g., 0. 1 to 2 watts).

[0037] A network controller 130 may couple to or communicate with a set of network nodes 110 and may provide coordination and control for these network nodes 110. The network controller 130 may communicate with the network nodes 110 via a backhaul communication link or a midhaul communication link. The network nodes 110 may communicate with one another directly or indirectly via a wireless or wireline backhaul communication link. In some aspects, the network controller 130 may be a CU or a core network device, or may include a CU or a core network device.

[0038] The UEs 120 may be dispersed throughout the wireless network 100, and each UE 120 may be stationary or mobile. A UE 120 may include, for example, an access terminal, a terminal, a mobile station, and/or a subscriber unit. A UE 120 may be a cellular phone (e.g., a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device, a biometric device, a wearable device (e.g., a smart watch, smart clothing, smart glasses, a smart wristband, smart jewelry (e.g., a smart ring or a smart bracelet)), an entertainment device (e.g., a music device, a video device, and/or a satellite radio), a vehicular component or sensor, a smart meter/sensor, industrial manufacturing equipment, a global positioning system device, a UE function of a network node, and/or any other suitable device that is configured to communicate via a wireless or wired medium.

[0039] Some UEs 120 may be considered machine-type communication (MTC) or evolved or enhanced machine-type communication (eMTC) UEs. An MTC UE and/or an eMTC UE may include, for example, a robot, a drone, a remote device, a sensor, a meter, a monitor, and/or a location tag, that may communicate with a network node, another device (e.g., a remote device), or some other entity. Some UEs 120 may be considered Intemet-of-Things (loT) devices, and/or may be implemented as NB-IoT (narrowband loT) devices. Some UEs 120 may be considered a Customer Premises Equipment. A UE 120 may be included inside a housing that houses components of the UE 120, such as processor components and/or memory components. In some examples, the processor components and the memory components may be coupled together. For example, the processor components (e.g., one or more processors) and the memory components (e.g., a memory) may be operatively coupled, communicatively coupled, electronically coupled, and/or electrically coupled.

[0040] In general, any number of wireless networks 100 may be deployed in a given geographic area. Each wireless network 100 may support a particular RAT and may operate on one or more frequencies. A RAT may be referred to as a radio technology, an air interface, or the like. A frequency may be referred to as a carrier, a frequency channel, or the like. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.

[0041] In some examples, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly using one or more sidelink channels (e.g., without using a network node 110 as an intermediary to communicate with one another). For example, the UEs 120 may communicate using peer-to-peer (P2P) communications, device-to-device (D2D) communications, a vehicle-to-everything (V2X) protocol (e.g., which may include a vehicle-to- vehicle (V2V) protocol, a vehicle-to-infrastructure (V2I) protocol, or a vehicle-to-pedestrian (V2P) protocol), and/or a mesh network. In such examples, a UE 120 may perform scheduling operations, resource selection operations, and/or other operations described elsewhere herein as being performed by the network node 110.

[0042] Devices of the wireless network 100 may communicate using the electromagnetic spectrum, which may be subdivided by frequency or wavelength into various classes, bands, channels, or the like. For example, devices of the wireless network 100 may communicate using one or more operating bands. In 5G NR, two initial operating bands have been identified as frequency range designations FR1 (410 MHz - 7.125 GHz) and FR2 (24.25 GHz - 52.6 GHz). It should be understood that although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “Sub-6 GHz” band in various documents and articles. A similar nomenclature issue sometimes occurs with regard to FR2, which is often referred to (interchangeably) as a “millimeter wave” band in documents and articles, despite being different from the extremely high frequency (EHF) band (30 GHz - 300 GHz) which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band.

[0043] The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Recent 5G NR studies have identified an operating band for these mid-band frequencies as frequency range designation FR3 (7.125 GHz - 24.25 GHz). Frequency bands falling within FR3 may inherit FR1 characteristics and/or FR2 characteristics, and thus may effectively extend features of FR1 and/or FR2 into mid-band frequencies. In addition, higher frequency bands are currently being explored to extend 5G NR operation beyond 52.6 GHz. For example, three higher operating bands have been identified as frequency range designations FR4a or FR4- 1 (52.6 GHz - 71 GHz), FR4 (52.6 GHz - 114.25 GHz), and FR5 (114.25 GHz - 300 GHz). Each of these higher frequency bands falls within the EHF band.

[0044] With the above examples in mind, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like, if used herein, may broadly represent frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. Further, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like, if used herein, may broadly represent frequencies that may include mid-band frequencies, may be within FR2, FR4, FR4-a or FR4-1, and/or FR5, or may be within the EHF band. It is contemplated that the frequencies included in these operating bands (e.g., FR1, FR2, FR3, FR4, FR4-a, FR4-1, and/or FR5) may be modified, and techniques described herein are applicable to those modified frequency ranges.

[0045] In some aspects, the UE 120 may include a communication manager 140. As described in more detail elsewhere herein, the communication manager 140 may transmit an indication of a requested signal length of a frequency dependent residual side band (FDRSB) reference signal; and receive the FDRSB reference signal based at least in part on the requested signal length. Additionally, or alternatively, the communication manager 140 may perform one or more other operations described herein.

[0046] In some aspects, the network node 110 may include a communication manager 150. As described in more detail elsewhere herein, the communication manager 150 may receive an indication of a requested signal length of an FDRSB reference signal; and transmit the FDRSB reference signal based at least in part on the requested signal length. Additionally, or alternatively, the communication manager 150 may perform one or more other operations described herein.

[0047] As indicated above, Fig. 1 is provided as an example. Other examples may differ from what is described with regard to Fig. 1.

[0048] Fig. 2 is a diagram illustrating an example 200 of a network node 110 in communication with a UE 120 in a wireless network 100, in accordance with the present disclosure. The network node 110 may be equipped with a set of antennas 234a through 234t, such as T antennas (T> 1). The UE 120 may be equipped with a set of antennas 252a through 252r, such as R antennas (R > 1). The network node 110 of example 200 includes one or more radio frequency components, such as antennas 234 and a modem 232. In some examples, a network node 110 may include an interface, a communication component, or another component that facilitates communication with the UE 120 or another network node. Some network nodes 110 may not include radio frequency components that facilitate direct communication with the UE 120, such as one or more CUs, or one or more DUs. [0049] At the network node 110, a transmit processor 220 may receive data, from a data source 212, intended for the UE 120 (or a set of UEs 120). The transmit processor 220 may select one or more modulation and coding schemes (MCSs) for the UE 120 based at least in part on one or more channel quality indicators (CQIs) received from that UE 120. The network node 110 may process (e.g., encode and modulate) the data for the UE 120 based at least in part on the MCS(s) selected for the UE 120 and may provide data symbols for the UE 120. The transmit processor 220 may process system information (e.g., for semi-static resource partitioning information (SRPI)) and control information (e.g., CQI requests, grants, and/or upper layer signaling) and provide overhead symbols and control symbols. The transmit processor 220 may generate reference symbols for reference signals (e.g., a cell-specific reference signal (CRS) or a demodulation reference signal (DMRS)) and synchronization signals (e.g., a primary synchronization signal (PSS) or a secondary synchronization signal (SSS)). A transmit (TX) multiple -input multiple -output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, the overhead symbols, and/or the reference symbols, if applicable, and may provide a set of output symbol streams (e.g., T output symbol streams) to a corresponding set of modems 232 (e.g., T modems), shown as modems 232a through 232t. For example, each output symbol stream may be provided to a modulator component (shown as MOD) of a modem 232. Each modem 232 may use a respective modulator component to process a respective output symbol stream (e.g., for OFDM) to obtain an output sample stream. Each modem 232 may further use a respective modulator component to process (e.g., convert to analog, amplify, filter, and/or upconvert) the output sample stream to obtain a downlink signal. The modems 232a through 232t may transmit a set of downlink signals (e.g., T downlink signals) via a corresponding set of antennas 234 (e.g., T antennas), shown as antennas 234a through 234t.

[0050] At the UE 120, a set of antennas 252 (shown as antennas 252a through 252r) may receive the downlink signals from the network node 110 and/or other network nodes 110 and may provide a set of received signals (e.g., R received signals) to a set of modems 254 (e.g., R modems), shown as modems 254a through 254r. For example, each received signal may be provided to a demodulator component (shown as DEMOD) of a modem 254. Each modem 254 may use a respective demodulator component to condition (e.g., filter, amplify, downconvert, and/or digitize) a received signal to obtain input samples. Each modem 254 may use a demodulator component to further process the input samples (e.g., for OFDM) to obtain received symbols. A MIMO detector 256 may obtain received symbols from the modems 254, may perform MIMO detection on the received symbols if applicable, and may provide detected symbols. A receive processor 258 may process (e.g., demodulate and decode) the detected symbols, may provide decoded data for the UE 120 to a data sink 260, and may provide decoded control information and system information to a controller/processor 280. The term “controller/processor” may refer to one or more controllers, one or more processors, or a combination thereof. A channel processor may determine a reference signal received power (RSRP) parameter, a received signal strength indicator (RSSI) parameter, a reference signal received quality (RSRQ) parameter, and/or a CQI parameter, among other examples. In some examples, one or more components of the UE 120 may be included in a housing.

[0051] The network controller 130 may include a communication unit 294, a controller/processor 290, and a memory 292. The network controller 130 may include, for example, one or more devices in a core network. The network controller 130 may communicate with the network node 110 via the communication unit 294.

[0052] One or more antennas (e.g., antennas 234a through 234t and/or antennas 252a through 252r) may include, or may be included within, one or more antenna panels, one or more antenna groups, one or more sets of antenna elements, and/or one or more antenna arrays, among other examples. An antenna panel, an antenna group, a set of antenna elements, and/or an antenna array may include one or more antenna elements (within a single housing or multiple housings), a set of coplanar antenna elements, a set of non-coplanar antenna elements, and/or one or more antenna elements coupled to one or more transmission and/or reception components, such as one or more components of Fig. 2.

[0053] On the uplink, at the UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information (e.g., for reports that include RSRP, RSSI, RSRQ, and/or CQI) from the controller/processor 280. The transmit processor 264 may generate reference symbols for one or more reference signals. The symbols from the transmit processor 264 may be precoded by a TX MIMO processor 266 if applicable, further processed by the modems 254 (e.g., for DFT-s-OFDM or CP-OFDM), and transmitted to the network node 110. In some examples, the modem 254 of the UE 120 may include a modulator and a demodulator. In some examples, the UE 120 includes a transceiver. The transceiver may include any combination of the antenna(s) 252, the modem(s) 254, the MIMO detector 256, the receive processor 258, the transmit processor 264, and/or the TX MIMO processor 266. The transceiver may be used by a processor (e.g., the controller/processor 280) and the memory 282 to perform aspects of any of the methods described herein (e.g., with reference to Figs. 5-10). [0054] At the network node 110, the uplink signals from UE 120 and/or other UEs may be received by the antennas 234, processed by the modem 232 (e.g., a demodulator component, shown as DEMOD, of the modem 232), detected by a MIMO detector 236 if applicable, and further processed by a receive processor 238 to obtain decoded data and control information sent by the UE 120. The receive processor 238 may provide the decoded data to a data sink 239 and provide the decoded control information to the controller/processor 240. The network node 110 may include a communication unit 244 and may communicate with the network controller 130 via the communication unit 244. The network node 110 may include a scheduler 246 to schedule one or more UEs 120 for downlink and/or uplink communications. In some examples, the modem 232 of the network node 110 may include a modulator and a demodulator. In some examples, the network node 110 includes a transceiver. The transceiver may include any combination of the antenna(s) 234, the modem(s) 232, the MIMO detector 236, the receive processor 238, the transmit processor 220, and/or the TX MIMO processor 230. The transceiver may be used by a processor (e.g., the controller/processor 240) and the memory 242 to perform aspects of any of the methods described herein (e.g., with reference to Figs. 5-10).

[0055] The controller/processor 240 of the network node 110, the controller/processor 280 of the UE 120, and/or any other component(s) of Fig. 2 may perform one or more techniques associated with FDRSB RSs, as described in more detail elsewhere herein. For example, the controller/processor 240 of the network node 110, the controller/processor 280 of the UE 120, and/or any other component(s) of Fig. 2 may perform or direct operations of, for example, process 700 of Fig. 7, process 800 of Fig. 8, and/or other processes as described herein. The memory 242 and the memory 282 may store data and program codes for the network node 110 and the UE 120, respectively. In some examples, the memory 242 and/or the memory 282 may include a non-transitory computer-readable medium storing one or more instructions (e.g., code and/or program code) for wireless communication. For example, the one or more instructions, when executed (e.g., directly, or after compiling, converting, and/or interpreting) by one or more processors of the network node 110 and/or the UE 120, may cause the one or more processors, the UE 120, and/or the network node 110 to perform or direct operations of, for example, process 700 of Fig. 7, process 800 of Fig. 8, and/or other processes as described herein. In some examples, executing instructions may include running the instructions, converting the instructions, compiling the instructions, and/or interpreting the instructions, among other examples.

[0056] In some aspects, the UE includes means for transmitting an indication of a requested signal length of an FDRSB reference signal; and/or means for receiving the FDRSB reference signal based at least in part on the requested signal length. The means for the UE to perform operations described herein may include, for example, one or more of communication manager 140, antenna 252, modem 254, MIMO detector 256, receive processor 258, transmit processor 264, TX MIMO processor 266, controller/processor 280, or memory 282.

[0057] In some aspects, the network node includes means for receiving an indication of a requested signal length of an FDRSB reference signal; and/or means for transmitting the FDRSB reference signal based at least in part on the requested signal length. The means for the network node to perform operations described herein may include, for example, one or more of communication manager 150, transmit processor 220, TX MIMO processor 230, modem 232, antenna 234, MIMO detector 236, receive processor 238, controller/processor 240, memory 242, or scheduler 246. [0058] While blocks in Fig. 2 are illustrated as distinct components, the functions described above with respect to the blocks may be implemented in a single hardware, software, or combination component or in various combinations of components. For example, the functions described with respect to the transmit processor 264, the receive processor 258, and/or the TX MIMO processor 266 may be performed by or under the control of the controller/processor 280. [0059] As indicated above, Fig. 2 is provided as an example. Other examples may differ from what is described with regard to Fig. 2.

[0060] Deployment of communication systems, such as 5G NR systems, may be arranged in multiple manners with various components or constituent parts. In a 5G NR system, or network, a network node, a network entity, a mobility element of a network, a RAN node, a core network node, a network element, a base station, or a network equipment may be implemented in an aggregated or disaggregated architecture. For example, a base station (such as a Node B (NB), an evolved NB (eNB), an NR base station, a 5G NB, an access point (AP), a TRP, or a cell, among other examples), or one or more units (or one or more components) performing base station functionality, may be implemented as an aggregated base station (also known as a standalone base station or a monolithic base station) or a disaggregated base station. “Network entity” or “network node” may refer to a disaggregated base station, or to one or more units of a disaggregated base station (such as one or more CUs, one or more DUs, one or more RUs, or a combination thereof).

[0061] An aggregated base station (e.g., an aggregated network node) may be configured to utilize a radio protocol stack that is physically or logically integrated within a single RAN node (e.g., within a single device or unit). A disaggregated base station (e.g., a disaggregated network node) may be configured to utilize a protocol stack that is physically or logically distributed among two or more units (such as one or more CUs, one or more DUs, or one or more RUs). In some examples, a CU may be implemented within a network node, and one or more DUs may be co-located with the CU, or alternatively, may be geographically or virtually distributed throughout one or multiple other network nodes. The DUs may be implemented to communicate with one or more RUs. Each of the CU, DU, and RU also can be implemented as virtual units, such as a virtual central unit (VCU), a virtual distributed unit (VDU), or a virtual radio unit (VRU), among other examples.

[0062] Base station-type operation or network design may consider aggregation characteristics of base station functionality. For example, disaggregated base stations may be utilized in an IAB network, an open radio access network (O-RAN (such as the network configuration sponsored by the O-RAN Alliance)), or a virtualized radio access network (vRAN, also known as a cloud radio access network (C-RAN)) to facilitate scaling of communication systems by separating base station functionality into one or more units that can be individually deployed. A disaggregated base station may include functionality implemented across two or more units at various physical locations, as well as functionality implemented for at least one unit virtually, which can enable flexibility in network design. The various units of the disaggregated base station can be configured for wired or wireless communication with at least one other unit of the disaggregated base station.

[0063] Fig. 3 is a diagram illustrating an example disaggregated base station architecture 300, in accordance with the present disclosure. The disaggregated base station architecture 300 may include a CU 310 that can communicate directly with a core network 320 via a backhaul link, or indirectly with the core network 320 through one or more disaggregated control units (such as a Near-RT RIC 325 via an E2 link, or a Non-RT RIC 315 associated with a Service Management and Orchestration (SMO) Framework 305, or both). A CU 310 may communicate with one or more DUs 330 via respective midhaul links, such as through Fl interfaces. Each of the DUs 330 may communicate with one or more RUs 340 via respective fronthaul links. Each of the RUs 340 may communicate with one or more UEs 120 via respective radio frequency (RF) access links. In some implementations, a UE 120 may be simultaneously served by multiple RUs 340.

[0064] Each of the units, including the CUs 310, the DUs 330, the RUs 340, as well as the Near-RT RICs 325, the Non-RT RICs 315, and the SMO Framework 305, may include one or more interfaces or be coupled with one or more interfaces configured to receive or transmit signals, data, or information (collectively, signals) via a wired or wireless transmission medium. Each of the units, or an associated processor or controller providing instructions to one or multiple communication interfaces of the respective unit, can be configured to communicate with one or more of the other units via the transmission medium. In some examples, each of the units can include a wired interface, configured to receive or transmit signals over a wired transmission medium to one or more of the other units, and a wireless interface, which may include a receiver, a transmitter or transceiver (such as an RF transceiver), configured to receive or transmit signals, or both, over a wireless transmission medium to one or more of the other units.

[0065] In some aspects, the CU 310 may host one or more higher layer control functions. Such control functions can include radio resource control (RRC) functions, packet data convergence protocol (PDCP) functions, or service data adaptation protocol (SDAP) functions, among other examples. Each control function can be implemented with an interface configured to communicate signals with other control functions hosted by the CU 310. The CU 310 may be configured to handle user plane functionality (for example, Central Unit - User Plane (CU-UP) functionality), control plane functionality (for example, Central Unit - Control Plane (CU-CP) functionality), or a combination thereof. In some implementations, the CU 310 can be logically split into one or more CU-UP units and one or more CU-CP units. A CU-UP unit can communicate bidirectionally with a CU-CP unit via an interface, such as the El interface when implemented in an O-RAN configuration. The CU 310 can be implemented to communicate with a DU 330, as necessary, for network control and signaling.

[0066] Each DU 330 may correspond to a logical unit that includes one or more base station functions to control the operation of one or more RUs 340. In some aspects, the DU 330 may host one or more of a radio link control (RLC) layer, a medium access control (MAC) layer, and one or more high physical (PHY) layers depending, at least in part, on a functional split, such as a functional split defined by the 3GPP. In some aspects, the one or more high PHY layers may be implemented by one or more modules for forward error correction (FEC) encoding and decoding, scrambling, and modulation and demodulation, among other examples. In some aspects, the DU 330 may further host one or more low PHY layers, such as implemented by one or more modules for a fast Fourier transform (FFT), an inverse FFT (iFFT), digital beamforming, or physical random access channel (PRACH) extraction and filtering, among other examples. Each layer (which also may be referred to as a module) can be implemented with an interface configured to communicate signals with other layers (and modules) hosted by the DU 330, or with the control functions hosted by the CU 310.

[0067] Each RU 340 may implement lower-layer functionality. In some deployments, an RU 340, controlled by a DU 330, may correspond to a logical node that hosts RF processing functions or low-PHY layer functions, such as performing an FFT, performing an iFFT, digital beamforming, or PRACH extraction and filtering, among other examples, based on a functional split (for example, a functional split defined by the 3GPP), such as a lower layer functional split. In such an architecture, each RU 340 can be operated to handle over the air (OTA) communication with one or more UEs 120. In some implementations, real-time and non-real- time aspects of control and user plane communication with the RU(s) 340 can be controlled by the corresponding DU 330. In some scenarios, this configuration can enable each DU 330 and the CU 310 to be implemented in a cloud-based RAN architecture, such as a vRAN architecture. [0068] The SMO Framework 305 may be configured to support RAN deployment and provisioning of non-virtualized and virtualized network elements. For non-virtualized network elements, the SMO Framework 305 may be configured to support the deployment of dedicated physical resources for RAN coverage requirements, which may be managed via an operations and maintenance interface (such as an 01 interface). For virtualized network elements, the SMO Framework 305 may be configured to interact with a cloud computing platform (such as an open cloud (O-Cloud) platform 390) to perform network element life cycle management (such as to instantiate virtualized network elements) via a cloud computing platform interface (such as an 02 interface). Such virtualized network elements can include, but are not limited to, CUs 310, DUs 330, RUs 340, non-RT RICs 315, and Near-RT RICs 325. In some implementations, the SMO Framework 305 can communicate with a hardware aspect of a 4G RAN, such as an open eNB (O-eNB) 311, via an 01 interface. Additionally, in some implementations, the SMO Framework 305 can communicate directly with each of one or more RUs 340 via a respective 01 interface. The SMO Framework 305 also may include a Non-RT RIC 315 configured to support functionality of the SMO Framework 305.

[0069] The Non-RT RIC 315 may be configured to include a logical function that enables non-real-time control and optimization of RAN elements and resources, Artificial Intelligence/Machine Learning (AI/ML) workflows including model training and updates, or policy-based guidance of applications/features in the Near-RT RIC 325. The Non-RT RIC 315 may be coupled to or communicate with (such as via an Al interface) the Near-RT RIC 325. The Near-RT RIC 325 may be configured to include a logical function that enables near-realtime control and optimization of RAN elements and resources via data collection and actions over an interface (such as via an E2 interface) connecting one or more CUs 310, one or more DUs 330, or both, as well as an O-eNB, with the Near-RT RIC 325.

[0070] In some implementations, to generate AI/ML models to be deployed in the Near-RT RIC 325, the Non-RT RIC 315 may receive parameters or external enrichment information from external servers. Such information may be utilized by the Near-RT RIC 325 and may be received at the SMO Framework 305 or the Non-RT RIC 315 from non-network data sources or from network functions. In some examples, the Non-RT RIC 315 or the Near-RT RIC 325 may be configured to tune RAN behavior or performance. For example, the Non-RT RIC 315 may monitor long-term trends and patterns for performance and employ AI/ML models to perform corrective actions through the SMO Framework 305 (such as reconfiguration via an 01 interface) or via creation of RAN management policies (such as Al interface policies).

[0071] As indicated above, Fig. 3 is provided as an example. Other examples may differ from what is described with regard to Fig. 3.

[0072] Fig. 4 is a diagram illustrating an example 400 of a communication having FDRSB, in accordance with the present disclosure. As shown in Fig. 4, a network node 110 may transmit a communication to a UE 120. The network node 110 may use multiple antenna elements (also referred to as “antennas”) to transmit the communication using beamforming. The communication may include signals transmitted via multiple time -frequency resources (e.g., via multiple subcarriers and/or resource blocks on one or more symbols and/or slots).

[0073] As shown in Fig. 4, the network node 110 may receive multiple streams 402 for transmission to the UE 120. The streams may include data and/or control signaling for transmission to the UE 120. A digital precoder 404 may receive the streams 402 and apply precoding to the streams 402. After applying the precoding to the streams 402, the digital precoder 404 may output digitally precoded streams 406. [0074] A set of in-phase and quadrature (IQ) modulators 408 (e.g., IQ modulators 408A through IQ modulators 408N) may receive the digitally precoded streams 406 from the digital precoder 404 (e.g., directly or indirectly). The IQ modulators 408 may modulate the digitally precoded streams 406 to map bits of the digitally precoded streams 406 to constellation points associated with bit values of the digitally precoded streams 406. For example, the IQ modulators 408 may apply modulation based at least in part on applying amplitudes, in a Q dimension and an I direction in an IQ plane, according to a modulation and coding scheme (MCS) of communications to the UE 120. However, the IQ modulators 408 may cause FDRSB (e.g., an IQ mismatch, an FDRSB impairment, and/or FDRSB error) to the digital precoded streams 406 based at least in part on, for example, imperfections of the IQ modulators 408. This FDRSB may cause signaling on a first subcarrier to cause interference with a second subcarrier that is a mirror of the first subcarrier about a carrier frequency. For example, the first subcarrier may be a distance from the carrier frequency in a positive direction (e.g., above the carrier frequency), and the second subcarrier may be the same distance from the carrier frequency in a negative direction (e.g., below the carrier frequency).

[0075] The IQ modulators 408 may provide modulated signals associated with the digitally precoded streams 406 to antenna elements 410 for transmission over the air to the UE 120. Based at least in part on digital precoding, the antenna elements 410 may transmit the modulated signals associated with the digitally precoded streams 406 via a transmission beam 412. In some examples, the antenna elements 410 may transmit the modulated signals via one or more transmission beams 412. As the modulated signals propagate over the air to the UE 120, channel conditions 414 may affect the modulated signals. For example, the channel conditions 414 may affect a signal -to-noise ratio (SNR) and/or a signal -to-interference-plus- noise ratio (SINR) of the modulated signals as received at the UE 120.

[0076] The UE 120 may receive the modulated signals having effects from channel conditions 414. Additionally, based at least in part on transmission using the IQ modulators 408, the modulated signals may have FDRSB. The antenna elements 416 may provide received streams 418 (e.g., the modulated signals having effects of channel conditions 414 and FDRSB) to a demodulator 420. In some examples, the demodulator 420 may be unable to correctly demodulate the received streams 418 based at least in part on the FDRSB associated with the IQ modulators 408. In these examples, the UE 120 and the network node 110 may consume power, processing, power, and/or communication resources to detect and correct demodulation errors or failures in the received streams 418. For example, the UE 120 may provide hybrid automatic repeat request (HARQ) acknowledgment (HARQ-ACK) feedback to indicate a demodulation and/or decoding error, which may trigger a retransmission of communications associated with the streams 402. [0077] As indicated above, Fig. 4 is provided as an example. Other examples may differ from what is described with regard to Fig. 4.

[0078] In some networks, a network node may be configured with dedicated hardware to internally measure and correct FDRSB for each antenna element. However, based at least in part on FDRSB being inconsistent (e.g., based at least in part on temperature or other variable conditions), the network node may periodically or aperiodically measure and correct the FDRSB for each antenna element. In some networks, network nodes may be configured with a high number of antennas (e.g., for massive MIMO and/or beam forming), which may add costs for the dedicated hardware and/or which may consume computing resources and/or consume time resources when internally measuring and correcting FDRSB for each antenna element. As a number of antenna elements increases, the computing resources and time resources consumed also increase.

[0079] In some aspects described herein, a UE may estimate and correct FDRSB of a communication. The UE may estimate FDRSB based at least in part on a reference signal (also referenced as an FDRSB RS or an FDRSB training signal, among other examples). The estimated FDRSB may include a total FDRSB that accounts for all transmission chains used to transmit a communication to the UE, all IQ modulators used to transmit the communication to the UE, and/or all FDRSB associated with individual IQ modulators used to transmit the communication to the UE, among other examples.

[0080] In some aspects, the reference signal may be configurable with different lengths (e.g., with durations that span one or more symbols). The UE may use a relatively long reference signal to estimate FDRSB for a relatively large number of IQ modulators or a relatively short reference signal to estimate FDRSB for a relatively small number of IQ modulators. The UE may use a relatively long reference signal to estimate FDRSB in relatively poor SNR conditions (e.g., to increase processing gain) or a relatively short reference signal to estimate FDRSB for relatively good SNR conditions.

[0081] In some aspects described herein, the UE and/or the network node may select a signal length of an FDRSB reference signal after establishing a communication link. In some aspects, the UE and/or the network node may select the signal length periodically, a-periodically based at least in part on changed conditions, based at least in part on a change in precoding at the UE or the network node (e.g., associated with a beam change), and/or based at least in part on a request from the UE or the network node, among other examples. In this way, the FDRSB reference signal may have a length that is based at least in part on conditions during communication, such as a temperature or an active beam (e.g., a precoding), among other examples. Having a selected length (e.g., from a set of candidate lengths) may conserve power, computing, network (e.g., via overhead), and/or communication resources that may have otherwise been used to transmit and receive an FDRSB reference signal that is unnecessarily long. Additionally, or alternatively, having a selected length (e.g., from a set of candidate lengths) may conserve power, computing, network (e.g., via overhead), and/or communication resources that may have otherwise been used based at least in part on inaccurately estimating the FDRSB and failing to decode communications having residual FDRSB.

[0082] Some aspects described herein may be used in networks using massive MIMO, with FDRSB estimation and correction performed by the UE.

[0083] In some aspects, the UE may transmit an indication of a requested signal length of an FDRSB reference signal. In some aspects, the requested signal length may be based at least in part on an estimation capability of the UE and/or SNR as observed at the UE for signals received from the network node. The length may be requested to be sufficiently long to support the UE in estimating numerous different FDRSBs when numerous IQ modulators are used (e.g., in massive MIMO). In some aspects, the indication of the requested signal length may include information for the network node to use in selection of the signal length. For example, the UE may transmit information such as a battery state, a power budget, and/or a computing resources budget for reception of the reference signal.

[0084] In some aspects, the UE may transmit the indication of the requested signal length via physical uplink control channel (PUCCH) or physical uplink shared channel (PUSCH). In some aspects, the network node may respond to the requested signal length via physical downlink control channel (PDCCH) or physical downlink shared channel (PDSCH).

[0085] In some aspects, the network node may respond to the requested signal length with an indication of an allocation of resources for the FDRSB reference signal. For example, the network node may indicate a slot number used to transmit the reference signal (e.g., training symbols). In some aspects, the reference signal may occupy a partial slot, a signal slot, or multiple slots. Additionally, or alternatively, the network node may indicate a number of reference signals transmitted.

[0086] In some aspects, the network node may group UEs with similar selected lengths into groups for transmission of the reference signal in a training session. For example, the network node may transmit a first FDRSB reference signal having a first length to a first set of UEs (e.g., based at least in part on having a same requested signal length or requested signal lengths with differences that satisfy a threshold). The network node may transmit the first FDRSB reference signal on a single beam or on multiple beams. The network node may transmit a second FDRSB reference signal having a second length to a second set of UEs (e.g., based at least in part on having a same requested signal length or requested signal lengths with differences that satisfy a threshold). [0087] In some aspects, the network node may select the FDRSB reference signal length to jointly serve a group of UEs that are time division multiplexing (TDM)-served on a same beam (e.g., by choosing a maximal required length). In this way, the network node may select a single FDRSB reference signal length that is configured to be used by the group of UEs that share the same beam.

[0088] In some aspects, the network node may configure FDRSB reference signals (e.g., training signals) for different UEs that are wirelessly linked to the network node, with the FDRSB reference signals having different lengths (e.g., depending on a number of reception antennas that are active in communication, SNR, and/or power constraints, among other examples), which may support a reduction in associated overhead.

[0089] In some aspects, the network node and/or the UE may select a periodicity to provide FDRSB reference signals and/or to request FDRSB reference signals. In some aspects, the network node and/or the UE may transmit or request an FDRSB reference signal based at least in part on aging of a previous FDRSB estimate, a temperature change at the network node, a temperature change at the UE, a change in a precoding at the network node, and/or a change in a precoding at the UE, among other examples.

[0090] For an allocation containing N_sc sub-carriers, each sub-carrier may experience a different FDRSB relative to other sub-carriers. However, an FDRSB curve for a set of adjacent subcarriers may have little variance (e.g., a small group of adjacent N_COherence sub-carriers). For example, for N_COherence = 20, the FDRSB may be assumed to be roughly the same for the set of adjacent subcarriers, and the UE may estimate FDRSB for the set of adjacent subcarriers based at least in part on one or more (e.g., but fewer than all) of the adjacent subcarriers. When one subcarrier is used to represent the set, a size of the set (e.g., a number of subcarriers and/or a total bandwidth of the subcarriers within the set) may be referred to as a resolution of the FDRSB estimation. In this way, the UE may reduce a number of parameters that need to be estimated: reduced N_tx ■ N_sc from- N_tx - N_sc => ^{t0 :} M -

‘''coherence

[0091] A number of available of equations for estimation by the UE may be: reduced N_tx ■ N_sc from- N_tx - N_sc => ^{t0 :} M -

‘''coherence

[0092] In this way, a ratio of equations to a number of parameters to be estimated may be: reduced N_tx ■ N_sc from- N_tx - N_sc => ^{t0 :} M -

‘''coherence

[0093] For example, for a massive MIMO with N_tx = 256, N_rx = 4, N_coherence = 20, the

UE may request tra n ng .symbols — 4 to achieve ratio equations .to .params — 1 (s-g-, to estimate parameters of FDRSB without processing gain). [0094] In some aspects, the UE may use an initial Ncoherence value, iteratively estimate the initial Ncoherence , and/or may receive the initial Ncoherence as an a-priori initial value from the network node.

[0095] Based at least in part the parameters mentioned in previous slide the UE’s request for a training signal whose length I^zraining .symbols satisfies <2tio_eq_Uations params > 1- Additionally, or alternatively, if the UE would benefit from processing gain for suppressing thermal noise (e.g., if SNR is below a threshold and/or if, for example, lOdB processing gain is needed), then the UE may target the processing gain (e.g., 10 log₁₀ r atio_{equations to params} = 10 dB) by requesting an associated number of training symbols (e.g., having a requested length), to satisfy, for example, RATIO >= 10. The UE may determine how much processing gain would be useful based at least in part an SNR estimation (e.g., at the UE), such that the higher the SNR the less processing gain is requested (e.g., based at least in part on an associated signal length requested).

[0096] Fig. 5 is a diagram of an example 500 associated with FDRSB reference signals, in accordance with the present disclosure. As shown in Fig. 5, a network node (e.g., network node 110, a CU, a DU, and/or an RU) may communicate with a UE (e.g., UE 120). In some aspects, the network node and the UE may be part of a wireless network (e.g., wireless network 100). The UE and the network node may have established a wireless connection prior to operations shown in Fig. 5.

[0097] As shown by reference number 505, the network node may transmit, and the UE may receive, configuration information. In some aspects, the UE may receive the configuration information via one or more of radio resource control (RRC) signaling, one or more medium access control (MAC) control elements (CEs), and/or downlink control information (DCI), among other examples. In some aspects, the configuration information may include an indication of one or more configuration parameters (e.g., already known to the UE and/or previously indicated by the network node or other network device) for selection by the UE, and/or explicit configuration information for the UE to use to configure the UE, among other examples.

[0098] In some aspects, the configuration information may indicate that the UE is to transmit and indication of a capability to use FDRSB reference signals with dynamically selected lengths (e.g., non-fixed lengths that may be updated during communications with the network node). [0099] The UE may configure itself based at least in part on the configuration information. In some aspects, the UE may be configured to perform one or more operations described herein based at least in part on the configuration information. [0100] As shown by reference number 510, the UE may transmit, and the network node may receive, a capabilities report. In some aspects, the capabilities report may indicate UE support for using FDRSB reference signals with dynamically selected lengths.

[0101] As shown by reference number 515, the UE may transmit, and the network node may receive, an indication of supported signal lengths of FDRSB reference signals (RSs). In some aspects, the supported signal lengths may include one or more signal lengths that may be dynamically selected (e.g., supporting updated from one supported signal length to another supported signal length during communication).

[0102] As shown by reference number 520, the UE may receive, and the network node may transmit, a request for an indication of a requested signal length of an FDRSB RS. In some aspects, the network node may transmit the request based at least in part on a change in precoding (e.g., based at least in part on an updated beam selection), a change in temperature at the network node or the UE, and/or an age of a previously transmitted requested signal length (e.g., satisfaction of a time threshold since the previously transmitted requested signal length). In some aspects, the request may include an indication of periodic resources for transmission of the requested signal length.

[0103] As shown by reference number 525, the UE may transmit, and the network node may receive, the indication of the requested signal length of the FDRSB RS. In some aspects, the UE may transmit the indication of the requested signal length based at least in part on, or independently from (e.g., in the absence of), the request for the indication of the requested signal described in connection with reference number 520. In some aspects, the indication of the requested signal length may indicate a number of symbols requested as the signal length. In some aspects, the UE may transmit the indication via an uplink control channel (e.g., PUCCH) or via a data channel (e.g., PUS CH).

[0104] In some aspects, the requested signal length may be based at least in part on a UE capability (e.g., computing resources, dedicated hardware, and/or power resources, among other examples) for estimating an FDRSB impairment using the FDRSB reference signal, an SNR of communications received at the UE, and/or a subcarrier granularity for estimating FDRSB impairment over a set of subcarriers. In some aspects, the granularity is based at least in part on an indication from the network node, an SNR at the UE, and/or an estimation of subcarrier coherence at the UE (e.g., an estimated number of subcarriers that have FDRSB impairments with differences that satisfy a threshold), among other examples.

[0105] In some aspects, the UE may transmit the indication of the requested signal length of the FDRSB RS based at least in part on an indication from a network node, a temperature at the network node, and/or a temperature at the UE, among other examples. [0106] As shown by reference number 530, the network node may select a length of the FDRSB RS. In some aspects, the network node may select the length of the FDRSB RS for the UE based at least in part on the indication of the requested signal length and/or based at least in part on additional requested signal lengths received from one or more additional UEs. In some aspects, the selected length of the FDRSB RS is based at least in part on a longest requested signal length from the UE and the one or more additional UEs (e.g., UEs that share a beam with the UE). In some aspects, the network node may select the length of the FDRSB RS from a set of candidate lengths of FDRSB RSs.

[0107] As shown by reference number 535, the UE may receive, and the network node may transmit, an indication of an allocation for the FDRSB RS. In some aspects, the allocation may indicate a bandwidth of the FDRSB RS, which may include subcarriers spanning a bandwidth to be used for communication. In some aspects, the allocation for the FDRSB RS may include an indication of a slot identifier (e.g., a slot number and/or slot ID) of a slot that is to include the FDRSB RS.

[0108] The allocation for the FDRSB RS may indicate a signal length of the FDRSB RS. In some aspects, the signal length of the FDRSB may be based at least in part on the requested signal length, as described in connection with reference number 525. In some aspects, the signal length may be equal to the requested signal length. In some aspects, the signal length may be at least as long as the requested signal length.

[0109] As shown by reference number 540, the UE may receive, and the network node may transmit, the FDRSB RS. In some aspects, the UE may receive the FDRSB RS according to the indication of the allocation described in connection with reference number 535. In some aspects, the network node transmits the FDRSB RS via multiple IQ modulators.

[0110] In some aspects, the UE may receive the FDRSB RS via a downlink control channel (e.g., PDCCH) or via a downlink data channel (e.g., PDSCH). In some aspects, the network node may transmit the FDRSB RS as a broadcast or multicast FDRSB RS associated with multiple UEs.

[OHl] As shown by reference number 545, the UE may configure FDRSB correction based at least in part on the FDRSB RS. For example, the UE may estimate the FDRSB from the FDRSB RS. In some aspects, the UE may estimate the FDRSB for individual subcarriers or sets of subcarriers (e.g., based at least in part on a resolution of the estimation) within the bandwidth over which the network node transmitted the FDRSB RS. Based at least in part on the FDRSB estimation, the UE may configure FDRSB correction to remove FDRSB from subcarriers of a subsequent communication. [0112] As shown by reference number 550, the UE may receive, and the network node may transmit, a communication. For example, the communication may include control information and/or data. The UE may receive the communication via a control channel or a data channel. [0113] As shown by reference number 555, the UE may apply FDRSB correction to the communication. For example, the UE may subtract the FDRSB estimation from signaling of the communication received via subchannels corresponding to values of the FDRSB estimation. [0114] Based at least in part on an FDRSB reference signal having a length that is dynamically selected may conserve power, computing, network (e.g., via overhead), and/or communication resources that may have otherwise been used to transmit and receive an FDRSB reference signal that is unnecessarily long. Additionally, or alternatively, having a selected length (e.g., from a set of candidate lengths) may conserve power, computing, network (e.g., via overhead), and/or communication resources that may have otherwise been used based at least in part on inaccurately estimating the FDRSB and failing to decode communications having residual FDRSB.

[0115] As indicated above, Fig. 5 is provided as an example. Other examples may differ from what is described with respect to Fig. 5.

[0116] Fig. 6 is a diagram illustrating an example 600 of a communication having FDRSB, in accordance with the present disclosure. As shown in Fig. 6, a network node 110 may transmit a communication to a UE 120. The network node 110 may use multiple antenna elements (also referred to as “antennas”) to transmit the communication using beamforming. The communication may include signals transmitted via multiple time -frequency resources (e.g., via multiple subcarriers and/or resource blocks on one or more symbols and/or slots).

[0117] As shown in Fig. 6, the network node 110 may receive multiple streams 602 for transmission to the UE 120. The streams may include data and/or control signaling for transmission to the UE 120. A digital precoder 604 may receive the streams 602 and apply precoding to the streams 602. After applying the precoding to the streams 602, the digital precoder 604 may output digitally precoded streams 606.

[0118] A set of IQ modulators 608 (e.g., IQ modulators 608A through IQ modulators 608N) may receive the digitally precoded streams 606 from the digital precoder 604 (e.g., directly or indirectly). The IQ modulators 608 may modulate the digitally precoded streams 606 to map bits of the digitally precoded streams 606 to constellation points associated with bit values of the digitally precoded streams 606. For example, the IQ modulators 608 may apply modulation based at least in part on applying amplitudes, in a Q dimension and an I direction in an IQ plane, according to a modulation and coding scheme (MCS) of communications to the UE 120. However, the IQ modulators 608 may cause FDRSB (e.g., an IQ mismatch, an FDRSB impairment, and/or FDRSB error) to the digital precoded streams 606 based at least in part on, for example, imperfections of the IQ modulators 608. This FDRSB may cause signaling on a first subcarrier to cause interference with a second subcarrier that is a mirror of the first subcarrier about a carrier frequency. For example, the first subcarrier may be a distance from the carrier frequency in a positive direction (e.g., above the carrier frequency), and the second subcarrier may be the same distance from the carrier frequency in a negative direction (e.g., below the carrier frequency).

[0119] The IQ modulators 608 may provide modulated signals associated with the digitally precoded streams 606 to antenna elements 610 for transmission over the air to the UE 120. Based at least in part on digital precoding, the antenna elements 610 may transmit the modulated signals associated with the digitally precoded streams 606 via a transmission beam 612. In some examples, the antenna elements 610 may transmit the modulated signals via one or more transmission beams 612. As the modulated signals propagate over the air to the UE 120, channel conditions 614 may affect the modulated signals. For example, the channel conditions 614 may affect an SNR and/or a signal -to-interference-plus-noise ratio (SINR) of the modulated signals as received at the UE 120.

[0120] The UE 120 may receive the modulated signals having effects from channel conditions 614. Additionally, based at least in part on transmission using the IQ modulators 608, the modulated signals may have FDRSB. The antenna elements 616 may provide received streams 618 (e.g., the modulated signals having effects of channel conditions 614 and FDRSB) to a network node FDRSB estimator 620 and a network node FDRSB corrector 622. The network node FDRSB estimator 620 may receive signals of an FDRSB RS to identify FDRSB for each subcarrier and/or for sets of subcarriers (e.g., based at least in part on a resolution of the estimation). The UE may store the estimation of the network node FDRSB an provide the estimation to the network node FDRSB corrector 622. The network node FDRSB corrector 622 may subtract, or otherwise combine, the estimation with the received streams 618. In this way, the network node FDRSB corrector 622 may correct the received streams 618 before providing corrected streams to the demodulator 624.

[0121] In some examples, the demodulator 624 may be able to correctly demodulate the received streams 618 based at least in part on the FDRSB correction. In these examples, the UE 120 and the network node 110 may conserve power, processing, power, and/or communication resources that may have otherwise been used to detect and correct demodulation errors or failures in the received streams 618.

[0122] As indicated above, Fig. 6 is provided as an example. Other examples may differ from what is described with regard to Fig. 6. [0123] Fig. 7 is a diagram illustrating an example process 700 performed, for example, by a UE, in accordance with the present disclosure. Example process 700 is an example where the UE (e.g., UE 120) performs operations associated with FDRSB reference signals.

[0124] As shown in Fig. 7, in some aspects, process 700 may include transmitting an indication of a requested signal length of an FDRSB reference signal (block 710). For example, the UE (e.g., using communication manager 140 and/or transmission component 904, depicted in Fig. 9) may transmit an indication of a requested signal length of an FDRSB reference signal, as described above.

[0125] As further shown in Fig. 7, in some aspects, process 700 may include receiving the FDRSB reference signal based at least in part on the requested signal length (block 720). For example, the UE (e.g., using communication manager 140 and/or reception component 902, depicted in Fig. 9) may receive the FDRSB reference signal based at least in part on the requested signal length, as described above.

[0126] Process 700 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.

[0127] In a first aspect, the indication of the requested signal length comprises an indication of a number of symbols.

[0128] In a second aspect, alone or in combination with the first aspect, process 700 includes receiving an indication of one or more of a slot identifier that includes the FDRSB reference signal, or a signal length of the FDRSB reference signal.

[0129] In a third aspect, alone or in combination with one or more of the first and second aspects, the requested signal length is based at least in part on one or more of a UE capability for estimating an FDRSB impairment using the FDRSB reference signal, an SNR of communications received at the UE, or a subcarrier granularity for estimating FDRSB impairment over a set of subcarriers.

[0130] In a fourth aspect, alone or in combination with one or more of the first through third aspects, the subcarrier granularity is based at least in part on one or more of an indication from a network node, an SNR at the UE, or an estimation of subcarrier coherence at the UE.

[0131] In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the FDRSB reference signal is transmitted using multiple IQ modulators.

[0132] In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, process 700 includes receiving a communication from a network node, and applying FDRSB correction to the communication based at least in part on reception of the FDRSB reference signal. [0133] In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, transmitting the indication of the requested signal length comprises transmitting the indication via an uplink control channel or an uplink data channel, and wherein receiving the FDRSB reference signal comprises receiving the FDRSB reference signal via a downlink control channel or a downlink data channel.

[0134] In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the FDRSB reference signal comprises a broadcast or multicast FDRSB reference signal associated with multiple UEs.

[0135] In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the FDRSB reference signal comprises a candidate FDRSB reference signal of a set of candidate FDRSB reference signals having different signal lengths.

[0136] In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the FDRSB reference signal has a signal length that is based at least in part on the requested signal length and one or more additional requested signal lengths associated with additional UEs.

[0137] In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, process 700 includes receiving a request for the requested signal length of the FDRSB reference signal.

[0138] In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, a periodicity of transmission of the indication of the requested signal length of the FDRSB reference signal is based at least in part on one or more of an indication from a network node, a temperature at the network node, or a temperature at the UE.

[0139] Although Fig. 7 shows example blocks of process 700, in some aspects, process 700 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Fig. 7. Additionally, or alternatively, two or more of the blocks of process 700 may be performed in parallel.

[0140] Fig. 8 is a diagram illustrating an example process 800 performed, for example, by a network node, in accordance with the present disclosure. Example process 800 is an example where the network node (e.g., network node 110) performs operations associated with FDRSB reference signals.

[0141] As shown in Fig. 8, in some aspects, process 800 may include receiving an indication of a requested signal length of an FDRSB reference signal (block 810). For example, the network node (e.g., using communication manager 150 and/or reception component 1002, depicted in Fig. 10) may receive an indication of a requested signal length of an FDRSB reference signal, as described above. [0142] As further shown in Fig. 8, in some aspects, process 800 may include transmitting the FDRSB reference signal based at least in part on the requested signal length (block 820). For example, the network node (e.g., using communication manager 150 and/or transmission component 1004, depicted in Fig. 10) may transmit the FDRSB reference signal based at least in part on the requested signal length, as described above.

[0143] Process 800 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.

[0144] In a first aspect, the indication of the requested signal length comprises an indication of a number of symbols.

[0145] In a second aspect, alone or in combination with the first aspect, process 800 includes transmitting an indication of one or more of a slot identifier that includes the FDRSB reference signal, or a signal length of the FDRSB reference signal.

[0146] In a third aspect, alone or in combination with one or more of the first and second aspects, the requested signal length is based at least in part on one or more of a UE capability for estimating an FDRSB impairment using the FDRSB reference signal, an SNR of communications received at the UE, or a subcarrier granularity for estimating FDRSB impairment over a set of subcarriers.

[0147] In a fourth aspect, alone or in combination with one or more of the first through third aspects, the subcarrier granularity is based at least in part on one or more of an indication from the network node, an SNR at the UE, or an estimation of subcarrier coherence at the UE.

[0148] In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, transmitting the FDRSB reference signal comprises transmitting the FDRSB reference signal using multiple IQ modulators.

[0149] In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, receiving the indication of the requested signal length comprises receiving the indication via an uplink control channel or an uplink data channel, and wherein transmitting the FDRSB reference signal comprises transmitting the FDRSB reference signal via a downlink control channel or a downlink data channel.

[0150] In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the FDRSB reference signal comprises a broadcast or multicast FDRSB reference signal associated with multiple UEs.

[0151] In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the FDRSB reference signal comprises a candidate FDRSB reference signal of a set of candidate FDRSB reference signals having different signal lengths. [0152] In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the FDRSB reference signal has a signal length that is based at least in part on the requested signal length and one or more additional requested signal lengths associated with one or more UEs.

[0153] In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, process 800 includes transmitting a first FDRSB reference signal to a first set of UEs having first additional requested signal lengths with a maximum difference that satisfies a first threshold or wherein the first additional requested signal lengths satisfy a second threshold, and transmitting a second FDRSB reference signal to a second set of UEs having second additional requested signal lengths with a maximum difference that satisfies the first threshold or wherein the second additional requested signal lengths satisfies a third threshold.

[0154] In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, process 800 includes transmitting a request for the requested signal length of the FDRSB reference signal.

[0155] In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, a periodicity of transmission of the indication of the requested signal length of the FDRSB reference signal is based at least in part on one or more of an indication from the network node, a temperature at the network node, or a temperature at a UE.

[0156] Although Fig. 8 shows example blocks of process 800, in some aspects, process 800 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Fig. 8. Additionally, or alternatively, two or more of the blocks of process 800 may be performed in parallel.

[0157] Fig. 9 is a diagram of an example apparatus 900 for wireless communication, in accordance with the present disclosure. The apparatus 900 may be a UE, or a UE may include the apparatus 900. In some aspects, the apparatus 900 includes a reception component 902 and a transmission component 904, which may be in communication with one another (for example, via one or more buses and/or one or more other components). As shown, the apparatus 900 may communicate with another apparatus 906 (such as a UE, a base station, or another wireless communication device) using the reception component 902 and the transmission component 904. As further shown, the apparatus 900 may include a communication manager 908 (e.g., the communication manager 140).

[0158] In some aspects, the apparatus 900 may be configured to perform one or more operations described herein in connection with Figs. 5-6. Additionally, or alternatively, the apparatus 900 may be configured to perform one or more processes described herein, such as process 700 of Fig. 7. In some aspects, the apparatus 900 and/or one or more components shown in Fig. 9 may include one or more components of the UE described in connection with Fig. 2. Additionally, or alternatively, one or more components shown in Fig. 9 may be implemented within one or more components described in connection with Fig. 2. Additionally, or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer- readable medium and executable by a controller or a processor to perform the functions or operations of the component.

[0159] The reception component 902 may receive communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus 906. The reception component 902 may provide received communications to one or more other components of the apparatus 900. In some aspects, the reception component 902 may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, de-mapping, equalization, interference cancellation, or decoding, among other examples), and may provide the processed signals to the one or more other components of the apparatus 900. In some aspects, the reception component 902 may include one or more antennas, a modem, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the UE described in connection with Fig. 2.

[0160] The transmission component 904 may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus 906. In some aspects, one or more other components of the apparatus 900 may generate communications and may provide the generated communications to the transmission component 904 for transmission to the apparatus 906. In some aspects, the transmission component 904 may perform signal processing on the generated communications (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples), and may transmit the processed signals to the apparatus 906. In some aspects, the transmission component 904 may include one or more antennas, a modem, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the UE described in connection with Fig. 2. In some aspects, the transmission component 904 may be co-located with the reception component 902 in a transceiver.

[0161] The transmission component 904 may transmit an indication of a requested signal length of an FDRSB reference signal. The reception component 902 may receive the FDRSB reference signal based at least in part on the requested signal length.

[0162] The reception component 902 may receive an indication of one or more of a slot identifier that includes the FDRSB reference signal, or a signal length of the FDRSB reference signal. [0163] The reception component 902 may receive a communication from a network node. [0164] The communication manager and/or reception component 902 may apply FDRSB correction to the communication based at least in part on reception of the FDRSB reference signal.

[0165] The reception component 902 may receive a request for the requested signal length of the FDRSB reference signal.

[0166] The number and arrangement of components shown in Fig. 9 are provided as an example. In practice, there may be additional components, fewer components, different components, or differently arranged components than those shown in Fig. 9. Furthermore, two or more components shown in Fig. 9 may be implemented within a single component, or a single component shown in Fig. 9 may be implemented as multiple, distributed components. Additionally, or alternatively, a set of (one or more) components shown in Fig. 9 may perform one or more functions described as being performed by another set of components shown in Fig. 9.

[0167] Fig. 10 is a diagram of an example apparatus 1000 for wireless communication, in accordance with the present disclosure. The apparatus 1000 may be a network node, or a network node may include the apparatus 1000. In some aspects, the apparatus 1000 includes a reception component 1002 and a transmission component 1004, which may be in communication with one another (for example, via one or more buses and/or one or more other components). As shown, the apparatus 1000 may communicate with another apparatus 1006 (such as a UE, a base station, or another wireless communication device) using the reception component 1002 and the transmission component 1004. As further shown, the apparatus 1000 may include a communication manager 1008 (e.g., the communication manager 150). The communication manager 1008 may support operations of the reception component 1002 and/or the transmission component 1004. For example, the communication manager 1008 may receive information associated with configuring reception and/or transmission of communications via the reception component 1002 and/or the transmission component 1004. Additionally, or alternatively, the communication manager 1008 may generate and/or provide control information to the reception component 1002 and/or the transmission component 1004.

[0168] In some aspects, the apparatus 1000 may be configured to perform one or more operations described herein in connection with Figs. 5-6. Additionally, or alternatively, the apparatus 1000 may be configured to perform one or more processes described herein, such as process 800 of Fig. 8. In some aspects, the apparatus 1000 and/or one or more components shown in Fig. 10 may include one or more components of the network node described in connection with Fig. 2. Additionally, or alternatively, one or more components shown in Fig. 10 may be implemented within one or more components described in connection with Fig. 2. Additionally, or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component.

[0169] The reception component 1002 may receive communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus 1006. The reception component 1002 may provide received communications to one or more other components of the apparatus 1000. In some aspects, the reception component 1002 may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, de-mapping, equalization, interference cancellation, or decoding, among other examples), and may provide the processed signals to the one or more other components of the apparatus 1000. In some aspects, the reception component 1002 may include one or more antennas, a modem, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the network node described in connection with Fig. 2.

[0170] The transmission component 1004 may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus 1006. In some aspects, one or more other components of the apparatus 1000 may generate communications and may provide the generated communications to the transmission component 1004 for transmission to the apparatus 1006. In some aspects, the transmission component 1004 may perform signal processing on the generated communications (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples), and may transmit the processed signals to the apparatus 1006. In some aspects, the transmission component 1004 may include one or more antennas, a modem, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the network node described in connection with Fig. 2. In some aspects, the transmission component 1004 may be co-located with the reception component 1002 in a transceiver.

[0171] The reception component 1002 may receive an indication of a requested signal length of an FDRSB reference signal. The transmission component 1004 may transmit the FDRSB reference signal based at least in part on the requested signal length.

[0172] The transmission component 1004 may transmit an indication of one or more of a slot identifier that includes the FDRSB reference signal, or a signal length of the FDRSB reference signal. [0173] The transmission component 1004 may transmit a first FDRSB reference signal to a first set of UEs having first additional requested signal lengths with a maximum difference that satisfies a first threshold or wherein the first additional requested signal lengths satisfy a second threshold.

[0174] The transmission component 1004 may transmit a second FDRSB reference signal to a second set of UEs having second additional requested signal lengths with a maximum difference that satisfies the first threshold or wherein the second additional requested signal lengths satisfies a third threshold.

[0175] The transmission component 1004 may transmit a request for the requested signal length of the FDRSB reference signal.

[0176] The number and arrangement of components shown in Fig. 10 are provided as an example. In practice, there may be additional components, fewer components, different components, or differently arranged components than those shown in Fig. 10. Furthermore, two or more components shown in Fig. 10 may be implemented within a single component, or a single component shown in Fig. 10 may be implemented as multiple, distributed components. Additionally, or alternatively, a set of (one or more) components shown in Fig. 10 may perform one or more functions described as being performed by another set of components shown in Fig. 10.

[0177] The following provides an overview of some Aspects of the present disclosure:

[0178] Aspect 1 : A method of wireless communication performed by a user equipment (UE), comprising: transmitting an indication of a requested signal length of a frequency dependent residual side band (FDRSB) reference signal; and receiving the FDRSB reference signal based at least in part on the requested signal length.

[0179] Aspect 2: The method of Aspect 1, wherein the indication of the requested signal length comprises an indication of a number of symbols.

[0180] Aspect 3: The method of any of Aspects 1-2, further comprising receiving an indication of one or more of: a slot identifier that includes the FDRSB reference signal, or a signal length of the FDRSB reference signal.

[0181] Aspect 4: The method of any of Aspects 1-3, wherein the requested signal length is based at least in part on one or more of: a UE capability for estimating an FDRSB impairment using the FDRSB reference signal, a signal-to-noise ratio (SNR) of communications received at the UE, or a subcarrier granularity for estimating FDRSB impairment over a set of subcarriers. [0182] Aspect 5: The method of Aspect 4, wherein the subcarrier granularity is based at least in part on one or more of: an indication from a network node, a signal-to-noise ratio (SNR) at the UE, or an estimation of subcarrier coherence at the UE. [0183] Aspect 6: The method of any of Aspects 1-5, wherein the FDRSB reference signal is transmitted using multiple IQ modulators.

[0184] Aspect 7: The method of any of Aspects 1-6, further comprising: receiving a communication from a network node; and applying FDRSB correction to the communication based at least in part on reception of the FDRSB reference signal.

[0185] Aspect 8: The method of any of Aspects 1-7, wherein transmitting the indication of the requested signal length comprises transmitting the indication via an uplink control channel or an uplink data channel, and wherein receiving the FDRSB reference signal comprises receiving the FDRSB reference signal via a downlink control channel or a downlink data channel.

[0186] Aspect 9: The method of any of Aspects 1-8, wherein the FDRSB reference signal comprises: a broadcast or multicast FDRSB reference signal associated with multiple UEs. [0187] Aspect 10: The method of any of Aspects 1-9, wherein the FDRSB reference signal comprises: a candidate FDRSB reference signal of a set of candidate FDRSB reference signals having different signal lengths.

[0188] Aspect 11: The method of any of Aspects 1-10, wherein the FDRSB reference signal has a signal length that is based at least in part on the requested signal length and one or more additional requested signal lengths associated with additional UEs.

[0189] Aspect 12: The method of any of Aspects 1-11, further comprising: receiving a request for the requested signal length of the FDRSB reference signal.

[0190] Aspect 13: The method of any of Aspects 1-12, wherein a periodicity of transmission of the indication of the requested signal length of the FDRSB reference signal is based at least in part on one or more of: an indication from a network node, a temperature at the network node, or a temperature at the UE.

[0191] Aspect 14: A method of wireless communication performed by a network node, comprising: receiving an indication of a requested signal length of a frequency dependent residual side band (FDRSB) reference signal; and transmitting the FDRSB reference signal based at least in part on the requested signal length.

[0192] Aspect 15: The method of Aspect 14, wherein the indication of the requested signal length comprises an indication of a number of symbols.

[0193] Aspect 16: The method of any of Aspects 14-15, further comprising transmitting an indication of one or more of: a slot identifier that includes the FDRSB reference signal, or a signal length of the FDRSB reference signal.

[0194] Aspect 17: The method of any of Aspects 14-16, wherein the requested signal length is based at least in part on one or more of: a user equipment (UE) capability for estimating an FDRSB impairment using the FDRSB reference signal, a signal-to-noise ratio (SNR) of communications received at the UE, or a subcarrier granularity for estimating FDRSB impairment over a set of subcarriers.

[0195] Aspect 18: The method of Aspect 17, wherein the subcarrier granularity is based at least in part on one or more of: an indication from the network node, a signal-to-noise ratio (SNR) at the UE, or an estimation of subcarrier coherence at the UE.

[0196] Aspect 19: The method of any of Aspects 14-18, wherein transmitting the FDRSB reference signal comprises: transmitting the FDRSB reference signal using multiple IQ modulators.

[0197] Aspect 20: The method of any of Aspects 14-19, wherein receiving the indication of the requested signal length comprises receiving the indication via an uplink control channel or an uplink data channel, and wherein transmitting the FDRSB reference signal comprises transmitting the FDRSB reference signal via a downlink control channel or a downlink data channel.

[0198] Aspect 21: The method of any of Aspects 14-20, wherein the FDRSB reference signal comprises: a broadcast or multicast FDRSB reference signal associated with multiple UEs.

[0199] Aspect 22: The method of any of Aspects 14-21, wherein the FDRSB reference signal comprises: a candidate FDRSB reference signal of a set of candidate FDRSB reference signals having different signal lengths.

[0200] Aspect 23: The method of any of Aspects 14-22, wherein the FDRSB reference signal has a signal length that is based at least in part on the requested signal length and one or more additional requested signal lengths associated with one or more user equipments (UEs).

[0201] Aspect 24: The method of Aspect 23, further comprising: transmitting a first FDRSB reference signal to a first set of UEs having first additional requested signal lengths with a maximum difference that satisfies a first threshold or wherein the first additional requested signal lengths satisfy a second threshold; and transmitting a second FDRSB reference signal to a second set of UEs having second additional requested signal lengths with a maximum difference that satisfies the first threshold or wherein the second additional requested signal lengths satisfies a third threshold.

[0202] Aspect 25: The method of any of Aspects 14-24, further comprising: transmitting a request for the requested signal length of the FDRSB reference signal.

[0203] Aspect 26: The method of any of Aspects 14-25, wherein a periodicity of transmission of the indication of the requested signal length of the FDRSB reference signal is based at least in part on one or more of: an indication from the network node, a temperature at the network node, or a temperature at a user equipment (UE).

[0204] Aspect 27 : An apparatus for wireless communication at a device, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of one or more of Aspects 1-26.

[0205] Aspect 28: A device for wireless communication, comprising a memory and one or more processors coupled to the memory, the one or more processors configured to perform the method of one or more of Aspects 1-26.

[0206] Aspect 29: An apparatus for wireless communication, comprising at least one means for performing the method of one or more of Aspects 1-26.

[0207] Aspect 30: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of one or more of Aspects 1-26.

[0208] Aspect 31 : A non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising one or more instructions that, when executed by one or more processors of a device, cause the device to perform the method of one or more of Aspects 1-26.

[0209] The foregoing disclosure provides illustration and description but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the aspects. [0210] As used herein, the term “component” is intended to be broadly construed as hardware and/or a combination of hardware and software. “Software” shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, and/or functions, among other examples, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. As used herein, a “processor” is implemented in hardware and/or a combination of hardware and software. It will be apparent that systems and/or methods described herein may be implemented in different forms of hardware and/or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems and/or methods is not limiting of the aspects. Thus, the operation and behavior of the systems and/or methods are described herein without reference to specific software code, since those skilled in the art will understand that software and hardware can be designed to implement the systems and/or methods based, at least in part, on the description herein.

[0211] As used herein, “satisfying a threshold” may, depending on the context, 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, or the like. [0212] Even though particular combinations of features are recited in the claims and/or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. Many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification. The disclosure of various aspects includes each dependent claim in combination with every other claim in the claim set. As used herein, a phrase referring to “at least one of’ a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover a, b, c, a + b, a + c, b + c, and a + b + c, as well as any combination with multiples of the same element (e.g., a + a, a + a + a, a + a + b, a + a + c, a + b + b, a + c + c, b + b, b + b + b, b + b + c, c + c, and c + c + c, or any other ordering of a, b, and c).

[0213] No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such. Also, as used herein, the articles “a” and “an” are intended to include one or more items and may be used interchangeably with “one or more.” Further, as used herein, the article “the” is intended to include one or more items referenced in connection with the article “the” and may be used interchangeably with “the one or more.” Furthermore, as used herein, the terms “set” and “group” are intended to include one or more items and may be used interchangeably with “one or more.” Where only one item is intended, the phrase “only one” or similar language is used. Also, as used herein, the terms “has,” “have,” “having,” or the like are intended to be open-ended terms that do not limit an element that they modify (e.g., an element “having” A may also have B). Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Also, as used herein, the term “or” is intended to be inclusive when used in a series and may be used interchangeably with “and/or,” unless explicitly stated otherwise (e.g., if used in combination with “either” or “only one of’).

Claims

WHAT IS CLAIMED IS:

1. A user equipment (UE) for wireless communication, comprising: a memory; and one or more processors, coupled to the memory, configured to: transmit an indication of a requested signal length of a frequency dependent residual side band (FDRSB) reference signal; and receive the FDRSB reference signal based at least in part on the requested signal length.

2. The UE of claim 1, wherein the indication of the requested signal length comprises an indication of a number of symbols.

3. The UE of claim 1, wherein the one or more processors are further configured to receive an indication of one or more of: a slot identifier that includes the FDRSB reference signal, or a signal length of the FDRSB reference signal.

4. The UE of claim 1, wherein the requested signal length is based at least in part on one or more of: a UE capability for estimating an FDRSB impairment using the FDRSB reference signal, a signal-to-noise ratio (SNR) of communications received at the UE, or a subcarrier granularity for estimating FDRSB impairment over a set of subcarriers.

5. The UE of claim 4, wherein the subcarrier granularity is based at least in part on one or more of: an indication from a network node, an SNR at the UE, or an estimation of subcarrier coherence at the UE.

6. The UE of claim 1, wherein the FDRSB reference signal is transmitted using multiple in-phase and quadrature (IQ) modulators.

7. The UE of claim 1, wherein the one or more processors are further configured to: receive a communication from a network node; and apply FDRSB correction to the communication based at least in part on reception of the FDRSB reference signal.

8. The UE of claim 1, wherein the one or more processors, to transmit the indication of the requested signal length, are configured to transmit the indication via an uplink control channel or an uplink data channel, and wherein the one or more processors, to receive the FDRSB reference signal, are configured to receive the FDRSB reference signal via a downlink control channel or a downlink data channel.

9. The UE of claim 1, wherein the FDRSB reference signal comprises: a broadcast or multicast FDRSB reference signal associated with multiple UEs.

10. The UE of claim 1, wherein the FDRSB reference signal comprises: a candidate FDRSB reference signal of a set of candidate FDRSB reference signals having different signal lengths.

11. The UE of claim 1, wherein the FDRSB reference signal has a signal length that is based at least in part on the requested signal length and one or more additional requested signal lengths associated with additional UEs.

12. The UE of claim 1, wherein the one or more processors are further configured to: receive a request for the requested signal length of the FDRSB reference signal.

13. The UE of claim 1, wherein a periodicity of transmission of the indication of the requested signal length of the FDRSB reference signal is based at least in part on one or more of: an indication from a network node, a temperature at the network node, or a temperature at the UE.

14. A network node for wireless communication, comprising: a memory; and one or more processors, coupled to the memory, configured to: receive an indication of a requested signal length of a frequency dependent residual side band (FDRSB) reference signal; and transmit the FDRSB reference signal based at least in part on the requested signal length.

15. The network node of claim 14, wherein the indication of the requested signal length comprises an indication of a number of symbols.

16. The network node of claim 14, wherein the one or more processors are further configured to transmit an indication of one or more of: a slot identifier that includes the FDRSB reference signal, or a signal length of the FDRSB reference signal.

17. The network node of claim 14, wherein the requested signal length is based at least in part on one or more of: a user equipment (UE) capability for estimating an FDRSB impairment using the FDRSB reference signal, a signal-to-noise ratio (SNR) of communications received at the UE, or a subcarrier granularity for estimating FDRSB impairment over a set of subcarriers.

18. The network node of claim 17, wherein the subcarrier granularity is based at least in part on one or more of: an indication from the network node, an SNR at the UE, or an estimation of subcarrier coherence at the UE.

19. The network node of claim 14, wherein the one or more processors, to transmit the FDRSB reference signal, are configured to: transmit the FDRSB reference signal using multiple IQ modulators.

20. The network node of claim 14, wherein the one or more processors, to receive the indication of the requested signal length, are configured to receive the indication via an uplink control channel or an uplink data channel, and wherein the one or more processors, to transmit the FDRSB reference signal, are configured to transmit the FDRSB reference signal via a downlink control channel or a downlink data channel.

21. The network node of claim 14, wherein the FDRSB reference signal comprises: a broadcast or multicast FDRSB reference signal associated with multiple UEs.

22. The network node of claim 14, wherein the FDRSB reference signal comprises: a candidate FDRSB reference signal of a set of candidate FDRSB reference signals having different signal lengths.

23. The network node of claim 14, wherein the FDRSB reference signal has a signal length that is based at least in part on the requested signal length and one or more additional requested signal lengths associated with one or more user equipments (UEs).

24. The network node of claim 23, wherein the one or more processors are further configured to: transmit a first FDRSB reference signal to a first set of UEs having first additional requested signal lengths with a maximum difference that satisfies a first threshold or wherein the first additional requested signal lengths satisfy a second threshold; and transmit a second FDRSB reference signal to a second set of UEs having second additional requested signal lengths with a maximum difference that satisfies the first threshold or wherein the second additional requested signal lengths satisfies a third threshold.

25. The network node of claim 14, wherein the one or more processors are further configured to: transmit a request for the requested signal length of the FDRSB reference signal.

26. The network node of claim 14, wherein a periodicity of transmission of the indication of the requested signal length of the FDRSB reference signal is based at least in part on one or more of: an indication from the network node, a temperature at the network node, or a temperature at a user equipment (UE).

27. A method of wireless communication performed by a user equipment (UE), comprising: transmitting an indication of a requested signal length of a frequency dependent residual side band (FDRSB) reference signal; and receiving the FDRSB reference signal based at least in part on the requested signal length.

28. The method of claim 27, wherein the requested signal length is based at least in part on one or more of: a UE capability for estimating an FDRSB impairment using the FDRSB reference signal, a signal-to-noise ratio (SNR) of communications received at the UE, or a subcarrier granularity for estimating FDRSB impairment over a set of subcarriers.

29. A method of wireless communication performed by a network node, comprising: receiving an indication of a requested signal length of a frequency dependent residual side band (FDRSB) reference signal; and transmitting the FDRSB reference signal based at least in part on the requested signal length.

30. The method of claim 29, further comprising: transmitting a first FDRSB reference signal to a first set of UEs having first additional requested signal lengths with a maximum difference that satisfies a first threshold or wherein the first additional requested signal lengths satisfy a second threshold; and transmitting a second FDRSB reference signal to a second set of UEs having second additional requested signal lengths with a maximum difference that satisfies the first threshold or wherein the second additional requested signal lengths satisfies a third threshold.