Reciprocity calibration for downlink channel transmission equalization

Abstract

This disclosure provides methods, components, devices and systems for reciprocity calibration for downlink channel transmission (Tx) equalization. For example, a user equipment (UE) may receive, via a downlink channel and via one or more ports, a set of downlink reference signals (DL-RSs) and may transmit feedback information associated with the set of DL-RSs. Additionally, the UE may transmit, via an uplink channel and via the one or more ports, a set of uplink reference signals (ULRSs) based on transmission of the feedback, reception of the DL-RSs, or both. Thus, a network entity may determine a channel response mismatch between the uplink channel and the downlink channel based on the feedback information and the set of UL-RSs, and may equalize one or more downlink messages in accordance with the channel response mismatch.

Description

Qualcomm Docket No 2500766WO1RECIPROCITY CALIBRATION FOR DOWNLINK CHANNEL TRANSMISSION EQUALIZATION CROSS REFERENCE

[0001] The present Application for Patent claims priority to Israel Patent Application No. 319783 by Barak et al., entitled “RECIPROCITY CALIBRATION FOR DOWNLINK CHANNEL TRANSMISSION EQUALIZATION,’’ filed March 21, 2025. assigned to the assignee hereof, and expressly incorporated by reference herein.TECHNICAL FIELD

[0002] This disclosure relates generally to wireless communication, and more specifically to systems, devices, methods, and techniques associated with reciprocity calibration for downlink channel transmission (TX) equalization.DESCRIPTION OF THE RELATED TECHNOLOGY

[0003] Communication systems are deployed to provide communication services such as voice, video, packet data, messaging, or broadcast, among others. A communication system may include a wireless communication network (such as a radio access network (RAN)) that supports communication between wireless communication devices such as network entities (such as base stations), client devices (such as one or more user equipments (UEs)), and others. Such devices may communicate with one another using a variety of protocols (such as radio access technologies (RATs)), including those of cellular-based systems such as fourth generation (4G) systems (such as Long Term Evolution (LTE) systems), fifth generation (5G) systems (such as 5G New Radio (5G-NR) systems), and sixth generation (6G) systems. A wireless communication network may support communication by implementing system resources (such as frequency resources, time resources, spatial resources) in accordance with a wireless communication protocol.SUMMARY

[0004] The systems, methods, and devices of this disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein. The following is a summary of some non-limiting aspects of the disclosure:Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO2

[0005] A method for wireless communications by a user equipment (UE) is described. The method may include receiving a first control message indicative of configuration information associated with a transmission equalization procedure, receiving, via a downlink channel and via one or more ports, a set of downlink reference signals in accordance with the configuration information, transmitting feedback information associated with the set of downlink reference signals, transmitting, via an uplink channel and via the one or more ports, a set of uplink reference signals in accordance with the configuration information and based on transmission of the feedback information, and receiving one or more downlink messages, where the one or more downlink messages are equalized, in accordance with the transmission equalization procedure, based on a channel response difference between the uplink channel and the downlink channel.

[0006] A UE for wireless communications is described. The UE may include a processing system that includes processor circuitry and memory circuitry that stores code. The processing system may be configured to cause the UE to receive a first control message indicative of configuration information associated with a transmission equalization procedure, receive, via a downlink channel and via one or more ports, a set of downlink reference signals in accordance with the configuration information, transmit feedback information associated with the set of downlink reference signals, transmit, via an uplink channel and via the one or more ports, a set of uplink reference signals in accordance with the configuration information and based on transmission of the feedback information, and receive one or more downlink messages, where the one or more downlink messages are equalized, in accordance with the transmission equalization procedure, based on a channel response difference between the uplink channel and the downlink channel.

[0007] Another UE for wireless communications is described. The UE may include means for receiving a first control message indicative of configuration information associated with a transmission equalization procedure, means for receiving, via a downlink channel and via one or more ports, a set of downlink reference signals in accordance w ith the configuration information, means for transmitting feedback information associated with the set of downlink reference signals, means for transmitting, via an uplink channel and via the one or more ports, a set of uplinkAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO3reference signals in accordance with the configuration information and based on transmission of the feedback information, and means for receiving one or more downlink messages, where the one or more downlink messages are equalized, in accordance with the transmission equalization procedure, based on a channel response difference between the uplink channel and the downlink channel.

[0008] A non-transitory computer-readable medium storing code for wireless communications is described. The code may include instructions executable by one or more processors to receive a first control message indicative of configuration information associated with a transmission equalization procedure, receive, via a downlink channel and via one or more ports, a set of downlink reference signals in accordance with the configuration information, transmit feedback information associated with the set of downlink reference signals, transmit, via an uplink channel and via the one or more ports, a set of uplink reference signals in accordance with the configuration information and based on transmission of the feedback information, and receive one or more downlink messages, where the one or more downlink messages are equalized, in accordance with the transmission equalization procedure, based on a channel response difference betw een the uplink channel and the downlink channel.

[0009] In some examples of the method, UEs, and non-transitory computer-readable medium described herein, the channel response difference is based on the feedback information and the set of uplink reference signals.

[0010] Some examples of the method, UEs, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for participating in communication of a re-calibration trigger message based on one or more trigger events, w here reception of the set of downlink reference signals in based on communication of the re-calibration trigger message.

[0011] In some examples of the method, UEs, and non-transitory computer-readable medium described herein, the re-calibration trigger message includes a re-calibration request message transmitted by the UE and the one or more trigger events include a change in temperature of the UE satisfying one or more temperature thresholds, a frequency drift of the UE satisfying one or more frequency drift thresholds, a change in one or more active antennas of the UE, expiration of a timer, or any combination thereof.Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO4

[0012] In some examples of the method, UEs, and non-transitory computer-readable medium described herein, the re-calibration trigger message includes a re-calibration command message received by the UE and the one or more trigger events include a change in bandwidth part of the UE, a change in a carrier aggregation of the UE, a change in temperature of a network entity satisfying one or more temperature change thresholds, a change in transmission gain exceeding one or more transmission gain thresholds, a change in reception gain exceeding one or more reception gain thresholds, expiration of a timer, the UE entering a sleep mode, or any combination thereof.

[0013] Some examples of the method, UEs, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting a capability message indicative of a capability of the UE to perform the transmission equalization procedure, where reception of the first control message may be based at least in art on transmission of the capability message.

[0014] Some examples of the method, UEs, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving a second control message triggering the transmission equalization procedure, where reception of the set of downlink reference signals may be based on reception of the second control message.BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 shows an example of a wireless communication system.

[0016] Figure 2 shows an example of a signaling diagram that supports reciprocity calibration for downlink channel transmission (TX) equalization.

[0017] Figures 3A and 3B show an example of a block diagram that supports reciprocity calibration for downlink channel Tx equalization.

[0018] Figure 4 shows an example of a process flow that supports reciprocity calibration for downlink channel Tx equalization.

[0019] Figure 5 shows a block diagram of a processing system that supports reciprocity calibration for downlink channel Tx equalization.

[0020] Figure 6 shows a diagram of a system including a device that supports reciprocity calibration for downlink channel Tx equalization.Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO5

[0021] Figure 7 shows a block diagram of a processing system that supports reciprocity calibration for downlink channel Tx equalization.

[0022] Figure 8 shows a diagram of a system including a device that supports reciprocity calibration for downlink channel Tx equalization.

[0023] Figures 9 and 10 show flowcharts illustrating methods that support reciprocity calibration for downlink channel Tx equalization.

[0024] Details of aspects and advantages of the subject matter in this disclosure are set forth in the drawings and accompanying descriptions. Like reference numbers and designations in the various drawings indicate like elements.DETAILED DESCRIPTION

[0025] A communication system may include a radio access network (RAN) that supports wireless communication. Communication of a RAN may be performed in accordance w ith one or more radio access technologies (RATs), including 4G, 5G, or 6G, among others, including technologies not explicitly mentioned herein. A RAT may employ access technologies (such as multiplexing technologies) including code division multiple access (CDMA), time division multiple access (TDMA). frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), time division synchronous code division multiple access (TD-SCDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM), among others. A RAT may support one or more service types, including machine type communication (MTC), massive MTC (mMTC), Internet of Things (loT), narrowband loT (NB-IoT), reduced capability (RedCap), enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), or public safety, among others.

[0026] To support these and other target verticals, a communication system (such as a RAN) may be designed to implement one or more of a modularized functional infrastructure, a disaggregated and service-based network architecture, network function virtualization, network slicing, multi-access edge computing, spatial processing or multipath techniques, loT or RedCap device connectivity and management, industrial connectivity, licensed and unlicensed spectrum access, sidelink or other device-to-device (D2D) direct communication (such as vehicle-to-every thing (V2X)), frequencyAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO6spectrum expansion, overlapping spectrum use, small cell deployments, non -terrestrial network (NTN) deployments, device aggregation, advanced duplex communication (such as sub-band full-duplex (SBFD)), multiple-subscriber implementations, high-precision positioning, radio frequency (RF) sensing, network energy savings (NES), low-power signaling and radios, or artificial intelligence or machine learning (AI / ML), among other examples.

[0027] The foregoing and other technological improvements may support use cases such as voice calls, messaging, data transfer, streaming, wireless data centers, extended reality (XR) and metaverse applications, vehicle connectivity, holographic and mixed reality communication, autonomous and collaborative robots, sensing networks, gesture monitoring, human-brain interfacing, digital twin applications, asset management, and universal coverage using non-terrestrial or aerial platforms, among other examples. As the demand for connectivity continues to increase, further improvements may be implemented, and other RATs. including 6G and beyond, may be introduced to enable new applications and use cases. The systems, methods, and devices described herein may enable one or more of the foregoing technologies or new technologies or support one or more of the foregoing use cases or new use cases.

[0028] Some wireless communications systems may support acquisition of channel system information (CSI) for transmission (Tx) precoding. For example, in some cases (e.g., Option 1), a network entity may not assume channel reciprocity between an uplink channel used to receive signaling from a user equipment (UE) and a downlink channel used to transmit signaling to the UE, such that the network entity may acquire CSI based on transmitting one or more CSI reference signals (CSI-RSs) to the UE and receiving, from the UE, feedback information (e.g., CSI) based on the one or more CSI-RS. In some other cases (e.g., Option 2). the network entity may assume channel reciprocity between the uplink channel and the downlink channel, such that the network entity may acquire (e.g., measure) CSI based on one or more sounding reference signals (SRSs) transmitted by the UE. However, in such cases, the assumption of channel reciprocity by the network entity may not be accurate. That is, while the uplink channel and the downlink channel, which may cumulatively be referred to as an over-the-air (OTA) channel, may be reciprocal, antenna transfer functions at each of the UE and the network entity, digital ambiguities at each of the UE and the network entity, analogAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO7impairments at each of the UE and the network entity, or any combination thereof, may not be reciprocal between the UE and the network entity. Thus, the CSI acquired by the network entity may be partial CSI due to the CSI not accounting for a residual channel response mismatch (e.g.. difference) between the uplink channel and the downlink channel that is based on the differences in antenna transfer functions, digital ambiguities, analog impairments, or any combination thereof. While the partial CSI may be sufficient to perform Tx precoding, the partial CSI may not be sufficient to perform Tx equalization. That is, because the CSI is partial CSI, the network entity may not be able to use the CSI to perform Tx equalization due to Tx equalization being based on full CSI (e.g., CSI accounting for the differences in antenna transfer functions, digital ambiguities, analog impairments, or any combination thereof).

[0029] Accordingly, aspects of the subject matter described in this disclosure relate to a Tx equalization procedure that includes online channel reciprocity7calibration to enable the network entity to perform Tx equalization based on CSI that accounts for the residual channel response mismatch between the downlink channel and the uplink channel. For example, the UE may receive, from the network entity on the uplink channel via one or more ports, a set of CSI-RS and may transmit, to the network entity, feedback information based on the set of CSI-RS. In some cases, the feedback information may include a set of raw time domain (TD) samples, a set of raw frequence domain (FD) samples, or both, of the set of CSI-RS compressed by the UE (e.g., channel estimation is performed by the network entity ) or may include a set of TD channel estimation samples based on the set of CSI-RS (e.g., after channel estimation is performed by the UE). Additionally, the UE may transmit, to the network entity on the downlink channel via the one or more ports, a set of SRSs. Thus, the network entity may estimate the residual channel response mismatch between the uplink channel and the downlink channel based on the feedback information and the set of SRSs, and may perform Tx equalization in accordance with the residual channel response mismatch.

[0030] In some cases, both the UE and the network entity may perform an initial channel reciprocity calibration (e.g., in accordance with Option 2), such that the one or more ports may include a single port arbitrarily selected by the UE. In some other cases, only the network entity7may perform the initial channel reciprocity calibration (e.g., in accordance w ith Option 2), such that the one or more ports may include all portsAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO8supported by the UE. Additionally, or alternatively, because the reciprocity calibration may retain accuracy for a threshold duration, the UE, the network entity, or both, may transmit a re-calibration trigger message based on one or more events, where the recalibration trigger message triggers the Tx equalization procedure that includes the reciprocity calibration. For example, in some cases, the re-calibration trigger message may be a re-calibration request message transmitted by the UE based on the one or more events occurring at the UE. Alternatively, the re-calibration trigger message may be a re-calibration command message transmitted by the network entity based on the one or more events occurring at the network entity.

[0031] Particular aspects of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. In some examples, by performing the reciprocity calibration, the described techniques may enable the network entity to account for the channel response mismatch when performing Tx equalization, which may result in improved communication performance, reduce complexity and power consumption at the UE, increased speed of Tx equalization updates, and improved Tx equalization robustness.

[0032] Figure 1 shows an example of a wireless communication system 100. The wireless communication system 100 includes a core network 150 and a RAN 120 that support communication with one or more devices, such as UEs 115. A RAN 120 may include one or more network entities 105 configured to support wireless communication with the UEs 115.

[0033] The wireless communication system 100 may support communication among network entities 105 and UEs 115 in accordance with a layered protocol stack. For example, in a user plane, communication at a bearer layer, a Packet Data Convergence Protocol (PDCP) layer, or Service Data Adaption Protocol (SDAP) layer may be Internet Protocol (IP)-based. A Radio Link Control (RLC) layer may perform packet segmentation and reassembly to communicate via logical channels. A Medium Access Control (MAC) layer may perform priority handling and multiplexing of logical channels into transport channels. A MAC layer also may implement error detection techniques, error correction techniques, or retransmissions. In a control plane, a Radio Resource Control (RRC) layer may provide establishment, configuration, and maintenance of an RRC connection between UEs 115 and a network entity 105 or aAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO9core network 150, supporting radio bearers for user plane data. A Physical (PHY) layer may map transport channels to physical channels.

[0034] A core network 150 may support user authentication, access authorization, tracking, IP connectivity7, and other access, routing, or mobility7functions (such as via network entities 105). A core network 150 may be a 5G core (5GC) or 6G core (6GC), and may include at least one control plane entity that manages access and mobility and at least one user plane entity that routes packets or interconnects to external networks (such as a serving gateway (S-GW), a Packet Data Network (PDN) gateway (P-GW), a user plane function (UPF)).

[0035] A netw ork entity7105 may support wireless communication in accordance with one or more coverage areas 110, and may be referred to as a network element, a network node, a RAN node, or network equipment, among other nomenclature. One or more of the network entities 105 may include or may be referred to as a base station. Depending on its capabilities, a base station may be referred to as aNodeB, an eNodeB (eNB), a next-generation NodeB or giga-NodeB (either of which may be referred to as a gNB), a 5G NB, a 6G NB, a next-generation eNB (ng-eNB), a Home NodeB. a Home eNodeB, or other suitable terminology. The wireless communication system 100 may include a heterogeneous network in which different ty pes of network entities 105 support communication for one or more coverage areas 110 using the same or different RATs.

[0036] In some examples, a network entity7105 may be implemented in an aggregated (such as monolithic, standalone) architecture, which may utilize a protocol stack that is physically or logically integrated within one network entity7105 (such as a single physical RAN node). In some other examples, a network entity7105 may7be implemented in a disaggregated architecture, which may utilize a protocol stack that is physically or logically distributed among multiple network entities 105, including in an integrated access and backhaul (IAB) network, an open RAN (O-RAN), or a virtualized RAN (vRAN). In a disaggregated architecture, a network entity7105 may include or be referred to as one or more of a central unit (CU) (such as CU 160), a distributed unit (DU) (such as DU 165), a radio unit (RU) (such as RU 170), or a combination thereof. The wireless communication system 100 may also implement a service-based architecture that provides a modular framework in which control plane functionality andAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO10common data repositories may be delivered through a set of interconnected network functions (NFs) that may access services of other NFs.

[0037] UEs 115 may be located in a coverage area 110 of one or more network entities 105, and may include or be referred to as an access terminal, a mobile station, a client device, or a subscriber unit. A UE 115 may be, include, or be coupled with a cellular phone, a wireless modem, a tablet device, a laptop computer, a wireless local loop (WLL) station, a camera, a medical or biometric device, a wearable device, a gaming device, an entertainment device, an XR device, a vehicular component or sensor, a smart meter or sensor, industrial manufacturing equipment, a Global Positioning System (GPS) or other positioning device, a robot or other device implementing artificial intelligence, a UE function of a network node, or any other wireless communication device or function that may communicate using a wireless medium.

[0038] The wireless communication system 100 may support various types of communication links among devices. For example, wireless communication between a network entity 105 and a UE 115 may be supported using one or more of a communication link 125 (such as a Uu interface), which may include downlink communication from a network entity 105 to a UE 115, uplink communication from a UE 115 to a network entity 105, or both. Direct wireless communication between UEs 115 may be supported using a communication link 135 (such as a device-to-device (D2D) communication link, a sidelink, a PC5 interface).

[0039] Communication between a network entity 105 and a core network 150 may be supported using a backhaul link 132 (such as an SI, N2, N3, NG, or other interface). In some implementations, communication between network entities 105 may be supported using a backhaul link 132 (such as an X2, Xn, or other interface) either directly (such as directly between network entities 105) or indirectly (such as via a core network 150). In some implementations (such as in a disaggregated architecture), communication between a CU 160 and a DU 165 may be supported using a midhaul link 162, and communication between a DU 165 and an RU may be supported using a fronthaul link 168. A backhaul link 132, a midhaul link 162, a fronthaul link 168, or any combination thereof may be or include one or more wired links (such as an electrical link, an optical fiber link) or one or more wireless links (such as a radio link, a wirelessAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO11optical link), among other examples or combinations thereof. Wireless backhaul, midhaul, or fronthaul may be implemented via one or more IAB nodes 104, which may act as a relay using resources of an IAB donor network entity 105 (such as via a wireless link 130).

[0040] The wireless communication system 100 may include one or more of a relay 172 that may steer or reflect signals transmitted by other entities, which may support any of the described communication links. A relay 172 may include active elements or passive elements, and may be in the form of a reconfigurable intelligent surface (RIS). An RIS may include tunable reflecting antenna arrays or metasurfaces, which may be used to enhance coverage or efficiency in multipath environments.

[0041] Network entities 105 and UEs 115 each may include one or multiple antennas. Multiple antennas of such devices may be used to employ techniques such as transmit diversity, receive diversity, MIMO communication, or beamforming, and may be organized or structured as one or more antenna panels, one or more antenna groups, one or more sets of antenna elements, or one or more antenna arrays, among other examples. As used herein, the term "‘antenna” may refer to one or more antennas, one or more antenna panels, one or more antenna groups, one or more sets of antenna elements, or one or more antenna arrays. The term “antenna panel” may refer to a group of antennas (such as antenna elements) arranged in an array or panel, which may facilitate beamforming by manipulating parameters associated with the group of antennas. In some implementations, an antenna panel may support RF beamforming for a signal transmitted or received via an antenna port. The term “antenna module” may refer to circuitry7including one or more antennas as well as one or more other components (such as filters, amplifiers, processors, beamformers) associated with integrating the antenna module into a device such as a network entity 105 or a UE 115.

[0042] Beamforming, such as directional transmission or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (such as at a network entity 105, at a UE 115) to shape or steer a beam 175 (such as an antenna beam, a transmit beam, a receive beam) along a spatial path (such as along a direction), which may include one or more paths betw een a transmitting device and a receiving device. Beamforming may be achieved by combining signals communicated via multiple antenna elements of an antenna array such that signalsAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO12propagating along some orientations (such as relative to the antenna array) experience constructive interference while others may experience destructive interference.Adjustments of signals communicated via the antenna elements may include a transmitting device or a receiving device applying phase offsets, amplitude offsets, or both to signals carried via (such as transmitted by, received by) antenna elements of the device, which may be defined by a beamforming weight set associated with a particular orientation (such as relative to the antenna array of the device).

[0043] Communication resources of the wireless communication system 100 (such as of a RAN 120) may refer to a resource in the frequency domain (such as a frequency resource, an RF resource), a resource in the time domain (such as a time resource), a resource in the spatial domain (such as a spatial resource, a spatial layer), or a combination thereof. The wireless communication system 100 may leverage orthogonality of such resources to convey different communications to or from different devices (such as for a communication link 125, for a communication link 135, for unicast communication, for multicast communication, for broadcast communication).

[0044] A frequency resource may refer to a frequency or range of frequencies (such as a bandwidth, a frequency channel) of a frequency band implemented for wireless communication. For example, a frequency resource may refer to a resource of a lower frequency band (such as Frequency Range 1 (FR1), between 425 MHz and 7.125 GHz), a mid-band (such as Frequency Range 3 (FR3), between 7.125 GHz and 24.25 GHz), or an upper frequency band (such as Frequency Range 2 (FR2), between 24.25 GHz and 71 GHz). Communication in the upper frequency band may be referred to as millimeter wave (mmW) communication, and communication above an upper frequency band (such as between mmW and THz frequencies, between 100 GHz and 1 THz) may be referred to as sub-Terahertz (sub-THz) communication.

[0045] A frequency resource may refer to a “carrier” (such as a frequency channel), or portion thereof, and a carrier bandwidth may be referred to as a “system bandwidth.” A carrier may be subdivided in the frequency domain, including into subcarriers, bandwidth parts (BWPs), or both. For example, a resource block (RB), such as a physical resource block (PRB), may be defined in accordance with a set of subcarriers (such as twelve consecutive subcarriers in the frequency domain), and a BWP may be configured in accordance with a set of RBs (such as a set of contiguous RBs).Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO13

[0046] A frequency resource may be configured to carry either downlink communication or uplink communication (such as in a frequency division duplexing (FDD) configuration), or may be configured to earn' both downlink and uplink communication (such as in a time division duplexing (TDD) configuration, in a subband full duplex (SBFD) configuration). One or more numerologies for a carrier may be supported, each associated with a subcarrier spacing (SCS) and a cyclic prefix (CP). Supported numerologies may vary by frequency range (such as FR1, FR2, FR3), and a carrier may be divided into portions (such as BWPs) having the same or different numerologies. BWPs may be configured as uplink BWPs or downlink BWPs (such as by a network entity 105), including in response to network conditions (such as to allocate uplink and downlink BWPs in response to traffic conditions), device capability (such as allocating BWPs with a greater quantity of RBs to UEs 115 with relatively higher capabilities), or both. A UE 115 may be configured with a set of multiple BWPs (such as a set of uplink BWPs, a set of downlink BWPs, or both), and a single BWP of a set (such as an active UL BWP, an active DL BWP, or both) may be active at a given time, such that communication of a UE 115 is supported by active BWP(s).

[0047] A time resource may refer to a duration of a frame (such as a radio frame, a frame structure), or portion thereof. For example, a frame may span a duration of 10 ms, and each frame may be identified by a system frame number (SFN). A frame may be subdivided in the time domain, including into subframes, slots, mini-slots, or a combination thereof. Slots or mini-slots may each include a respective quantity of symbols (such as symbol durations, symbol periods, OFDM symbols), which may be a function of a configured CP. A duration of a symbol is a function of the SCS or frequency band of operation.

[0048] A spatial resource may refer to an antenna, an antenna direction, an antenna port, a signal direction (such as a beamforming direction), or other resource that supports spatial orthogonality. A device (such as a network entity 105, a UE 115) may perform communications of a given frequency resource and time resource with a single spatial resource (such as communication without regard to spatial orthogonality).Additionally, or alternatively, a device may implement multiple spatial resources to support multiple signal streams using resources that are overlapping in the time and frequency domains (such as to support MIMO techniques).Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO14

[0049] Signals of the wireless communication system 100 (such as of a RAN 120) may be communicated using one or more resource elements (REs), and an RE may refer to a resource that corresponds to one subcarrier in the frequency domain and one symbol in the time domain. An RE may be used to convey a modulation symbol corresponding to one or more bits of information (such as of a physical channel, of a reference signal) in accordance with a modulation scheme. For example, a quadrature phase shift keying (QPSK) or quadrature amplitude modulation (QAM) technique may be implemented to communicate one or more bits that are distinguished in accordance with phase components, amplitude components, or both of a signal conveyed using a RE. A quantity of bits carried by an RE may depend on an order of the modulation scheme, and a relatively higher order may correspond to a relatively higher rate of communication. A device may support communication of REs using multiple subcarriers concurrently by implementing multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM), among others.

[0050] Physical channels may carry information using modulation symbols conveyed by corresponding REs. Physical shared channels (such as for communicating user data) may include a physical downlink shared channel (PDSCH) for communicating user data in a downlink direction and a physical uplink shared channel (PUSCH) for communicating user data in an uplink direction. Physical control channels (such as for managing communication via physical channels) may include a physical downlink control channel (PDCCH) for communicating downlink control information (DCI) and a physical uplink control channel (PUCCH) for communicating uplink control information (UCI). A network entity 105 may indicate (such as schedule, allocate) communication resources for aUE 115 using DCI, including indicating downlink resources of a PDSCH (such as in accordance w ith a downlink grant), uplink resources of a PUSCH (such as in accordance with an uplink grant), or a combination thereof. A control region (such as a control resource set (CORESET)) for a physical control channel may be configured in accordance with a pattern of REs in the time and frequency domains, and one or more control regions may be configured for a set of UEs. A UE 115 may monitor control regions for control information according to one or more search space sets, which may include a common search space set (such as forAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO15sending control information to one or more UEs 115), UE-specific search space sets (such as for sending control information to a UE 115), or a combination thereof. A physical broadcast channel (PBCH) may be used to broadcast parameters to UEs 115 to synchronize with a network entity 105 and establish communications (such as to establish a communication link 125).

[0051] Reference signals may be communicated to establish reference characteristics (such as a frequency reference, a temporal reference, a spatial reference, a signal quality reference) between devices of a RAN 120, which may support communication using physical channels. Reference signals communicated between network entities 105 and UEs 115 may include synchronization signals (such as a primary synchronization signal (PSS), a secondary synchronization signal (SSS)) that support temporal synchronization, channel state information-reference signals (CSI-RSs) that support evaluating downlink channel characteristics, sounding reference signals (SRSs) that support evaluating uplink channel characteristics, demodulation reference signals (DMRSs) that support demodulation, or phase tracking reference signals (PTRSs) for evaluating oscillator characteristics, among others. Network entities 105 and UEs 115 may receive and measure transmitted reference signals to support one or more of these and other functions.

[0052] Some wireless devices, such as a UE 115 and a network entity 105, may perform reciprocity calibration assuming a conventional downlink receiver. That is, a conventional downlink receiver may be a receiver (e.g., UE receiver) that performs channel estimation and equalization. Thus, to assume channel reciprocity, the following alignment condition, represented in Equation 1, may be maintained by each of the UE 115 and the network entity 105 (e.g., per frequency component):all chains = 0: N - 1 (1)where T[k] may represent a transmit power for a k-th antenna, R[k] may represent a receive power for the k-th antenna, and N may represent a quantity of chains. Thus, the alignment condition represented in Equation 1 may ensure that a ratio of the transmit power to the receive power is the same for all antennas.

[0053] Compensations supported by the UE 115 and the network entity 105 to maintain the alignment condition may be applied for all chains (e.g., Tx chains, Rx Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO16chains) except for a reference chain (e.g., idx = 0). The alignment condition may be equivalent to achieving channel reciprocity7(e.g., Tx / Rx reciprocity) up to a complex function that varies slowly over a frequency range, is the same for all uplink and downlink paths (e.g.. after a convention calibration procedure), or both. Thus, the network entity 105-a may use estimated CSI (e.g., as described with reference to the first method of CSI acquisition and the second method of CSI acquisition discussed with reference to Figure 2) to calculate a Tx precoding matrix and the complex function may be captured as part of an estimated reception (Rx) channel on a receiver side (e.g.. UE-side) and may be accounted for by an applied Rx equalization. That is, convention (e.g., initial) channel reciprocity calibration may be performed in accordance with the following Equation 2:where WDL[k] may represent the downlink channel, HUL[k] may represent the uplink channel, and, to support Tx equalization. |

[0054] However, maintaining the alignment condition, represented in Equation 1, between chains for the network entity 105 and chains for the UE 115 may be challenging. To maintain the alignment condition, one or more of the following mechanisms may be implemented: factory calibration for nominal temperature (e.g., viable for both the network entity 105 and the UE 115), boot-up calibration (e.g.. viable for the network entity 105 and partially viable for the UE 115 with limitations on idle Tx power and potential interference), online calibration (e.g., viable for the network entity' 105 during idle periods or periods reserved by the network entity' 105), and characterization or factory calibration over temperature (e.g., Tx / Rx gains, challenging to meet performance requirements).

[0055] Devices of the wireless communication system 100 may be configured to support one or more aspects of the described techniques for reciprocity calibration for downlink channel Tx equalization. For example, a UE 115 may include a processing system 140, and a network entity' 105 may include a processing system 145, each of which may be configured to cause the respective device to perform (such as being configured as means for performing) one or more of the described operations. ByAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO17configuring a processing system 140, a processing system 145, or a combination thereof in accordance with the described techniques, the communication system 100 (such as the RAN 120) may support accounting for a channel response mismatch, between an uplink channel and a downlink, when performing Tx equalization, which may result in improved communication performance, reduce complexity and power consumption at the UE, increased speed of Tx equalization updates, and improved Tx equalization robustness.

[0056] Figure 2 shows an example of a signaling diagram 200 that supports reciprocity calibration for downlink channel Tx equalization. In some cases, the signaling diagram 200 may implement or be implemented by aspects of the wireless communications system 100. For example, the signaling diagram 200 may include one or more UEs 115 (e.g., aUE 115-a) and one or more network entities 105 (e.g., a network entity7105-a), which may be examples of the corresponding devices as described herein.

[0057] Some wireless communications systems may support one or more methods for a network entity 105. such as the network entity 105-a, to acquire CSI (e.g.. for Tx precoding). A first method of CSI acquisition (e.g., option 1) may be based on the network entity 105-a not assuming channel reciprocity between an uplink channel used to receive signaling from a UE 115, such as the UE 115-a, and a downlink channel used to transmit signaling to the UE 115-a. That is, the network entity 105-a may assume that the uplink channel is associated with different channel conditions (e.g., CSI) than the downlink channel. In such cases, the network entity 105-a may transmit one or more CSI-RSs to the UE 115-a, the UE 115-a may receive the one or more CSI-RSs, and the UE 115-a may report, to the network entity7105-a. feedback indictive of downlink CSI based on the one or more CSI-RS.

[0058] A second method of CSI acquisition (e.g., option 2) may be based on the network entity 105-a assuming channel reciprocity between the uplink channel and the downlink channel. That is, the network entity 105-a may assume that the uplink channel is associated with the same channel conditions (e.g., CSI) as the downlink channel. In some cases, the uplink channel and the downlink channel may cumulatively be referred to as an over-the-air (OTA) channel. In such cases, the UE 115-a may transmit, to the network entity 105-a, one or more SRSs, the network entity 105-a may receive the oneAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO18or more SRSs, and the network entity 105-a may estimate uplink CSI based on the one or more SRSs. Because the second method is based on the reciprocity assumption of the OTA channel between the UE 115-a and the network entity 105-a, the network entity 105-a may assume that the uplink CSI is also representative of downlink CSI. The second method of CSI acquisition may be preferred over the first method of CSI acquisition based on the second method being associated with no processing at the UE 115-a and no CSI feedback signaling, which may result in lower OTA traffic overhead, less processing at the UE 115-a, lower latency, more flexibility with non-codebook-based precoding in downlink, more efficient MU-MIMO in downlink, or any combination thereof (e.g., as compared to the first method).

[0059] However, while the second method of CSI acquisition may be preferred over the first method of CSI acquisition, the second method may be associated with complexities due to the assumption of channel reciprocity being inaccurate. That is, channel estimation may be performed by a wireless device (e.g., modem), such as the UE 115-a or the network entity 105-a, to estimate an overall transfer function which includes the OTA channel, a Tx antenna function, a Rx antenna function, one or more Tx digital ambiguities (e.g., group delay), one or more Rx digital ambiguities, one or more Tx analog impairments (e.g., phase offset, droop response), one or more Rx analog impairments, or any combination thereof. However, from the aforementioned list of components of the overall transfer function, only the OTA channel may be reciprocal, the Tx antenna function and the Rx antenna function may be reasonable reciprocal (e.g., reciprocal within a threshold tolerance), and the other components (e.g., the one or more Tx digital ambiguities, the one or more Rx digital ambiguities, the one or more Tx analog impairments, and the one or more Rx analog impairments) may not be reciprocal. Some of the non-reciprocal components (e.g., responses) may be deterministic and may be known based on a design of a respective wireless device, such that some of the non-reciprocal components may be compensated (e.g., precompensated). However, some other non-reciprocal components may not be deterministic and may vary over time, such that they may not be compensated.

[0060] While both Tx precoding and Tx equalization may be based on reciprocity correction in accordance with acquired CSI, reciprocity correction for the Tx precoding may be based on partial CSI knowledge, as acquired via the second method of CSIAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO19acquisition, and reciprocity correction for Tx equalization may be based on full CSI knowledge, which may not be achieved via the second method of CSI acquisition. That is, the second method of CSI acquisition (e.g., and thus reciprocity calibration for Tx precoding) may not account for the non-reciprocal components of the overall transfer function, such that the Tx precoding may not account for a residual channel response mismatch (e.g., difference, calibration gap) between the uplink channel and the downlink channel. While the network entity 105-a may be capable of performing Tx precoding without accounting for the residual channel response mismatch (e.g., with partial CSI knowledge), the network entity 105-a may not be capable of performing Tx equalization without accounting for the residual channel response mismatch.

[0061] Accordingly, techniques described herein may support online channel reciprocity calibration to support Tx equalization (e.g., to support aTx equalizationbased w aveform in downlink). That is, after performing convention (e.g., initial) reciprocity calibration, as described with reference to Figure 1 (e.g., in accordance with Option 2), the UE 115 -a and the network entity 105-a may additionally perform an online channel reciprocity calibration procedure, as described herein, to support Tx equalization. The online channel reciprocity calibration procedure may be performed as part of an operational flow (e.g., online calibration).

[0062] For example, in some cases (e.g., Case 1), both the network entity 105-a and the UE 115-a may maintain Tx to Rx alignment between respective chains (e.g., the conventional reciprocity calibration took place on both the netw ork entity -side and the UE-side). In such cases, the online channel reciprocity calibration procedure may include each of the netw ork entity 105-a and the UE 115-a arbitrarily selecting a respective port (e.g., from a respective set of ports) to be used for transmission and reception during the online channel reciprocity calibration procedure. Thus, the network entity may transmit, to the UE 115-a (e g., after downlink data 235), a set of downlink reference signals (DL-RSs) 205 via a first port selected by the network entity 105-a (e.g., from a set of ports of the network entity 105-a). The UE 115-a may receive the set of DL-RSs 205 via a second port selected by the UE 115-a (e.g., from a set of ports of the UE 115-a) and may transmit feedback 215 in response to (e.g., based on) the set of DL-RSs 205. Additionally, the UE 115-a may transmit, to the network entity 105-a via the second port (e.g., before uplink data 240), a set of uplink reference signals (UL-RSs)Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO20220, such that the network entity 105-a may receive the set of UL-RSs 220 via the first port. Thus, the network entity 105-a may use the feedback 215 and the set of UL-RSs 220 to estimate a residual channel response mismatch and may account for the residual channel response mismatch during Tx equalization. That is. the network entity 105-a may estimate the downlink channel (e.g., effective downlink channel), HDL[k], in accordance with a reciprocity correction (e.g., calibration parameter), reciprocity _correction[k], applicable to all ports (e.g., of the set of ports of the network entity 105-a) in accordance with the following Equation 3:WDL[k] = transpose (HUL[k]~) ■ reciprocity_correction[k] (3) In other words, a value of the reciprocity correction may be the same for all ports of the UE 115-a. Thus, the network entity 105-a may perform Tx equalization in accordance with the estimated downlink channel.

[0063] In some other cases (e g., Case 2), only the network entity 105-a may maintain Tx to Rx alignment between the chains (e.g., the conventional reciprocity calibration took place on only the network entity-side). In such cases, the online channel reciprocity calibration procedure (e.g.. complementary reciprocity’ calibration procedure) may include the network entity 105-a arbitrarily selecting a port (e.g., from the set of ports of the netw ork entity 105-a), such as the first port, to be used for transmission and reception during the online channel reciprocity' calibration procedure. Thus, the network entity may transmit, to the UE 115-a. a set of DL-RSs 205 to the UE 115-a via the first port selected by the network entity 105-a. The UE 115-a may receive the set of DL-RSs 205 via all ports of the UE 115-a (e.g., all ports of the set of ports of the UE 115-a) and may transmit feedback 215 in response to (e.g., based on) the set of DL-RSs 205. Additionally, the UE 115-a may transmit, to the network entity 105-a via all the ports of the UE 115-a, a set of UL-RSs 220, such that the network entity 105-a may receive the set of UL-RSs 220 via the first port. Thus, the netw ork entity’ 105-a may use the feedback 215 and the set of UL-RSs 220 to estimate the residual channel response mismatch and may account for the residual channel response mismatch during Tx equalization. That is, the network entity 105-a may estimate the downlink channel (e.g., effective downlink channel), HDL[k], in accordance with a respective reciprocity correction, reciprocity _correction[k] [port], for each port (e.g., of the set of ports of the network entity’ 105-a) in accordance with the following Equation 4:Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO21WDL[k] = transpose(HUL[k]) ■ reciprocity :orrection[k][port] (4) In other words, a value of the reciprocity correction may depend on a port of the UE 115-a, such that each port of the UE 115-a is associated with a respective reciprocity¬ correction. Thus, the network entity 105-a may perform Tx equalization in accordance with the estimated downlink channel.

[0064] In some cases, the one or more reciprocity corrections (e.g., calibration parameters) may change over time (e.g., after a threshold duration), such that one or more reciprocity corrections may not be valid (e.g., accurate) after one or more events (e.g., events that require reciprocity re-calibration). In such cases, the one or more events may be identified (e.g., detected) by the network entity 105-a, the UE 115-a, or both. For example, in some cases, the network entity 105-a may detect one or more first events associated with triggering reciprocity re-calibration (e.g., calibration refresh), such that the network entity 105-a may transmit a control message triggering reciprocity re-calibration (e.g., re-calibration command message) based on detecting at least one of the one or more first events. Additionally, or alternatively, the UE 115-a may detect one or more second events associated with triggering reciprocity re-calibration, such that the UE 115-a may transmit a control message requesting the triggering of reciprocity recalibration (e.g., re-calibration request message, tx _pre eq reciprocity cal req) based on detecting at least one of the one or more second events. In either case, triggering reciprocity re-calibration may include the UE 115-a and the network entity 105-a performing the online channel reciprocity calibration procedure.

[0065] The one or more first events detected by the network entity 105-a may include the network entity 105-a switching to, or assigning, a new carrier aggregation (CA), BWP, or both, for the UE 115-a (e.g., when the network entity 105-a assigns a new CA / BWP to the UE 115-a, a reciprocity calibration update will be required), a temperature of the network entity 105-a changing by at least a first threshold temperature change (e.g., the temperature of the network entity 105-a changing by more than 10 degrees since a last calibration), a change in Tx / Rx gain exceeding a first threshold gain change, a timeout, the UE 115-a entering a sleep mode, or any combination thereof. In such cases, detection of at least one of the one or more first events may trigger repetition of the conventional reciprocity calibration procedure (e.g.,Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO22internal tx rc alignment), repetition of the online channel reciprocity calibration procedure (e.g., online tx pre eq reciprocity cal), or both (e.g., full recalibration).

[0066] The one or more second events detected by the UE 115-a may include a temperature of the UE 115-a changing by at least a second threshold temperature change (e.g., the temperature of the UE 115-a changing by more than 10 degrees since a last calibration), a frequency drift exceeding a threshold frequency drift (e.g.. 5 ppm), a change in Tx / Rx gain exceeding a second threshold gain change, a timeout, an active antenna subset change (e.g., due to blockage), or any combination thereof. In such cases, detection of at least one of the one or more first events may trigger repetition of the conventional reciprocity calibration procedure (e.g.. internal _tx_rc alignment), repetition of the online channel reciprocity calibration procedure (e.g., online tx pre eq reciprocity cal), or both (e.g., full recalibration).

[0067] In some cases, when at least one of the one or more first events or the one or more second events occurs (e.g., requiring online reciprocity re-calibration), a Tx equalization waveform may not be used by the network entity 105 -a until the recalibration (e.g., or calibration) is complete. Similarly, once are-calibration request message is transmitted by the UE 115-a, the Tx equalization waveform may not be used by the network entity’ 105 -a until the re-calibration (e.g., or calibration) is complete. Additionally, or alternatively, the UE 115-a may transmit a capability message indicating a capability of the UE 115-a to support the online channel reciprocity calibration procedure. Additionally, or alternatively, the capability message may indicate whether the UE 115-a is capable of addressing conventional local chain alignment on the UE-side (e.g., tx_rx_alignment_capability).

[0068] The set of UL-RSs 220 (e.g., uplink pilot signals), the set of DL-RSs 210 (e.g., dow nlink pilot signals), or both, may be associated with one or more operation parameters. For example, the set of UL-RSs 220, the set of DL-RSs 210, or both, may be associated with a high frequency density (e.g.. to support accurate channel response estimation), may be non -precoded, may be non-pre-equalized, may be associated with low overhead (e.g., relative to the complete reciprocity re-calibration procedure), may be transmitted with less than a threshold time gap (e.g., guard period 245) between the set of UL-RSs 220 and the set of DL-RSs 210 (e.g., to ensure that any possible channel aging effect is negligible), or any combination thereof.Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO23

[0069] In some cases, the set of DL-RSs 210 (e.g., CSI-RS) may be associated wi th a first threshold (e.g., maximum) density with a single port, where the first threshold is three resource elements (REs) 230 per resource block (RB) (e.g., p — 3). However, the first threshold density may be insufficient to achieve a threshold level of calibration precision. As such, the set of DL-RSs 210 may be associated with an RS configuration for 1-port DL-RSs 210 (e.g., 1 port CSI-RS) with a density of six REs 230 per RB (e.g., p = 6). For example, the RS configuration may indicate 1 port (e g., X — 1), a density of six REs 230 per RB (e.g., p = 6). no code division multiplexing (CDM), k E {k0, kg + 2, kg + 4, kg + 6, kg + 8, kg + 10}; kg = 0,1; k' = 0, and I = lg,' lg = 8,9, . . .,13. Additionally, or alternatively, the set of DL-RSs 210 may be associated with TD repetition on one or more adjacent symbols 225 (e.g., repetition of a same DLRS 210 over time) to achieve a threshold calibration accuracy (e.g., at low signal-to-noise ratio (SNR)). For example, multiple single port RS resources associated with the RS configuration may be allocated on consecutive OFDM symbols 225 to support TD repetition (e.g.. configured like tracking reference signal (TRS) configurations assuming M TD repetitions), where the multiple single port RS resources may form a resource set (e.g., NZP-CSI-RS-ResourceSet) including AL periodic single port RS resources (e.g., NZP-CSI-RS, p — 6). In such cases, the resource set may be configured with a parameter “calibration-info’' equal to “true."’

[0070] The set of UL-RSs 220 (e.g., SRS) may similarly be associated with a density of six REs 230 per RB (e.g., p = 6) and may be repeated on up to 12 consecutive OFDM symbols 225 (e.g., Comb2 and N^bG{1,2,4,8,12}. That is, the set of UL-RSs 220 may be configured (e.g., design) for channel estimation via uplink and may be flexible enough to support the reciprocity calibration as described herein. In some cases, the set of UL-RSs may be antenna switching SRS, codebook-based SRS, or both. Additionally, or alternatively, the set of UL-RSs 220 may be configured with a quantity of resources that have a cumulative quantity of ports to enable support of all UE Rx antennas (e g., for Case 2, as described herein).

[0071] As described herein, the UE 115 -a may transmit feedback 215 in response to the set of DL-RSs 220. During reception of the set of DL-RSs 210 and the UL-RSs 220 (e.g., as part of the reciprocity calibration procedure), both downlink and uplink receivers may apply configured (e.g., typically applied) RF front end (FE) and digitalAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO24FE (DFE) compensations. Additionally, the online channel reciprocity calibration procedure may not account for temporary or common impairments that are eliminated on the Rx side and on the Tx side during the corresponding reception procedures, and thus may not be addressed as part of the effective dow nlink channel. As such, any sampling time offset (STO), common phase error (CPE), and frequency offset (FO) may be removed from corresponding DL-RS samples and UL-RS samples.

[0072] The UE 115-a may support multiple methods for sampling and compressing the feedback 215, which may similarly be referred to as DL-RS feedback 215. In some cases, the feedback 215 may include a raw DL-RS signal (e.g., a raw signal of the DL-RSs 210, raw sample compression before channel estimation). That is, the UE 115-a may compress raw DL-RS samples (e.g., FD samples or TD samples) of the DL-RS s 210 prior to performing channel estimation. In such cases, the UE 115-a may compress FD correlation-based or raw TD samples of the DL-RSs 210 (e.g., depending on SNR regime, pilot configuration, and channel characteristics). In the case of FD sample compression, the DL-RSs 210 may be associated with a threshold FD density to support FD correlation between consecutive FD samples, which may allow effective compression with a negligible (e.g., less than a threshold amount) of distortion (e.g., supporting accurate channel estimation). Additionally, assuming TD repetitions of the DL-RSs 210 with a same sequence on adjacent OFDM symbols 225, 2D compression may be capable of exploiting high TD correlation (e.g., TD correlation above a threshold correlation), thus adding an additional compression dimension to both FD and TD compression, which may enable channel estimation combining over repetitions rather than sample combining before channel estimation. When the feedback 215 includes the raw DL-RS samples of the DL-RSs 210 (e.g., in the set of DL-RSs 210), the network entity 105 -a may perform the channel estimation based on the raw DL-RS samples received from the UE 115-a. That is, calibration procedures may be conducted at the network entity -side, thus enabling use of more extensive and dedicated processing capabilities (e.g.. as compared to the UE-side).

[0073] Additionally, or alternatively, the feedback 215 may include channel estimation samples of the DL-RSs 210 (e.g., in the set of DL-RSs 210). That is, the UE 115-a may perform channel estimation based on the set of DL-RSs 210 (e.g., rather than the network entity 105-a) to generate a set of TD channel estimation samples and mayAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO25compress the set of TD channel estimation samples (e.g., only actual TD channel taps with non-negligible power after TD response cleaning) for transmission via the feedback 215. In such cases, instantaneous impairment removal may be performed at the UE-side. In some cases, the feedback 215 may include a combination of raw DL-RS samples and channel estimation samples.

[0074] Additionally, or alternatively, the network entity 105-a may indicate to the UE 1 15-a whether the feedback 215 is to include raw DL-RS samples, channel estimation samples, or both, for the set of DL-RSs 210, may indicate one or more parameters associated with generation of the feedback 215, or both. For example, the UE 115-a may support multiple reporting schemes (e.g., different sample sharing and / or quantization schemes), where each reporting scheme is associated with a type of feedback 215 (e.g., raw DL-RS samples, channel estimation samples, or both) and a respective set of parameters used to generate the feedback 215, such that the network entity 105-a may indicate which reporting scheme is to be used by the UE 115-a. In either case, the indicated (e.g., selected) reporting scheme may be based on one or more conditions, such as SNR regime, channel characteristics, DL-RS configuration, or any combination thereof. That is, the indicated reporting scheme may be selected (e.g., adapted) to achieve a threshold calibration performance, a threshold overhead, or both, under varying channel conditions. By fitting the feedback 215 (e.g., quantization and reporting scheme) to operational SNR, channel characteristics, DL-RS configuration, or any combination thereof, the UE 115-a (e.g., and the network entity 105-a) may achieve better compression efficiency and high-quality channel estimation across different scenarios (e.g., as compared to using a same reporting scheme for all scenarios). In some cases, selection and adaption of a reporting scheme from the multiple reporting schemes may be dynamically adjusted based on real-time SNR, channel FD correlation measurements, or both.

[0075] Figures 3A and 3B show an example of a block diagram 300 that supports reciprocity calibration for downlink channel Tx equalization. In some cases, the block diagram 300 may implement or be implemented by aspects of the wireless communications system 100, the signaling diagram 200, or both. For example, the block diagram 300 may include one or more UEs 115 (e.g., a UE 115-b) and one or moreAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO26network entities 105 (e.g., a network entity 105-b), which may be examples of the corresponding devices as described herein.

[0076] As described herein, the UE 115-b and the network entity 105-b may support an online channel reciprocity calibration procedure for Tx equalization and the online channel reciprocity calibration procedure may include operations depicted in the block diagram 300. In the following description of the block diagram 300, the operations between the UE 115-b and the network entity 105-b may be communicated in a different order than described herein or the operations performed by the UE 115-b and the network entity' 105-b may be performed in a different order or a different time. Some operations may also be omitted from the block diagram 300, and other operations may be added to the block diagram 300.

[0077] In some cases (e.g.. not depicted), the network entity’ 105-b may transmit, to the UE 115-b, a first control signaling (e.g., one or more first control messages) indicating configuration information associated with the online channel reciprocity’ calibration procedure. In such cases, the configuration information may indicate one or more first parameters associated with a set of DL-RSs, one or more second parameters associated with a set of UL-RS, a reporting scheme (e.g., a feedback type, one or more compression parameters, or both, as described with reference to Figure 2) to be used by the UE 115-b, or any combination thereof. In some cases, a field in the configuration information may indicate which reporting scheme of multiple reporting schemes is to be used by the UE 115-b, where a value of 0 in the field indicates a first reporting scheme and a value of 1 in the field indicates a second reporting scheme. Additionally, or alternatively, the network entity’ 105-b may transmit, to the UE 115-b, a second signaling (e.g., the same as or different than the first control signaling) triggering the online channel reciprocity calibration procedure.

[0078] In some cases, at 305, the network entity 105-b may transmit and, at 310, the UE 115-a may receive a set of DL-RSs (e.g., CSI-RS) based on reception of the first control signaling, the second control signaling, or both. At 315, the UE 115-a may generate feedback based on the set of DL-RSs in accordance with the indicated reporting configuration and, at 320, may transmit the feedback to the network entity 105-b. Thus, at 325, the network entity 105-b may process the feedback.Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO27

[0079] In some cases (e.g., the reporting scheme is indicated via the value of 0 corresponding to raw samples indication), as depicted in Figure 3B, the UE 115-b may generate the feedback in accordance with a first reporting scheme corresponding to raw DL-RS samples. In such cases, the UE 115-a may generate a set of FD samples, TD samples, or both, based on the set of DL-RSs and, at 315-a, may compress the set of FD samples, TD samples, or both, before transmitting the compressed set of FD samples, TD samples, or both, at 315-b. Thus, at 325-a, the network entity 105-b may process the feedback by reconstructing the DL-RSs based on the compressed set of FD samples, TD samples, or both, and may perform downlink channel estimation based on the reconstruction.

[0080] In some other cases (e.g., the reporting scheme is indicated via the value of 1 corresponding to downlink channel estimation sample indication), the UE 115-b may generate the feedback in accordance with a second reporting scheme corresponding to TD channel estimation samples. In such cases, the UE 115-b may perform channel estimation to generate, at 315-c, a set of TD channel estimation samples based on the set of DL-RS, may compress, at 315-d, the set of TD channel estimation samples, and, at 315-e, may transmit the compressed set of TD channel estimation samples. Thus, at 325-b, the network entity 105-b may process the feedback by reconstructing the TD channel estimation samples (e.g., reconstruct the downlink channel samples).

[0081] Additionally, at 330, the UE 115-b may transmit and, at 335, the network entity 105-b may receive a set of UL-RSs (e.g., SRS). In some cases, transmission of the set of UL-RSs may be based on reception of the set of DL-RSs, transmission of the feedback, or both. In some cases, transmission of the set of UL-RSs may occur before transmission of the feedback, after transmission of the feedback, or simultaneously to transmission of the feedback. Thus, at 340, the network entity 105-b may process the set of UL-RSs. In some cases, processing the set of UL-RSs may include, at 340-a, performing channel estimation based on the set of UL-RSs. Alternatively, processing the set of UL-RSs may include, at 340-b, performing channel estimation based on the set of UL-RSs and. at 340-c, evaluating a compensation response. That is, at 340-c, the network entity 105-b may estimate a residual channel response between an uplink channel used to receive the set of UL-RSs and a downlink channel used to transit the set of DL-RSs. Thus, at 345, the network entity 105-b may perform Tx equalization basedAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO28on the residual channel response (e.g., based on calibrated downlink channel estimation).

[0082] In some cases (e.g., not depicted), each of the UE 115-b and the network entity 105-b may include a respective logic unit. A first logic unit at the network entity' 105-b may monitor for one or more first events (e g., as described with reference to Figure 2), and, if at least one of the one of the one or more first events is detected, may transmit the second control signaling triggering the online channel reciprocity calibration procedure (e.g., for calibration or re-calibration). Similarly, a second logic unit at the UE 115-b may monitor for one or more second events and, if at least one of the one or more second events is detected, may transmit a request message (e.g., calibration request message) to the network entity 105-b, requesting to perform (e.g., trigger) the online channel reciprocity calibration procedure (e.g., for calibration or recalibration). Thus, the first logic unit may receive the request message and may trigger transmission of the second control signaling based on reception of the request message. In any case, the first logic unit may trigger transmission of the set of DL-RSs, the second logic unit may trigger transmission of the set of UL-RSs, or both.

[0083] Figure 4 shows an example of a process flow 400 that supports reciprocity calibration for downlink channel Tx equalization. In some cases, the process flow 400 may implement or be implemented by aspects of the wireless communications system 100, the signaling diagram 200, block diagram 300, or any combination thereof. For example, the process flow 400 may include one or more UEs 115 (e.g., a UE 115-c) and one or more network entities 105 (e.g., a network entity 105-c), which may be examples of the corresponding devices as described herein. In the follow ing description of the process flow 400, the operations between the UE 115-c and the network entity 105-c may be communicated in a different order than the example order shown, or the operations performed by the UE 115-c and the network entity 105-c may be performed in different orders or at different times. Some operations may also be omitted from the process flow 400, and other operations may be added to the process flow 400.

[0084] In some cases, at 405, the UE 115-c may transmit, to the network entity' 105-c, a capability message indicative of a capability of the UE 115-a to perform a Tx equalization procedure (e.g.. including an online channel reciprocity calibration procedure as described herein).Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO29

[0085] At 410, the UE 115-c may receive, from the network entity 105-c, a first control message indicating configuration information associated with the transmission equalization procedure. In some cases, the configuration information may indicate a reporting scheme, from a set of reporting schemes, to be used by the UE 115-c to generate feedback information for a set of DL-RSs. Additionally, or alternatively, the configuration information may indicate a density of the set of DL-RSs, a quantity of repetitions of the set of DL-RSs, a density of a set of UL-RSs, a quantity of repetitions of the set of UL-RSs, a type of feedback information, one or more compression parameters associated with generation of the feedback information, one or more trigger events associated with performing the Tx equalization procedure, or any combination thereof.

[0086] In some cases, at 415, the UE 115-c may receive, from the network entity 105-c, a second control message (e.g., the same as or different from the first control message) triggering the Tx equalization procedure (e.g.. triggering the online channel reciprocity calibration procedure).

[0087] At 420, the UE 115-c may receive, from the network entity 105-c via a downlink channel, the set of DL-RSs in accordance with the configuration information. In such cases, the set of DL-RSs may include a set of CSI-RSs associated with a density of 6 REs per RB. In some examples, the set of CSI-RSs may include at least a first subset of CSI-RSs received via a first symbol and a second subset of CSI-RSs received via a second symbol, where the first symbol and second symbol are adjacent and where the second subset of CSI-RSs are repetitions of the first subset of CSI-RSs.

[0088] In some cases, the UE 115-c may receive the set of DL-RSs via a single port arbitrarily selected by the UE 115-c (e.g., from all ports of the UE 115-c) based on TX-to-RX alignment being maintained by the UE 115-c and the network entity 10-c (e.g., in accordance with a conventional reciprocity calibration procedure as described herein). In some other cases, the UE 115-c may receive the set of DL-RSs via all port of the UE 115-c (e.g., all ports configured for the UE 115-c) based on the Tx-to-Rx alignment being maintained by only the network entity 10-c (e.g., in accordance with a conventional reciprocity calibration procedure as described herein).

[0089] In some cases, at 425, the UE 115-c may generate the feedback information for the set of DL-RSs in accordance with a first reporting scheme (e.g., as indicated via Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO30the configuration information). That is, at 425, the UE 115-c may compress a set of raw channel samples (e.g., TD samples, FD samples, or both) of the set of DL-RSs.

[0090] Additionally, or alternatively, at 430, the UE 115-c may generate the feedback information for the set of DL-RSs in accordance with a second reporting scheme (e.g., as indicated via the configuration information). That is, at 430, the UE 115-c may perform channel estimation based on the set of DL-RSs to generate a set of channel estimation samples.

[0091] At 435, the UE 115-c may transmit, to the network entity 105-c, feedback information associated with the set of DL-RSs. As described herein, the feedback information may include the compressed set of raw channel samples, the set of channel estimation samples, or a combination thereof.

[0092] At 440, the UE 115-c may transmit, to the network entity 105-c via an uplink channel, the set of UL-RSs. In such cases, the set of UL-RSs may include a set of SRSs associated with a same density as the set of CSI-RS.

[0093] In some cases (e.g.. when the feedback information was generated in accordance with the first reporting scheme), at 445, the network entity 1 5-c may perform channel estimation based on the compressed set of raw channel samples.

[0094] At 450, the network entity may estimate a residual channel response mismatch (e.g., difference) between the uplink channel and the downlink channel based on the set of UL-RSs and the feedback information (e.g., and the result of the channel estimation at 445). While an OTA channel corresponding to the uplink and the downlink channel may be reciprocal, the residual channel response mismatch may account for one or more non-reciprocal components of a communication chain between the UE 115-c and the network entity 105-c (e.g., antenna transfer functions, digital ambiguities, analog impairments). Thus, the network entity 105-c may generate one or more reciprocity correction factors (e.g., one when the single port of the UE 115-c is used, multiple when all ports of the UE 115-c are used) and may determine an effective downlink channel (e.g., corresponding to the downlink channel) based on the one or more reciprocity correction factors (e.g.. and based on an effective uplink channel corresponding to the uplink channel).Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO31

[0095] Thus, at 455, the network entity 105-c may transmit, to the UE 115-c, one or more downlink messages equalized in accordance with the effective downlink channel (e.g., in accordance with the residual channel response mismatch).

[0096] In some cases, at 460, the UE 115-c and the network entity 105-c may communicate one or more re-calibration trigger messages based on one or more trigger events. In such cases, the one or more events may be events that may invalidate the one or more reciprocity correction factors, such that use of the one or more reciprocity correction factors may result in an inaccurate determination (e.g., estimation) of the effective downlink channel (e.g., a current effective downlink channel).

[0097] In some cases, the one or more re-calibration trigger messages may include a re-calibration request message transmitted by the UE 115-c based on detection of the one or more trigger events by the UE 115-c. In such cases, the one or more events may include a change in temperature of the UE 1 15-c satisfying one or more first temperature thresholds, a frequency drift of the UE 115-c satisfying one or more frequency drift thresholds, a change in one or more active antennas of the UE 115-c, expiration of a first timer, or any combination thereof. Additionally, or alternatively, one or more re-calibration trigger messages may include a re-calibration command message transmitted by the netw ork entity 105-c based on reception of the re-calibration request message, based on detection of the one or more trigger events by the netw ork entity 105-c, or both. In such cases, the one or more trigger events may include a change in BWP of the UE 115-c, a change in a CA of the UE 115-c, a change in temperature of the network entity 105-c satisfying one or more second temperature thresholds, a change in Tx gain exceeding one or more Tx gain thresholds, a change in Rx gain exceeding one or more Rx gain thresholds, expiration of a second timer, the UE 115-c entering a sleep mode, or any combination thereof.

[0098] In some cases, any combination of steps 405 through 450 may be considered part of the online channel reciprocity calibration procedure, such that any of steps 405 through 455 may be considered part of the Tx equalization procedure. That is, the online channel reciprocity' calibration procedure may be part of the Tx equalization procedure.

[0099] Figure 5 shows an example of a processing system 520 that supports reciprocity calibration for downlink channel Tx equalization. A processing system 520 may be an example of a processing system 140 (such as of a UE 115) and may include a Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO32configuration component 525, a reference signal component 530, a reporting component 535, a transmission equalization component 540, a re-calibration component 545, a capability component 550, a feedback component 555, or any combination thereof. A processing system 520, or various component thereof, may be an example of means for performing (such as a means for causing a UE 115 to perform) various techniques described herein.

[0100] The configuration component 525 may be configured to cause the UE 1 15 to receive a first control message indicative of configuration information associated with a transmission equalization procedure. The reference signal component 530 may be configured to cause the UE 115 to receive, via a downlink channel and via one or more ports, a set of downlink reference signals in accordance with the configuration information. The reporting component 535 may be configured to cause the UE 115 to transmit feedback information associated with the set of downlink reference signals. In some examples, the reference signal component 530 may be configured to cause the UE 115 to transmit, via an uplink channel and via the one or more ports, a set of uplink reference signals in accordance with the configuration information and based on transmission of the feedback information. The transmission equalization component 540 may be configured to cause the UE 115 to receive one or more downlink messages, where the one or more downlink messages are equalized, in accordance with the transmission equalization procedure, based on a channel response difference between the uplink channel and the downlink channel.

[0101] In some examples, the channel response difference is based on the feedback information and the set of uplink reference signals.

[0102] In some examples, the one or more ports include a single port selected by the UE from a set of multiple ports of the UE. In some examples, a transmission-to-reception alignment is maintained by the UE and a network entity in communication with the UE.

[0103] In some examples, the one or more ports include a set of multiple ports of the UE. In some examples, a transmission-to-reception alignment is maintained by a network entity and not by the UE, the network entity in communication with the UE.Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO33

[0104] In some examples, the re-calibration component 545 may be configured to cause the UE 115 to participate in communication of a re-calibration trigger message based on one or more trigger events, where reception of the set of downlink reference signals in based on communication of the re-calibration trigger message.

[0105] In some examples, the re-calibration trigger message includes a recalibration request message transmitted by the UE. In some examples, the one or more trigger events include a change in temperature of the UE satisfying one or more temperature thresholds, a frequency drift of the UE satisfy ing one or more frequency drift thresholds, a change in one or more active antennas of the UE, expiration of a timer, or any combination thereof.

[0106] In some examples, the re-calibration trigger message includes a recalibration command message received by the UE. In some examples, the one or more trigger events include a change in bandwidth part of the UE, a change in a carrier aggregation of the UE, a change in temperature of a network entity satisfying one or more temperature change thresholds, a change in transmission gain exceeding one or more transmission gain thresholds, a change in reception gain exceeding one or more reception gain thresholds, expiration of a timer, the UE entering a sleep mode, or any combination thereof.

[0107] In some examples, the capability component 550 may be configured to cause the UE 115 to transmit a capability message indicative of a capability of the UE to perform the transmission equalization procedure, where reception of the first control message is based at least in art on transmission of the capability message.

[0108] In some examples, the set of downlink reference signals includes a set of channel state information reference signals. In some examples, the set of channel state information reference signals is associated with a density of six resource elements per resource block.

[0109] In some examples, the set of channel state information reference signals includes a first subset of channel information reference signals received via a first symbol and a second subset of channel information reference signals received via a second symbol. In some examples, the second symbol is adjacent to the first symbol.Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO34

[0110] In some examples, the set of uplink reference signals includes a set of sounding reference signals. In some examples, the set of sounding reference signals is associated with a same density as the set of downlink reference signals.[OHl] In some examples, the feedback component 555 may be configured to cause the UE 115 to compress a set of raw channel samples of the set of downlink reference signals, where the feedback information includes the compressed set of raw channel samples.

[0112] In some examples, the feedback component 555 may be configured to cause the UE 115 to perform channel estimation based on the set of downlink reference signals to generate a set of channel estimation samples, where the feedback information includes the set of channel estimation samples.

[0113] In some examples, the transmission equalization component 540 may be configured to cause the UE 115 to receive a second control message triggering the transmission equalization procedure, where reception of the set of downlink reference signals is based on reception of the second control message.

[0114] In some examples, the first control message and the second control message are a same control message. In some examples, the configuration information is indicative of a density of the set of downlink reference signals, a quantity of repetitions of the set of downlink reference signals, a density of the set of uplink reference signals, a uantity of repetitions of the set of uplink reference signals, a type of the feedback information, one or more compression parameters associated with generation of the feedback information, one or more trigger events associated with performance of the transmission equalization procedure, or any combination thereof.

[0115] In some examples, the configuration information is indicative of a density of the set of downlink reference signals, a quantity of repetitions of the set of downlink reference signals, a density of the set of uplink reference signals, a quantity of repetitions of the set of uplink reference signals, a type of the feedback information, one or more compression parameters associated with generation of the feedback information, one or more trigger events associated with performance of the transmission equalization procedure, or any combination thereof.Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO35

[0116] A processing system 520 may include or be a component of one or more chips, systems-on-chips (SoCs), chipsets, packages, components, or devices that individually or collectively constitute or include a processing system. A processing system 520 may interface with other components of a processing system 520. For example, operations described with reference to a processing system 520, or various components thereof, may be performed by or with other such components, including a receiver, a transmitter, a transceiver, a modem, a user interface, a modulator / demodulator, an encoder / decoder, or any combination thereof (such as of the processing system 520, coupled with the processing system 520, of a processing system 520).

[0117] By including or configuring a processing system 520 for operation in a processing system 520 as described herein, the processing system 520 may support techniques reciprocity7calibration for downlink channel Tx equalization, which may result in reduced processing, reduced power consumption, and more efficient utilization of communication resources.

[0118] Figure 6 shows an example of a system 600 including a device 605 that supports reciprocity calibration for downlink channel Tx equalization. The device 605 may be an example of or include components of UE 115. The device 605 may communicate (such as wirelessly) with one or more other devices (such as netw ork entities 105, UEs 115). The device 605 may include components for transmitting and receiving communication, which may include a processing system 620, an input / output (I / O) controller, such as an I / O controller 610, a transceiver 615, antenna(s) 625, a memory7630, and a processor 640. Components of the device 605 may be coupled (such as operatively, communicatively, functionally, electronically, electrically, in electronic communication) a bus 655.

[0119] The transceiver 615 may support bi-directional communication via antenna(s) 625, and may support transmission operations, reception operations, or both, as described herein. The transceiver 615 may implement functionality' of a modem (such as a wireless modem) and may include one or more RF chains. An RF chain may include one or more filters, mixers, oscillators, amplifiers, analog-to-digital converters (ADCs), and other components that convert between an analog signal (such as for transmission or reception via an air interface) and a digital signal (such as for digitalAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO36processing at the device 605). The transceiver 615 may modulate symbols and provide the modulated symbols to antenna(s) 625 for transmission, and demodulate symbols from signals received using antenna(s) 625.

[0120] The processor 640 may be a general-purpose processing component that supports various operations (such as applications) of the device 605. The memory 630 may be a general-purpose storage component that stores code executable by the processor 640. Such code may include instructions that, when executed by the processor 640, cause the device 605 to perform various functions (such as to support an application of the device 605). The I / O controller 610 may manage inputs and outputs for the device 605, may manage peripherals not integrated into the device 605, or may represent a physical connection (such as port) to an external peripheral. The processor 640 may interact with a modem, a keyboard, a mouse, a touchscreen, or other device (such as via I / O controller 610). In some implementations, a user may interact with the device 605 via the I / O controller 610 or via hardware components controlled by the I / O controller 610.

[0121] The processing system 620 may be an example of a processing system 140 or a processing system 500. For example, the processing system 620 may include processor circuitry 645 and memory circuitry 650 that stores code, and may be configured to cause the device 605 to perform operations that support reciprocity¬ calibration for downlink channel Tx equalization. Although the processing system 620 is illustrated as a separate component, which may involve a separate chip, chipset, or other module, in some implementations, one or more functions described with reference to the processing system 620 may be supported by or performed by a transceiver 615, antenna(s) 625, a processor 640, memory 630. or any combination thereof, such that a processing system 620 may include one or more of a transceiver 615. antenna(s) 625, a processor 640, memory 630, or any combination thereof.

[0122] By including or configuring the processing system 620 for operation in the device 605 as described herein, may support techniques for reciprocity calibration for downlink channel Tx equalization, which may result in improved communication reliability , reduced latency, improved user experience related to reduced processing, reduced power consumption, more efficient utilization of communication resources,Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO37improved coordination between devices, longer battery life, and improved utilization of processing capability.

[0123] Figure 7 shows an example of a processing system 720 that supports reciprocity calibration for downlink channel Tx equalization. A processing system 720 may be an example of a processing system 145 (such as network entity 105) and may include a configuration component 725. a reference signal component 730. a feedback component 735, a transmission equalization component 740, are-calibration component 745, a channel estimation component 750, or any combination thereof. A processing system 720, or various component thereof, may be an example of means for performing (such as a means for causing a network entity 105 to perform) various techniques described herein.

[0124] The configuration component 725 may be configured to cause the network entity’ 105 to output a first control message indicative of configuration information associated with a transmission equalization procedure. The reference signal component 730 may be configured to cause the network entity 105 to output, via a downlink channel and via a selected port, a set of downlink reference signals in accordance with the configuration information. The feedback component 735 may be configured to cause the network entity 105 to obtain feedback information associated w ith the set of downlink reference signals. In some examples, the reference signal component 730 may be configured to cause the network entity 105 to obtain, via an uplink channel and via the selected port, a set of uplink reference signals in accordance with the configuration information and based on transmission of the feedback information. The transmission equalization component 740 may be configured to cause the network entity 105 to output one or more downlink messages, where the one or more downlink messages are equalized, in accordance with the transmission equalization procedure, based on a channel response difference between the uplink channel and the downlink channel, where the channel response difference is based on the feedback information and the set of uplink reference signals.

[0125] In some examples, the transmission equalization component 740 may be configured to cause the network entity 105 to estimate the channel response difference between the uplink channel and the downlink channel based on the feedback information and the set of uplink reference signals.Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO38

[0126] In some examples, the re-calibration component 745 may be configured to cause the network entity 105 to participate in communication of a re-calibration trigger message based on one or more trigger events, where reception of the set of downlink reference signals in based on communication of the re-calibration trigger message.

[0127] In some examples, the re-calibration trigger message includes a recalibration request message obtained by the network entity. In some examples, the one or more trigger events include a change in temperature of a UE satisfying one or more temperature thresholds, a frequency drift of the UE satisfy ing one or more frequency drift thresholds, a change in one or more active antennas of the UE, expiration of a timer, or any combination thereof.

[0128] In some examples, the re-calibration trigger message includes a recalibration command message output by the network entity. In some examples, the one or more trigger events include a change in bandwidth part of a UE, a change in carrier aggregation of the UE, a change in temperature of the network entity satisfying one or more temperature change thresholds, a change in transmission gain exceeding one or more transmission gain thresholds, a change in reception gain exceeding one or more reception gain thresholds, expiration of a timer, the UE entering a sleep mode, or any combination thereof.

[0129] In some examples, the feedback component 735 may be configured to cause the network entity 105 to obtain a capability message indicative of a capability of a UE to perform the transmission equalization procedure, where output of the first control message is based on obtaining the capability message.

[0130] In some examples, the set of downlink reference signals include a set of channel state information reference signals. In some examples, the set of channel state information reference signals is associated with a density of six resource elements per resource block.

[0131] In some examples, the set of channel state information reference signals include a first subset of channel information reference signals output via a first symbol and a second subset of channel information reference signals output via a second symbol. In some examples, the second symbol is adjacent to the first symbol.Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO39

[0132] In some examples, the set of uplink reference signals include a set of sounding reference signals. In some examples, the set of sounding reference signals is associated with a same density as the set of downlink reference signals.

[0133] In some examples, the feedback information includes a compressed set of raw channel samples associated with the set of downlink reference signals, and the channel estimation component 750 may be configured to cause the network entity 105 to perform channel estimation based on the compressed set of raw channel samples, where the one or more downlink messages are equalized based on the channel estimation.

[0134] In some examples, the feedback information includes a set of channel estimation samples associated with the set of downlink reference signals.

[0135] In some examples, the transmission equalization component 740 may be configured to cause the network entity 105 to output a second control message triggering the transmission equalization procedure, where output of the set of downlink reference signals is based on output of the second control message.

[0136] In some examples, the first control message and the second control message are a same control message. In some examples, the configuration information is indicative of a density of the set of downlink reference signals, a quantity of repetitions of the set of downlink reference signals, a density of the set of uplink reference signals, a uantity of repetitions of the set of uplink reference signals, a type of the feedback information, one or more compression parameters associated with generation of the feedback information, one or more trigger events associated with performance of the transmission equalization procedure, or any combination thereof.

[0137] In some examples, the configuration information is indicative of a density of the set of downlink reference signals, a quantity of repetitions of the set of downlink reference signals, a density of the set of uplink reference signals, a quantity of repetitions of the set of uplink reference signals, a type of the feedback information, one or more compression parameters associated with generation of the feedback information, one or more trigger events associated with performance of the transmission equalization procedure, or any combination thereof.Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO40

[0138] A processing system 720 may include or be an example of one or more chips, SoCs, chipsets, packages, components, or devices that individually or collectively constitute or include a processing system. A processing system 720 may interface with other components of a network entity 105. For example, operations described with reference to a processing system 720, or various components thereof, may be performed by or with other such components, including a receiver, a transmitter, a transceiver, a modem, a user interface, a modulator / demodulator, an encoder / decoder, or any combination thereof (such as of the processing system 720, coupled with the processing system 720, of a network entity 105). Operations described herein with reference to the processing system 720, or various components thereof, may be performed by or with other such components, including a CU 160, a DU 165, an RU 170, or any combination thereof. Each of one or more of any of such components, or subcomponents thereof (such as one or more processors, one or more memories), may communicate, directly or indirectly, with one another. The communication may include communication within a protocol layer of a protocol stack, communication associated with a logical channel of a protocol stack (such as between protocol layers of a protocol stack, within a device, component, or virtualized component associated with a network entity 105. between devices, components, or virtualized components associated with a network entity 105), or any combination thereof.

[0139] By including or configuring a processing system 720 for operation in a processing system 720 as described herein, the processing system 720 may support techniques for reciprocity calibration for downlink channel Tx equalization, which may result in reduced processing, reduced power consumption, and more efficient utilization of communication resources, among other advantages.

[0140] Figure 8 shows an example of a system 800 including a device 805 that supports reciprocity calibration for downlink channel Tx equalization. The device 805 may communicate (such as via one or more wired interfaces or one or more wireless interfaces) with other network devices or netw ork equipment such as a core network 150-b, other network entities 105, UEs 115, or any combination thereof. The device 805 may include components for transmitting and receiving communication, which may include a processing system 820, a transceiver 810, antenna(s) 815, a memory 825, and a processor 830. Components of the device 805 may be coupled (such as operatively,Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO41communicatively, functionally, electronically, electrically, in electronic communication) via one or more interfaces.

[0141] The transceiver 810 may communicate bi-directionally with another transceiver via wired or wireless links, and may support transmission operations, reception operations, or both, as described herein. The transceiver 810 may include a modem to modulate and demodulate signals, to provide the modulated signals for transmission (such as via antenna(s) 815, via a wired interface), and to demodulate received signals (such as received via antenna(s) 815, received via a wired interface). The transceiver 810 may be operable to support communication via one or more communication links (such as a communication link 125-b, a backhaul link 132-b, a midhaul link 162-b, fronthaul link 168-b).

[0142] The processor 830 may be a general-purpose processing component that supports various operations (such as applications) of the device 805. The memory 825 may be a general-purpose storage component that stores code executable by the processor 830. Such code may include instructions that, when executed by the processor 830, cause the device 805 to perform various functions (such as to support an application of the device 805).

[0143] For examples in which the device 805 is a network entity 105 in a disaggregated architecture, one or more components of the device 805 may be located at one or more of a CU 160-b, a DU 165-b, or an RU 170-b, one or more of which may include aspects of the processing system 820, the processor 830, the memory 825, or the transceiver 810. Functions of the device 805 may be performed at different components or an operation may be divided between different components (such as different functions being supported by aspects of the CU 160-b, the DU 165-b, or the RU 170-b, the transceiver 810, the processor 830, the memory7825, the processing system 820, or any combination thereof). For example, the processing system 820 may be a component of one or more of the CU 160-b, the DU 165-b, or the RU 170-b. In some examples, interfaces between components of device 805 (such as CU 160-b, DU 165-b, RU 170-b) may support communication at a protocol layer or between protocol layers of a protocol stack.

[0144] In some examples, the processing system 820 may manage aspects of communication with the core network 150-b (such as via a backhaul link 132). For Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO42example, the processing system 820 may manage the transfer of data communication for UEs 115 with a gateway of the core network 150-b. In some examples, the processing system 820 may manage communication with one or more other network entities 105 and may include a controller or scheduler for controlling communication with UEs 115 (such as in cooperation with the one or more other network entities 105). In some examples, the processing system 820 may support an interface (such as X2 interface, Xn interface) to provide communication between network entities 105.

[0145] The processing system 820 may be an example of a processing system 145 or a processing system 700. For example, the processing system 820 may include processor circuitry 835 and memory circuitry 840 that stores code, and the processing system 820 may be configured to cause the device 805 to perform operations that support reciprocity calibration for downlink channel Tx equalization. Although the processing system 820 is illustrated as a separate component, which may involve a separate chip, chipset, or other module, in some implementations, one or more functions described with reference to the processing system 820 may be supported by or performed by a transceiver 810, antenna(s) 815, a processor 830, memory 825, or any combination thereof, such that a processing system 820 may include one or more of a transceiver 810, antenna(s) 815, a processor 830, memory 825, or any combination thereof. Further, processor circuitry 835 and memory circuitry 840 each may be implemented at the device 805 in accordance with an aggregated architecture, or the processor circuitry 835 and the memory circuitry 840 may be implemented at one or more of a CU 1604), a DU 165-b, or an RU 170-b in accordance with a disaggregated architecture.

[0146] By including or configuring the processing system 820 for operation in the device 805 as described herein, may support techniques for reciprocity calibration for downlink channel Tx equalization, which may result in improved communication reliability7, reduced latency, improved user experience related to reduced processing, reduced power consumption, more efficient utilization of communication resources, improved coordination between devices, longer battery life, and improved utilization of processing capability.

[0147] Figure 9 shows an example of a method 900 that supports reciprocity calibration for downlink channel Tx equalization. Operations of the method 900 may beAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO43performed by a UE or its components (such as using a processing system configured to cause the UE 115 to perform one or more of the operations) as described herein.

[0148] At 905, the method may include receiving a first control message indicative of configuration information associated with a transmission equalization procedure. In some examples, aspects of the operations of 905 may be performed by a configuration component 525.

[0149] At 910, the method may include receiving, via a downlink channel and via one or more ports, a set of dow nlink reference signals in accordance with the configuration information. In some examples, aspects of the operations of 910 may be performed by a reference signal component 530.

[0150] At 915, the method may include transmitting feedback information associated with the set of downlink reference signals. In some examples, aspects of the operations of 915 may be performed by a reporting component 535.

[0151] At 920, the method may include transmitting, via an uplink channel and via the one or more ports, a set of uplink reference signals in accordance with the configuration information and based on transmission of the feedback information. In some examples, aspects of the operations of 920 may be performed by a reference signal component 530.

[0152] At 925, the method may include receiving one or more downlink messages, where the one or more downlink messages are equalized, in accordance with the transmission equalization procedure, based on a channel response difference between the uplink channel and the downlink channel. In some examples, aspects of the operations of 925 may be performed by a transmission equalization component 540.

[0153] Figure 10 shows an example of a method 1000 that supports reciprocity calibration for downlink channel Tx equalization. Operations of the method 1000 may be performed by a network entity 105 or its components (such as using a processing system configured to cause the network entity to perform one or more operations) as described herein.

[0154] At 1005, the method may include outputting a first control message indicative of configuration information associated with a transmission equalizationAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO44procedure. In some examples, aspects of the operations of 1005 may be performed by a configuration component 725.

[0155] At 1010, the method may include outputting, via a downlink channel and via a selected port, a set of downlink reference signals in accordance with the configuration information. In some examples, aspects of the operations of 1010 may be performed by a reference signal component 730.

[0156] At 1015, the method may include obtaining feedback information associated with the set of downlink reference signals. In some examples, aspects of the operations of 1015 may be performed by a feedback component 735.

[0157] At 1020, the method may include obtaining, via an uplink channel and via the selected port, a set of uplink reference signals in accordance with the configuration information and based on transmission of the feedback information. In some examples, aspects of the operations of 1020 may be performed by a reference signal component 730.

[0158] At 1025, the method may include outputting one or more downlink messages, where the one or more downlink messages are equalized, in accordance with the transmission equalization procedure, based on a channel response difference between the uplink channel and the downlink channel, where the channel response difference is based on the feedback information and the set of uplink reference signals. In some examples, aspects of the operations of 1025 may be performed by a transmission equalization component 740.

[0159] The following provides an overview of aspects of the present disclosure:

[0160] Aspect 1 : A method for wireless communications at a UE, comprising: receiving a first control message indicative of configuration information associated with a Tx equalization procedure; receiving, via a dow nlink channel and via one or more ports, a set of DL-RSs in accordance with the configuration information; transmitting feedback information associated with the set of DL-RSs; transmitting, via an uplink channel and via the one or more ports, a set of UL-RSs in accordance with the configuration information and based at least in part on transmission of the feedback information; and receiving one or more downlink messages, wherein the one or more downlink messages are equalized, in accordance with the Tx equalization procedure.Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO45based at least in part on a channel response difference between the uplink channel and the downlink channel.

[0161] Aspect 2: The method of aspect 1, wherein the channel response difference is based at least in part on the feedback information and the set of UL-RSs.

[0162] Aspect 3: The method of aspects 1 through 2, wherein the one or more ports comprise a single port selected by the UE from a plurality of ports of the UE, and a Tx-to-Rx alignment is maintained by the UE and a network entity in communication ith the UE.

[0163] Aspect 4: The method of any of aspects 1 through 3. wherein the one or more ports comprise a plurality of ports of the UE, and a Tx-to-Rx alignment is maintained by a network entity and not by the UE, the netw ork entity in communication with the UE.

[0164] Aspect 5: The method of any of aspects 1 through 4, further comprising: participating in communication of a re-calibration trigger message based at least in part on one or more trigger events, wherein reception of the set of DL-RSs in based at least in part on communication of the re-calibration trigger message.

[0165] Aspect 6: The method of aspect 5, wherein the re-calibration trigger message comprises a re-calibration request message transmitted by the UE, and the one or more trigger events comprise a change in temperature of the UE satisfying one or more temperature thresholds, a frequency drift of the UE satisfying one or more frequency drift thresholds, a change in one or more active antennas of the UE. expiration of a timer, or any combination thereof.

[0166] Aspect 7: The method of any of aspects 5 through 6, wherein the recalibration trigger message comprises a re-calibration command message received by the UE, and the one or more trigger events comprise a change in bandwidth part of the UE, a change in a carrier aggregation of the UE. a change in temperature of a network entity satisfying one or more temperature change thresholds, a change in transmission gain exceeding one or more Tx gain thresholds, a change in reception gain exceeding one or more Rx gain thresholds, expiration of a timer, the UE entering a sleep mode, or any combination thereof.Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO46

[0167] Aspect 8: The method of any of aspects 1 through 7, further comprising: transmitting a capability message indicative of a capability of the UE to perform the Tx equalization procedure, wherein reception of the first control message is based at least in art on transmission of the capability message.

[0168] Aspect 9: The method of any of aspects 1 through 8. wherein the set of DL-RSs comprises a set of channel state information reference signals, and the set of channel state information reference signals is associated with a density of six resource elements per resource block.

[0169] Aspect 10: The method of aspect 9, wherein the set of channel state information reference signals comprises a first subset of CSI-RSs received via a first symbol and a second subset of CSI-RSs received via a second symbol, and the second symbol is adjacent to the first symbol.

[0170] Aspect 11 : The method of any of aspects 1 through 10, wherein the set of UL-RSs comprises a set of SRSs, and the set of SRSs is associated with a same density as the set of DL-RSs.

[0171] Aspect 12: The method of any of aspects 1 through 11, further comprising: compressing a set of raw7channel samples of the set of DL-RSs, wherein the feedback information comprises the compressed set of raw channel samples.

[0172] Aspect 13: The method of any of aspects 1 through 12, further comprising: performing channel estimation based at least in part on the set of DL-RSs to generate a set of channel estimation samples, wherein the feedback information comprises the set of channel estimation samples.

[0173] Aspect 14: The method of any of aspects 1 through 13, further comprising: receiving a second control message triggering the Tx equalization procedure, wherein reception of the set of DL-RSs is based at least in part on reception of the second control message.

[0174] Aspect 15: The method of aspect 14, wherein the first control message and the second control message are a same control message, and the configuration information is indicative of a density’ of the set of DL-RSs, a quantity of repetitions of the set of DL-RSs, a density of the set of UL-RSs, a quantity of repetitions of the set of UL-RSs, a type of the feedback information, one or more compression parameters Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO47associated with generation of the feedback information, one or more trigger events associated with performance of the Tx equalization procedure, or any combination thereof.

[0175] Aspect 16: The method of any of aspects 1 through 15, wherein the configuration information is indicative of a density of the set of DL-RSs, a quantity of repetitions of the set of DL-RSs. a density of the set of UL-RSs, a quantity of repetitions of the set of UL-RSs, a type of the feedback information, one or more compression parameters associated with generation of the feedback information, one or more trigger events associated with performance of the Tx equalization procedure, or any combination thereof.

[0176] Aspect 17: A method for wireless communications at a network entity , comprising: outputting a first control message indicative of configuration information associated with a Tx equalization procedure; outputting, via a downlink channel and via a selected port, a set of DL-RSs in accordance with the configuration information; obtaining feedback information associated with the set of DL-RSs; obtaining, via an uplink channel and via the selected port, a set of UL-RSs in accordance with the configuration information and based at least in part on transmission of the feedback information; and outputting one or more downlink messages, wherein the one or more downlink messages are equalized, in accordance with the Tx equalization procedure, based at least in part on a channel response difference between the uplink channel and the downlink channel, wherein the channel response difference is based at least in part on the feedback information and the set of UL-RSs.

[0177] Aspect 18: The method of aspect 17, further comprising: estimating the channel response difference between the uplink channel and the downlink channel based at least in part on the feedback information and the set of UL-RSs.

[0178] Aspect 19: The method of any of aspects 17 through 18, further comprising: participating in communication of a re-calibration trigger message based at least in part on one or more trigger events, wherein reception of the set of DL-RSs in based at least in part on communication of the re-calibration trigger message.

[0179] Aspect 20: The method of aspect 19, wherein the re-calibration trigger message comprises a re-calibration request message obtained by the network entity, andAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO48the one or more trigger events comprise a change in temperature of a UE satisfying one or more temperature thresholds, a frequency drift of the UE satisfying one or more frequency drift thresholds, a change in one or more active antennas of the UE, expiration of a timer, or any combination thereof.

[0180] Aspect 21 : The method of any of aspects 19 through 20, wherein the recalibration trigger message comprises a re-calibration command message output by the network entity, and the one or more trigger events comprise a change in bandwidth part of a UE, a change in carrier aggregation of the UE, a change in temperature of the network entity satisfy ing one or more temperature change thresholds, a change in transmission gain exceeding one or more Tx gain thresholds, a change in reception gain exceeding one or more Rx gain thresholds, expiration of a timer, the UE entering a sleep mode, or any combination thereof.

[0181] Aspect 22: The method of any of aspects 17 through 21, further comprising: obtaining a capability message indicative of a capability of a UE to perform the Tx equalization procedure, wherein output of the first control message is based at least in part on obtaining the capability message.

[0182] Aspect 23: The method of any of aspects 17 through 22, wherein the set of DL-RSs comprise a set of channel state information reference signals, and the set of channel state information reference signals is associated with a density of six resource elements per resource block.

[0183] Aspect 24: The method of aspect 23, wherein the set of channel state information reference signals comprise a first subset of CSI-RSs output via a first symbol and a second subset of CSI-RSs output via a second symbol, and the second symbol is adjacent to the first symbol.

[0184] Aspect 25: The method of any of aspects 17 through 24. wherein the set of UL-RSs comprise a set of SRSs, and the set of SRSs is associated with a same density as the set of DL-RSs.

[0185] Aspect 26: The method of any of aspects 17 through 25, wherein the feedback information comprises a compressed set of raw channel samples associated with the set of DL-RSs, and wherein the method further comprises: performing channel estimation based at least in part on the compressed set of raw channel samples, whereinAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO49the one or more downlink messages are equalized based at least in part on the channel estimation.

[0186] Aspect 27: The method of any of aspects 17 through 26, wherein the feedback information comprises a set of channel estimation samples associated with the set of DL-RSs.

[0187] Aspect 28: The method of any of aspects 17 through 27, wherein further comprising: outputting a second control message triggering the Tx equalization procedure, wherein output of the set of DL-RSs is based at least in part on output of the second control message.

[0188] Aspect 29: The method of aspect 28, wherein the first control message and the second control message are a same control message, and the configuration information is indicative of a density of the set of DL-RSs, a quantity of repetitions of the set of DL-RSs, a density of the set of UL-RSs. a quantity of repetitions of the set of UL-RSs, a type of the feedback information, one or more compression parameters associated with generation of the feedback information, one or more trigger events associated with performance of the Tx equalization procedure, or any combination thereof.

[0189] Aspect 30: The method of any of aspects 17 through 29, wherein the configuration information is indicative of a density of the set of DL-RSs, a quantity’ of repetitions of the set of DL-RSs, a density of the set of UL-RSs, a quantity of repetitions of the set of UL-RSs, a type of the feedback information, one or more compression parameters associated with generation of the feedback information, one or more trigger events associated with performance of the Tx equalization procedure, or any combination thereof.

[0190] Aspect 31 : A UE for wireless communications, comprising a processing system that includes processor circuitry and memory circuitry that stores code, the processing system configured to cause the UE to perform a method of any of aspects 1 through 16.

[0191] Aspect 32: A UE for wireless communications, comprising at least one means for performing a method of any of aspects 1 through 16.Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO50

[0192] Aspect 33: A n on-transitory computer-readable medium storing code for wireless communications, the code comprising instructions executable by one or more processors to perform a method of any of aspects 1 through 16.

[0193] Aspect 34: A network entity for wireless communications, comprising a processing system that includes processor circuitry and memory circuitry that stores code, the processing system configured to cause the network entity to perform a method of any of aspects 17 through 30.

[0194] Aspect 35: A network entity for wireless communications, comprising at least one means for performing a method of any of aspects 17 through 30.

[0195] Aspect 36: A non-transitory computer-readable medium storing code for wireless communications, the code comprising instructions executable by one or more processors to perform a method of any of aspects 17 through 30.

[0196] It should be noted that methods described herein describe possible implementations. Other implementations in accordance with the described techniques are possible, including implementations in which operations are rearranged or otherwise modified relative to the described methods. Further, aspects from two or more of the described methods may be combined.

[0197] Although aspects of 5 G or 6G systems may be described for purposes of example and corresponding terminology' may be used in the description, the techniques described herein are applicable beyond 5G, or 6G networks. For example, the described techniques may be applicable to other communication systems such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.20, Flash-OFDM, or other systems and radio technologies not explicitly mentioned herein.

[0198] As used herein, a processing system (such as a processing system 140, a processing system 145) includes processor (or “processing’") circuitry' in the form of one or multiple processors, microprocessors, processing units (such as central processing units (CPUs), graphics processing units (GPUs), neural processing units (NPUs) (also referred to as neural network processors or deep learning processors (DLPs)), or digital signal processors (DSPs)), processing blocks, application-specific integrated circuits (ASICs), programmable logic devices (PLDs), or other discrete gate or transistor logic or circuitry (any one or more of which may be generally referred to herein individuallyAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO51as a “processor” or collectively as “the processor” or “the processor circuitry”). Such processors may be individually or collectively configurable or configured to perform functions or operations described herein. A group of processors collectively configurable or configured to cause a device to perform a set of functions may include a first processor configured to cause the device to perform a first function of the set and a second processor configured to cause the device to perform a second function of the set. In some other examples, each of a group of processors may be configured to cause a device to perform a same set of functions.

[0199] As used herein, a processing system (such as a processing system 140, a processing system 145) also includes memory circuitry in the form of one or multiple memory devices, memory blocks, memory elements, or other discrete gate or transistor logic or circuitry, each of which may include or implement tangible storage media such as random-access memory (RAM) or read-only memory (ROM), or combinations thereof (any one or more of which may be generally referred to herein individually as a “memory” or collectively as “the memory” or “the memory circuitry”). One or more of the memories may be coupled (such as operatively, communicatively, electronically, electrically) with one or more processors of the processor circuitry and may individually or collectively store processor-executable code or instructions (such as software) that, when executed by one or more of the processors, may cause a device (such as configure the device, using one or more of the processors) to perform functions or operations described herein. Additionally, or alternatively, in some examples, one or more of the processors may be configured to cause a device to perform functions or operations described herein without requiring configuration by software. As used herein, “software” shall be construed 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, or functions, among other examples, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0200] As used herein, a processing system (such as a processing system 140, a processing system 145) may include or be coupled with one or more modems (such as a cellular modem, a 5G-compliant modem, a 6G-compliant modem). In some examples,Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO52one or more processors of a processing system may include or implement one or more of the modems. A processing system also may include or be coupled with multiple radios (collectively “the radio”), multiple RF chains, or multiple transceivers, each of which may in turn be coupled with one or more of multiple antennas. In some examples, one or more processors of a processing system may include or implement one or more of the radios, RF chains, or transceivers. An RF chain may include one or more fdters, mixers, oscillators, amplifiers, analog-to-digital converters (ADCs), or other devices that convert between an analog signal (such as for transmission or reception via an air interface) and a digital signal (such as for processing by processor circuitry).

[0201] As described herein, being “configured to,” being “configurable to,” and being “operable to” may be used interchangeably and may be associated with a capability, when executing code (such as processor-executable code) stored in memory circuitry7or otherwise, to perform one or more of the functions described herein.

[0202] As used herein, the term “determine” or “determining” can encompass one or more of a variety' of actions. For example, “determining” can include one or more of calculating, computing, processing, deriving, detecting, estimating, looking up. inferring, ascertaining, measuring, resolving, selecting, obtaining, identifying, interpreting, demodulating, decoding, reading, establishing, forming, or generating, among other examples. In some such examples, determining can involve a processing system performing some type of calculating, computing, deriving, estimating, inferring, ascertaining, resolving, predicting, or other processing to obtain one or more numerical values, sets, elements, or other information or results. In some such examples, determining can involve a processing system identifying, looking up, investigating or otherwise obtaining some type of value, set, element, or other information or result from a table, data structure, database, or an implementation of memory, such as from a larger set of values, sets, or elements or other information or results. In some such examples, determining can involve a processing system identifying, interpreting, demodulating, decoding, detecting, reading, or otherwise obtaining some ty pe of value, set, element, or other information or result signaled in. for example, a received wireless signal. In some such examples, determining can involve a processing system performing a measurement, such as on a received signal.Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO53

[0203] As used herein, the phrase “associated with” is intended to be interpreted in the inclusive sense, unless otherwise explicitly indicated. For example, the phrase “associated with” is not to be construed as a reference to a closed set of conditions, factors, criteria, elements, components or actions, among other examples. Specifically, unless a phrase refers to “associated with only ‘a,’” or the equivalent in context, whatever it is that is “associated with ‘a,’” may be associated with “a” alone or associated with a combination of “a” and one or more other conditions, factors, criteria, elements, components or actions, among other examples. The phrase “associated with” may be interpreted to mean or be interchanged with “in association with,” “in accordance with,” “based on,” “based at least in part on,” “as a function of,” “in response to,” “responsive to,” “using,” “coupled with,” in communication with,” “configured with,” “included with,” or “in cooperation with,” as appropriate in the relevant context unless otherwise explicitly indicated. Additionally, the use of such phrases does not indicate that what follows the phrase is the focal point or primary factor associated with the limitation preceding the phrase.

[0204] As used herein, a phrase referring to “at least one of’ or “one or more of’ a list of items refers to any combination of those items, including single members. For example, “at least one of: a, b, or c” is intended to cover: a, b, c, a-b, a-c, b-c, and a-b-c. Additionally, as used herein, a phrase referring to “a” or "an” element refers to one or more of such elements acting individually or collectively to perform the recited function(s). Thus, the terms “a,” “at least one,” “one or more,” and “at least one of one or more” may be interchangeable. For instance, for a claim that refers to “a” component performing one or more functions, each of the individual functions may be performed by a single component or by any combination of multiple components, and subsequent reference to a component introduced with the article “a” using the term “the” may refer to any or all of the single or multiple components. Thus, a component introduced with the article “a” may be understood to mean “one or more” components, and referring to “the” component subsequently in the claims may be understood to be equivalent to referring to “at least one of the one or more” components. Additionally, as used herein, a “set” can refer to one or more items, and a “subset” can refer to a whole set or less than the whole set, but not an empty set. Additionally, as used herein, the term “or” is intended to be interpreted in the inclusive sense, such as when referring to a series, andAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO54may be used interchangeably with the term ‘"and / or,” unless otherwise explicitly indicated (for example, if used in conjunction with “either” or “only one of’). For example, “a or b” may include a only, b only, or a combination of a and b.

[0205] The disclosure is provided to enable a person having ordinary7skill in the art to implement the described techniques. Modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the techniques disclosed herein may be applied with other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.Attorney Docket No. PY3032.WO (1149586276)

Claims

Qualcomm Docket No 2500766WO55CLAIMSWhat is claimed is:

1. A user equipment (UE), comprising:one or more memories storing processor-executable code; and one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the UE to:receive a first control message indicative of configuration information associated with a transmission equalization procedure;receive, via a downlink channel and via one or more ports, a set of downlink reference signals in accordance with the configuration information;transmit feedback information associated with the set of downlink reference signals;transmit, via an uplink channel and via the one or more ports, a set of uplink reference signals in accordance with the configuration information and based at least in part on transmission of the feedback information; and receive one or more downlink messages, wherein the one or more downlink messages are equalized, in accordance with the transmission equalization procedure, based at least in part on a channel response difference between the uplink channel and the downlink channel.

2. The UE of claim 1, wherein the channel response difference is based at least in part on the feedback information and the set of uplink reference signals.

3. The UE of claim 1, wherein the one or more ports comprise a single port selected by the UE from a plurality of ports of the UE, and wherein a transmission-to-reception alignment is maintained by the UE and a network entity in communication with the UE.

4. The UE of claim 1, wherein the one or more ports comprise a plurality of ports of the UE, and wherein a transmission-to-reception alignment is maintained by a network entity and not by the UE, the network entity in communication with the UE.Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO565. The UE of claim 1, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to:participate in communication of a re-calibration trigger message based at least in part on one or more trigger events, wherein reception of the set of downlink reference signals in based at least in part on communication of the re-calibration trigger message.

6. The UE of claim 5, wherein the re-calibration trigger message comprises a re-calibration request message transmitted by the UE, and wherein the one or more trigger events comprise a change in temperature of the UE satisfying one or more temperature thresholds, a frequency drift of the UE satisfying one or more frequency drift thresholds, a change in one or more active antennas of the UE, expiration of a timer, or any combination thereof.

7. The UE of claim 5, wherein the re-calibration trigger message comprises a re-calibration command message received by the UE, and wherein the one or more trigger events comprise a change in bandwidth part of the UE, a change in a carrier aggregation of the UE, a change in temperature of a network entity satisfy ing one or more temperature change thresholds, a change in transmission gain exceeding one or more transmission gain thresholds, a change in reception gain exceeding one or more reception gain thresholds, expiration of a timer, the UE entering a sleep mode, or any combination thereof.

8. The UE of claim 1, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to:transmit a capability message indicative of a capability of the UE to perform the transmission equalization procedure, wherein reception of the first control message is based at least in art on transmission of the capability' message.

9. The UE of claim 1, wherein the set of downlink reference signals comprises a set of channel state information reference signals, and wherein the set of channel state information reference signals is associated with a density of six resource elements per resource block.Attorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO5710. The UE of claim 9, wherein the set of channel state information reference signals comprises a first subset of channel information reference signals received via a first symbol and a second subset of channel information reference signals received via a second symbol, and wherein the second symbol is adjacent to the first symbol.

11. The UE of claim 1, wherein the set of uplink reference signals comprises a set of sounding reference signals, and wherein the set of sounding reference signals is associated with a same density as the set of downlink reference signals.

12. The UE of claim 1, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to:compress a set of raw channel samples of the set of downlink reference signals, wherein the feedback information comprises the compressed set of raw channel samples.

13. The UE of claim 1, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to:perform channel estimation based at least in part on the set of downlink reference signals to generate a set of channel estimation samples, wherein the feedback information comprises the set of channel estimation samples.

14. The UE of claim 1, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to:receive a second control message triggering the transmission equalization procedure, wherein reception of the set of downlink reference signals is based at least in part on reception of the second control message.

15. The UE of claim 14, wherein the first control message and the second control message are a same control message, and wherein the configuration information is indicative of a density of the set of downlink reference signals, a quantity of repetitions of the set of downlink reference signals, a density of the set of uplink reference signals, a quantity of repetitions of the set of uplink reference signals, a type of the feedback information, one or more compression parameters associated withAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO58generation of the feedback information, one or more trigger events associated with performance of the transmission equalization procedure, or any combination thereof.

16. The UE of claim 1, wherein the configuration information is indicative of a density of the set of downlink reference signals, a quantity of repetitions of the set of downlink reference signals, a density of the set of uplink reference signals, a quantity of repetitions of the set of uplink reference signals, a type of the feedback information, one or more compression parameters associated with generation of the feedback information, one or more trigger events associated with performance of the transmission equalization procedure, or any combination thereof.

17. A method for wireless communications at a user equipment (UE), comprising:receiving a first control message indicative of configuration information associated with a transmission equalization procedure;receiving, via a downlink channel and via one or more ports, a set of downlink reference signals in accordance with the configuration information:transmitting feedback information associated with the set of downlink reference signals;transmitting, via an uplink channel and via the one or more ports, a set of uplink reference signals in accordance with the configuration information and based at least in part on transmission of the feedback information; andreceiving one or more downlink messages, wherein the one or more downlink messages are equalized, in accordance with the transmission equalization procedure, based at least in part on a channel response difference between the uplink channel and the downlink channel.

18. The method of claim 17, wherein the channel response difference is based at least in part on the feedback information and the set of uplink reference signals.

19. The method of claim 17, further comprising:participating in communication of a re-calibration trigger message based at least in part on one or more trigger events, wherein reception of the set of downlinkAttorney Docket No. PY3032.WO (1149586276)Qualcomm Docket No 2500766WO59reference signals in based at least in part on communication of the re-calibration trigger message.

20. A user equipment (UE) for wireless communications, comprising: means for receiving a first control message indicative of configuration information associated with a transmission equalization procedure;means for receiving, via a downlink channel and via one or more ports, a set of downlink reference signals in accordance with the configuration information;means for transmitting feedback information associated with the set of downlink reference signals;means for transmitting, via an uplink channel and via the one or more ports, a set of uplink reference signals in accordance with the configuration information and based at least in part on transmission of the feedback information; andmeans for receiving one or more downlink messages, wherein the one or more downlink messages are equalized, in accordance with the transmission equalization procedure, based at least in part on a channel response difference betw een the uplink channel and the downlink channel, wherein the channel response difference is based at least in part on the feedback information and the set of uplink reference signals.Attorney Docket No. PY3032.WO (1149586276)

Images