Techniques for downlink channel estimation

Abstract

Methods, systems, and apparatus for conducting wireless communications are described herein. The techniques described herein enable user equipment (UE) to determine a channel estimate associated with a downlink channel. In some examples, a network entity can determine a projection matrix and can send control signaling indicative of the projection matrix to the UE. The UE can determine the channel estimate associated with the downlink channel based on the projection matrix. The UE can receive data signaling from the network entity, and the UE can demodulate the data signaling based on the channel estimate, which is at least partially based on the projection matrix.

Description

Cross-referencing

[0001] This patent application claims the benefit of U.S. Patent Application No. 18 / 500,737, filed November 2, 2023, entitled “TECHNIQUES FORDOWNLINK CHANNEL ESTIMATION”, which has been assigned to the assignee of this application and is expressly incorporated herein by reference. Technical Field

[0002] The following text relates to wireless communications, including techniques for downlink channel estimation. Background Technology

[0003] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, message sending and receiving, broadcasting, and so on. These systems can support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth-generation (4G) systems (such as Long Term Evolution (LTE) systems, LTE-A Advanced (LTE-A) systems, or LTE-A Pro systems) and fifth-generation (5G) systems (which may be referred to as New Radio (NR) systems). These systems may employ technologies such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal FDMA (OFDMA), or Discrete Fourier Transform Extended Orthogonal Frequency Division Multiplexing (DFT-S-OFDM). A wireless multiple access communication system may include one or more base stations, each supporting wireless communication of communication devices, which may be referred to as User Equipment (UE). Summary of the Invention

[0004] The described techniques relate to improved methods, systems, devices, and apparatuses supporting techniques for downlink channel estimation. For example, the described techniques enable a user equipment (UE) to determine a channel estimate associated with a downlink channel. In some examples, a network entity may determine a projection matrix and may send control signaling indicative of the projection matrix to the UE. The UE may determine the channel estimate associated with the downlink channel based on the projection matrix. The UE may receive data signaling from the network entity, and the UE may demodulate the data signaling based at least in part on the channel estimate based on the projection matrix.

[0005] A method for wireless communication by a UE is described. The method may include: transmitting a first control signaling to a network entity, the first control signaling including a first shift time offset indication associated with a downlink channel of a cell associated with the network entity; receiving, based on transmitting the first control signaling, second control signaling from the network entity indicating a projection matrix associated with the downlink channel; receiving, based on receiving the second control signaling, data signaling from the network entity on the downlink channel; and demodulating the data signaling according to a channel estimation based on the projection matrix associated with the downlink channel.

[0006] A UE for wireless communication is described. The UE may include one or more memories storing processor-executable code and one or more processors coupled to the one or more memories. The one or more processors may operate individually or jointly to execute code causing the UE to: transmit a first control signaling to a network entity, the first control signaling including a first shift time offset indication associated with a downlink channel of a cell associated with the network entity; receive, based on transmitting the first control signaling, a second control signaling from the network entity indicating a projection matrix associated with the downlink channel; receive data signaling from the network entity on the downlink channel based on receiving the second control signaling; and demodulate the data signaling according to a channel estimate associated with the downlink channel based on the projection matrix.

[0007] Another UE for wireless communication is described. The UE may include: means for transmitting first control signaling to a network entity, the first control signaling including a first shift time offset indication associated with a downlink channel of a cell associated with the network entity; means for receiving, based on transmitting the first control signaling, second control signaling from the network entity indicating a projection matrix associated with the downlink channel; means for receiving data signaling from the network entity on the downlink channel based on receiving the second control signaling; and means for demodulating the data signaling according to a channel estimate based on the projection matrix associated with the downlink channel.

[0008] A non-transitory computer-readable medium storing code for wireless communication is described. The code may include instructions executable by a processor to: transmit a first control signaling to a network entity, the first control signaling including a first shift time offset indication associated with a downlink channel of a cell associated with the network entity; receive from the network entity, based on transmitting the first control signaling, a second control signaling indicating a projection matrix associated with the downlink channel; receive data signaling from the network entity on the downlink channel based on receiving the second control signaling; and demodulate the data signaling according to a channel estimate associated with the downlink channel based on the projection matrix.

[0009] In some examples of the methods, user equipment (UE), and non-transitory computer-readable media described herein, the downlink and uplink channels of a cell may be time-division multiplexed.

[0010] In some examples of the methods, user equipment (UE), and nontransitory computer-readable media described herein, receiving data signaling may include operations, features, components, or instructions for: receiving reference signals from network entities; and determining channel estimates based on projection matrices and reference signals.

[0011] In some examples of the methods, user equipment (UE), and non-transitory computer-readable media described herein, determining a channel estimate may include operations, features, components, or instructions for: descrambling a reference signal; and determining a channel estimate based on a projection matrix and the descrambled reference signal.

[0012] In some examples of the methods, user equipment (UE), and non-transitory computer-readable media described herein, the projection matrix may be based on time-domain channel autocorrelation associated with the uplink channel of the cell, noise covariance associated with the uplink channel, fast Fourier transform matrix based on a first shift time offset indication, or a combination thereof.

[0013] Some examples of the methods, user equipment (UE), and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending third control signaling to a network entity that indicates a channel power delay distribution associated with the UE, wherein the projection matrix may be based on the channel power delay distribution.

[0014] Some examples of the methods, user equipment (UE), and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending third control signaling to a network entity indicating a channel state information report associated with a downlink channel, wherein the projection matrix may be based on the channel state information report.

[0015] Some examples of the methods, user equipment (UE), and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for: sending to a network entity a third control signaling indicating a second shift time offset indication associated with a downlink channel, wherein the second shift time offset indication may be different from a first shift time offset indication; receiving from the network entity a fourth control signaling indicating a second projection matrix associated with the downlink channel based on sending the third control signaling; receiving from the network entity a second data signaling on the downlink channel based on receiving the fourth control signaling; and demodulating the second data signaling according to a second channel estimate that may be based on the second projection matrix.

[0016] A method for wireless communication by a network entity is described. The method may include: receiving a first control signaling from a UE, the first control signaling indicating a first shift time offset indication associated with a downlink channel of a cell associated with the network entity; transmitting to the UE a second control signaling indicating a projection matrix associated with the downlink channel, wherein the projection matrix is ​​determined based on the first shift time offset indication; and transmitting data signaling to the UE on the downlink channel based on transmitting the second control signaling.

[0017] A network entity for wireless communication is described. The network entity may include one or more memories storing processor-executable code and one or more processors coupled to the one or more memories. The one or more processors may operate individually or jointly to execute code to cause the network entity to: receive first control signaling from a UE, the first control signaling indicating a first shift time offset indication associated with a downlink channel of a cell associated with the network entity; transmit to the UE second control signaling indicating a projection matrix associated with the downlink channel, wherein the projection matrix is ​​determined based on the first shift time offset indication; and transmit data signaling to the UE on the downlink channel based on transmitting the second control signaling.

[0018] Another network entity for wireless communication is described. This network entity may include: components for receiving first control signaling from a UE, the first control signaling indicating a first shift time offset indication associated with a downlink channel of a cell associated with the network entity; components for transmitting second control signaling to the UE indicating a projection matrix associated with the downlink channel, wherein the projection matrix is ​​determined based on the first shift time offset indication; and components for transmitting data signaling to the UE on the downlink channel based on transmitting the second control signaling.

[0019] A non-transitory computer-readable medium storing code for wireless communication is described. The code may include instructions executable by a processor to: receive a first control signaling from a UE indicating a first shift time offset indication associated with a downlink channel of a cell associated with a network entity; transmit to the UE a second control signaling indicating a projection matrix associated with the downlink channel, wherein the projection matrix is ​​determined based on the first shift time offset indication; and transmit data signaling to the UE on the downlink channel based on transmitting the second control signaling.

[0020] The methods, network entities, and some examples of nontransitory computer-readable media described herein may also include operations, features, components, or instructions for determining a channel estimate associated with an uplink channel of a cell, wherein the projection matrix may be determined based on the channel estimate.

[0021] In some examples of the methods, network entities, and non-transitory computer-readable media described herein, the downlink and uplink channels of a cell may be time-division multiplexed.

[0022] The methods, network entities, and some examples of non-transitory computer-readable media described herein may also include operations, features, components, or instructions for transmitting reference signals to the UE based on a transmitted projection matrix.

[0023] Some examples of the methods, network entities, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving a third control signaling from a UE indicating a channel state information report associated with a downlink, wherein the projection matrix may be based on the channel state information report.

[0024] Some examples of the methods, network entities, and nontransitory computer-readable media described herein may also include operations, features, components, or instructions for determining a projection matrix in response to receiving a first control signaling, based on a time-domain channel autocorrelation associated with the uplink channel of the cell, a noise covariance associated with the uplink channel, a fast Fourier transform matrix based on a first shift time offset indication, or a combination thereof.

[0025] In some examples of the methods, network entities, and nontransitory computer-readable media described herein, determining the projection matrix may include operations, features, components, or instructions for determining the Fast Fourier Transform matrix based on the power delay distribution associated with the network entity.

[0026] In some examples of the methods, network entities, and nontransitory computer-readable media described herein, determining the projection matrix may include operations, features, components, or instructions for determining time-domain channel autocorrelation based on the power delay distribution associated with the network entity.

[0027] In some examples of the methods, network entities, and nontransitory computer-readable media described herein, determining the projection matrix may include operations, features, components, or instructions for: receiving third control signaling from the UE indicating a channel power delay distribution associated with the UE; and determining the projection matrix based on the channel power delay distribution associated with the UE.

[0028] The methods described herein, network entities, and some examples of non-transitory computer-readable media may also include operations, features, components, or instructions for sending a fourth control signaling to the UE based on determining a change in the power delay distribution associated with the network entity, the fourth control signaling indicating a second projection matrix associated with a channel estimate of the uplink channel of the network entity.

[0029] Some examples of the methods, network entities, and nontransitory computer-readable media described herein may also include operations, features, components, or instructions for: receiving from the UE a third control signaling indicating a second shift time offset indication associated with a downlink channel of the UE, wherein the second shift time offset indication may be different from the first shift time offset indication; and sending to the UE a fourth control signaling based on sending the third control signaling, the fourth control signaling indicating a second projection matrix associated with a channel estimate of an uplink channel of the network entity. Attached Figure Description

[0030] Figure 1 An example of a wireless communication system supporting techniques for downlink channel estimation according to one or more aspects of this disclosure is shown.

[0031] Figure 2 An example of a wireless communication system supporting techniques for downlink channel estimation according to one or more aspects of this disclosure is shown.

[0032] Figure 3 An example of a process flow supporting a technique for downlink channel estimation according to one or more aspects of this disclosure is shown.

[0033] Figure 4 and Figure 5 A block diagram of an apparatus supporting techniques for downlink channel estimation according to one or more aspects of this disclosure is shown.

[0034] Figure 6 A block diagram of a communication manager supporting techniques for downlink channel estimation according to one or more aspects of this disclosure is shown.

[0035] Figure 7 A diagram of a system including devices supporting techniques for downlink channel estimation according to one or more aspects of this disclosure is shown.

[0036] Figure 8 and Figure 9 A block diagram of an apparatus supporting techniques for downlink channel estimation according to one or more aspects of this disclosure is shown.

[0037] Figure 10 A block diagram of a communication manager supporting techniques for downlink channel estimation according to one or more aspects of this disclosure is shown.

[0038] Figure 11 A diagram of a system including devices supporting techniques for downlink channel estimation according to one or more aspects of this disclosure is shown.

[0039] Figures 12 to 15A flowchart illustrating a method for supporting downlink channel estimation according to one or more aspects of this disclosure is shown. Detailed Implementation

[0040] Wireless communication systems can support channel estimation. For example, wireless devices can estimate channel resources to maintain high data throughput. Channel estimation can be a complex process performed by the user equipment (UE) of the communication system. The UE can complete channel estimation for the downlink channel before demodulating data signaling, and the UE can delay decoding the data until the channel estimation is complete. The channel estimation process performed by the UE can introduce processing time delays, which contribute to the overall demodulation process delay at the UE. Additionally, the channel estimation process performed by the UE can consume significant amounts of device power.

[0041] The techniques for downlink channel estimation described herein can reduce latency at the UE and reduce power consumption by the UE. In some examples, a network entity can determine a projection matrix and send control signaling indicating the projection matrix to the UE. The UE can determine a channel estimate associated with the downlink channel based on the projection matrix. The UE can receive data signaling from the network entity, and the UE can demodulate the data signaling based on the channel estimate, which is at least partially based on the projection matrix.

[0042] In some examples, the network entity may determine the projection matrix based on the time-domain channel autocorrelation associated with the uplink channel, the noise covariance associated with the uplink channel, the fast Fourier transform matrix, or a combination thereof. In some cases, the UE sends control signaling to the network entity indicating a shift time offset indication associated with the downlink channel, and the network entity determines the fast Fourier transform matrix based on the shift time offset indication. After receiving the projection matrix, the UE may determine the channel estimate associated with the downlink channel based on the projection matrix (e.g., using a reference signal received from the network entity).

[0043] The aspects of this disclosure are first described in the context of a wireless communication system. The aspects of this disclosure are also described in the context of a process flow. The aspects of this disclosure are further illustrated and described by means of, and with reference to, apparatus diagrams, system diagrams, and flowcharts relating to techniques used for downlink channel estimation.

[0044] Figure 1Examples of wireless communication systems 100 supporting techniques for downlink channel estimation according to one or more aspects of this disclosure are shown. Wireless communication system 100 may include one or more network entities 105, one or more UEs 115, and a core network 130. In some examples, wireless communication system 100 may be a Long Term Evolution (LTE) network, an Advanced LTE (LTE-A) network, an LTE-A Pro network, a New Radio (NR) network, or a network operating under other systems and radio technologies, including future systems and radio technologies not explicitly mentioned herein.

[0045] Network entity 105 may be distributed across a geographical area to form wireless communication system 100, and may include devices employing different forms or having different capabilities. In various examples, network entity 105 may be referred to as a network element, mobility element, radio access network (RAN) node, or network equipment, among other designations. In some examples, network entity 105 and UE 115 may wirelessly communicate via one or more communication links 125 (e.g., radio frequency (RF) access links). For example, network entity 105 may support coverage area 110 (e.g., a geographical coverage area) within which UE 115 and network entity 105 may establish one or more communication links 125. Coverage area 110 may be an example of a geographical area within which network entity 105 and UE 115 may support the transmission of signals according to one or more radio access technologies (RATs).

[0046] UE 115 can be distributed throughout the coverage area 110 of wireless communication system 100, and each UE 115 can be stationary or mobile, or stationary and mobile at different times. UE 115 can be devices in different forms or with different capabilities. Figure 1 Some example UE 115s are illustrated herein. The UE 115 described herein can be able to support various types of devices (such as, e.g., ...). Figure 1 It communicates with other UEs (115 or network entity 105) as shown.

[0047] As described herein, nodes of the wireless communication system 100 (which may be referred to as network nodes or wireless nodes) may be network entity 105 (e.g., any network entity described herein), UE 115 (e.g., any UE described herein), network controller, apparatus, device, computing system, one or more components, or another suitable processing entity configured to perform any of the techniques described herein. For example, a node may be UE 115. Alternatively, a node may be network entity 105. Furthermore, a first node may be configured to communicate with a second or third node. In one aspect of this example, the first node may be UE 115, the second node may be network entity 105, and the third node may be UE 115. In another aspect of this example, the first node may be UE 115, the second node may be network entity 105, and the third node may be network entity 105. In other aspects of this example, the first node, the second node, and the third node may be different from these examples. Similarly, references to UE 115, network entity 105, device, equipment, computing system, etc., may include disclosures of UE 115, network entity 105, device, equipment, computing system, etc., as nodes. For example, a disclosure that UE 115 is configured to receive information from network entity 105 also discloses that a first node is configured to receive information from a second node.

[0048] In some examples, network entity 105 may communicate with core network 130, communicate with each other, or both. For example, network entity 105 may communicate with core network 130 via one or more backhaul communication links 120 (e.g., according to S1, N2, N3, or other interface protocols). In some examples, network entities 105 may communicate with each other directly (e.g., directly between network entities 105) or indirectly (e.g., via core network 130) via backhaul communication links 120 (e.g., according to X2, Xn, or other interface protocols). In some examples, network entities 105 may communicate with each other via midhaul communication link 162 (e.g., according to midhaul interface protocol) or fronthaul communication link 168 (e.g., according to fronthaul interface protocol) or any combination thereof. Backhaul communication link 120, midhaul communication link 162, or fronthaul communication link 168 may be or include one or more wired links (e.g., electrical links, fiber optic links), one or more wireless links (e.g., radio links, wireless optical links), etc., or various combinations thereof. UE 115 can communicate with core network 130 via communication link 155.

[0049] One or more network entities in network entity 105 described herein may include or be referred to as base station 140 (e.g., transceiver base station, radio base station, NR base station, access point, radio transceiver, node B, eNodeB (eNB), next-generation node B or gigabit node B (any of which may be referred to as gNB), 5G NB, next-generation eNB (ng-eNB), home node B, home evolution node B, or other suitable terms). In some examples, network entity 105 (e.g., base station 140) may be implemented in an aggregated (e.g., monolithic, standalone) base station architecture that may be configured to utilize a protocol stack that is physically or logically integrated within a single network entity 105 (e.g., a single RAN node, such as base station 140).

[0050] In some examples, network entity 105 may be implemented in a decomposed architecture (e.g., a decomposed base station architecture, a decomposed RAN architecture) that can be configured to utilize protocol stacks physically or logically distributed across two or more network entities 105, such as an integrated access backhaul (IAB) network, an open RAN (O-RAN) (e.g., a network configuration sponsored by the O-RAN Alliance), or a virtualized RAN (vRAN) (e.g., a cloud RAN (C-RAN)). For example, network entity 105 may include one or more of the following: a central unit (CU) 160, a distributed unit (DU) 165, a radio unit (RU) 170, a RAN intelligent controller (RIC) 175 (e.g., a near real-time RIC, a non-real-time RIC), a service management and orchestration (SMO) 180 system, or any combination thereof. 170 may also be referred to as a radio headend, intelligent radio headend, remote radio headend (RRH), remote radio unit (RRU), or transmit / receive point (TRP). One or more components of network entity 105 in a decomposed RAN architecture may be co-located, or one or more components of network entity 105 may be located in distributed locations (e.g., separate physical locations). In some examples, one or more network entities 105 in a decomposed RAN architecture may be implemented as virtual units (e.g., virtual CU (VCU), virtual DU (VDU), virtual RU (VRU)).

[0051] The functional splitting among CU 160, DU 165, and RU 170 is flexible and can support different functionalities depending on which functions (e.g., network layer functions, protocol layer functions, baseband functions, RF functions, and any combination thereof) are performed at CU 160, DU 165, or RU 170. For example, a protocol stack functional splitting can be used between CU 160 and DU 165, allowing CU 160 to support one or more layers of the protocol stack, and DU 165 to support one or more different layers of the protocol stack. In some examples, CU 160 can host higher protocol layer (e.g., Layer 3 (L3), Layer 2 (L2)) functionalities and signaling (e.g., Radio Resource Control (RRC), Serving Data Adaptation Protocol (SDAP), Packet Data Convergence Protocol (PDCP)). CU 160 can connect to one or more DU 165 or RU 170, and one or more DU 165 or RU 170 can host lower protocol layers, such as Layer 1 (L1) (e.g., Physical (PHY) layer) or L2 (e.g., Radio Link Control (RLC) layer, Medium Access Control (MAC) layer) functionality and signaling, and each can be at least partially controlled by CU 160. Additionally or alternatively, a protocol stack functional split can be employed between DU 165 and RU 170, such that DU 165 can support one or more layers of the protocol stack, and RU 170 can support one or more different layers of the protocol stack. DU 165 can support one or more different cells (e.g., via one or more RU 170). In some cases, functional decomposition between CU 160 and DU 165, or between DU 165 and RU 170, can be performed within the protocol layer (e.g., some functions of the protocol layer can be performed by one of CU 160, DU 165, or RU 170, while other functions of the protocol layer can be performed by different of CU 160, DU 165, or RU 170). CU 160 can be further functionally decomposed into CU control plane (CU-CP) and CU user plane (CU-UP) functions. CU 160 can be connected to one or more DU 165 via midhaul communication link 162 (e.g., F1, F1-c, F1-u), and DU 165 can be connected to one or more RU 170 via fronthaul communication link 168 (e.g., open fronthaul (FH) interface). In some examples, the midhaul communication link 162 or the fronthaul communication link 168 may be implemented based on the interfaces (e.g., channels) between the layers of the protocol stack, which are supported by the corresponding network entities 105 communicating via such communication links.

[0052] In some wireless communication systems (e.g., wireless communication system 100), the infrastructure and spectrum resources for radio access may support wireless backhaul link capabilities to supplement wired backhaul connections, thereby providing an IAB network architecture (e.g., to core network 130). In some cases, in an IAB network, one or more network entities 105 (e.g., IAB node 104) may be partially controlled by each other. One or more IAB nodes 104 may be referred to as donor entities or IAB donors. One or more DU 165s or one or more RU 170s may be partially controlled by one or more CU 160s associated with donor network entity 105 (e.g., donor base station 140). One or more donor network entities 105 (e.g., IAB donors) may communicate with one or more additional network entities 105 (e.g., IAB node 104) via supported access and backhaul links (e.g., backhaul communication link 120). IAB node 104 may include an IAB mobile terminal (IAB-MT) controlled (e.g., scheduled) by a DU 165 of a coupled IAB donor. The IAB-MT may include a separate set of antennas for relaying communication with UE 115, or may share the same antennas (e.g., those of RU 170) for access to IAB node 104 via DU 165 of IAB node 104. (e.g., referred to as a virtual IAB-MT (vIAB-MT)). In some examples, IAB node 104 may include a DU 165 that supports communication links with additional entities (e.g., IAB node 104, UE 115) within a relay chain or configuration (e.g., downstream) of the access network. In such cases, one or more components of the decomposed RAN architecture (e.g., one or more IAB nodes 104 or components of IAB node 104) may be configured to operate according to the techniques described herein.

[0053] In the context of applying the techniques described herein to a decomposed RAN architecture, one or more components of the decomposed RAN architecture may be configured to support techniques for downlink channel estimation as described herein. For example, some operations described as being performed by UE 115 or network entity 105 (e.g., base station 140) may additionally or alternatively be performed by one or more components of the decomposed RAN architecture (e.g., IAB node 104, DU 165, CU 160, RU 170, RIC 175, SMO 180).

[0054] UE 115 may include or be referred to as a mobile device, wireless device, remote device, handheld device, or subscriber device, or any other suitable term, wherein "device" may also be referred to as a cell, station, terminal, or client, etc. UE 115 may also include or be referred to as a personal electronic device, such as a cellular phone, personal digital assistant (PDA), tablet computer, laptop computer, or personal computer. In some examples, UE 115 may include or be referred to as a wireless local loop (WLL) station, Internet of Things (IoT) device, Internet of Everything (IoE) device, or machine-type communication (MTC) device, etc., which may be implemented in various objects such as appliances or vehicles, meters, etc.

[0055] The UE 115 described herein can communicate with various types of devices, such as other UEs 115 that sometimes act as relays, network entities 105, and network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, etc. Figure 1 As shown.

[0056] UE 115 and network entity 105 can wirelessly communicate with each other via one or more communication links 125 (e.g., access links) using resources associated with one or more carriers. The term "carrier" can refer to a set of RF spectrum resources having a physical layer structure defined for supporting communication link 125. For example, a carrier for communication link 125 may include a portion of the RF spectrum band (e.g., a bandwidth portion (BWP)) operating according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling coordinating carrier operation, user data, or other signaling. Wireless communication system 100 may support communication with UE 115 using carrier aggregation or multi-carrier operation. Depending on the carrier aggregation configuration, UE 115 may be configured using multiple downlink component carriers and one or more uplink component carriers. Carrier aggregation may be used in conjunction with both frequency division duplex (FDD) component carriers and time division duplex (TDD) component carriers. Communication between network entity 105 and other devices can refer to communication between these devices and any part of network entity 105 (e.g., entity, sub-entity). For example, the terms “send,” “receive,” or “communicate” when referring to network entity 105 can refer to any part of the RAN’s network entity 105 (e.g., base station 140, CU160, DU 165, RU 170) communicating with another device (e.g., directly or via one or more other network entities 105).

[0057] The signal waveform transmitted via a carrier may include multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques, such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform extended OFDM (DFT-S-OFDM)). In a system employing MCM, a resource element may refer to a resource of one symbol period (e.g., the duration of one modulation symbol) and one subcarrier, in which case the symbol period and subcarrier spacing may be inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the decoding rate of the modulation scheme, or both), such that a relatively high number of resource elements (e.g., in the transmission duration) and a relatively high modulation scheme order may correspond to a relatively high communication rate. Wireless communication resources may refer to a combination of RF spectrum resources, temporal resources, and spatial resources (e.g., spatial layers or beams), and the use of multiple spatial resources may increase the data rate or data integrity used for communication with UE 115.

[0058] The time interval for network entity 105 or UE 115 can be expressed as a multiple of a basic time unit, such as the sampling period. seconds, of which It can represent the supported subcarrier spacing, and This can represent the supported Discrete Fourier Transform (DFT) size. The time interval of the communication resources can be organized according to radio frames, each with a specified duration (e.g., 10 milliseconds (ms)). Each radio frame can be identified by a System Frame Number (SFN) (e.g., ranging from 0 to 1023).

[0059] Each frame may include multiple consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some examples, a frame may (e.g., in the time domain) be divided into subframes, and each subframe may be further divided into a number of time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include a number of symbol periods (e.g., depending on the length of the cyclic prefix appended to each symbol period). In some wireless communication systems 100, time slots may be further divided into multiple micro-time slots associated with one or more symbols. Excluding the cyclic prefix, each symbol period may be associated with one or more (e.g., The duration of a symbol period is associated with a (number) sampling period. The duration of a symbol period can depend on the subcarrier spacing or the operating frequency band.

[0060] A subframe, time slot, micro-time slot, or symbol can be the smallest scheduling unit of the wireless communication system 100 (e.g., in the time domain) and can be referred to as a transmission time interval (TTI). In some examples, the duration of the TTI (e.g., the number of symbol periods in the TTI) can be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communication system 100 can be dynamically selected (e.g., in a burst of shortened TTIs (sTTIs)).

[0061] Depending on the technology, carriers can be used to multiplex physical channels for communication. For example, one or more of Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), or hybrid TDM-FDM techniques can be used to multiplex physical control channels and physical data channels for signaling via a downlink carrier. The control region (e.g., control resource set (CORESET)) of the physical control channel can be defined by a set of symbol periods and can extend across the system bandwidth of the carrier or a subset of that bandwidth. One or more control regions (e.g., CORESET) can be configured for a set of UEs 115. For example, one or more UEs in UE 115 can monitor or search for control regions to obtain control information based on one or more search space sets, and each search space set can include one or more control channel candidates in one or more aggregation levels arranged in a concatenated manner. The aggregation level of control channel candidates can refer to the amount of control channel resources (e.g., control channel elements (CCEs)) associated with coded information for a control information format having a given payload size. The search space set may include: a common search space set configured to transmit control information to multiple UEs 115, and a UE-specific search space set used to transmit control information to a specific UE 115.

[0062] In some examples, network entity 105 (e.g., base station 140, RU 170) may be mobile, and thus provide communication coverage to mobile coverage areas 110. In some examples, different coverage areas 110 associated with different technologies may overlap, but the different coverage areas 110 may be supported by the same network entity 105. In some other examples, overlapping coverage areas 110 associated with different technologies may be supported by different network entities 105. The wireless communication system 100 may include, for example, a heterogeneous network in which different types of network entities 105 use the same or different radio access technologies to provide coverage for various coverage areas 110.

[0063] Wireless communication system 100 may be configured to support ultra-reliable communication or low-latency communication, or various combinations thereof. For example, wireless communication system 100 may be configured to support ultra-reliable low-latency communication (URLLC). UE 115 may be designed to support ultra-reliable or low-latency or critical functions. Ultra-reliable communication may include private or group communication and may be supported by one or more services, such as push-to-talk, video, or data. Support for ultra-reliable, low-latency functions may include prioritization of services, and such services may be used for public safety or general business applications. The terms “ultra-reliable,” “low-latency,” and “ultra-reliable low-latency” are used interchangeably herein.

[0064] In some examples, UE 115 may be configured to support direct communication with other UE 115s via device-to-device (D2D) communication link 135 (e.g., according to peer-to-peer (P2P), D2D, or sidelink protocols). In some examples, one or more UE 115s performing D2D communication in a group may be within the coverage area 110 of network entity 105 (e.g., base station 140, RU 170), which may support aspects of such D2D communication configured (e.g., scheduled by network entity 105). In some examples, one or more UE 115s in such a group may be outside the coverage area 110 of network entity 105, or may otherwise be unable or not configured to receive transmissions from network entity 105. In some examples, the group of UE 115s communicating via D2D communication may support a one-to-many (1:M) system, where each UE 115 transmits to each of the other UE 115s in the group. In some examples, network entity 105 may facilitate the scheduling of resources used for D2D communication. In other examples, D2D communication may be performed between UEs 115 without involving network entity 105.

[0065] Core network 130 provides user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. Core network 130 may be an evolved packet core (EPC) or a 5G core (5GC), and may include at least one control plane entity (e.g., a Mobility Management Entity (MME), Access and Mobility Management Function (AMF)) for managing access and mobility, and at least one user plane entity (e.g., a Serving Gateway (S-GW), Packet Data Network (PDN) Gateway (P-GW), or User Plane Function (UPF)) for routing packets or interconnecting to external networks. The control plane entity manages non-access stratum (NAS) functions, such as mobility, authentication, and bearer management of UE 115 served by network entity 105 (e.g., base station 140) associated with core network 130. User IP packets can be delivered through user plane entities, which provide IP address allocation and other functions. User plane entities may connect to one or more network operator IP services 150. IP services 150 may include access to the Internet, intranets, IP Multimedia Subsystem (IMS), or packet-switched streaming services.

[0066] Wireless communication system 100 can operate using one or more frequency bands in the range of 300 MHz to 300 GHz. Generally, the area from 300 MHz to 3 GHz is referred to as the Ultra High Frequency (UHF) band or decimeter band because the wavelength range is approximately one decimeter to one meter in length. UHF waves may be blocked or redirected by buildings and environmental features (which may be referred to as clusters), but these waves are sufficient to penetrate structures so that macrocells can provide service to UE 115 located indoors. Compared to communication using smaller frequencies and longer waves in the High Frequency (HF) or Very High Frequency (VHF) portions of the spectrum below 300 MHz, communication using UHF waves can be associated with smaller antennas and shorter ranges (e.g., less than 100 km).

[0067] Wireless communication system 100 may utilize licensed and unlicensed RF spectrum bands. For example, wireless communication system 100 may use unlicensed frequency bands (such as the 5 GHz Industrial, Scientific, and Medical (ISM) band) to employ licensed assisted access (LAA), LTE unlicensed (LTE-U) radio access technology, or NR technology. When operating with unlicensed RF spectrum bands, devices such as network entity 105 and UE 115 may employ carrier sensing for collision detection and avoidance. In some examples, operation using unlicensed frequency bands may be combined with component carriers operating with licensed frequency bands based on carrier aggregation configurations (e.g., LAA). Operation using unlicensed spectrum may include downlink transmission, uplink transmission, P2P transmission, or D2D transmission, etc.

[0068] Network entity 105 (e.g., base station 140, RU 170) or UE 115 may be equipped with multiple antennas that can be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communication, or beamforming. The antennas of network entity 105 or UE 115 may be located within one or more antenna arrays or antenna panels, which can support MIMO operation or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly such as an antenna tower. In some examples, the antennas or antenna arrays associated with network entity 105 may be located at different geographical locations. Network entity 105 may include an antenna array having a collection of multiple rows and columns of antenna ports that network entity 105 can use to support beamforming for communication with UE 115. Similarly, UE 115 may include one or more antenna arrays that can support various MIMO or beamforming operations. Additionally or alternatively, the antenna panel may support RF beamforming for signals transmitted via the antenna ports.

[0069] Beamforming (also known as spatial filtering, directional transmission, or directional reception) is a signal processing technique that can be used at a transmitting or receiving device (e.g., network entity 105, UE 115) to shape or guide an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting and receiving devices. Beamforming can be achieved by combining signals transmitted via antenna elements of an antenna array such that some signals propagating along a specific orientation relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to the signals transmitted via the antenna elements may include applying amplitude shifts, phase shifts, or both to the signals carried via the antenna elements associated with the device. The adjustments associated with each of these antenna elements may be defined by a beamforming weight set associated with a specific orientation (e.g., relative to the antenna array of the transmitting or receiving device or relative to some other orientation).

[0070] Network entity 105 or UE 115 may use beam scanning technology as part of beamforming operations. For example, network entity 105 (e.g., base station 140, RU 170) may use multiple antennas or antenna arrays (e.g., antenna panels) to perform beamforming operations for directional communication with UE 115. Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted multiple times by network entity 105 along different directions. For example, network entity 105 may transmit signals according to different beamforming weight sets associated with different transmission directions. Transmission along different beam directions may be used to identify (e.g., by a transmitting device (such as network entity 105) or by a receiving device (such as UE 115)) the beam direction for later transmission or reception by network entity 105.

[0071] Some signals (such as data signals associated with a specific receiving device) may be transmitted by a transmitting device (e.g., transmitting network entity 105, transmitting UE 115) along a single beam direction (e.g., the direction associated with the receiving device (such as receiving network entity 105 or receiving UE 115). In some examples, the beam direction associated with transmission along a single beam direction may be determined based on the signals transmitted along one or more beam directions. For example, UE 115 may receive one or more signals transmitted by network entity 105 along different directions and may report to network entity 105 an indication of signals received by UE 115 with the highest signal quality or other acceptable signal quality.

[0072] In some examples, transmissions performed by a device (e.g., network entity 105 or UE 115) may be performed using multiple beam directions, and the device may use a combination of digital pre-decoding or beamforming to generate a combined beam for transmission (e.g., from network entity 105 to UE 115). UE 115 may report feedback indicating pre-decoding weights for one or more beam directions, and this feedback may correspond to a set of beams configured across the system bandwidth or one or more sub-bands. Network entity 105 may transmit reference signals (e.g., cell-specific reference signals (CRS), channel state information reference signals (CSI-RS)) that may or may not be pre-decoded. UE 115 may provide feedback for beam selection, which may be a pre-decoding matrix indicator (PMI) or codebook-based feedback (e.g., multi-panel codebook, linear combination codebook, port selection codebook). Although these techniques are described with reference to signals transmitted by network entity 105 (e.g., base station 140, RU 170) along one or more directions, UE 115 may use similar techniques to transmit signals multiple times along different directions (e.g., to identify the beam direction used by UE 115 for subsequent transmission or reception), or to transmit signals along a single direction (e.g., to transmit data to a receiving device).

[0073] A receiving device (e.g., UE 115) may perform reception operations according to multiple reception configurations (e.g., directional listening) when receiving various signals (such as synchronization signals, reference signals, beam selection signals, or other control signals) from a transmitting device (e.g., network entity 105). For example, the receiving device may perform reception according to multiple reception directions by: receiving via different antenna subarrays; processing the received signal according to different antenna subarrays; receiving according to different sets of reception beamforming weights (e.g., different directional listening weight sets) applied to signals received at multiple antenna elements of the antenna array; or processing the received signal according to different sets of reception beamforming weights applied to signals received at multiple antenna elements of the antenna array. Any of these operations may be referred to as “listening” according to different reception configurations or reception directions. In some examples, the receiving device may use a single reception configuration to receive along a single beam direction (e.g., when a data signal is received). A single receiver configuration can be aligned along a beam direction determined based on listening according to different receiver configuration directions (e.g., a beam direction determined to have the highest signal strength, highest signal-to-noise ratio (SNR), or other acceptable signal quality based on listening according to multiple beam directions).

[0074] Wireless communication systems can support channel estimation. For example, a wireless device can estimate channel resources to maintain high data throughput. Channel estimation can be a complex process performed by UE 115 of communication system 100. UE 115 can complete channel estimation for the downlink channel before demodulating data signaling, and UE 115 can delay data decoding until channel estimation is complete. The channel estimation process performed by UE 115 can introduce processing time delays, which contribute to the overall demodulation process delay at UE 115. Additionally, the channel estimation process performed by UE 115 may consume significant device power.

[0075] Techniques used for downlink channel estimation can reduce latency at UE 115 and reduce power consumption by UE 115. In some examples, network entity 105 can determine a projection matrix and send control signaling indicating the projection matrix to UE 115. UE 115 can determine a channel estimate associated with the downlink channel based on the projection matrix. UE 115 can receive data signaling from network entity 105, and UE 115 can demodulate the data signaling based on the channel estimate, which is at least partially based on the projection matrix.

[0076] In some examples, network entity 105 may determine the projection matrix based on the time-domain channel autocorrelation associated with the uplink channel, the noise covariance associated with the uplink channel, and the fast Fourier transform matrix. In some cases, UE 115 sends control signaling to network entity 105 indicating a shift time offset indication associated with the downlink channel, and network entity 105 determines the fast Fourier transform matrix based on the shift time offset indication. After receiving the projection matrix, UE 115 may determine the channel estimate associated with the downlink channel based on the projection matrix (e.g., using a reference signal received from network entity 105).

[0077] Figure 2 An example of a wireless communication system 200 supporting techniques for downlink channel estimation according to one or more aspects of this disclosure is shown. The wireless communication system 200 may implement aspects of the wireless communication system 100, or may be implemented by aspects of the wireless communication system. For example, the wireless communication system 200 includes a UE 115-a, which may be an example of UE 115 as described herein. The wireless communication system 200 may also include a network entity 105-a, which may be an example of network entity 105 as described herein.

[0078] UE 115-a can communicate with network entity 105-a using communication link 125-a. Communication link 125-a can be an example of an NR or LTE link between UE 115-a and network entity 105-a. Communication link 125-a can include a bidirectional link that enables both uplink and downlink communication. For example, UE 115-a can use communication link 125-a to send uplink signals (e.g., uplink transmissions), such as uplink control signaling and uplink data signals, to network entity 105-a, and network entity 105-a can use communication link 125-a to send downlink signals (e.g., downlink transmissions), such as downlink control signaling and downlink data signals, to UE 115-a.

[0079] In some examples, UE 115-a may perform channel estimation to determine channel characteristics and estimate the channel resources of communication link 125-a to maintain high data throughput. Channel estimation can be one of the most complex processes at UE 115-a in an OFDM communication system. In some examples, channel estimation may be performed based on the transmitted pilots before demodulating the received data. UE 115-a may delay decoding of the data until the channel estimation process is complete. Therefore, improving the processing time delay of channel estimation can reduce the overall demodulation process latency at UE 115-a. Furthermore, the channel estimation process can consume significant UE device power and may significantly increase the complexity of the demodulation process for each downlink time slot reception, primarily due to large matrix inversion operations. For example, reducing the power consumption of UE 115-a may be relevant when UE 115-a is a device such as augmented reality glasses or virtual reality glasses.

[0080] In some examples, a portion of the channel estimation process for UE 115-a may be performed by network entity 105-a by utilizing the reciprocity of the uplink and downlink channels (e.g., when communication link 125-a is a TDD communication link). Network entity 105-a may perform calculations for downlink channel estimation and may send control signaling to UE 115-a indicative of the values ​​of the calculated values. Network entity 105-a may determine time-domain autocorrelation ( ) and delay spread. Furthermore, network entity 105-a can determine the noise covariance ( ) based on the CSI RS report from UE 115-a. Using time-channel autocorrelation, delay spread, and noise covariance, network entity 105-a can perform a portion of the computations that replace the role of UE 115-a in the channel estimation computation associated with the downlink channel. In some cases, network entity 105-a can compute the projection matrix and can send control signaling indicative of the projection matrix to UE 115-a once in several time slots. UE 115-a can multiply the projection matrix with the observation data to produce an estimated time-domain channel. UE 115-a can utilize the reciprocity and computation from network entity 105-a to determine a low-complexity channel estimate that reduces latency and power consumption.

[0081] In some examples, network entity 105-a can calculate the projection matrix based on the following mathematical equations used for single-input and single-output communication systems, and these mathematical equations can be applied to multiple-input and multiple-output communication systems. For example, the observed pilot signal (e.g., DMRS OFDM symbol) at UE115-a can be expressed by the expression Description, in which y It is the observed signal vector, which is the size of the number of subcarriers (Nsc) multiplied by 1. d It is the transmit pilot vector, which is Nsc multiplied by 1. n It is an additive noise vector of size Nsc multiplied by 1, and H Diag It is an Nsc multiplied by an Nsc diagonal matrix, where the frequency domain channel lies on the diagonal. The first transformation is ,in D It is an Nsc multiplied by an Nsc diagonal matrix, where the pilots are located on the diagonal, and H It is a vector of Nsc multiplied by the frequency domain channel. From the frequency domain channel... H to time domain channel h The transformation can be caused by Given, among which h It is a time-domain channel vector of size DS multiplied by 1, where DS is the delay spread in tap units, and F c It is a Fast Fourier Transform matrix that divides the pilot signals into rows and columns based on the occupied subcarriers. Assume the pilot power is unity power (e.g., 1 (0 dB)). This is a descrambled channel. The time-domain channel linear minimum mean square error (LMMSE) estimator from the descrambled channel can be obtained from... Given, among which It is the expectation operator. and ,in Time-domain autocorrelation and It is the noise covariance. The LMMSE time-domain channel estimator can be derived from... Given, where Ψ is the projection matrix. Network entity 105-a can calculate the projection matrix that results in the time-domain channel at network entity 105-a. Network entity 105-a can send control signaling to UE 115-a indicating the projection matrix on the downlink. UE 115-a can complete the construction of the estimated time-domain channel as the projection matrix multiplied by the descrambled signal (e.g., Ψ*z).

[0082] In some examples, to determine the downlink channel estimate, UE 115-a may send control signaling 205, which includes a shift time offset indication associated with the downlink channel of the cell associated with network entity 105-a. UE 115-a may estimate the position of the first tap of the channel relative to the channel's Fast Fourier Transform window (e.g., shift time offset). For example, UE 115-a may determine the correlation calculation between the observed pilot and the reference pilot. In some cases, the shift time offset indication may be sent on the physical uplink control channel. Network entity 105-a may use the shift time offset information to calculate the Fast Fourier Transform matrix (…). F c ).

[0083] Network entity 105-a can calculate the projection matrix (Ψ) as For example, network entity 105-a can determine time-domain autocorrelation ( ), noise covariance ( ) and Fast Fourier Transform matrix ( F c The projection matrix components of ). In some cases, network entity 105-a can use the channel power delay distribution from the uplink channel estimate to determine the time-domain autocorrelation ( Network entity 105-a can use reciprocity to derive downlink channel estimates. Without the reciprocity assumption, UE 115-a can send control signaling 210 on the uplink channel to network entity 105-a indicating the channel power delay distribution associated with UE 115-a, and network entity 105-a can use the channel power delay distribution from UE 115-a to determine time-domain autocorrelation. In some examples, network entity 105-a may determine the Fast Fourier Transform matrix based on the occupied bandwidth of UE 115-a, the shift time offset provided by UE 115-a, and the delay spread from the power delay distribution estimation performed by network entity 105-a. F cIn some cases, UE 115-a may transmit control signaling indicating the channel power delay distribution on the uplink channel, and network entity 105-a may use the delay spread from the power delay distribution estimate provided by UE 115-a to determine the Fast Fourier Transform matrix (Fc). In some cases, network entity 105-a may use information from CSI-RS reports (e.g., CSI-RS reports from UE 115-a) to determine the noise covariance. For example, UE 115-a may send control signaling 215 to network entity 105-a indicating a CSI-RS report associated with the downlink channel. In some examples, network entity 105-a may use an identity matrix multiplied by a default signal-to-noise ratio to determine the noise covariance. ).

[0084] After determining the projection matrix (Ψ), network entity 105-a may send control signaling 220 to UE 115-a indicating the calculated projection matrix. In some cases, the physical downlink control channel may be used to send the projection matrix. Network entity 105-a may send a reference signal 225 to UE 115-a. In some examples, UE 115 may descramble the reference signal. UE 115-a may determine the channel estimate by multiplying the projection matrix by the descrambled reference signal. UE 115-a may receive data signaling 230 from network entity 105-a on the downlink channel. UE 115-a may demodulate the data signaling based on the channel estimate of the downlink channel based on the projection matrix.

[0085] In some cases, whenever one of the parameters used to determine the projection matrix (such as shift time offset, noise covariance, etc.) is involved, the result is often not obtained. ) and time-domain autocorrelation ( When the projection matrix changes, network entity 105-a can determine the updated projection matrix and send control signaling to UE 115-a indicating the updated projection matrix. For example, if the shift time offset changes, UE 115-a can send control signaling to network entity 105-a indicating the updated shift time offset, and the network entity can use the updated shift time offset to determine the updated projection matrix.

[0086] Figure 3 Examples of process flow 300 supporting techniques for downlink channel estimation according to one or more aspects of this disclosure are shown. In some examples, process flow 300 may be implemented as described in reference respectively. Figure 1 and Figure 2The described aspects of the wireless communication systems 100 and 200, or those implemented therein. For example, process flow 300 can be implemented by network entity 105-b, which can be as described in reference... Figure 1 and Figure 2 An example of network entity 105 is described. Process flow 300 can be implemented by UE 115-b, which can be as shown in the reference. Figure 1 and Figure 2 An example of a UE as described.

[0087] In some examples, the operations illustrated in process flow 300 may be performed by hardware (e.g., including circuits, processing blocks, logic components, and other components), code (e.g., software executed by a processor), or any combination thereof. Alternative examples are possible, some of which may be performed in a different order than described or not at all. In some cases, steps may include additional features not mentioned below, or additional steps may be added.

[0088] At position 305, UE 115-b may send a first control signaling to network entity 105-b, the first control signaling including a first shift time offset indication associated with a downlink channel of the cell associated with network entity 105-a. In some examples, the downlink channel and the uplink channel are time-division multiplexed.

[0089] At 310, UE 115-b can send control signaling to network entity 105-b indicating a channel state information report associated with the downlink channel.

[0090] At 315, network entity 105-b may determine the projection matrix associated with the downlink channel. In some examples, network entity 105-b may determine the channel estimate associated with the uplink channel of the cell, and the projection matrix may be determined at least partially based on the channel estimate. In some cases, the projection matrix may be at least partially based on channel state information reports. In some cases, the projection matrix may be at least partially based on the time-domain channel autocorrelation associated with the uplink channel of the cell, the noise covariance associated with the uplink channel, the fast Fourier transform matrix indicated by a first shift time offset, or a combination thereof. In some cases, network entity 105-b may determine the fast Fourier transform matrix at least partially based on the power delay distribution associated with network entity 105-b. In some examples, network entity 105-b may determine the time-domain channel autocorrelation at least partially based on the power delay distribution associated with network entity 105-b. In some cases, network entity 105-b may receive control signaling from UE 115-b indicating the channel power delay distribution associated with UE 115-b, and network entity 105-b may determine the projection matrix based at least in part on the channel power delay distribution associated with UE 115-b.

[0091] At 320, UE 115-b can receive a second control signaling from network entity 105-b indicating the projection matrix associated with the uplink channel.

[0092] At 325, UE 115-b can receive a reference signal from network entity 105-b.

[0093] At 330, UE 115-b may determine the channel estimate associated with the downlink channel based at least in part on the projection matrix. In some cases, UE 115-b may determine the channel estimate associated with the downlink channel based at least in part on the projection matrix (e.g., using a reference signal). In some examples, UE 115-b may descramble the reference signal and may determine the channel estimate based at least in part on the projection matrix and the descrambled reference signal (e.g., multiplying the projection matrix by the descrambled reference signal).

[0094] At 335, UE 115-b can receive data signaling from network entity 105-b on the downlink channel.

[0095] At 340, UE 115-b can demodulate data signaling based on channel estimates associated with the downlink channel, which are at least partially based on the projection matrix.

[0096] One or more steps in the process of performing channel estimation using the projection matrix may be repeated based on variations in associated parameters (e.g., shift time offset, time-domain autocorrelation, noise covariance). In some cases, UE 115-b may send third control signaling to network entity 105-b indicating a second shift time offset indication associated with the downlink channel, and the second shift time offset indication is different from the first shift time offset indication. UE 115-b may receive control signaling from network entity 105-b indicating a second projection matrix associated with the downlink channel, at least in part based on sending control signaling indicating the second shift time offset indication. UE 115-b may receive second data signaling on the downlink channel from network entity 105-b, at least in part based on receiving control signaling indicating the second projection matrix. UE 115-b may demodulate the second data signaling based on a second channel estimation, at least in part based on the second projection matrix.

[0097] In some examples, network entity 105-b may send control signaling to UE 115-b, at least in part, based on determining a change in the power delay distribution associated with network entity 105-b, indicating a second projection matrix associated with the channel estimate of the uplink channel of the network entity.

[0098] Figure 4 A block diagram 400 illustrates a device 405 supporting techniques for downlink channel estimation according to one or more aspects of this disclosure. Device 405 may be an example of aspects of UE 115 as described herein. Device 405 may include a receiver 410, a transmitter 415, and a communication manager 420. Device 405, or one or more components of device 405 (e.g., receiver 410, transmitter 415, and communication manager 420), may include at least one processor that may be coupled to at least one memory to individually or jointly support or implement the described techniques. Each of these components may communicate with each other (e.g., via one or more buses).

[0099] Receiver 410 may provide components for receiving information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to techniques used for downlink channel estimation). The information may be passed to other components of device 405. Receiver 410 may utilize a single antenna or a collection of antennas.

[0100] Transmitter 415 may provide components for transmitting signals generated by other components of device 405. For example, transmitter 415 may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels associated with techniques used for downlink channel estimation). In some examples, transmitter 415 may be co-located with receiver 410 in a transceiver module. Transmitter 415 may utilize a single antenna or a collection of multiple antennas.

[0101] The communication manager 420, receiver 410, transmitter 415, or various combinations thereof, or various components thereof, may be examples of components used to perform various aspects of the techniques for downlink channel estimation as described herein. For example, the communication manager 420, receiver 410, transmitter 415, or various combinations thereof, or components thereof, may be able to perform one or more of the functions described herein.

[0102] In some examples, the communication manager 420, receiver 410, transmitter 415, or various combinations or components thereof may be implemented in hardware (e.g., in communication management circuitry). The hardware may include at least one of a processor, digital signal processor (DSP), central processing unit (CPU), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA) or other programmable logic device, microcontroller, discrete gate or transistor logic device, discrete hardware component, or any combination thereof, configured as or otherwise individually or collectively to support components for performing the functions described herein. In some examples, at least one processor and at least one memory coupled to said at least one processor may be configured to perform one or more of the functions described herein (e.g., executing instructions stored in at least one memory individually or collectively by one or more processors).

[0103] Additionally or alternatively, the communication manager 420, receiver 410, transmitter 415, or various combinations or components thereof may be implemented in code executed by at least one processor (e.g., as communication management software or firmware). If implemented in code executed by at least one processor, the functionality of the communication manager 420, receiver 410, transmitter 415, or various combinations or components thereof may be performed by any combination of a general-purpose processor, DSP, CPU, ASIC, FPGA, microcontroller, or these or other programmable logic devices (e.g., configured as or otherwise individually or jointly to support components for performing the functions described in this disclosure).

[0104] In some examples, the communication manager 420 may be configured to use or otherwise cooperate with the receiver 410, transmitter 415, or both to perform various operations (e.g., receiving, acquiring, monitoring, outputting, transmitting). For example, the communication manager 420 may receive information from the receiver 410, transmit information to the transmitter 415, or be integrated with the receiver 410, transmitter 415, or both to acquire information, output information, or perform various other operations as described herein.

[0105] Communication manager 420 may support wireless communication according to examples disclosed herein. For example, communication manager 420 may be capable of, configured to, or operable to support components for transmitting first control signaling to a network entity, the first control signaling including a first shift time offset indication associated with a downlink channel of a cell associated with the network entity. Communication manager 420 may be capable of, configured to, or operable to support components for receiving, from a network entity, second control signaling indicating a projection matrix associated with the downlink channel based on transmitting the first control signaling. Communication manager 420 may be capable of, configured to, or operable to support components for receiving data signaling from a network entity on a downlink channel based on receiving the second control signaling. Communication manager 420 may be capable of, configured to, or operable to support components for demodulating data signaling based on a channel estimate associated with the downlink channel based on the projection matrix.

[0106] By including or configuring a communication manager 420 according to an example as described herein, device 405 (e.g., controlling receiver 410, transmitter 415, communication manager 420 or a combination thereof or at least one processor otherwise coupled to them) can support techniques for reducing processing, reducing power consumption and utilizing communication resources more efficiently.

[0107] Figure 5 A block diagram 500 of a device 505 supporting techniques for downlink channel estimation according to one or more aspects of this disclosure is shown. Device 505 may be an example of aspects of device 405 or UE 115 as described herein. Device 505 may include receiver 510, transmitter 515, and communication manager 520. Device 505, or one or more components of device 505 (e.g., receiver 510, transmitter 515, and communication manager 520), may include at least one processor that may be coupled to at least one memory to support the described techniques. Each of these components may communicate with each other (e.g., via one or more buses).

[0108] Receiver 510 may provide components for receiving information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to techniques used for downlink channel estimation). The information may be passed to other components of device 505. Receiver 510 may utilize a single antenna or a collection of antennas.

[0109] Transmitter 515 may provide components for transmitting signals generated by other components of device 505. For example, transmitter 515 may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels associated with techniques used for downlink channel estimation). In some examples, transmitter 515 may be co-located with receiver 510 in a transceiver module. Transmitter 515 may utilize a single antenna or a collection of multiple antennas.

[0110] Device 505 or its various components may be examples of parts used to perform various aspects of techniques for downlink channel estimation as described herein. For example, communication manager 520 may include shift time offset manager 525, projection matrix manager 530, data signaling manager 535, demodulation manager 540, or any combination thereof. Communication manager 520 may be examples of aspects of communication manager 420 as described herein. In some examples, communication manager 520 or its various components may be configured to use or otherwise cooperate with receiver 510, transmitter 515, or both to perform various operations (e.g., receiving, acquiring, monitoring, outputting, transmitting). For example, communication manager 520 may receive information from receiver 510, transmit information to transmitter 515, or be integrated in combination with receiver 510, transmitter 515, or both to acquire information, output information, or perform various other operations as described herein.

[0111] Communication manager 520 may support wireless communication according to examples disclosed herein. Shift time offset manager 525 is capable of, configured to, or operable to support components for transmitting first control signaling to a network entity, the first control signaling including a first shift time offset indication associated with a downlink channel of a cell associated with the network entity. Projection matrix manager 530 is capable of, configured to, or operable to support components for receiving second control signaling from a network entity, indicating a projection matrix associated with the downlink channel, based on the transmission of the first control signaling. Data signaling manager 535 is capable of, configured to, or operable to support components for receiving data signaling from a network entity on a downlink channel based on the receipt of the second control signaling. Demodulation manager 540 is capable of, configured to, or operable to support components for demodulating data signaling based on a channel estimate associated with the downlink channel based on the projection matrix.

[0112] Figure 6 A block diagram 600 illustrates a communication manager 620 supporting techniques for downlink channel estimation according to one or more aspects of this disclosure. The communication manager 620 may be an example of aspects of the communication manager 420, communication manager 520, or both as described herein. The communication manager 620 or its various components may be examples of parts for performing various aspects of the techniques for downlink channel estimation as described herein. For example, the communication manager 620 may include a shift time offset manager 625, a projection matrix manager 630, a data signaling manager 635, a demodulation manager 640, a reference signal manager 645, a channel estimation manager 650, a power delay distribution manager 655, a channel state information reporting manager 660, a descrambling manager 665, or any combination thereof. Each of these components, or its components or sub-components (e.g., one or more processors, one or more memories), may communicate directly or indirectly with each other (e.g., via one or more buses).

[0113] Communication manager 620 may support wireless communication according to examples disclosed herein. Shift time offset manager 625 is capable of, configured to, or operable to support components for transmitting first control signaling to a network entity, the first control signaling including a first shift time offset indication associated with a downlink channel of a cell associated with the network entity. Projection matrix manager 630 is capable of, configured to, or operable to support components for receiving second control signaling from a network entity, indicating a projection matrix associated with the downlink channel, based on the transmission of the first control signaling. Data signaling manager 635 is capable of, configured to, or operable to support components for receiving data signaling from a network entity on a downlink channel based on the receipt of the second control signaling. Demodulation manager 640 is capable of, configured to, or operable to support components for demodulating data signaling based on a channel estimate associated with the downlink channel based on the projection matrix.

[0114] In some examples, the downlink and uplink channels of a cell are time-division multiplexed.

[0115] In some examples, to support the reception of data signaling, the reference signal manager 645 is capable of, configured to, or operable to support components for receiving reference signals from network entities. In some examples, to support the reception of data signaling, the channel estimation manager 650 is capable of, configured to, or operable to support components for determining channel estimates based on the projection matrix and the reference signal.

[0116] In some examples, to support determination of channel estimation, descrambling manager 665 is capable of, configured to, or operable to support components for descrambling the reference signal. In some examples, to support determination of channel estimation, channel estimation manager 650 is capable of, configured to, or operable to support components for determining channel estimation based on the projection matrix and the descrambled reference signal.

[0117] In some examples, the projection matrix is ​​based on the time-domain channel autocorrelation associated with the cell's uplink channel, the noise covariance associated with the uplink channel, the fast Fourier transform matrix based on the first shift time offset indication, or a combination thereof.

[0118] In some examples, the power delay distribution manager 655 is capable of, configured to, or able to operate to support components for sending third control signaling to network entities that indicates the channel power delay distribution associated with the UE, wherein the projection matrix is ​​based on the channel power delay distribution.

[0119] In some examples, the channel state information report manager 660 is capable of, configured to, or able to operate to support components for sending third control signaling to network entities that indicates a channel state information report associated with a downlink channel, wherein the projection matrix is ​​based on the channel state information report.

[0120] In some examples, the shift time offset manager 625 is capable of, configured to, or operable to support components for sending third control signaling to a network entity indicating a second shift time offset indication associated with a downlink channel, wherein the second shift time offset indication is different from the first shift time offset indication. In some examples, the projection matrix manager 630 is capable of, configured to, or operable to support components for receiving from a network entity a fourth control signaling indicating a second projection matrix associated with a downlink channel based on the transmission of the third control signaling. In some examples, the data signaling manager 635 is capable of, configured to, or operable to support components for receiving second data signaling from a network entity on a downlink channel based on the receipt of the fourth control signaling. In some examples, the demodulation manager 640 is capable of, configured to, or operable to support components for demodulating second data signaling based on a second channel estimate based on the second projection matrix.

[0121] Figure 7 A diagram of a system 700 including device 705 supporting techniques for downlink channel estimation according to one or more aspects of this disclosure is shown. Device 705 may be an example of device 405, device 505, or UE 115 as described herein, or may include components thereof. Device 705 may communicate with one or more network entities 105, one or more UEs 115, or any combination thereof (e.g., wirelessly). Device 705 may include components for bidirectional voice and data communication, including components for transmitting and receiving communications, such as a communication manager 720, an input / output (I / O) controller 710, a transceiver 715, an antenna 725, at least one memory 730, code 735, and at least one processor 740. These components may communicate electronically or be coupled in other ways (e.g., operational ground, communication ground, functional ground, electronic ground, electrical ground) via one or more buses (e.g., bus 745).

[0122] I / O controller 710 manages the input and output signals of device 705. I / O controller 710 can also manage peripheral devices not integrated into device 705. In some cases, I / O controller 710 may represent a physical connection or port to an external peripheral device. In some cases, I / O controller 710 may utilize an operating system such as iOS. ® ANDROID ® MS-DOS ®MS-WINDOWS ® OS / 2 ® UNIX ® LINUX ® Alternatively, the I / O controller 710 may represent or interact with a modem, keyboard, mouse, touchscreen, or similar device. In some cases, the I / O controller 710 may be implemented as part of one or more processors, such as at least one processor 740. In some cases, a user may interact with the device 705 via the I / O controller 710 or via hardware components controlled by the I / O controller 710.

[0123] In some cases, device 705 may include a single antenna 725. However, in other cases, device 705 may have more than one antenna 725, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. Transceiver 715 may communicate bidirectionally via one or more antennas 725 as described herein, or via a wired or wireless link. For example, transceiver 715 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. Transceiver 715 may also include a modem for: modulating packets; providing the modulated packets to one or more antennas 725 for transmission; and demodulating packets received from one or more antennas 725. Transceiver 715, or transceiver 715 and one or more antennas 725, may be an example of transmitter 415, transmitter 515, receiver 410, receiver 510, or any combination thereof or components thereof as described herein.

[0124] At least one memory 730 may include random access memory (RAM) and read-only memory (ROM). At least one memory 730 may store computer-readable, computer-executable code 735, including instructions that, when executed by at least one processor 740, cause device 705 to perform the various functions described herein. Code 735 may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, code 735 may not be directly executable by at least one processor 740, but may enable a computer (e.g., when compiled and executed) to perform the functions described herein. In some cases, among other things, at least one memory 730 may also include a basic I / O system (BIOS) that controls basic hardware or software operations, such as interaction with peripheral components or devices.

[0125] At least one processor 740 may include intelligent hardware devices (e.g., general-purpose processors, DSPs, CPUs, microcontrollers, ASICs, FPGAs, programmable logic devices, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, at least one processor 740 may be configured to operate a memory array using a memory controller. In some other cases, the memory controller may be integrated into at least one processor 740. At least one processor 740 may be configured to execute computer-readable instructions stored in memory (e.g., at least one memory 730) to cause device 705 to perform various functions (e.g., functions or tasks supporting techniques for downlink channel estimation). For example, device 705 or components of device 705 may include at least one processor 740 and at least one memory 730 coupled to or coupled to at least one processor 740, wherein at least one processor 740 and at least one memory 730 are configured to perform the various functions described herein. In some examples, at least one processor 740 may include multiple processors, and at least one memory 730 may include multiple memories. One or more of a plurality of processors may be coupled to one or more of a plurality of memories, which may be configured individually or collectively to perform the various functions described herein. In some examples, at least one processor 740 may be a component of a processing system, which may refer to a system of machines (such as a series of machines), circuitry (including, for example, one or both of processor circuitry (which may include at least one processor 740) and memory circuitry (which may include at least one memory 730)) or components that receive or receive input and process the input to produce, generate or obtain a set of outputs. The processing system may be configured to perform one or more of the functions described herein. Thus, at least one processor 740 or a processing system including at least one processor 740 may be configured, capable of being configured, or operable to cause device 705 to perform one or more of the functions described herein. Furthermore, as described herein, “configured to,” “capable of being configured,” and “operable to” are used interchangeably and may be associated with the ability to perform one or more of the functions described herein when executing code stored in at least one memory 730 or otherwise.

[0126] The communication manager 720 may support wireless communication according to examples disclosed herein. For example, the communication manager 720 may be capable of, configured to, or operable to support components for transmitting first control signaling to a network entity, the first control signaling including a first shift time offset indication associated with a downlink channel of a cell associated with the network entity. The communication manager 720 may be capable of, configured to, or operable to support components for receiving, from a network entity, second control signaling indicating a projection matrix associated with the downlink channel based on transmitting the first control signaling. The communication manager 720 may be capable of, configured to, or operable to support components for receiving data signaling from a network entity on a downlink channel based on receiving the second control signaling. The communication manager 720 may be capable of, configured to, or operable to support components for demodulating data signaling based on a channel estimate associated with the downlink channel based on the projection matrix.

[0127] By including or configuring a communication manager 720 according to an example as described herein, device 705 can support techniques for reducing latency, improving and reducing user experience related to processing, reducing power consumption, utilizing communication resources more efficiently, improving coordination between devices, extending battery life, and improving the utilization of processing power.

[0128] In some examples, the communication manager 720 may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using a transceiver 715, one or more antennas 725, or any combination thereof, or otherwise cooperating with them. Although the communication manager 720 is illustrated as a separate component, in some examples, one or more functions described with reference to the communication manager 720 may be supported by or performed by at least one processor 740, at least one memory 730, code 735, or any combination thereof. For example, code 735 may include instructions that can be executed by at least one processor 740 to cause device 705 to perform various aspects of the techniques for downlink channel estimation as described herein, or at least one processor 740 and at least one memory 730 may be otherwise configured to perform or support such operations individually or jointly.

[0129] Figure 8A block diagram 800 illustrates a device 805 supporting techniques for downlink channel estimation according to one or more aspects of this disclosure. Device 805 may be an example of aspects of network entity 105 as described herein. Device 805 may include a receiver 810, a transmitter 815, and a communication manager 820. Device 805, or one or more components of device 805 (e.g., receiver 810, transmitter 815, and communication manager 820), may include at least one processor that may be coupled to at least one memory to individually or jointly support or implement the described techniques. Each of these components may communicate with each other (e.g., via one or more buses).

[0130] Receiver 810 may provide components for acquiring (e.g., receiving, determining, identifying) information (such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units)) associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack). The information may be passed to other components of device 805. In some examples, receiver 810 may support acquiring information by receiving signals via one or more antennas. Additionally or alternatively, receiver 810 may support acquiring information by receiving signals via one or more wired (e.g., electrical, fiber optic) interfaces, wireless interfaces, or any combination thereof.

[0131] Transmitter 815 may provide components for outputting (e.g., transmitting, providing, conveying, transmitting) information generated by other components of device 805. For example, transmitter 815 may output information associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack), such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units). In some examples, transmitter 815 may support outputting information by transmitting signals via one or more antennas. Additionally or alternatively, transmitter 815 may support outputting information by transmitting signals via one or more wired (e.g., electrical, fiber optic) interfaces, wireless interfaces, or any combination thereof. In some examples, transmitter 815 and receiver 810 may be co-located in a transceiver, which may include or be coupled to a modem.

[0132] The communication manager 820, receiver 810, transmitter 815, or various combinations thereof, or various components thereof, may be examples of components used to perform various aspects of the techniques for downlink channel estimation as described herein. For example, the communication manager 820, receiver 810, transmitter 815, or various combinations thereof, or components thereof, may be able to perform one or more of the functions described herein.

[0133] In some examples, the communication manager 820, receiver 810, transmitter 815, or various combinations or components thereof may be implemented in hardware (e.g., in communication management circuitry). The hardware may include at least one of a processor, DSP, CPU, ASIC, FPGA, or other programmable logic device, microcontroller, discrete gate or transistor logic, discrete hardware component, or any combination thereof, configured as or otherwise individually or collectively to support components for performing the functions described herein. In some examples, at least one processor and at least one memory coupled to said at least one processor may be configured to perform one or more of the functions described herein (e.g., executing instructions stored in at least one memory individually or collectively by one or more processors).

[0134] Additionally or alternatively, the communication manager 820, receiver 810, transmitter 815, or various combinations or components thereof may be implemented in code executed by at least one processor (e.g., as communication management software or firmware). If implemented in code executed by at least one processor, the functionality of the communication manager 820, receiver 810, transmitter 815, or various combinations or components thereof may be performed by any combination of a general-purpose processor, DSP, CPU, ASIC, FPGA, microcontroller, or these or other programmable logic devices (e.g., configured as or otherwise individually or collectively to support components for performing the functions described in this disclosure).

[0135] In some examples, the communication manager 820 may be configured to use or otherwise cooperate with the receiver 810, transmitter 815, or both to perform various operations (e.g., receiving, acquiring, monitoring, outputting, transmitting). For example, the communication manager 820 may receive information from the receiver 810, transmit information to the transmitter 815, or be integrated with the receiver 810, transmitter 815, or both to acquire information, output information, or perform various other operations as described herein.

[0136] The communication manager 820 may support wireless communication according to examples disclosed herein. For example, the communication manager 820 may be capable of, configured to, or operable to support components for receiving first control signaling from a UE, the first control signaling indicating a first shift time offset indication associated with a downlink channel of a cell associated with a network entity. The communication manager 820 may be capable of, configured to, or operable to support components for transmitting to the UE second control signaling indicating a projection matrix associated with the downlink channel, wherein the projection matrix is ​​determined based on the first shift time offset indication. The communication manager 820 may be capable of, configured to, or operable to support components for transmitting data signaling to the UE on the downlink channel based on transmitting the second control signaling.

[0137] By including or configuring a communication manager 820 according to an example as described herein, device 805 (e.g., controlling receiver 810, transmitter 815, communication manager 820 or a combination thereof or at least one processor otherwise coupled to them) can support techniques for reducing processing, reducing power consumption and utilizing communication resources more efficiently.

[0138] Figure 9 A block diagram 900 illustrates a device 905 supporting techniques for downlink channel estimation according to one or more aspects of this disclosure. Device 905 may be an example of aspects of device 805 or network entity 105 as described herein. Device 905 may include a receiver 910, a transmitter 915, and a communication manager 920. Device 905, or one or more components of device 905 (e.g., receiver 910, transmitter 915, and communication manager 920), may include at least one processor that may be coupled to at least one memory to support the described techniques. Each of these components may communicate with each other (e.g., via one or more buses).

[0139] Receiver 910 may provide components for acquiring (e.g., receiving, determining, identifying) information (such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units)) associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack). The information may be passed to other components of device 905. In some examples, receiver 910 may support acquiring information by receiving signals via one or more antennas. Additionally or alternatively, receiver 910 may support acquiring information by receiving signals via one or more wired (e.g., electrical, fiber optic) interfaces, wireless interfaces, or any combination thereof.

[0140] Transmitter 915 may provide components for outputting (e.g., transmitting, providing, conveying, transmitting) information generated by other components of device 905. For example, transmitter 915 may output information associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack), such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units). In some examples, transmitter 915 may support outputting information by transmitting signals via one or more antennas. Additionally or alternatively, transmitter 915 may support outputting information by transmitting signals via one or more wired (e.g., electrical, fiber optic) interfaces, wireless interfaces, or any combination thereof. In some examples, transmitter 915 and receiver 910 may be co-located in a transceiver, which may include or be coupled to a modem.

[0141] Device 905 or its various components may be examples of parts used to perform various aspects of techniques for downlink channel estimation as described herein. For example, communication manager 920 may include shift time offset manager 925, projection matrix manager 930, data signaling manager 935, or any combination thereof. Communication manager 920 may be examples of aspects of communication manager 820 as described herein. In some examples, communication manager 920 or its various components may be configured to use or otherwise cooperate with receiver 910, transmitter 915, or both to perform various operations (e.g., receiving, acquiring, monitoring, outputting, transmitting). For example, communication manager 920 may receive information from receiver 910, transmit information to transmitter 915, or be integrated in combination with receiver 910, transmitter 915, or both to acquire information, output information, or perform various other operations as described herein.

[0142] Communication manager 920 may support wireless communication according to examples disclosed herein. Shift time offset manager 925 is capable of, configured to, or operable to support components for receiving first control signaling from the UE, the first control signaling indicating a first shift time offset indication associated with a downlink channel of a cell associated with a network entity. Projection matrix manager 930 is capable of, configured to, or operable to support components for transmitting to the UE a second control signaling indicating a projection matrix associated with the downlink channel, wherein the projection matrix is ​​determined based on the first shift time offset indication. Data signaling manager 935 is capable of, configured to, or operable to support components for transmitting data signaling to the UE on the downlink channel based on transmitting the second control signaling.

[0143] Figure 10A block diagram 1000 of a communication manager 1020 supporting techniques for downlink channel estimation according to one or more aspects of this disclosure is shown. The communication manager 1020 may be an example of aspects of the communication manager 820, communication manager 920, or both as described herein. The communication manager 1020 or its various components may be examples of parts for performing various aspects of the techniques for downlink channel estimation as described herein. For example, the communication manager 1020 may include a shift time offset manager 1025, a projection matrix manager 1030, a data signaling manager 1035, a channel estimation manager 1040, a reference signal manager 1045, a channel state information reporting manager 1050, a power delay distribution manager 1055, a fast Fourier transform matrix manager 1060, a channel autocorrelation manager 1065, or any combination thereof. Each of these components, or its components or sub-components (e.g., one or more processors, one or more memories), may communicate directly or indirectly with each other (e.g., via one or more buses). This communication may include communication within the protocol layers of the protocol stack, communication associated with logical channels of the protocol stack (e.g., between protocol layers of the protocol stack, within devices, components, or virtualization components associated with network entity 105, between devices, components, or virtualization components associated with network entity 105), or any combination thereof.

[0144] Communication manager 1020 may support wireless communication according to examples disclosed herein. Shift time offset manager 1025 is capable of, configured to, or operable to support components for receiving first control signaling from the UE, the first control signaling indicating a first shift time offset indication associated with a downlink channel of a cell associated with a network entity. Projection matrix manager 1030 is capable of, configured to, or operable to support components for transmitting to the UE a second control signaling indicating a projection matrix associated with a downlink channel, wherein the projection matrix is ​​determined based on the first shift time offset indication. Data signaling manager 1035 is capable of, configured to, or operable to support components for transmitting data signaling to the UE on the downlink channel based on transmitting the second control signaling.

[0145] In some examples, the channel estimation manager 1040 is capable of, configured to, or able to operate to support components for determining channel estimates associated with the uplink channel of a cell, wherein the projection matrix is ​​determined based on the channel estimates.

[0146] In some examples, the downlink and uplink channels of a cell are time-division multiplexed.

[0147] In some examples, the reference signal manager 1045 is capable of, configured to, or able to operate to support components for transmitting reference signals to the UE based on a transmission projection matrix.

[0148] In some examples, the channel state information report manager 1050 is capable of, configured to, or able to operate to support components for receiving third control signaling from the UE that indicates a channel state information report associated with a downlink channel, wherein the projection matrix is ​​based on the channel state information report.

[0149] In some examples, the projection matrix manager 1030 is capable of, configured to, or able to operate to support components for determining the projection matrix in response to receiving a first control signaling, based on the time-domain channel autocorrelation associated with the uplink channel of the cell, the noise covariance associated with the uplink channel, the fast Fourier transform matrix based on a first shift time offset indication, or a combination thereof.

[0150] In some examples, to support the determination of the projection matrix, the Fast Fourier Transform Matrix Manager 1060 is capable of, configured to, or operable to support components for determining the Fast Fourier Transform matrix based on the power delay distribution associated with network entities.

[0151] In some examples, in order to support the determination of the projection matrix, the channel autocorrelation manager 1065 can be configured or operated to support components for determining time-domain channel autocorrelation based on the power delay distribution associated with network entities.

[0152] In some examples, to support the determination of the projection matrix, the power delay distribution manager 1055 is capable of, configured to, or operable to support components for receiving third control signaling from the UE indicating the channel power delay distribution associated with the UE. In some examples, to support the determination of the projection matrix, the projection matrix manager 1030 is capable of, configured to, or operable to support components for determining the projection matrix based on the channel power delay distribution associated with the UE.

[0153] In some examples, the projection matrix manager 1030 is capable of, configured to, or able to operate to support components for sending a fourth control signaling to the UE based on determining a change in the power delay distribution associated with a network entity, the fourth control signaling indicating a second projection matrix associated with a channel estimate of the uplink channel of the network entity.

[0154] In some examples, the shift time offset manager 1025 is capable of, configured to, or operable to support components for receiving from the UE a third control signaling indicating a second shift time offset indication associated with a downlink channel of the UE, wherein the second shift time offset indication is different from the first shift time offset indication. In some examples, the projection matrix manager 1030 is capable of, configured to, or operable to support components for transmitting a fourth control signaling to the UE based on the transmission of the third control signaling, which indicates a second projection matrix associated with a channel estimate of an uplink channel of a network entity.

[0155] Figure 11 A diagram of a system 1100 including a device 1105 supporting techniques for downlink channel estimation according to one or more aspects of this disclosure is shown. Device 1105 may be an example of device 805, device 905, or network entity 105 as described herein, or may include components thereof. Device 1105 may communicate with one or more network entities 105, one or more UEs 115, or any combination thereof, and this communication may include communication via one or more wired interfaces, one or more wireless interfaces, or any combination thereof. Device 1105 may include components supporting output and obtaining communication, such as a communication manager 1120, a transceiver 1110, an antenna 1115, at least one memory 1125, code 1130, and at least one processor 1135. These components may communicate electronically or otherwise (e.g., operative ground, communicative ground, functional ground, electronic ground, electrical ground) via one or more buses (e.g., bus 1140).

[0156] Transceiver 1110 may support bidirectional communication via a wired link, a wireless link, or both, as described herein. In some examples, transceiver 1110 may include a wired transceiver and be capable of bidirectional communication with another wired transceiver. Additionally or alternatively, in some examples, transceiver 1110 may include a wireless transceiver and be capable of bidirectional communication with another wireless transceiver. In some examples, device 1105 may include one or more antennas 1115 that are capable of (e.g., concurrently) transmitting or receiving wireless transmissions. Transceiver 1110 may also include a modem for: modulating a signal; providing the modulated signal for transmission (e.g., via one or more antennas 1115, via a wired transmitter); receiving the modulated signal (e.g., from one or more antennas 1115, from a wired receiver); and demodulating the signal. In some embodiments, transceiver 1110 may include one or more interfaces, such as one or more interfaces coupled to one or more antennas 1115 configured to support various receive or acquire operations, or one or more interfaces coupled to one or more antennas 1115 configured to support various transmit or output operations, or combinations thereof. In some embodiments, transceiver 1110 may include one or more processors or one or more memory components or be configured to couple to one or more processors or one or more memory components capable of operating to perform or support operations based on received or acquired information or signals, or to generate information or other signals for transmission or other output, or any combination thereof. In some embodiments, transceiver 1110, or transceiver 1110 and one or more antennas 1115, or transceiver 1110 and one or more antennas 1115 and one or more processors or one or more memory components (e.g., at least one processor 1135, at least one memory 1125, or both) may be included in a chip or chip assembly mounted in device 1105. In some examples, transceiver 1110 may be able to operate to support communication via one or more communication links (e.g., communication link 125, backhaul communication link 120, midhaul communication link 162, fronthaul communication link 168).

[0157] At least one memory 1125 may include RAM, ROM, or any combination thereof. At least one memory 1125 may store computer-readable, computer-executable code 1130 including instructions that, when executed by one or more of at least one processor 1135, cause device 1105 to perform the various functions described herein. Code 1130 may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, code 1130 may not be directly executable by one of the at least one processor 1135, but may enable a computer (e.g., when compiled and executed) to perform the functions described herein. In some cases, at least one memory 1125 may also include a BIOS, among other things, that controls basic hardware or software operation, such as interaction with peripheral components or devices. In some examples, at least one processor 1135 may include multiple processors, and at least one memory 1125 may include multiple memories. One or more of the multiple processors may be coupled to one or more of the multiple memories, which may be configured individually or collectively to perform the various functions described herein (e.g., as part of a processing system).

[0158] At least one processor 1135 may include intelligent hardware devices (e.g., general-purpose processors, DSPs, ASICs, CPUs, FPGAs, microcontrollers, programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or any combination thereof). In some cases, at least one processor 1135 may be configured to operate a memory array using a memory controller. In some other cases, the memory controller may be integrated into one or more of the at least one processor 1135. At least one processor 1135 may be configured to execute computer-readable instructions stored in a memory (e.g., one or more of at least one memory 1125) to cause device 1105 to perform various functions (e.g., functions or tasks supporting techniques for downlink channel estimation). For example, device 1105 or components of device 1105 may include at least one processor 1135 and at least one memory 1125 coupled to one or more of the at least one processor 1135, wherein at least one processor 1135 and at least one memory 1125 are configured to perform the various functions described herein. At least one processor 1135 may be an example of a cloud computing platform (e.g., one or more physical nodes and supporting software such as an operating system, virtual machine, or container instance) that can (e.g., by executing code 1130) host functions for performing the functions of device 1105. At least one processor 1135 may be any one or more suitable processors capable of executing scripts or instructions of one or more software programs stored in device 1105 (such as within one or more memories of at least one memory 1125). In some examples, at least one processor 1135 may include multiple processors, and at least one memory 1125 may include multiple memories. One or more of the multiple processors may be coupled to one or more of the multiple memories, which may be configured individually or collectively to perform the various functions described herein. In some examples, at least one processor 1135 may be a component of a processing system, which may refer to a system of machines (such as a series of machines), circuits (including, for example, one or both of processor circuitry (which may include at least one processor 1135) and memory circuitry (which may include at least one memory 1125)) or components that receive or acquire input and process the input to produce, generate, or acquire a set of outputs. The processing system may be configured to perform one or more of the functions described herein. Therefore, at least one processor 1135 or a processing system including at least one processor 1135 may be configured, can be configured, or can operate to cause the device 1105 to perform one or more of the functions described herein.Furthermore, as described herein, “configured to,” “capable of being configured to,” and “capable of operating to” are used interchangeably and can be associated with the ability to perform one or more of the functions described herein when executing code stored in at least one memory 1125 or otherwise.

[0159] In some examples, bus 1140 may support communication at the protocol layer of the protocol stack (e.g., within a protocol layer). In some examples, bus 1140 may support communication associated with logical channels of the protocol stack (e.g., between protocol layers of the protocol stack), which may include communication performed within components of device 1105, or communication performed between different components of device 1105 that are co-addressable or may be located in different locations (e.g., where device 1105 may refer to a system in which one or more of communication manager 1120, transceiver 1110, at least one memory 1125, code 1130 and at least one processor 1135 may be located in one component of different components or partitioned between different components).

[0160] In some examples, the communication manager 1120 may manage (e.g., via one or more wired or wireless backhaul links) various aspects of communication with the core network 130. For example, the communication manager 1120 may manage the delivery of data communications by client devices, such as one or more UEs 115. In some examples, the communication manager 1120 may manage communication with other network entities 105 and may include a controller or scheduler for cooperating with other network entities 105 to control communication with UE 115. In some examples, the communication manager 1120 may support an X2 interface within LTE / LTE-A wireless communication network technology to provide communication between network entities 105.

[0161] The communication manager 1120 may support wireless communication according to examples disclosed herein. For example, the communication manager 1120 may be capable of, configured to, or operable to support components for receiving first control signaling from a UE, the first control signaling indicating a first shift time offset indication associated with a downlink channel of a cell associated with a network entity. The communication manager 1120 may be capable of, configured to, or operable to support components for transmitting to the UE second control signaling indicating a projection matrix associated with the downlink channel, wherein the projection matrix is ​​determined based on the first shift time offset indication. The communication manager 1120 may be capable of, configured to, or operable to support components for transmitting data signaling to the UE on the downlink channel based on transmitting the second control signaling.

[0162] By including or configuring a communication manager 1120 according to an example as described herein, device 1105 can support techniques for improving communication reliability, reducing latency, improving and reducing user experience related to processing, reducing power consumption, utilizing communication resources more efficiently, improving coordination between devices, extending battery life, and improving the utilization of processing power.

[0163] In some examples, the communication manager 1120 may be configured to use or otherwise coordinate with the transceiver 1110, one or more antennas 1115 (e.g., where applicable), or any combination thereof to perform various operations (e.g., receiving, acquiring, monitoring, outputting, transmitting). Although the communication manager 1120 is illustrated as a separate component, in some examples, one or more functions described with reference to the communication manager 1120 may be supported or performed by the transceiver 1110, one or more processors in at least one processor 1135, one or more memories in at least one memory 1125, code 1130, or any combination thereof (e.g., by a processing system including at least a portion of at least one processor 1135, at least one memory 1125, code 1130, or any combination thereof). For example, code 1130 may include instructions that can be executed by one or more processors in at least one processor 1135 to cause the device 1105 to perform various aspects of the techniques for downlink channel estimation as described herein, or at least one processor 1135 and at least one memory 1125 may be otherwise configured to perform or support such operations individually or jointly.

[0164] Figure 12 A flowchart illustrating a method 1200 for downlink channel estimation, according to various aspects of this disclosure, is shown. Operation of method 1200 can be implemented by a UE or its components as described herein. For example, operation of method 1200 can be performed by, as referenced... Figures 1 to 7 The UE 115 described herein performs the following: In some examples, the UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the described functions.

[0165] At 1205, the method may include sending a first control signaling to a network entity, the first control signaling including a first shift time offset indication associated with a downlink channel of a cell associated with the network entity. Operation of block 1205 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1205 may be derived from references... Figure 6 The described shift time offset manager 625 is executed.

[0166] At 1210, the method may include receiving second control signaling from a network entity, based on sending a first control signaling, an indication of a projection matrix associated with a downlink channel. The operation of block 1210 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1210 may be provided by reference to [reference needed]. Figure 6 The described projection matrix manager 630 is executed.

[0167] At 1215, the method may include receiving data signaling from a network entity on a downlink channel based on receiving a second control signaling. The operation of block 1215 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1215 may be derived from references... Figure 6 The data signaling manager 635 described is executed.

[0168] At 1220, the method may include demodulating data signaling based on a channel estimate associated with the downlink channel based on a projection matrix. The operation of block 1220 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1220 may be derived from references... Figure 6 The demodulation manager 640 described is executed.

[0169] Figure 13 A flowchart illustrating a method 1300 for downlink channel estimation, according to various aspects of this disclosure, is shown. Operation of method 1300 can be implemented by a UE or its components as described herein. For example, operation of method 1300 can be performed by, as referenced... Figures 1 to 7 The UE 115 described herein performs the following: In some examples, the UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the described functions.

[0170] At 1305, the method may include sending a first control signaling to a network entity, the first control signaling including a first shift time offset indication associated with a downlink channel of a cell associated with the network entity. Operation of block 1305 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1305 may be provided by reference to [reference needed]. Figure 6 The described shift time offset manager 625 is executed.

[0171] At 1310, the method may include receiving second control signaling from a network entity, based on sending a first control signaling, an indication of a projection matrix associated with a downlink channel. Operation of block 1310 may be performed according to examples as disclosed herein. In some examples, aspects of operation of 1310 may be provided by reference to [reference needed]. Figure 6 The described projection matrix manager 630 is executed.

[0172] At 1315, the method may include receiving data signaling from a network entity on a downlink channel based on receiving a second control signaling. The operation of block 1315 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1315 may be derived from references... Figure 6 The data signaling manager 635 described is executed.

[0173] At 1320, the method may include receiving a reference signal from a network entity. The operation of block 1325 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1325 may be determined by reference... Figure 6 The reference signal manager 645 described is executed.

[0174] At 1325, the method may include determining a channel estimate based on the projection matrix and a reference signal. The operation of block 1330 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1330 may be derived from, as in the reference... Figure 6 The described channel estimation manager 650 is executed.

[0175] At 1330, the method may include demodulating data signaling based on a channel estimate associated with the downlink channel based on a projection matrix. The operation of block 1320 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1320 may be derived from references... Figure 6 The demodulation manager 640 described is executed.

[0176] Figure 14 A flowchart illustrating a method 1400 for downlink channel estimation, according to various aspects of this disclosure, is shown. The operation of method 1400 may be implemented by a network entity or its components as described herein. For example, the operation of method 1400 may be implemented by, as referenced... Figures 1 to 3 as well as Figures 8 to 11 The described network entity performs the functions. In some examples, the network entity may execute a set of instructions to control the functional elements of the network entity to perform the described functions. Additionally or alternatively, the network entity may use dedicated hardware to perform aspects of the described functions.

[0177] At 1405, the method may include receiving a first control signaling from the UE, the first control signaling indicating a first shift time offset indication associated with a downlink channel of a cell associated with a network entity. Operation of block 1405 may be performed according to examples as disclosed herein. In some examples, aspects of operation of 1405 may be provided by reference to... Figure 10 The described shift time offset manager 1025 is executed.

[0178] At 1410, the method may include sending a second control signaling to the UE indicating a projection matrix associated with the downlink channel, wherein the projection matrix is ​​determined based on a first shift time offset indication. The operation of block 1410 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1410 may be provided by reference to [reference needed]. Figure 10 The described projection matrix manager 1030 is executed.

[0179] At 1415, the method may include sending data signaling to the UE on the downlink channel based on sending a second control signaling. The operation of block 1415 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1415 may be provided by reference to [reference needed]. Figure 10 The data signaling manager 1035 described is executed.

[0180] Figure 15 A flowchart illustrating a method 1500 for downlink channel estimation, exemplifying various aspects of this disclosure, is shown. The operation of method 1500 can be implemented by a network entity or its components as described herein. For example, the operation of method 1500 can be implemented by, as referenced... Figures 1 to 3 as well as Figures 8 to 11 The described network entity performs the functions. In some examples, the network entity may execute a set of instructions to control the functional elements of the network entity to perform the described functions. Additionally or alternatively, the network entity may use dedicated hardware to perform aspects of the described functions.

[0181] At 1505, the method may include receiving a first control signaling from the UE, the first control signaling indicating a first shift time offset indication associated with a downlink channel of a cell associated with a network entity. Operation of block 1505 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1505 may be provided by reference to... Figure 10 The described shift time offset manager 1025 is executed.

[0182] At 1510, the method may include determining a channel estimate associated with the uplink channel of the cell, wherein the projection matrix is ​​determined based on the channel estimate. The operation of block 1520 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1520 may be derived from references... Figure 10 The described channel estimation manager 1040 is executed.

[0183] At 1515, the method may include sending a second control signaling to the UE indicating a projection matrix associated with the downlink channel, wherein the projection matrix is ​​determined based on a first shift time offset indication. The operation of block 1510 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1510 may be provided by reference to [reference needed]. Figure 10 The described projection matrix manager 1030 is executed.

[0184] At 1520, the method may include sending data signaling to the UE on the downlink channel based on sending a second control signaling. The operation of block 1515 may be performed according to the examples disclosed herein. In some examples, aspects of the operation of 1515 may be derived from references... Figure 10 The data signaling manager 1035 described is executed.

[0185] The following provides an overview of the various aspects of this disclosure: Aspect 1: A method for wireless communication by a UE, the method comprising: transmitting a first control signaling to a network entity, the first control signaling including a first shift time offset indication associated with a downlink channel of a cell associated with the network entity; receiving from the network entity, at least in part based on transmitting the first control signaling, a second control signaling indicating a projection matrix associated with the downlink channel; receiving from the network entity, at least in part based on receiving the second control signaling, data signaling on the downlink channel; and demodulating the data signaling based on a channel estimate associated with the downlink channel based at least in part on the projection matrix.

[0186] Aspect 2: According to the method of aspect 1, the downlink channel and uplink channel of the cell are time-division multiplexed.

[0187] Aspect 3: The method according to any one of Aspects 1 to 2, wherein receiving the data signaling further includes: receiving a reference signal from the network entity; and determining the channel estimate based at least in part on the projection matrix and the reference signal.

[0188] Aspect 4: According to the method of aspect 3, determining the channel estimate further includes: descrambling the reference signal; and determining the channel estimate based at least in part on the projection matrix and the descrambled reference signal.

[0189] Aspect 5: The method according to any one of Aspects 1 to 4, wherein the projection matrix is ​​based at least in part on time-domain channel autocorrelation associated with the uplink channel of the cell, noise covariance associated with the uplink channel, fast Fourier transform matrix at least in part based on the first shift time offset indication, or a combination thereof.

[0190] Aspect 6: The method according to any one of Aspects 1 to 5, the method further comprising: sending to the network entity a third control signaling indicating a channel power delay distribution associated with the UE, wherein the projection matrix is ​​at least partially based on the channel power delay distribution.

[0191] Aspect 7: The method according to any one of Aspects 1 to 6, the method further comprising: sending to the network entity a third control signaling indicating a channel state information report associated with the downlink channel, wherein the projection matrix is ​​at least partially based on the channel state information report.

[0192] Aspect 8: The method according to any one of Aspects 1 to 7, the method further comprising: sending to the network entity a third control signaling indicating a second shift time offset indication associated with the downlink channel, wherein the second shift time offset indication is different from the first shift time offset indication; receiving from the network entity a fourth control signaling indicating a second projection matrix associated with the downlink channel based at least in part on sending the third control signaling; receiving from the network entity a second data signaling on the downlink channel based at least in part on receiving the fourth control signaling; and demodulating the second data signaling based on a second channel estimation based at least in part on the second projection matrix.

[0193] Aspect 9: A method for wireless communication by a network entity, the method comprising: receiving a first control signaling from a UE, the first control signaling indicating a first shift time offset indication associated with a downlink channel of a cell associated with the network entity; transmitting to the UE a second control signaling indicating a projection matrix associated with the downlink channel, wherein the projection matrix is ​​determined at least in part based on the first shift time offset indication; and transmitting data signaling to the UE on the downlink channel at least in part based on transmitting the second control signaling.

[0194] Aspect 10: According to the method of aspect 9, transmitting the second control signaling further includes: determining a channel estimate associated with an uplink channel of the cell, wherein the projection matrix is ​​determined at least in part based on the channel estimate.

[0195] Aspect 11: The method according to any one of Aspects 9 to 10, wherein the downlink channel and uplink channel of the cell are time-division multiplexed.

[0196] Aspect 12: The method according to any one of aspects 9 to 11, the method further comprising: transmitting a reference signal to the UE at least in part based on transmitting the projection matrix.

[0197] Aspect 13: The method according to any one of Aspects 9 to 12, the method further comprising: receiving from the UE a third control signaling indicating a channel state information report associated with the downlink channel, wherein the projection matrix is ​​at least partially based on the channel state information report.

[0198] Aspect 14: The method according to any one of Aspects 9 to 13, the method further comprising: in response to receiving the first control signaling, determining the projection matrix based at least in part on time-domain channel autocorrelation associated with the uplink channel of the cell, noise covariance associated with the uplink channel, fast Fourier transform matrix indicated by the first shift time offset, or a combination thereof.

[0199] Aspect 15: According to the method of aspect 14, determining the projection matrix further includes: determining the fast Fourier transform matrix based at least in part on the power delay distribution associated with the network entity.

[0200] Aspect 16: The method according to any one of Aspects 14 to 15, wherein determining the projection matrix further comprises: determining the time-domain channel autocorrelation based at least in part on the power delay distribution associated with the network entity.

[0201] Aspect 17: The method according to any one of Aspects 9 to 16, wherein determining the projection matrix further comprises: receiving from the UE a third control signaling indicating a channel power delay distribution associated with the UE; and determining the projection matrix based at least in part on the channel power delay distribution associated with the UE.

[0202] Aspect 18: The method according to any one of Aspects 9 to 17, the method further comprising: sending a fourth control signaling to the UE based at least in part on determining a change in the power delay distribution associated with the network entity, the fourth control signaling indicating a second projection matrix associated with a channel estimate of the uplink channel of the network entity.

[0203] Aspect 19: The method according to any one of Aspects 9 to 18, the method further comprising: receiving from the UE a third control signaling indicating a second shift time offset indication associated with the downlink channel of the UE, wherein the second shift time offset indication is different from the first shift time offset indication; and transmitting to the UE a fourth control signaling at least in part based on transmitting the third control signaling, the fourth control signaling indicating a second projection matrix associated with a channel estimate of the uplink channel of the network entity.

[0204] Aspect 20: A UE for wireless communication, the UE comprising: one or more memories storing processor-executable code; and one or more processors coupled to the one or more memories and capable of operating individually or jointly to execute the code to cause the UE to perform a method according to any one of aspects 1 to 8.

[0205] Aspect 21: A UE for wireless communication, the UE comprising at least one component for performing the method according to any one of aspects 1 to 8.

[0206] Aspect 22: A non-transitory computer-readable medium storing code for wireless communication, said code including instructions executable by a processor to perform the method according to any one of aspects 1 to 8.

[0207] Aspect 23: A network entity for wireless communication, the network entity comprising: one or more memories storing processor-executable code; and one or more processors coupled to the one or more memories and capable of operating individually or jointly to execute the code to cause the network entity to perform a method according to any one of aspects 9 to 19.

[0208] Aspect 24: A network entity for wireless communication, the network entity comprising at least one component for performing the method according to any one of aspects 9 to 19.

[0209] Aspect 25: A non-transitory computer-readable medium storing code for wireless communication, said code including instructions executable by a processor to perform the method according to any one of aspects 9 to 19.

[0210] It should be noted that the methods described herein describe possible specific implementations, and the operations and steps can be rearranged or otherwise modified, and other specific implementations are also possible. Furthermore, aspects from two or more of these methods can be combined.

[0211] While aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for illustrative purposes, and the terms LTE, LTE-A, LTE-A Pro, or NR may be used in most of the description, the techniques described herein are also applicable to networks other than LTE, LTE-A, LTE-A Pro, or NR networks. For example, the techniques described are applicable to a variety of other wireless communication systems, such as Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and other systems and radio technologies not explicitly mentioned herein.

[0212] The information and signals described herein can be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or optical particles, or any combination thereof.

[0213] The various exemplary blocks and components described herein can be implemented or performed using a general-purpose processor, DSP, ASIC, CPU, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, or any combination thereof, designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in alternative embodiments, a processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors cooperating with a DSP core, or any other such configuration). Any function or operation described herein that can be performed by a processor may be performed by multiple processors capable of performing the described functions or operations individually or jointly.

[0214] The functions described herein can be implemented using hardware, software executed by a processor, firmware, or any combination thereof. When implemented using software executed by a processor, the functions can be stored as one or more instructions or code on a computer-readable medium or transmitted using one or more instructions or code on a computer-readable medium. Other examples and specific implementations are within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described herein can be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination of these. Features implementing the functions can also be physically located in various locations, including portions distributed such that the functions are implemented in different physical locations.

[0215] Computer-readable media includes both non-transitory computer storage media and communication media, encompassing any medium that facilitates the transfer of a computer program from one location to another. Non-transitory storage media can be any available medium accessible by a general-purpose or special-purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compressed optical disc (CD) ROM or other optical disc storage, disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code components in the form of instructions or data structures, and accessible by a general-purpose or special-purpose computer or a general-purpose or special-purpose processor. Furthermore, any connection is appropriately referred to as computer-readable media. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included within the definition of computer-readable media. As used herein, disks and optical discs include CDs, laser discs, optical discs, digital multifunction discs (DVDs), floppy disks, and Blu-ray discs. Disks can magnetically reproduce data, and optical discs can optically reproduce data using lasers. Combinations of the above are also included within the scope of computer-readable media. Any function or operation described herein that can be performed by memory can be performed by multiple memories capable of performing the described function or operation individually or jointly.

[0216] As used herein, the word "or" in a list of items (e.g., a list of items accompanied by phrases such as "at least one of" or "one or more of") in the claims indicates an inclusive list, such that a list of at least one of, for example, A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Furthermore, as used herein, the phrase "based on" should not be construed as a reference to a closed set of conditions. For example, an example step described as "based on condition A" could be based on both condition A and condition B without departing from the scope of this disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "at least partially based on".

[0217] As used herein, including in claims, the article “a” preceding a noun is open-ended and is understood to refer to “at least one” or “one or more” of those nouns. Therefore, the terms “a,” “at least one,” “one or more,” and “at least one of one or more” are interchangeable. For example, where a claim enumerates “components” performing one or more functions, each of the individual functions may be performed by a single component or by any combination of multiple components. Thus, the term “component” having a characteristic or performing a function may refer to “at least one of one or more components” having a particular characteristic or performing a particular function. Subsequent references to a component introduced with the article “a” using the terms “the” or “the” may refer to any or all of the one or more components. For example, a component introduced with the article “a” may be understood to mean “one or more components,” and subsequent reference to “component” in a claim may be understood to be equivalent to referring to “at least one of the one or more components.” Similarly, subsequent references to a component introduced with the terms “the” or “the” as “one or more components” may refer to any or all of the one or more components. For example, reference to "one or more components" in subsequent claims can be understood as equivalent to reference to "at least one of the one or more components".

[0218] The term "determine" encompasses a variety of actions, and therefore, "determine" can include calculation, computation, processing, derivation, investigation, lookup (such as by searching in a table, database, or other data structure), identification, and similar actions. Furthermore, "determine" can include receiving (e.g., receiving information), accessing (e.g., accessing data stored in memory), etc. Moreover, "determine" can include parsing, acquiring, selecting, choosing, building, and other similar actions.

[0219] In the accompanying drawings, similar components or features may have the same reference numerals. Furthermore, various components of the same type can be distinguished by adding a dash after the reference numeral and a second reference numeral to differentiate them. If only the first reference numeral is used in the description, the description can be applied to any of the similar components having the same first reference numeral, regardless of the second or other subsequent reference numerals.

[0220] The description herein, illustrated with reference to the accompanying drawings, describes an example configuration and does not represent all achievable examples or those within the scope of the claims. The term "example" as used herein means "serving as an example, instance, or illustration," not "preferred" or "advantageous over other examples." The detailed description includes specific details used to provide an understanding of the described techniques. However, these techniques can be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form to avoid obscuring the concept of the described examples.

[0221] The description herein is provided to enable those skilled in the art to implement or use this disclosure. Various modifications to this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the scope of this disclosure. Therefore, this disclosure is not limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A user equipment (UE), the user equipment (UE) comprising: One or more memories, wherein the one or more memories store processor-executable code; and One or more processors, coupled to one or more memories and capable of operating individually or jointly to execute the code to enable the UE: Send a first control signaling message to a network entity, the first control signaling message including a first shift time offset indication associated with a downlink channel of a cell associated with the network entity; At least in part, the network entity receives second control signaling indicating a projection matrix associated with the downlink channel based on the transmission of the first control signaling; Data signaling is received from the network entity on the downlink channel based at least in part on the receipt of the second control signaling; as well as The data signaling is demodulated based on a channel estimate associated with the downlink channel, which is at least partially based on the projection matrix.

2. The UE according to claim 1, wherein the downlink channel and uplink channel of the cell are time-division multiplexed.

3. The UE according to claim 1, wherein, In order to receive the data signaling, the one or more processors can also operate individually or jointly to execute the code to enable the UE to: Receive reference signals from the network entity; as well as The channel estimate is determined at least in part based on the projection matrix and the reference signal.

4. The UE according to claim 3, wherein, To determine the channel estimate, the one or more processors can also operate individually or jointly to execute the code to enable the UE to: Descramble the reference signal; as well as The channel estimate is determined at least in part based on the projection matrix and the descrambled reference signal.

5. The UE of claim 1, wherein the projection matrix is ​​based at least in part on time-domain channel autocorrelation associated with the uplink channel of the cell, noise covariance associated with the uplink channel, fast Fourier transform matrix at least in part based on the first shift time offset indication, or a combination thereof.

6. The UE of claim 1, wherein the one or more processors are further capable of operating individually or jointly to execute the code to cause the UE to: A third control signaling is sent to the network entity indicating a channel power delay distribution associated with the UE, wherein the projection matrix is ​​at least partially based on the channel power delay distribution.

7. The UE of claim 1, wherein the one or more processors are further capable of operating individually or jointly to execute the code to cause the UE to: A third control signaling is sent to the network entity indicating a channel state information report associated with the downlink channel, wherein the projection matrix is ​​at least partially based on the channel state information report.

8. The UE of claim 1, wherein the one or more processors are further capable of operating individually or jointly to execute the code to cause the UE to: Send a third control signaling to the network entity indicating a second shift time offset indication associated with the downlink channel, wherein the second shift time offset indication is different from the first shift time offset indication; At least in part, the network entity receives a fourth control signaling indicating a second projection matrix associated with the downlink channel, based on the transmission of the third control signaling. The second data signaling is received from the network entity on the downlink channel based at least in part on the receipt of the fourth control signaling; as well as The second data signaling is demodulated based on a second channel estimate, which is at least partially based on the second projection matrix.

9. A network entity, the network entity comprising: One or more memories, wherein the one or more memories store processor-executable code; and One or more processors, coupled to one or more memories and capable of operating individually or jointly to execute the code to enable the network entity: Receive a first control signaling from the user equipment (UE), the first control signaling indicating a first shift time offset indication associated with a downlink channel of a cell associated with the network entity; Send a second control signaling to the UE indicating a projection matrix associated with the downlink channel, wherein the projection matrix is ​​determined at least in part based on the first shift time offset indication; as well as Data signaling is sent to the UE on the downlink channel, at least in part, based on the transmission of the second control signaling.

10. The network entity of claim 9, wherein the one or more processors are further capable of operating individually or jointly to execute the code to cause the network entity to: Determine a channel estimate associated with the uplink channel of the cell, wherein the projection matrix is ​​determined at least in part based on the channel estimate.

11. The network entity of claim 9, wherein the downlink channel and uplink channel of the cell are time-division multiplexed.

12. The network entity of claim 9, wherein the one or more processors are further capable of operating individually or jointly to execute the code to cause the network entity to: The reference signal is sent to the UE based at least in part on the transmission of the projection matrix.

13. The network entity of claim 9, wherein the one or more processors are further capable of operating individually or jointly to execute the code to cause the network entity to: The UE receives a third control signaling indicating a channel state information report associated with the downlink channel, wherein the projection matrix is ​​at least partially based on the channel state information report.

14. The network entity of claim 9, wherein the one or more processors are further capable of operating individually or jointly to execute the code to cause the network entity to: In response to receiving the first control signaling, the projection matrix is ​​determined at least in part based on the time-domain channel autocorrelation associated with the uplink channel of the cell, the noise covariance associated with the uplink channel, the fast Fourier transform matrix indicated by the first shift time offset, or a combination thereof.

15. The network entity according to claim 14, wherein, To determine the projection matrix, the one or more processors can also operate individually or jointly to execute the code to make the network entity: The Fast Fourier Transform matrix is ​​determined at least in part based on the power delay distribution associated with the network entity.

16. The network entity according to claim 14, wherein, To determine the projection matrix, the one or more processors can also operate individually or jointly to execute the code to make the network entity: The time-domain channel autocorrelation is determined at least in part based on the power delay distribution associated with the network entity.

17. The network entity according to claim 9, wherein, To determine the projection matrix, the one or more processors can also operate individually or jointly to execute the code to make the network entity: Receive from the UE a third control signaling indicating the channel power delay distribution associated with the UE; and The projection matrix is ​​determined at least in part based on the channel power delay distribution associated with the UE.

18. The network entity of claim 9, wherein the one or more processors are further capable of operating individually or jointly to execute the code to cause the network entity to: A fourth control signaling is sent to the UE based at least in part on determining a change in the power delay distribution associated with the network entity, the fourth control signaling indicating a second projection matrix associated with a channel estimate of the uplink channel of the network entity.

19. The network entity of claim 9, wherein the one or more processors are further capable of operating individually or jointly to execute the code to cause the network entity to: The UE receives a third control signaling indicating a second shift time offset indication associated with the downlink channel of the UE, wherein the second shift time offset indication is different from the first shift time offset indication; and The fourth control signaling is sent to the UE at least in part based on the transmission of the third control signaling, the fourth control signaling indicating a second projection matrix associated with the channel estimation of the uplink channel of the network entity.

20. A method for wireless communication by a user equipment (UE), the method comprising: Send a first control signaling message to a network entity, the first control signaling message including a first shift time offset indication associated with a downlink channel of a cell associated with the network entity; At least in part, the network entity receives second control signaling indicating a projection matrix associated with the downlink channel based on the transmission of the first control signaling; Data signaling is received from the network entity on the downlink channel based at least in part on the receipt of the second control signaling; as well as The data signaling is demodulated based on a channel estimate associated with the downlink channel, which is at least partially based on the projection matrix.

21. The method of claim 20, wherein receiving the data signaling further comprises: Receive reference signals from the network entity; as well as The channel estimate is determined at least in part based on the projection matrix and the reference signal.

22. The method of claim 21, wherein determining the channel estimate further comprises: Descramble the reference signal; as well as The channel estimate is determined at least in part based on the projection matrix and the descrambled reference signal.

23. The method of claim 20, wherein the projection matrix is ​​based at least in part on time-domain channel autocorrelation associated with the uplink channel of the cell, noise covariance associated with the uplink channel, fast Fourier transform matrix at least in part based on the first shift time offset indication, or a combination thereof.

24. The method according to claim 20, further comprising: A third control signaling is sent to the network entity indicating a channel power delay distribution associated with the UE, wherein the projection matrix is ​​at least partially based on the channel power delay distribution.

25. The method according to claim 20, further comprising: A third control signaling is sent to the network entity indicating a channel state information report associated with the downlink channel, wherein the projection matrix is ​​at least partially based on the channel state information report.

26. A method for wireless communication by a network entity, the method comprising: Receive a first control signaling from the user equipment (UE), the first control signaling indicating a first shift time offset indication associated with a downlink channel of a cell associated with the network entity; Send a second control signaling to the UE indicating a projection matrix associated with the downlink channel, wherein the projection matrix is ​​determined at least in part based on the first shift time offset indication; as well as Data signaling is sent to the UE on the downlink channel, at least in part, based on the transmission of the second control signaling.

27. The method of claim 26, wherein sending the second control signaling further comprises: Determine a channel estimate associated with the uplink channel of the cell, wherein the projection matrix is ​​determined at least in part based on the channel estimate.

28. The method according to claim 26, further comprising: The reference signal is sent to the UE based at least in part on the transmission of the projection matrix.

29. The method according to claim 26, further comprising: In response to receiving the first control signaling, the projection matrix is ​​determined at least in part based on the time-domain channel autocorrelation associated with the uplink channel of the cell, the noise covariance associated with the uplink channel, the fast Fourier transform matrix indicated by the first shift time offset, or a combination thereof.

30. The method of claim 26, wherein determining the projection matrix further comprises: Receive from the UE a third control signaling indicating the channel power delay distribution associated with the UE; as well as The projection matrix is ​​determined at least in part based on the channel power delay distribution associated with the UE.

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