WO2021030930A1

WO2021030930A1 - Downlink precoding configuration for user equipment mobility scenarios

Info

Publication number: WO2021030930A1
Application number: PCT/CN2019/100929
Authority: WO
Inventors: June Namgoong; Pavan Kumar Vitthaladevuni; Joseph Binamira Soriaga; Bo Chen; Alexandros MANOLAKOS; Yu Zhang
Original assignee: Qualcomm Incorporated
Priority date: 2019-08-16
Filing date: 2019-08-16
Publication date: 2021-02-25

Abstract

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a base station (BS) may configure at least one reference signal resource set containing at least one reference signal resource for transmitting a plurality of reference signals across a plurality of time instances. The BS may receive based at least in part on configuring the reference signal resource set, at least one of the plurality of reference signals. The BS may determine channel information based at least in part on the at least one reference signal and a lag time between receiving the at least one reference signal and a downlink channel transmission. The BS may predict a downlink channel using the channel information. Numerous other aspects are provided.

Description

DOWNLINK PRECODING CONFIGURATION FOR USER EQUIPMENT MOBILITY SCENARIOS

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wireless communication and to techniques and apparatuses for downlink precoding configuration for user equipment mobility scenarios.

BACKGROUND

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, and/or the like) . Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, orthogonal frequency-division multiple access (OFDMA) systems, single-carrier frequency-division multiple access (SC-FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and Long Term Evolution (LTE) . LTE/LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP) .

A wireless communication network may include a number of base stations (BSs) that can support communication for a number of user equipment (UEs) . A user equipment (UE) may communicate with a base station (BS) via the downlink and uplink. The downlink (or forward link) refers to the communication link from the BS to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the BS. As will be described in more detail herein, a BS may be referred to as a Node B, a gNB, an access point (AP) , a radio head, a transmit receive point (TRP) , a New Radio (NR) BS, a 5G Node B, and/or the like.

The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different user equipment to communicate on a municipal, national, regional, and even global level. New Radio (NR) , which may also be referred to as 5G, is a set of enhancements to the LTE mobile standard promulgated by the Third Generation Partnership Project (3GPP) . NR is designed to better support mobile broadband Internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) (CP-OFDM) on the downlink (DL) , using CP-OFDM and/or SC-FDM (e.g., also known as discrete Fourier transform spread OFDM (DFT-s-OFDM) ) on the uplink (UL) , as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation. However, as the demand for mobile broadband access continues to increase, there exists a need for further improvements in LTE and NR technologies. Preferably, these improvements should be applicable to other multiple access technologies and the telecommunication standards that employ these technologies.

SUMMARY

In some aspects, a method of wireless communication, performed by a base station (BS) , may include configuring at least one reference signal resource set containing at least one reference signal resource for transmitting a plurality of reference signals across a plurality of time instances; receiving, based at least in part on configuring the reference signal resource set, at least one of the plurality of reference signals; determining channel information based at least in part on the at least one reference signal and a lag time between receiving the at least one reference signal and a downlink channel transmission; and predicting a downlink channel using the channel information.

In some aspects, a method of wireless communication, performed by a user equipment (UE) , may include receiving first configuration information configuring at least one reference signal resource set containing at least one reference signal resource which includes at least one reference signal; receiving the at least one reference signal for channel information determination from a base station (BS) ; receiving second configuration information identifying a lag time between at least one of the reference signal and a target slot; determining channel information for the target slot based at least in part on the reference signal and a lag time; and reporting the channel information to the BS before the target slot.

In some aspects, a BS for wireless communication may include memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to configure at least one reference signal resource set containing at least one reference signal resource for transmitting a plurality of reference signals across a plurality of time instances; receive, based at least in part on configuring the reference signal resource set, at least one of the plurality of reference signals; determine channel information based at least in part on the at least one reference signal and a lag time between receiving the at least one reference signal and a downlink channel transmission; and predict a downlink channel using the channel information.

In some aspects, a UE for wireless communication may include memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to receive first configuration information configuring at least one reference signal resource set containing at least one reference signal resource which includes at least one reference signal; receive the at least one reference signal for channel information determination from a base station (BS) ; receive second configuration information identifying a lag time between at least one of the reference signal and a target slot; determine channel information for the target slot based at least in part on the reference signal and a lag time; and report the channel information to the BS before the target slot.

In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a UE, may cause the one or more processors to: configure at least one reference signal resource set containing at least one reference signal resource for transmitting a plurality of reference signals across a plurality of time instances; receive, based at least in part on configuring the reference signal resource set, at least one of the plurality of reference signals; determine channel information based at least in part on the at least one reference signal and a lag time between receiving the at least one reference signal and a downlink channel transmission; and predict a downlink channel using the channel information.

In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a UE, may cause the one or more processors to: receive first configuration information configuring at least one reference signal resource set containing at least one reference signal resource which includes at least one reference signal; receive the at least one reference signal for channel information determination from a base station (BS) ; receive second configuration information identifying a lag time between at least one of the reference signal and a target slot; determine channel information for the target slot based at least in part on the reference signal and a lag time; and report the channel information to the BS before the target slot.

In some aspects, an apparatus for wireless communication may include means for configuring at least one reference signal resource set containing at least one reference signal resource for transmitting a plurality of reference signals across a plurality of time instances; means for receiving, based at least in part on configuring the reference signal resource set, at least one of the plurality of reference signals; means for determining channel information based at least in part on the at least one reference signal and a lag time between receiving the at least one reference signal and a downlink channel transmission; and means for predicting a downlink channel using the channel information.

In some aspects, an apparatus for wireless communication may include means for receiving first configuration information configuring at least one reference signal resource set containing at least one reference signal resource which includes at least one reference signal; means for receiving the at least one reference signal for channel information determination from a base station (BS) ; means for receiving second configuration information identifying a lag time between at least one of the reference signal and a target slot; means for determining channel information for the target slot based at least in part on the reference signal and a lag time; and means for reporting the channel information to the BS before the target slot.

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

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

BRIEF DESCRIPTION OF THE DRAWINGS

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

Fig. 1 is a block diagram conceptually illustrating an example of a wireless communication network, in accordance with various aspects of the present disclosure.

Fig. 2 is a block diagram conceptually illustrating an example of a base station in communication with a UE in a wireless communication network, in accordance with various aspects of the present disclosure.

Fig. 3A is a block diagram conceptually illustrating an example of a frame structure in a wireless communication network, in accordance with various aspects of the present disclosure.

Fig. 3B is a block diagram conceptually illustrating an example synchronization communication hierarchy in a wireless communication network, in accordance with various aspects of the present disclosure.

Fig. 4 is a block diagram conceptually illustrating an example slot format with a normal cyclic prefix, in accordance with various aspects of the present disclosure.

Fig. 5 illustrates an example logical architecture of a distributed radio access network (RAN) , in accordance with various aspects of the present disclosure.

Fig. 6 illustrates an example physical architecture of a distributed RAN, in accordance with various aspects of the present disclosure.

Figs. 7 and 8 are diagrams illustrating examples of downlink precoding configuration for user equipment mobility scenarios, in accordance with various aspects of the present disclosure.

Fig. 9 is a diagram illustrating an example process performed, for example, by a base station, in accordance with various aspects of the present disclosure.

Fig. 10 is a diagram illustrating an example process performed, for example, by a user equipment, in accordance with various aspects of the present disclosure.

DETAILED DESCRIPTION

Various aspects of the disclosure are described more fully hereinafter with reference to the accompanying drawings. This disclosure may, however, be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Based at least in part on the teachings herein one skilled in the art should appreciate that the scope of the disclosure is intended to cover any aspect of the disclosure disclosed herein, whether implemented independently of or combined with any other aspect of the disclosure. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method which is practiced using other structure, functionality, or structure and functionality in addition to or other than the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim.

Several aspects of telecommunication systems will now be presented with reference to various apparatuses and techniques. These apparatuses and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, and/or the like (collectively referred to as “elements” ) . These elements may be implemented using hardware, software, or combinations thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

It should be noted that while aspects may be described herein using terminology commonly associated with 3G and/or 4G wireless technologies, aspects of the present disclosure can be applied in other generation-based communication systems, such as 5G and later, including NR technologies.

Fig. 1 is a diagram illustrating a wireless network 100 in which aspects of the present disclosure may be practiced. The wireless network 100 may be an LTE network or some other wireless network, such as a 5G or NR network. The wireless network 100 may include a number of BSs 110 (shown as BS 110a, BS 110b, BS 110c, and BS 110d) and other network entities. A BS is an entity that communicates with user equipment (UEs) and may also be referred to as a base station, a NR BS, a Node B, a gNB, a 5G node B (NB) , an access point, a transmit receive point (TRP) , and/or the like. Each BS may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to a coverage area of a BS and/or a BS subsystem serving this coverage area, depending on the context in which the term is used.

A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or another type of cell. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs having association with the femto cell (e.g., UEs in a closed subscriber group (CSG) ) . A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In the example shown in Fig. 1, a BS 110a may be a macro BS for a macro cell 102a, a BS 110b may be a pico BS for a pico cell 102b, and a BS 110c may be a femto BS for a femto cell 102c. A BS may support one or multiple (e.g., three) cells. The terms “eNB” , “base station” , “NR BS” , “gNB” , “TRP” , “AP” , “node B” , “5G NB” , and “cell” may be used interchangeably herein.

In some aspects, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a mobile BS. In some aspects, the BSs may be interconnected to one another and/or to one or more other BSs or network nodes (not shown) in the wireless network 100 through various types of backhaul interfaces such as a direct physical connection, a virtual network, and/or the like using any suitable transport network.

Wireless network 100 may also include relay stations. A relay station is an entity that can receive a transmission of data from an upstream station (e.g., a BS or a UE) and send a transmission of the data to a downstream station (e.g., a UE or a BS) . A relay station may also be a UE that can relay transmissions for other UEs. In the example shown in Fig. 1, a relay station 110d may communicate with macro BS 110a and a UE 120d in order to facilitate communication between BS 110a and UE 120d. A relay station may also be referred to as a relay BS, a relay base station, a relay, and/or the like.

Wireless network 100 may be a heterogeneous network that includes BSs of different types, e.g., macro BSs, pico BSs, femto BSs, relay BSs, and/or the like. These different types of BSs may have different transmit power levels, different coverage areas, and different impacts on interference in wireless network 100. For example, macro BSs may have a high transmit power level (e.g., 5 to 40 Watts) whereas pico BSs, femto BSs, and relay BSs may have lower transmit power levels (e.g., 0.1 to 2 Watts) .

A network controller 130 may couple to a set of BSs and may provide coordination and control for these BSs. Network controller 130 may communicate with the BSs via a backhaul. The BSs may also communicate with one another, e.g., directly or indirectly via a wireless or wireline backhaul.

UEs 120 (e.g., 120a, 120b, 120c, 120d, 120e) may be dispersed throughout wireless network 100, and each UE may be stationary or mobile. A UE may also be referred to as an access terminal, a terminal, a mobile station, a subscriber unit, a station, and/or the like. A UE may be a cellular phone (e.g., a smart phone) , a personal digital assistant (PDA) , a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or equipment, biometric sensors/devices, wearable devices (smart watches, smart clothing, smart glasses, smart wrist bands, smart jewelry (e.g., smart ring, smart bracelet) ) , an entertainment device (e.g., a music or video device, or a satellite radio) , a vehicular component or sensor, smart meters/sensors, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium.

Some UEs may be considered machine-type communication (MTC) or evolved or enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, and/or the like, that may communicate with a base station, another device (e.g., remote device) , or some other entity. A wireless node may provide, for example, connectivity for or to a network (e.g., a wide area network such as Internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered Internet-of-Things (IoT) devices, and/or may be implemented as NB-IoT (narrowband internet of things) devices. Some UEs may be considered a Customer Premises Equipment (CPE) . UE 120 may be included inside a housing that houses components of UE 120, such as processor components, memory components, and/or the like.

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

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

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

Fig. 2 shows a block diagram of a design 200 of base station 110 and UE 120, which may be one of the base stations and one of the UEs in Fig. 1. Base station 110 may be equipped with T antennas 234a through 234t, and UE 120 may be equipped with R antennas 252a through 252r, where in general T ≥ 1 and R ≥ 1.

At base station 110, a transmit processor 220 may receive data from a data source 212 for one or more UEs, select one or more modulation and coding schemes (MCS) for each UE based at least in part on channel quality indicators (CQIs) received from the UE, process (e.g., encode and modulate) the data for each UE based at least in part on the MCS (s) selected for the UE, and provide data symbols for all UEs. Transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI) and/or the like) and control information (e.g., CQI requests, grants, upper layer signaling, and/or the like) and provide overhead symbols and control symbols. Transmit processor 220 may also generate reference symbols for reference signals (e.g., the cell-specific reference signal (CRS) ) and synchronization signals (e.g., the primary synchronization signal (PSS) and secondary synchronization signal (SSS) ) . A transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, the overhead symbols, and/or the reference symbols, if applicable, and may provide T output symbol streams to T modulators (MODs) 232a through 232t. Each modulator 232 may process a respective output symbol stream (e.g., for OFDM and/or the like) to obtain an output sample stream. Each modulator 232 may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. T downlink signals from modulators 232a through 232t may be transmitted via T antennas 234a through 234t, respectively. According to various aspects described in more detail below, the synchronization signals can be generated with location encoding to convey additional information.

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

On the uplink, at UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information (e.g., for reports comprising RSRP, RSSI, RSRQ, CQI, and/or the like) from controller/processor 280. Transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from transmit processor 264 may be precoded by a TX MIMO processor 266 if applicable, further processed by modulators 254a through 254r (e.g., for DFT-s-OFDM, CP-OFDM, and/or the like) , and transmitted to base station 110. At base station 110, the uplink signals from UE 120 and other UEs may be received by antennas 234, processed by demodulators 232, detected by a MIMO detector 236 if applicable, and further processed by a receive processor 238 to obtain decoded data and control information sent by UE 120. Receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to controller/processor 240. Base station 110 may include communication unit 244 and communicate to network controller 130 via communication unit 244. Network controller 130 may include communication unit 294, controller/processor 290, and memory 292.

Controller/processor 240 of base station 110, controller/processor 280 of UE 120, and/or any other component (s) of Fig. 2 may perform one or more techniques associated with downlink precoding configuration for user equipment mobility scenarios, as described in more detail elsewhere herein. For example, controller/processor 240 of base station 110, controller/processor 280 of UE 120, and/or any other component (s) of Fig. 2 may perform or direct operations of, for example, process 900 of Fig. 9, process 1000 of Fig. 10, and/or other processes as described herein.

Memories

242 and 282 may store data and program codes for base station 110 and UE 120, respectively. In some aspects, memory 242 and/or memory 282 may comprise a non-transitory computer-readable medium storing one or more instructions for wireless communication. For example, the one or more instructions, when executed by one or more processors of the base station 110 and/or the UE 120, may perform or direct operations of, for example, process 900 of Fig. 9, process 1000 of Fig. 10, and/or other processes as described herein. A scheduler 246 may schedule UEs for data transmission on the downlink and/or uplink.

In some aspects, UE 120 may include means for receiving, when operating in a mobility scenario, a reference signal for channel information determination from a BS, means for determining channel information based at least in part on the reference signal and a lag time between receiving the reference signal and a downlink channel transmission, means for reporting the channel information to the BS to enable a downlink channel prediction, and/or the like. In some aspects, such means may include one or more components of UE 120 described in connection with Fig. 2, such as controller/processor 280, transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252, DEMOD 254, MIMO detector 256, receive processor 258, and/or the like.

In some aspects, base station 110 may include means for configuring, for a UE operating in a mobility scenario, a reference signal resource for transmitting a reference signal, means for receiving, based at least in part on configuring the reference signal resource, the reference signal, means for determining channel information based at least in part on the reference signal and a lag time between receiving the reference signal and a downlink channel transmission, means for predicting a downlink channel using the channel information, and/or the like. In some aspects, such means may include one or more components of base station 110 described in connection with Fig. 2, such as antenna 234, DEMOD 232, MIMO detector 236, receive processor 238, controller/processor 240, transmit processor 220, TX MIMO processor 230, MOD 232, antenna 234, and/or the like.

As indicated above, Fig. 2 is provided as an example. Other examples may differ from what is described with regard to Fig. 2.

Fig. 3A shows an example frame structure 300 for frequency division duplexing (FDD) in a telecommunications system (e.g., NR) . The transmission timeline for each of the downlink and uplink may be partitioned into units of radio frames (sometimes referred to as frames) . Each radio frame may have a predetermined duration (e.g., 10 milliseconds (ms) ) and may be partitioned into a set of Z (Z ≥ 1) subframes (e.g., with indices of 0 through Z-1) . Each subframe may have a predetermined duration (e.g., 1 ms) and may include a set of slots (e.g., 2 ^m slots per subframe are shown in Fig. 3A, where m is a numerology used for a transmission, such as 0, 1, 2, 3, 4, and/or the like) . Each slot may include a set of L symbol periods. For example, each slot may include fourteen symbol periods (e.g., as shown in Fig. 3A) , seven symbol periods, or another number of symbol periods. In a case where the subframe includes two slots (e.g., when m = 1) , the subframe may include 2L symbol periods, where the 2L symbol periods in each subframe may be assigned indices of 0 through 2L–1. In some aspects, a scheduling unit for the FDD may be frame-based, subframe-based, slot-based, symbol-based, and/or the like.

While some techniques are described herein in connection with frames, subframes, slots, and/or the like, these techniques may equally apply to other types of wireless communication structures, which may be referred to using terms other than “frame, ” “subframe, ” “slot, ” and/or the like in 5G NR. In some aspects, a wireless communication structure may refer to a periodic time-bounded communication unit defined by a wireless communication standard and/or protocol. Additionally, or alternatively, different configurations of wireless communication structures than those shown in Fig. 3A may be used.

In certain telecommunications (e.g., NR) , a base station may transmit synchronization signals. For example, a base station may transmit a primary synchronization signal (PSS) , a secondary synchronization signal (SSS) , and/or the like, on the downlink for each cell supported by the base station. The PSS and SSS may be used by UEs for cell search and acquisition. For example, the PSS may be used by UEs to determine symbol timing, and the SSS may be used by UEs to determine a physical cell identifier, associated with the base station, and frame timing. The base station may also transmit a physical broadcast channel (PBCH) . The PBCH may carry some system information, such as system information that supports initial access by UEs.

In some aspects, the base station may transmit the PSS, the SSS, and/or the PBCH in accordance with a synchronization communication hierarchy (e.g., a synchronization signal (SS) hierarchy) including multiple synchronization communications (e.g., SS blocks) , as described below in connection with Fig. 3B.

Fig. 3B is a block diagram conceptually illustrating an example SS hierarchy, which is an example of a synchronization communication hierarchy. As shown in Fig. 3B, the SS hierarchy may include an SS burst set, which may include a plurality of SS bursts (identified as SS burst 0 through SS burst B-1, where B is a maximum number of repetitions of the SS burst that may be transmitted by the base station) . As further shown, each SS burst may include one or more SS blocks (identified as SS block 0 through SS block (b _{max_SS}-1) , where b _{max_SS}-1 is a maximum number of SS blocks that can be carried by an SS burst) . In some aspects, different SS blocks may be beam-formed differently. An SS burst set may be periodically transmitted by a wireless node, such as every X milliseconds, as shown in Fig. 3B. In some aspects, an SS burst set may have a fixed or dynamic length, shown as Y milliseconds in Fig. 3B.

The SS burst set shown in Fig. 3B is an example of a synchronization communication set, and other synchronization communication sets may be used in connection with the techniques described herein. Furthermore, the SS block shown in Fig. 3B is an example of a synchronization communication, and other synchronization communications may be used in connection with the techniques described herein.

In some aspects, an SS block includes resources that carry the PSS, the SSS, the PBCH, and/or other synchronization signals (e.g., a tertiary synchronization signal (TSS) ) and/or synchronization channels. In some aspects, multiple SS blocks are included in an SS burst, and the PSS, the SSS, and/or the PBCH may be the same across each SS block of the SS burst. In some aspects, a single SS block may be included in an SS burst. In some aspects, the SS block may be at least four symbol periods in length, where each symbol carries one or more of the PSS (e.g., occupying one symbol) , the SSS (e.g., occupying one symbol) , and/or the PBCH (e.g., occupying two symbols) .

In some aspects, the symbols of an SS block are consecutive, as shown in Fig. 3B. In some aspects, the symbols of an SS block are non-consecutive. Similarly, in some aspects, one or more SS blocks of the SS burst may be transmitted in consecutive radio resources (e.g., consecutive symbol periods) during one or more slots. Additionally, or alternatively, one or more SS blocks of the SS burst may be transmitted in non-consecutive radio resources.

In some aspects, the SS bursts may have a burst period, whereby the SS blocks of the SS burst are transmitted by the base station according to the burst period. In other words, the SS blocks may be repeated during each SS burst. In some aspects, the SS burst set may have a burst set periodicity, whereby the SS bursts of the SS burst set are transmitted by the base station according to the fixed burst set periodicity. In other words, the SS bursts may be repeated during each SS burst set.

The base station may transmit system information, such as system information blocks (SIBs) on a physical downlink shared channel (PDSCH) in certain slots. The base station may transmit control information/data on a physical downlink control channel (PDCCH) in C symbol periods of a slot, where B may be configurable for each slot. The base station may transmit traffic data and/or other data on the PDSCH in the remaining symbol periods of each slot.

As indicated above, Figs. 3A and 3B are provided as examples. Other examples may differ from what is described with regard to Figs. 3A and 3B.

Fig. 4 shows an example slot format 410 with a normal cyclic prefix. The available time frequency resources may be partitioned into resource blocks. Each resource block may cover a set of subcarriers (e.g., 12 subcarriers) in one slot and may include a number of resource elements. Each resource element may cover one subcarrier in one symbol period (e.g., in time) and may be used to send one modulation symbol, which may be a real or complex value.

An interlace structure may be used for each of the downlink and uplink for FDD in certain telecommunications systems (e.g., NR) . For example, Q interlaces with indices of 0 through Q –1 may be defined, where Q may be equal to 4, 6, 8, 10, or some other value. Each interlace may include slots that are spaced apart by Q frames. In particular, interlace q may include slots q, q + Q, q + 2Q, etc., where q ∈ {0, …, Q –1} .

A UE may be located within the coverage of multiple BSs. One of these BSs may be selected to serve the UE. The serving BS may be selected based at least in part on various criteria such as received signal strength, received signal quality, path loss, and/or the like. Received signal quality may be quantified by a signal-to-noise-and-interference ratio (SNIR) , or a reference signal received quality (RSRQ) , or some other metric. The UE may operate in a dominant interference scenario in which the UE may observe high interference from one or more interfering BSs.

While aspects of the examples described herein may be associated with NR or 5G technologies, aspects of the present disclosure may be applicable with other wireless communication systems. New Radio (NR) may refer to radios configured to operate according to a new air interface (e.g., other than Orthogonal Frequency Divisional Multiple Access (OFDMA) -based air interfaces) or fixed transport layer (e.g., other than Internet Protocol (IP) ) . In aspects, NR may utilize OFDM with a CP (herein referred to as cyclic prefix OFDM or CP-OFDM) and/or SC-FDM on the uplink, may utilize CP-OFDM on the downlink and include support for half-duplex operation using time division duplexing (TDD) . In aspects, NR may, for example, utilize OFDM with a CP (herein referred to as CP-OFDM) and/or discrete Fourier transform spread orthogonal frequency-division multiplexing (DFT-s-OFDM) on the uplink, may utilize CP-OFDM on the downlink and include support for half-duplex operation using TDD. NR may include Enhanced Mobile Broadband (eMBB) service targeting wide bandwidth (e.g., 80 megahertz (MHz) and beyond) , millimeter wave (mmW) targeting high carrier frequency (e.g., 60 gigahertz (GHz) ) , massive MTC (mMTC) targeting non-backward compatible MTC techniques, and/or mission critical targeting ultra reliable low latency communications (URLLC) service.

In some aspects, a single component carrier bandwidth of 100 MHz may be supported. NR resource blocks may span 12 sub-carriers with a sub-carrier bandwidth of 60 or 120 kilohertz (kHz) over a 0.1 millisecond (ms) duration. Each radio frame may include 40 slots and may have a length of 10 ms. Consequently, each slot may have a length of 0.25 ms. Each slot may indicate a link direction (e.g., DL or UL) for data transmission and the link direction for each slot may be dynamically switched. Each slot may include DL/UL data as well as DL/UL control data.

Beamforming may be supported and beam direction may be dynamically configured. MIMO transmissions with precoding may also be supported. MIMO configurations in the DL may support up to 8 transmit antennas with multi-layer DL transmissions up to 8 streams and up to 2 streams per UE. Multi-layer transmissions with up to 2 streams per UE may be supported. Aggregation of multiple cells may be supported with up to 8 serving cells. Alternatively, NR may support a different air interface, other than an OFDM-based interface. NR networks may include entities such as central units or distributed units.

As indicated above, Fig. 4 is provided as an example. Other examples may differ from what is described with regard to Fig. 4.

Fig. 5 illustrates an example logical architecture of a distributed RAN 500, according to aspects of the present disclosure. A 5G access node 506 may include an access node controller (ANC) 502. The ANC may be a central unit (CU) of the distributed RAN 500. The backhaul interface to the next generation core network (NG-CN) 504 may terminate at the ANC. The backhaul interface to neighboring next generation access nodes (NG-ANs) may terminate at the ANC. The ANC may include one or more TRPs 508 (which may also be referred to as BSs, NR BSs, Node Bs, 5G NBs, APs, gNB, or some other term) . As described above, “TRP” may be used interchangeably with “cell. ”

The TRPs 508 may be a distributed unit (DU) . The TRPs may be connected to one ANC (ANC 502) or more than one ANC (not illustrated) . For example, for RAN sharing, radio as a service (RaaS) , and service specific AND deployments, the TRP may be connected to more than one ANC. A TRP may include one or more antenna ports. The TRPs may be configured to individually (e.g., dynamic selection) or jointly (e.g., joint transmission) serve traffic to a UE.

The local architecture of RAN 500 may be used to illustrate fronthaul communication. The architecture may be defined to support fronthauling solutions across different deployment types. For example, the architecture may be based at least in part on transmit network capabilities (e.g., bandwidth, latency, and/or jitter) .

The architecture may share features and/or components with LTE. According to aspects, the next generation AN (NG-AN) 510 may support dual connectivity with NR. The NG-AN may share a common fronthaul for LTE and NR.

The architecture may enable cooperation between and among TRPs 508. For example, cooperation may be preset within a TRP and/or across TRPs via the ANC 502. According to aspects, no inter-TRP interface may be needed/present.

According to aspects, a dynamic configuration of split logical functions may be present within the architecture of RAN 500. The packet data convergence protocol (PDCP) , radio link control (RLC) , or medium access control (MAC) protocol may be adaptably placed at the ANC or TRP.

According to various aspects, a BS may include a central unit (CU) (e.g., ANC 502) and/or one or more distributed units (e.g., one or more TRPs 508) .

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

Fig. 6 illustrates an example physical architecture of a distributed RAN 600, according to aspects of the present disclosure. A centralized core network unit (C-CU) 602 may host core network functions. The C-CU may be centrally deployed. C-CU functionality may be offloaded (e.g., to advanced wireless services (AWS) ) , in an effort to handle peak capacity.

A centralized RAN unit (C-RU) 604 may host one or more ANC functions. Optionally, the C-RU may host core network functions locally. The C-RU may have distributed deployment. The C-RU may be closer to the network edge.

A distributed unit (DU) 606 may host one or more TRPs. The DU may be located at edges of the network with radio frequency (RF) functionality.

As indicated above, Fig. 6 is provided as an example. Other examples may differ from what is described with regard to Fig. 6.

In some communications systems, a UE or a BS may use a reference signal to obtain parameters to determine a downlink beam. For example, a UE may transmit an uplink sounding reference signal (SRS) to enable a BS to determine a downlink beam. During mobility scenarios, such as when a UE is traveling in a fast moving vehicle , Doppler effect may reduce an accuracy of downlink beam. For example, in a case of a multiple-input single-output (MISO) channel, a beamforming gain loss may be determined as:

L= |J ₀ (2πf _dT) | ²

where L represents the beamforming gain loss, J ₀ represents a zeroth order Bessel function, f _d represents a Doppler spread (e.g., which may relate to a carrier frequency and a relative speed) , and T represents a time gap between a received reference signal and a transmitted physical downlink shared channel (PDSCH) . As a result, when a UE is traveling at high speeds, a delay between when a channel measurement upon which the downlink precoding is based is performed and when the downlink precoding is used results in the downlink precoding being outdated and the beamforming gain loss increasing.

As an example, in TDD based communications systems, based at least in part on a time gap between a BS performing a channel estimation procedure and a use of results of the channel estimation procedure, the Doppler effect may result in reduced beamforming accuracy. Similarly, in FDD based communications systems, based at least in part on a time gap between a BS transmission of a channel state information reference signal (CSI-RS) (e.g., which a UE may use to report a channel quality indication (CQI) ) and a subsequent physical downlink shared channel (PDSCH) , the Doppler effect may result in reduced beamforming accuracy. As the Doppler effect increases at increased speeds of the UE relative to the BS, beamforming accuracy decreases. A decrease in beamforming accuracy results in reduced network performance, increased likelihood of dropped communications, and/or the like.

Some aspects described herein enable improved downlink precoding for UE mobility scenarios. For example, the BS and the UE may implement a precoding scheme to reduce Doppler effect-based inaccuracies. In this case, the BS and/or UE may determine channel information and the BS may predict a downlink channel based at least in part on a reference signal and a lag time between receiving the reference signal and a corresponding downlink transmission. In this way, by accounting for the lag time, the BS and the UE enable improved beamforming, thereby improving network performance, reducing a likelihood of dropped communications, and/or the like.

Fig. 7 is a diagram illustrating an example 700 of downlink precoding configuration for user equipment mobility scenarios, in accordance with various aspects of the present disclosure. As shown in Fig. 7, example 700 includes a BS 110 and a UE 120.

As further shown in Fig. 7, and by reference number 710, BS 110 may configure UE 120 with SRS resources. For example, BS 110 may provide information identifying one or more resources for UE 120 to transmit a reference signal, such as a SRS to enable channel estimation, which are phase coherent across the SRS transmissions. In some aspects, BS 110 may configure a particular type of SRS. For example, BS 110 may configure a periodic SRS, a semi-persistent SRS, and/or the like. Additionally, or alternatively, BS 110 may configure an aperiodic SRS. For example, BS 110 may transmit information to configure the aperiodic SRS for a single slot, for a plurality of slots, and/or the like. In some aspects, BS 110 may configure a dedicated SRS. For example, BS 110 may configure an SRS for Doppler-effect mitigation. Additionally, or alternatively, BS 110 may configure an SRS for Doppler-effect mitigation and other uses, such as for timing alignment, timing estimation, channel quality determination, and/or the like. In this case, UE 120 may use the same spatial domain transmission filter for an SRS for Doppler-effect mitigation and for a reference SRS transmission.

As further shown in Fig. 7, and by reference number 720, UE 120 may transmit an SRS. For example, UE 120 may transmit the SRS to BS 110 to enable BS 110 to determine a downlink channel. In some aspects, UE 120 may transmit a plurality of SRSs associated with a plurality of PDSCH transmissions. In some aspects, UE 120 may transmit one or more SRSs using a plurality of antennas. For example, UE 120 and BS 110 may include antenna arrays for transmission and reception. In this case, antennas may be paired such that, for example, a transmit antenna of UE 120 is paired with a receive antenna of BS 110 or a transmit antenna of BS 110 is paired with a receive antenna of UE 120. An antenna pair may be associated with a path of the channel impulse response for which a channel tap estimate may be determined, as described below.

As further shown in Fig. 7, and by reference number 730, BS 110 may determine channel information based at least in part on the SRS and may predict a downlink channel using the channel information. For example, BS 110 may determine a time-domain correlation for each path of the channel impulse response associated with each antenna pair for which BS 110 is to transmit a PDSCH and UE 120 is to receive the PDSCH. In some aspects, BS 110 may determine a channel tap estimate. For example, BS 110 may estimate a tap (or a path) of a delay-time domain channel impulse response for a transmit-receive (TX-RX) antenna element pair (i, j) (e.g., a channel tap) :

where i is an antenna index of an antenna of BS 110, j is an antenna index of an antenna of UE 120 paired with the antenna of BS 110, l represents a delay index, and n represents a time index. The estimate of the channel tap

obtained from the SRS is denoted by

The term “TX-RX antenna element pair” will be used interchangeably with the terms “antenna pair” , “antenna element pair” and “TX-RX antenna pair” .

In some aspects, BS 110 may weight the channel tap estimate

by a time-domain correlation:

where E [·] represents an ensemble average, and T represents a lag between receiving the SRS from UE 120 and transmitting a PDSCH. In this case, BS 110 may obtain a prediction of the channel tap at a time T as:

Predicted value of

To perform the prediction, in some aspects, BS 110 may track a time-domain correlation for each channel tap of each transmit-receive (TX-RX) antenna pair (e.g.,

Additionally, or alternatively, BS 110 may track a phase component of a time-domain correlation for each path, which may be averaged over TX-RX antenna pairs. In this way, BS 110 may estimate a center of mass of a Doppler spectrum for each path. For example, BS 110 may determine for each path:

and compute a phase:

Θ _l=phase [r _l] .

In this case, BS 110 may obtain a prediction of the channel tap at a time T as:

Predicted value of

where the weights r _l and

may be referred to as a Doppler correction.

In some aspects, BS 110 may predict a downlink channel. For example, based at least in part on determining a channel tap estimate of a delay-time domain channel impulse response for a TX-RX antenna pair, a time-domain correlation for each channel tap of each TX-RX antenna pair, and/or the like, BS 110 may predict a downlink channel. In this way, BS 110 enables transmission of a PDSCH to UE 120 with a reduced likelihood of a dropped communication.

As indicated above, Fig. 7 is provided as an example. Other examples may differ from what is described with respect to Fig. 7.

Fig. 8 is a diagram illustrating an example 800 of downlink precoding configuration for user equipment mobility scenarios, in accordance with various aspects of the present disclosure. As shown in Fig. 8, example 800 includes a BS 110 and a UE 120.

As further shown in Fig. 8, and by reference number 810, BS 110 may transmit a CSI-RS to UE 120. For example, BS 110 may provide the CSI-RS to UE 120 to enable channel estimation and channel information determination. In some aspects, BS 110 may provide a periodic CSI-RS, a semi-persistent CSI-RS, an aperiodic CSI-RS, and/or the like. For example, BS 110 may provide a periodic CSI-RS configured using a radio resource control (RRC) configuration message. Additionally, or alternatively, BS 110 may provide an aperiodic CSI-RS that persists over several slots. In this case, the aperiodic CSI-RS may be configured using a downlink control information (DCI) . Similarly, BS 110 may configure a semi-persistent CSI-RS on a physical uplink shared channel (PUSCH) using a DCI, a medium access control (MAC) control element (CE) , and/or the like. In some aspects, BS 110 may configure a plurality of CSI-RSs that are quasi-co-located with respect to a Doppler spread and/or a Doppler shift.

In some aspects, BS 110 may configure the CSI-RS with a particular periodicity for CSI-RS resources. For example, BS 110 may configure a plurality of CSI-RSs with the same periodicity of slots but with different slot offsets. In this way, BS 110 may enable UE 120 to measure a pair of CSI-RSs at different slot offsets. In some aspects, BS 110 may configure UE 120 to measure a plurality of pairs of CSI-RSs. For example, BS 110 may configure UE 120 to measure a first pair of CSI-RSs to determine a complex Doppler correction (which may be obtained similarly to r _l or

as described above) for a first offset value and a second pair of CSI-RSs to determine a complex Doppler correction for a second offset value.

As further shown in Fig. 8, and by

reference numbers

820 and 830, UE 120 may determine channel information and report the channel information to BS 110. For example, UE 120 may determine the channel information and provide the channel information to BS 110. In some aspects, UE 120, UE 120 may report a complex Doppler correction for one or more paths or channels. In some aspects, BS 110 may configure UE 120 to report the complex Doppler correction for a set of most significant paths. For example, BS 110 may cause UE 120 to report the complex Doppler correction for a threshold quantity of most significant paths.

Additionally, or alternatively, UE 120 may report the complex Doppler correction for one or more paths that are within a threshold signal strength of a strongest path (e.g., a path with a highest signal strength) . In this case, BS 110 may configure the threshold signal strength. In some aspects, UE 120 may provide the channel information in connection with a bundled CSI-RS. For example, UE 120 may provide the channel information using a tracking reference signal. In some aspects, UE 120 may provide information identifying a precoding matrix indicator (PMI) .

In some aspects, UE 120 may report the complex Doppler correction based at least in part on a particular timeline. For example, BS 110 may configure a timer for UE 120 for tracking a time period to report the complex Doppler correction. In this case, UE 120 may report the complex Doppler correction for one or more CSI-RSs occurring during the time period at a time specified based at least in part on the timer.

As further shown in Fig. 8, and by reference number 840, BS 110 may predict a downlink channel. For example, using channel information received from UE 120, BS 110 may predict the downlink channel in a manner similar to that described above with regard to Fig. 7. In some aspects, BS 110 may transmit a downlink channel based at least in part on predicting the downlink channel. For example, BS 110 may precode and transmit a PDSCH in accordance with a prediction of the downlink channel.

As indicated above, Fig. 8 is provided as an example. Other examples may differ from what is described with respect to Fig. 8.

Fig. 9 is a diagram illustrating an example process 900 performed, for example, by a BS, in accordance with various aspects of the present disclosure. Example process 900 is an example where a BS (e.g., BS 110 and/or the like) performs operations associated with downlink precoding configuration for user equipment mobility scenarios.

As shown in Fig. 9, in some aspects, process 900 may include configuring at least one reference signal resource set containing at least one reference signal resource for transmitting a plurality of reference signals across a plurality of time instances (block 910) . For example, the BS (e.g., using transmit processor 220, receive processor 238, controller/processor 240, memory 242, and/or the like) may configure at least one reference signal resource set containing at least one reference signal resource for transmitting a plurality of reference signals across a plurality of time instances, as described above.

As further shown in Fig. 9, in some aspects, process 900 may include receiving, based at least in part on configuring the reference signal resource set, at least one of the plurality of reference signals (block 920) . For example, the BS (e.g., using transmit processor 220, receive processor 238, controller/processor 240, memory 242, and/or the like) may receive, based at least in part on configuring the reference signal resource set, at least one of the plurality of reference signals, as described above.

As further shown in Fig. 9, in some aspects, process 900 may include determining channel information based at least in part on the at least one reference signal and a lag time between receiving the at least one reference signal and a downlink channel transmission (block 930) . For example, the BS (e.g., using transmit processor 220, receive processor 238, controller/processor 240, memory 242, and/or the like) may determine channel information based at least in part on the at least one reference signal and a lag time between receiving the at least one reference signal and a downlink channel transmission, as described above.

As further shown in Fig. 9, in some aspects, process 900 may include predicting a downlink channel using the channel information (block 940) . For example, the BS (e.g., using transmit processor 220, receive processor 238, controller/processor 240, memory 242, and/or the like) may predict a downlink channel using the channel information, as described above.

Process 900 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.

In a first aspect, predicting the downlink channel comprises: predicting the downlink channel based at least in part on a delay-time domain channel impulse response tap for an antenna element pair.

In a second aspect, alone or in combination with the first aspect, predicting the downlink channel includes weighting each channel tap estimate, of a plurality of channel tap estimates, based at least in part on a set of weighting factors determined based at least in part on the channel information.

In a third aspect, alone or in combination with one or more of the first and second aspects, process 900 includes tracking a time-domain correlation for a plurality of channels of an antenna element pair; and determining the channel information includes obtaining the channel information based at least in part on the time-domain correlation for the plurality of channels.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, process 900 includes tracking a phase component of a time-domain correlation for a plurality of paths averaged over an antenna element pair; and determining the channel information includes obtaining the channel information based at least in part on the phase component of the time-domain correlation for the plurality of paths.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, process 900 includes estimating a center of mass of a Doppler spectrum for each path of a plurality of paths of an antenna element pair; and determining the channel information includes determining the channel information based at least in part on the center of mass of the Doppler spectrum for each path.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the plurality of reference signals are sounding reference signals.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the plurality of reference signals includes at least one of a periodic reference signal, an aperiodic reference signal, or a semi-persistent reference signal.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the plurality of reference signals are phase coherent.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the plurality of reference signals are defined for one or more mobility scenarios.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the plurality of reference signals and one or more other types of reference signals are associated with a same spatial domain transmission filter.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, the channel information includes a Doppler correction.

Although Fig. 9 shows example blocks of process 900, in some aspects, process 900 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Fig. 9. Additionally, or alternatively, two or more of the blocks of process 900 may be performed in parallel.

Fig. 10 is a diagram illustrating an example process 1000 performed, for example, by a UE, in accordance with various aspects of the present disclosure. Example process 1000 is an example where a UE (e.g., UE 120 and/or the like) performs operations associated with downlink precoding configuration for user equipment mobility scenarios.

As shown in Fig. 10, in some aspects, process 1000 may include receiving first configuration information configuring at least one reference signal resource set containing at least one reference signal resource which includes at least one reference signal (block 1010) . For example, the UE (e.g., using receive processor 258, transmit processor 264, controller/processor 280, memory 282, and/or the like) may receive first configuration information configuring at least one reference signal resource set containing at least one reference signal resource which includes at least one reference signal, as described above.

As further shown in Fig. 10, in some aspects, process 1000 may include receiving the at least one reference signal for channel information determination from a base station (BS) (block 1020) . For example, the UE (e.g., using receive processor 258, transmit processor 264, controller/processor 280, memory 282, and/or the like) may receive the at least one reference signal for channel information determination from a base station (BS, as described above.

As further shown in Fig. 10, in some aspects, process 1000 may include receiving second configuration information identifying a lag time between at least one of the reference signal and a target slot (block 1030) . For example, the UE (e.g., using receive processor 258, transmit processor 264, controller/processor 280, memory 282, and/or the like) may receive second configuration information identifying a lag time between at least one of the reference signal and a target slot, as described above.

As further shown in Fig. 10, in some aspects, process 1000 may include determining channel information for the target slot based at least in part on the reference signal and a lag time (block 1040) . For example, the UE (e.g., using receive processor 258, transmit processor 264, controller/processor 280, memory 282, and/or the like) may determine channel information for the target slot based at least in part on the reference signal and a lag time, as described above.

As further shown in Fig. 10, in some aspects, process 1000 may include reporting the channel information to the BS before the target slot (block 1050) . For example, the UE (e.g., using receive processor 258, transmit processor 264, controller/processor 280, memory 282, and/or the like) may report the channel information to the BS before the target slot, as described above.

Process 1000 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.

In a first aspect, process 1000 includes receiving third configuration information configuring the reporting of the channel information.

In a second aspect, alone or in combination with the first aspect, the channel information includes a Doppler correction for a particular subset of paths of an antenna element pair or a particular path of the antenna element pair with a particular characteristic.

In a third aspect, alone or in combination with one or more of the first and second aspects, the channel information is determined based at least in part on a least one of: one or more channel state information reference signal (CSI-RS) transmissions that span a plurality of time domain symbols, one or more tracking reference signal transmission, or one or more CSI-RS reference signals associated with a CSI-RS resource set configured with a higher layer parameter, or a combination thereof.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, process 1000 includes receiving third configuration information configuring at least one channel state information reference signal in connection with a particular port; and determining the channel information comprises: determining the channel information based at least in part on the at least one channel state information reference signals using the particular port.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the at least one channel state information reference signals includes a periodic signal, a semi-persistent signal, or an aperiodic signal.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the at least one channel state information reference signal are persistent across a plurality of slots.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, process 1000 includes receiving third configuration information configuring channel state information reference signals that are quasi-co-located in connection with a Doppler spread or Doppler shift; and determining the channel information includes determining the channel information based at least in part on the channel state information reference signals.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, process 1000 includes receiving third configuration information configurating a plurality of channel state information reference signal resources; and determining the channel information includes determining the channel information based at least in part on the plurality of channel state information reference signal resources.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, determining the channel information includes determining the channel information based at least in part on a slot offset for the plurality of channel state information reference signal resources.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the plurality of channel state information reference signal resources is based at least in part on: a radio resource control (RRC) configuration message, a medium access control (MAC) control element (CE) activation message, or a downlink control information (DCI) triggering message, or a combination thereof.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, determining the channel information includes determining the channel information using at least one pair of channel state information reference signal (CSI-RS) resources of the plurality of channel state information reference signal resources.

In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, a pair of CSI-RS resources are associated with the same CSI-RS resource set, the same periodicity, and different slot offsets.

In a thirteenth aspect, alone or in combination with one or more of the first through twelfth aspects, the channel information includes a precoding matrix indicator.

In a fourteenth aspect, alone or in combination with one or more of the first through thirteenth aspects, reporting the channel information comprises: reporting the channel information for a prior set of channel state information reference signal resources in accordance with a time value.

Although Fig. 10 shows example blocks of process 1000, in some aspects, process 1000 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Fig. 10. Additionally, or alternatively, two or more of the blocks of process 1000 may be performed in parallel.

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

As used herein, the term “component” is intended to be broadly construed as hardware, firmware, and/or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, and/or a combination of hardware and software.

As used herein, satisfying a threshold may, depending on the context, refer to a value being greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, and/or the like.

It will be apparent that systems and/or methods described herein may be implemented in different forms of hardware, firmware, and/or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems and/or methods is not limiting of the aspects. Thus, the operation and behavior of the systems and/or methods were described herein without reference to specific software code-it being understood that software and hardware can be designed to implement the systems and/or methods based, at least in part, on the description herein.

Even though particular combinations of features are recited in the claims and/or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. In fact, many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification. Although each dependent claim listed below may directly depend on only one claim, the disclosure of various aspects includes each dependent claim in combination with every other claim in the claim set. A phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c) .

No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such. Also, as used herein, the articles “a” and “an” are intended to include one or more items, and may be used interchangeably with “one or more. ” Furthermore, as used herein, the terms “set” and “group” are intended to include one or more items (e.g., related items, unrelated items, a combination of related and unrelated items, and/or the like) , and may be used interchangeably with “one or more. ” Where only one item is intended, the phrase “only one” or similar language is used. Also, as used herein, the terms “has, ” “have, ” “having, ” and/or the like are intended to be open-ended terms. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise.

Claims

A method of wireless communication performed by a base station (BS) , comprising:

configuring at least one reference signal resource set containing at least one reference signal resource for transmitting a plurality of reference signals across a plurality of time instances;

receiving, based at least in part on configuring the reference signal resource set, at least one of the plurality of reference signals;

determining channel information based at least in part on the at least one reference signal and a lag time between receiving the at least one reference signal and a downlink channel transmission; and

predicting a downlink channel using the channel information.
The method of claim 1, wherein predicting the downlink channel comprises:

predicting the downlink channel based at least in part on a delay-time domain channel impulse response tap for an antenna element pair.
The method of claim 1, wherein predicting the downlink channel comprises:

weighting each channel tap estimate, of a plurality of channel tap estimates, based at least in part on a set of weighting factors determined based at least in part on the channel information.
The method of claim 1, further comprising:

tracking a time-domain correlation for a plurality of channels of an antenna element pair; and

wherein determining the channel information comprises:

obtaining the channel information based at least in part on the time-domain correlation for the plurality of channels.
The method of claim 1, further comprising:

tracking a phase component of a time-domain correlation for a plurality of paths averaged over an antenna element pair; and

wherein determining the channel information comprises:

obtaining the channel information based at least in part on the phase component of the time-domain correlation for the plurality of paths.
The method of claim 1, further comprising:

estimating a center of mass of a Doppler spectrum for each path of a plurality of paths of an antenna element pair; and

wherein determining the channel information comprises:

determining the channel information based at least in part on the center of mass of the Doppler spectrum for each path.
The method of claim 1, wherein the plurality of reference signals are sounding reference signals.
The method of claim 1, wherein the plurality of reference signals includes at least one of a periodic reference signal, an aperiodic reference signal, or a semi-persistent reference signal.
The method of claim 1, wherein the plurality of reference signals are phase coherent.
The method of claim 1, wherein the plurality of reference signals are defined for one or more mobility scenarios.
The method of claim 1, wherein the plurality of reference signals and one or more other types of reference signals are associated with a same spatial domain transmission filter.
The method of claim 1, wherein the channel information includes a Doppler correction.
A method of wireless communication performed by a user equipment (UE) , comprising:

receiving first configuration information configuring at least one reference signal resource set containing at least one reference signal resource which includes at least one reference signal;

receiving the at least one reference signal for channel information determination from a base station (BS) ;

receiving second configuration information identifying a lag time between at least one of the reference signal and a target slot;

determining channel information for the target slot based at least in part on the reference signal and a lag time; and

reporting the channel information to the BS before the target slot.
The method of claim 13, further comprising:

receiving third configuration information configuring the reporting of the channel information.
The method of claim 13, wherein the channel information includes a Doppler correction for a particular subset of paths of an antenna element pair or a particular path of the antenna element pair with a particular characteristic.
The method of claim 13, wherein the channel information is determined based at least in part on a least one of:

one or more channel state information reference signal (CSI-RS) transmissions that span a plurality of time domain symbols,

one or more tracking reference signal transmission, or

one or more CSI-RS reference signals associated with a CSI-RS resource set configured with a higher layer parameter, or

a combination thereof.
The method of claim 13, further comprising:

receiving third configuration information configuring at least one channel state information reference signal in connection with a particular port; and

wherein determining the channel information comprises:

determining the channel information based at least in part on the at least one channel state information reference signals using the particular port.
The method of claim 17, wherein the at least one channel state information reference signals includes a periodic signal, a semi-persistent signal, or an aperiodic signal.
The method of claim 17, wherein the at least one channel state information reference signal are persistent across a plurality of slots.
The method of claim 13, further comprising:

receiving third configuration information configuring channel state information reference signals that are quasi-co-located in connection with a Doppler spread or Doppler shift; and

wherein determining the channel information comprises:

determining the channel information based at least in part on the channel state information reference signals.
The method of claim 13, further comprising:

receiving third configuration information configurating a plurality of channel state information reference signal resources; and

wherein determining the channel information comprises:

determining the channel information based at least in part on the plurality

of channel state information reference signal resources.
The method of claim 21, wherein determining the channel information comprises:

determining the channel information based at least in part on a slot offset for the plurality of channel state information reference signal resources.
The method of claim 21, wherein the plurality of channel state information reference signal resources is based at least in part on:

a radio resource control configuration message,

a medium access control control element activation message, or

a downlink control information triggering message, or

a combination thereof.
The method of claim 21, wherein determining the channel information comprises:

determining the channel information using at least one pair of channel state information reference signal (CSI-RS) resources of the plurality of channel state information reference signal resources.
The method of claim 24, wherein a pair of CSI-RS resources are associated with the same CSI-RS resource set, the same periodicity, and different slot offsets.
The method of claim 13, wherein the channel information includes a precoding matrix indicator.
The method of claim 13, wherein reporting the channel information comprises:

reporting the channel information for a prior set of channel state information reference signal resources in accordance with a time value.
A base station (BS) for wireless communication, comprising:

a memory; and

one or more processors operatively coupled to the memory, the memory and the one or more processors configured to:

configure at least one reference signal resource set containing at least one reference signal resource for transmitting a plurality of reference signals across a plurality of time instances;

receive, based at least in part on configuring the reference signal resource set, at least one of the plurality of reference signals;

determine channel information based at least in part on the at least one reference signal and a lag time between receiving the at least one reference signal and a downlink channel transmission; and

predict a downlink channel using the channel information.
A user equipment (UE) for wireless communication, comprising:

a memory; and

one or more processors operatively coupled to the memory, the memory and the one or more processors configured to:

receive first configuration information configuring at least one reference signal resource set containing at least one reference signal resource which includes at least one reference signal;

receive the at least one reference signal for channel information determination from a base station (BS) ;

receive second configuration information identifying a lag time between at least one of the reference signal and a target slot;

determine channel information for the target slot based at least in part on the reference signal and a lag time; and

report the channel information to the BS before the target slot.
A non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions comprising:

one or more instructions that, when executed by one or more processors of a base station (BS) , cause the one or more processors to:

configure at least one reference signal resource set containing at least one reference signal resource for transmitting a plurality of reference signals across a plurality of time instances;

receive, based at least in part on configuring the reference signal resource set, at least one of the plurality of reference signals;

determine channel information based at least in part on the at least one reference signal and a lag time between receiving the at least one reference signal and a downlink channel transmission; and

predict a downlink channel using the channel information.
A non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions comprising:

one or more instructions that, when executed by one or more processors of a user equipment (UE) , cause the one or more processors to:

receive first configuration information configuring at least one reference signal resource set containing at least one reference signal resource which includes at least one reference signal;

receive the at least one reference signal for channel information determination from a base station (BS) ;

receive second configuration information identifying a lag time between at least one of the reference signal and a target slot;

determine channel information for the target slot based at least in part on the reference signal and a lag time; and

report the channel information to the BS before the target slot.
An apparatus for wireless communication, comprising:

means for configuring at least one reference signal resource set containing at least one reference signal resource for transmitting a plurality of reference signals across a plurality of time instances;

means for receiving, based at least in part on configuring the reference signal resource set, at least one of the plurality of reference signals;

means for determining channel information based at least in part on the at least one reference signal and a lag time between receiving the at least one reference signal and a downlink channel transmission; and

means for predicting a downlink channel using the channel information.
An apparatus for wireless communication, comprising:

means for receiving first configuration information configuring at least one reference signal resource set containing at least one reference signal resource which includes at least one reference signal;

means for receiving the at least one reference signal for channel information determination from a base station (BS) ;

means for receiving second configuration information identifying a lag time between at least one of the reference signal and a target slot;

means for determining channel information for the target slot based at least in part on the reference signal and a lag time; and

means for reporting the channel information to the BS before the target slot.