CN117178601A - Beam-specific timing precompensation - Google Patents

Abstract

Aspects relate to a user equipment sending an uplink transmission on a first receive beam of a first beam pair link and on a second receive beam of a second beam pair link. The base station receives uplink transmissions on a first transmit beam of a first beam pair link and a second transmit beam of a second beam pair link via first transmit and receive points and second transmit and receive points associated with the base station. The base station transmits downlink transmissions on a first transmit beam having a first beam-specific timing pre-compensation and on a second transmit beam having a second beam-specific timing pre-compensation. The first beam-specific timing pre-compensation and the second beam-specific timing pre-compensation are based on a timing difference between reception of the uplink transmission via the first TRP and via the second TRP. The user equipment receives the beam specific timing precompensation.

Description

Beam-specific timing precompensation

Cross Reference to Related Applications

The present application claims priority to pending non-provisional application No. 17/569,260 filed on day 1 and 5 of 2022 to the united states patent and trademark office, which is assigned to the assignee of the present application and is hereby expressly incorporated by reference as if fully set forth below for all applicable purposes. The priority of pending application No. 63/138,395, filed by the U.S. patent and trademark office at 2021, month 1, and 16, which is assigned to the assignee of the present application and which is expressly incorporated herein by reference as if fully set forth below for all applicable purposes.

Technical Field

The techniques discussed below relate generally to wireless communication systems that utilize beam-specific timing precompensation.

Background

High Speed Trains (HSTs) may utilize a Single Frequency Network (SFN) to facilitate wireless communications. User Equipment (UE) located within the HST moves with a predetermined path or trajectory (e.g., in the case where the path/trajectory follows a train track) and at speeds exceeding 300 km per hour. Remote radio heads or Transmission and Reception Points (TRP) may be deployed along a predetermined path and associated with a base station. In an SFN, multiple TRPs may serve a single UE and transmit on the same time-frequency resource. Due to densification, SFNs can be used to provide spatial diversity gain, where adjacent TRPs transmit the same data in the same time-frequency resource to simultaneously provide signals (bearer data) from multiple TRPs to the UE.

Disclosure of Invention

The following presents a simplified summary of one or more aspects of the disclosure in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated features of the disclosure, and is intended to neither identify key or critical elements of all aspects of the disclosure nor delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present some concepts of one or more aspects of the disclosure in a form as a prelude to the more detailed description that is presented later.

In one example, a method of wireless communication at a base station is disclosed. The method comprises the following steps: receiving, via a first Transmit and Receive Point (TRP) associated with the base station, an uplink transmission on a first transmit beam of a first beam-to-link; receiving, via a second TRP associated with the base station, an uplink transmission on a second transmit beam of a second beam pair link; transmitting a downlink transmission on a first transmit beam having a first beam-specific timing precompensation via a first TRP; and transmitting a downlink transmission via a second TRP on a second transmit beam having a second beam specific timing precompensation, wherein the first beam specific timing precompensation and the second beam specific timing precompensation are based on a timing difference between reception of the uplink transmission via the first TRP and reception of the uplink transmission via the second TRP.

In another example, a base station for wireless communication is disclosed. The base station includes a transceiver, a memory, and a processor communicatively coupled to the transceiver and the memory. In this example, the processor and memory are configured to: receiving, via a first Transmit and Receive Point (TRP) associated with the base station, an uplink transmission on a first transmit beam of a first beam-to-link; receiving, via a second TRP associated with the base station, an uplink transmission on a second transmit beam of a second beam pair link; transmitting a downlink transmission on a first transmit beam having a first beam-specific timing precompensation via a first TRP; and transmitting a downlink transmission via a second TRP on a second transmit beam having a second beam specific timing precompensation, wherein the first beam specific timing precompensation and the second beam specific timing precompensation are based on a timing difference between reception of the uplink transmission via the first TRP and reception of the uplink transmission via the second TRP.

In another example, a method of wireless communication at a User Equipment (UE) is disclosed. According to this example, the method includes: transmitting an uplink transmission on a first receive beam of a first beam pair link; transmitting an uplink transmission on a second receive beam of the second beam pair link; and receiving a downlink transmission, the downlink transmission indicating: a first beam specific timing pre-compensation applied to a first transmit beam of a first beam pair link and a second beam specific timing pre-compensation applied to a second transmit beam of a second beam pair link.

In additional examples, a User Equipment (UE) for wireless communication is disclosed. The UE includes a transceiver, a memory, and a processor communicatively coupled to the transceiver and the memory. In this example, the processor and memory are configured to: transmitting an uplink transmission on a first receive beam of a first beam pair link; transmitting an uplink transmission on a second receive beam of the second beam pair link; and receiving a downlink transmission, the downlink transmission indicating: a first beam specific timing pre-compensation applied to a first transmit beam of a first beam pair link and a second beam specific timing pre-compensation applied to a second transmit beam of a second beam pair link.

These and other aspects will become more fully understood upon reading the following detailed description. Other aspects, features and examples will become apparent to those of ordinary skill in the art upon review of the following description of specific exemplary aspects in conjunction with the accompanying drawings. While each feature may be discussed with respect to certain examples and figures below, all examples may include one or more of the advantageous features discussed herein. In other words, while one or more examples may be discussed as having certain advantageous features, one or more of such features may also be used in accordance with the various examples discussed herein. Similarly, while examples may be discussed below as device, system, or method examples, it should be understood that such examples may be implemented in a variety of devices, systems, and methods.

Drawings

Fig. 1 is a schematic diagram of a wireless communication system in accordance with some aspects.

Fig. 2 is a schematic diagram of an example of a Radio Access Network (RAN) in accordance with some aspects.

Fig. 3 is a schematic diagram of radio resources in an air interface utilizing Orthogonal Frequency Division Multiplexing (OFDM), in accordance with some aspects.

Fig. 4 is a diagram illustrating an example of a wireless communication system supporting beamforming and/or multiple-input multiple-output (MIMO) in accordance with some aspects.

Fig. 5 is a diagram illustrating an example of communication between a base station and a UE using beamforming in accordance with some aspects.

Fig. 6A is a graph of uncompensated effective Power Delay Profile (PDP) over time at multiple delay locations without beam-specific timing precompensation, according to some aspects.

Fig. 6B is a graph of a precompensated effective Power Delay Profile (PDP) over time at multiple delay locations with beam specific timing precompensation, according to some aspects.

Fig. 7 is a right side elevation view of a vehicle in an environment illustrating an example of beam-specific timing precompensation in a high speed train single frequency network according to some aspects.

Fig. 8 is a signaling diagram illustrating exemplary signaling for beam-specific timing precompensation according to some aspects.

Fig. 9 is a signaling diagram illustrating exemplary signaling for beam-specific timing precompensation according to some aspects.

Fig. 10 is a signaling diagram illustrating exemplary signaling for beam-specific timing precompensation according to some aspects.

Fig. 11 is a block diagram illustrating an example of a hardware implementation of a base station employing a processing system in accordance with some aspects.

Fig. 12 is a flow chart of a method of wireless communication utilizing beam-specific timing precompensation, according to some aspects.

Fig. 13 is a flow diagram of a method of wireless communication utilizing beam-specific timing precompensation, according to some aspects.

Fig. 14 is a block diagram illustrating an example of a hardware implementation of a User Equipment (UE) employing a processing system in accordance with some aspects.

Fig. 15 is a flow diagram of a method of wireless communication utilizing beam-specific timing precompensation, according to some aspects.

Fig. 16 is a flow diagram of a method of wireless communication utilizing beam-specific timing precompensation in accordance with some aspects.

Fig. 17A and 17B are illustrations of single frequency network configurations according to some aspects.

Fig. 18 is an illustration of a single frequency network configuration in accordance with some aspects.

Detailed Description

The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. It will be apparent, however, to one skilled in the art that the concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring the concepts.

While aspects and examples are described in this disclosure by way of illustration of some examples, those skilled in the art will appreciate that additional implementations and use cases may be implemented in many different arrangements and scenarios. The innovations described herein may be implemented across many different platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, aspects and/or use may be implemented by integrating chip examples with other non-module component-based devices (e.g., end user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchase devices, medical devices, artificial Intelligence (AI) enabled devices, etc.). While some examples may or may not be specific to use cases or applications, the innovations described may appear to be of various applicability. Implementations may range from chip-level or modular components to non-modular, non-chip-level implementations, and further to Original Equipment Manufacturer (OEM) devices or systems that aggregate, distribute, or incorporate one or more aspects of the described innovations. In some practical arrangements, a device incorporating the described aspects and features may also have to include additional components and features for implementation and practice of the examples claimed and described. For example, the transmission and reception of wireless signals must include several components (e.g., hardware components including antennas, radio Frequency (RF) chains (RF chains), power amplifiers, modulators, buffers, processors, interleavers, adders/summers, etc.) for analog and digital purposes. It is intended that the innovations described herein may be practiced in a variety of devices, chip-scale components, systems, distributed arrangements, end-user devices, etc., having a variety of sizes, shapes, and configurations.

The electromagnetic spectrum is typically subdivided into various categories, bands, channels, etc., based on frequency/wavelength. In 5G NR, two initial operating bands have been identified as frequency range names FRI (410 MHz-7.125 GHz) and FR2 (24.25 GHz-52.6 GHz). It should be appreciated that although a portion of FR1 is greater than 6GHz, FR1 is often (interchangeably) referred to as the "Sub-6 GHz" band in various documents and articles. Similar naming problems sometimes occur with respect to FR2, which is commonly (interchangeably) referred to in documents and articles as the "millimeter wave" band, although it is different from the Extremely High Frequency (EHF) band (30 Ghz-300 Ghz) which is recognized by the International Telecommunications Union (ITU) as the "millimeter wave" band.

The frequency between FR1 and FR2 is commonly referred to as the mid-band frequency. Recent 5G NR studies have determined the operating band of these mid-band frequencies as frequency range designation FR3 (7.125 GHz-24.25 GHz). The frequency bands falling within FR3 may inherit FR1 features and/or FR2 features, and thus may effectively extend the features of FR1 and/or FR2 to mid-band frequencies. In addition, higher frequency bands are currently being explored to extend the operation of 5G NR above 52.6 GHz. For example, three higher operating bands have been identified as frequency range names FR4-a or FR4-1 (52.6 GHz-71 GHz), FR4 (52.6 GHz-114.25 GHz) and FR5 (114.25 GHz-300 GHz). Each of these higher frequency bands falls within the EHF frequency band.

In view of the above, unless specifically stated otherwise, it should be understood that, if used herein, the term "sub-6GHz" or the like may broadly represent frequencies that may be less than 6GHz, may be within FR1, or may include mid-band frequencies. Furthermore, unless specifically stated otherwise, it should be understood that, if used herein, the term "millimeter wave" or the like may broadly mean frequencies that may include mid-band frequencies, may be within FR2, FR4-a, or FR4-1 and/or FR5, or may be within the EHF band.

A base station (e.g., a gNode B (gNB)) may provide a set of Transmission Configuration Indication (TCI) status configurations to a UE via a Radio Resource Control (RRC) message. Each TCI state may include quasi co-location (QCL) information indicating one or more downlink reference signals from which various radio channel characteristics of a downlink channel or downlink signal may be inferred. Examples of QCL information include QCL-type, which indicates spatial characteristics (e.g., beam direction and/or beam width) of a beam associated with a particular downlink reference signal. From the QCL-type information, the UE may infer the beam on which the downlink channel or downlink signal may be transmitted.

Examples of uplink channels include a Physical Uplink Shared Channel (PUSCH), a Physical Uplink Control Channel (PUCCH), and a Physical Random Access Channel (PRACH). Examples of the downlink channel include a Physical Downlink Shared Channel (PDSCH), a Physical Downlink Control Channel (PDCCH), and a Physical Broadcast Channel (PBCH). Examples of the uplink signal include a demodulation reference signal (DM-RS) (for PUSCH and PUCCH), a phase tracking reference signal (PT-RS) (for PUSCH), and a Sounding Reference Signal (SRS). Examples of the downlink signal include a demodulation reference signal (DM-RS) (for PDSCH, PDCCH, and PBCH), a synchronization signal (e.g., PSS and/or SSS), a phase tracking reference signal (PT-RS), and a Channel State Information (CSI) reference signal (CSI-RS). Once these TCI state configurations are provided to the UE, the gNB may activate or deactivate the TCI state provided for the given UE by sending, for example, a Media Access Control (MAC) control element (MAC-CE). The MAC-CE is identified by a MAC subheader comprising a serving cell ID, a bandwidth part (BWP) ID, and a parameter Ti indicating an active or inactive state of the TCI with TCI-StateId i. Here, i is an integer index value for indexing a TCI state list previously provided to the UE. The base station may then select one of the activated TCI states to transmit a downlink channel or downlink signal to the UE. For example, the base station may indicate a downlink channel or a particular TCI state of the channel within Downlink Control Information (DCI) of a scheduled downlink channel or signal.

High Speed Trains (HSTs) may utilize a Single Frequency Network (SFN) to facilitate wireless communications. In SFN, multiple transmit-receive points (TRPs) of a base station (e.g., which may be deployed in a Remote Radio Head (RRH) configuration) may serve a UE and transmit the same downlink channels and signals to the UE on the same time-frequency resources. The base station may configure each TRP to transmit downlink channels or signals to the UE using a different beam (e.g., a different TCI state) associated with the TRP. However, due to the different locations of the TRPs relative to the UE and the different paths based on the different beams, the transmission from each TRP may arrive at the UE at different times, which may increase delay spread, resulting in Inter Symbol Interference (ISI).

Accordingly, aspects described herein include a UE sending one or more uplink transmissions to a base station through a plurality of Transmission and Reception Points (TRPs) associated with the base station while the UE is within a mobile vehicle in an SFN. According to some aspects, the vehicle may be a high speed train. The base station may receive uplink transmissions from the UE at the plurality of TRPs and may obtain (e.g., estimate, calculate, determine, derive) a timing difference between the timing of a downlink transmission to the UE on a first beam of a first TRP and the timing of the same downlink transmission to the same UE on a second beam of a second TRP by determining the timing difference of the uplink transmissions received at the respective TRPs. Based on the timing difference, the base station may then determine a first beam-specific timing pre-compensation for the first beam and a second beam-specific timing pre-compensation for the second beam. The base station may then transmit an indication of at least one of the first beam-specific timing precompensation or the second beam-specific timing precompensation to the UE. Then, the base station may pre-compensate a first beam through a first TRP according to the first beam-specific timing and pre-compensate a second beam through a second TRP according to the second beam-specific timing to transmit a Physical Downlink Shared Channel (PDSCH) transmission to the UE.

The various concepts presented throughout this disclosure may be implemented on a variety of telecommunication systems, network architectures, and communication standards. Referring now to fig. 1, various aspects of the present disclosure are shown with reference to a wireless communication system 100 as a non-limiting illustrative example. The wireless communication system 100 includes three interaction domains: a core network 102, a Radio Access Network (RAN) 104, and a User Equipment (UE) 106. By means of the wireless communication system 100, the UE 106 may be enabled to perform data communication with an external data network 110, such as, but not limited to, the internet.

RAN 104 may implement any suitable wireless communication technology or technologies to provide radio access to UEs 106. As one example, RAN 104 may operate in accordance with the 3 rd generation partnership project (3 GPP) New Radio (NR) specification (commonly referred to as 5G). As another example, the RAN 104 may operate under a mix of 5 GNRs and an evolved universal terrestrial radio access network (eUTRAN) standard, commonly referred to as Long Term Evolution (LTE). The 3GPP refers to this hybrid RAN as the next generation RAN, or NG-RAN. Of course, many other examples may be utilized within the scope of the present disclosure.

As shown, RAN 104 includes a plurality of base stations 108. In a broad sense, a base station is a network element in a radio access network responsible for transmitting or receiving radio to or from a UE in one or more cells. In different technologies, standards, or contexts, a base station may be referred to variously by those skilled in the art as a base station transceiver (BTS), a radio base station, a radio transceiver, a transceiver function, a Basic Service Set (BSS), an Extended Service Set (ESS), an Access Point (AP), a Node B (NB), an eNode B (eNB), a gNode B (gNB), a Transmission and Reception Point (TRP), or some other suitable terminology. In some examples, a base station may include two or more TRPs, which may be co-located or non-co-located. Each TRP may communicate on the same or different carrier frequencies within the same or different frequency bands. In examples where RAN 104 operates in accordance with both LTE and 5G NR standards, one of the base stations may be an LTE base station and the other base station may be a 5G NR base station.

RAN 104 is also shown to support wireless communications for a plurality of mobile devices. A mobile device may be referred to as a User Equipment (UE) in the 3GPP standard, but may also be referred to by those skilled in the art as a Mobile Station (MS), a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless communication device, a remote device, a mobile subscriber station, an Access Terminal (AT), a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, or some other suitable terminology. The UE may be a device (e.g., a mobile device) that provides access to network services to a user.

In this disclosure, a "mobile" device does not necessarily have mobility and may be stationary. The term mobile device or mobile equipment generally refers to a variety of devices and technologies. The UE may include a plurality of hardware structural components sized, shaped, and arranged to facilitate communication; such components may include an antenna, an antenna array, an RF chain, a TX chain, an amplifier, one or more processors, and so forth, electrically coupled to each other. For example, some non-limiting examples of mobile devices include mobile phones, cellular phones (handsets), smart phones, session Initiation Protocol (SIP) phones, laptops, personal Computers (PCs), notebooks, netbooks, smartbooks, tablets, personal Digital Assistants (PDAs), and a wide variety of embedded systems, e.g., corresponding to "internet of things" (IoT).

The mobile apparatus may also be an automobile or other vehicle, a remote sensor or actuator, a robot or robotic device, a satellite radio, a Global Positioning System (GPS) device, an object tracking device, an unmanned aerial vehicle, a multi-axis aircraft, a four-axis aircraft, a remote control device, a consumer and/or wearable device (such as glasses, a wearable camera, a virtual reality device, a smart watch, a health or fitness tracker), a digital audio player (e.g., MP3 player), a camera, a game console, and the like. The mobile device may also be a digital home or smart home device such as a home audio, video and/or multimedia device, appliance, vending machine, smart lighting, home security system, smart meter, etc. The mobile device may also be a smart energy device, a security device, a solar panel or solar array, a municipal infrastructure device (e.g., smart grid) that controls power, lighting, water, etc., an industrial automation and enterprise device, a logistics controller, and/or agricultural equipment, etc. In addition, the mobile device may provide connected medical or telemedicine support, such as remote healthcare. The telemedicine devices may include telemedicine monitoring devices and telemedicine management devices whose communications may be given priority or access over other types of data, for example, in terms of priority access to transmit critical service data and/or related QoS for transmitting critical service data.

Wireless communication between RAN 104 and UE 106 may be described as utilizing an air interface. Transmissions from a base station (e.g., base station 108) to one or more UEs (e.g., similar to UE 106) over an air interface may be referred to as Downlink (DL) transmissions. According to certain aspects of the present disclosure, the term downlink may refer to a point-to-multipoint transmission initiated at a base station (e.g., base station 108). Another way to describe this scheme may be to use the term broadcast channel multiplexing. The transmission from a UE (e.g., UE 106) to a base station (e.g., base station 108) may be referred to as an Uplink (UL) transmission. According to further aspects of the disclosure, the term uplink may refer to a point-to-point transmission initiated at a UE (UE 106).

In some examples, access to the air interface may be scheduled, where a scheduling entity (e.g., base station 108) allocates resources for communications between some or all devices and equipment within its service area or cell. Within the present disclosure, a scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more scheduled entities (e.g., UEs 106), as discussed further below. That is, for scheduled communications, multiple UEs 106, which may be scheduled entities, may utilize resources allocated by the scheduling entity 108.

Base station 108 is not the only entity that can be used as a scheduling entity. That is, in some examples, a UE may act as a scheduling entity to schedule resources for one or more scheduled entities (e.g., one or more other UEs). For example, a UE may communicate directly with other UEs in a peer-to-peer or device-to-device manner and/or relay configuration.

As shown in fig. 1, scheduling entity 108 may broadcast downlink traffic 112 to one or more scheduled entities (e.g., one or more UEs 106). Broadly, the scheduling entity 108 is a node or device responsible for scheduling traffic in a wireless communication network, including downlink traffic 112, and in some examples, uplink traffic 116 from one or more scheduled entities (e.g., one or more UEs 106) to the scheduling entity 108. On the other hand, a scheduled entity (e.g., UE 106) is a node or device that receives downlink control 114 information, including but not limited to scheduling information (e.g., grants), synchronization or timing information, or other control information from another entity in the wireless communication network, such as scheduling entity 108. A scheduled entity (e.g., UE 106) may send uplink control 118 information including one or more uplink control channels to scheduling entity 108. The uplink control 118 information may include various packet types and categories including pilot, reference signals, and information configured to enable or assist in decoding uplink data transmissions.

Further, uplink and/or downlink control information and/or traffic information may be transmitted on waveforms that may be time-divided into frames, subframes, slots, and/or symbols. As used herein, a symbol may refer to a unit of time in an Orthogonal Frequency Division Multiplexing (OFDM) waveform in which each subcarrier carries one Resource Element (RE). One slot may carry 7 or 14 OFDM symbols. One subframe may refer to a duration of 1 ms. Multiple subframes or slots may be grouped together to form a single frame or radio frame. In the present disclosure, one frame may refer to a predetermined duration (e.g., 10 ms) for wireless transmission, where each frame is composed of, for example, 10 subframes of 1ms each. Of course, these definitions are not required, and any suitable scheme for organizing waveforms may be utilized, and the various temporal divisions of the waveforms may have any suitable duration.

In general, the base station 108 may include a backhaul interface for communicating with the backhaul portion 120 of the wireless communication system 100. Backhaul portion 120 may provide a link between base station 108 and core network 102. Further, in some examples, the backhaul network may provide interconnection between the various base stations 108. Various types of backhaul interfaces may be employed, such as direct physical connections using any suitable transport network, virtual networks, and the like.

The core network 102 may be part of the wireless communication system 100 and may be independent of the radio access technology used in the RAN 104. In some examples, the core network 102 may be configured according to a 5G standard (e.g., 5 GC). In other examples, core network 102 may be configured according to a 4G Evolved Packet Core (EPC) or any other suitable standard or configuration.

Referring now to fig. 2, a schematic diagram of an example of a Radio Access Network (RAN) 200 in accordance with some aspects of the present disclosure is provided as an illustrative example and not a limiting example. In some examples, RAN 200 may be the same as RAN 104 described above and shown in fig. 1.

The geographic area covered by the RAN 200 may be divided into a plurality of cellular areas (cells) that may be uniquely identified by User Equipment (UE) based on an identification broadcast over the geographic area from an access point or base station. Fig. 2 illustrates cells 202, 204, 206, and 208, where each cell may include one or more sectors (not shown). A sector is a sub-region of a cell. All sectors within a cell are served by the same base station. The radio links within a sector may be identified by a single logical identification belonging to the sector. In a cell divided into sectors, multiple sectors within a cell may be formed by groups of antennas, with each antenna being responsible for communication with UEs in a portion of the cell.

Various base station arrangements may be utilized. For example, in fig. 2, two base stations (base station 210 and base station 212) are shown in cells 202 and 204. A third base station (base station 214) is shown controlling a Remote Radio Head (RRH) 216 in cell 206. That is, the base station may have an integrated antenna or may be connected to the antenna or RRH 216 through a feeder cable. In the example shown, cells 202, 204, and 206 may be referred to as macro cells because base stations 210, 212, and 214 support cells having large sizes. In addition, a base station 218 is shown in cell 208, which may overlap with one or more macro cells. In this example, cell 208 may be referred to as a small cell (e.g., a micro cell, pico cell, femto cell, home base station, home node B, home eNode B, etc.) because base station 218 supports cells having a relatively small size. The cell size may be determined according to system design and component constraints.

It should be appreciated that RAN 200 may include any number of radio base stations and cells. Furthermore, relay nodes may be deployed to extend the size or coverage area of a given cell. The base stations 210, 212, 214, 218 provide wireless access points to the core network for any number of mobile devices. In some examples, base stations 210, 212, 214, and/or 218 may be the same as or similar to scheduling entity 108 described above and shown in fig. 1.

Fig. 2 also includes an Unmanned Aerial Vehicle (UAV) 220, which may be an unmanned aerial vehicle or a quad-rotor. UAV 220 may be configured to function as a base station, or more specifically as a mobile base station. That is, in some examples, the cells may not necessarily be stationary, and the geographic area of the cells may move according to the location of a mobile base station, such as UAV 220.

Within RAN 200, a cell may include UEs that may communicate with one or more sectors of each cell. Further, each base station 210, 212, 214, 218, and 220 may be configured to provide an access point to the core network 102 (see fig. 1) for all UEs in the respective cell. For example, UEs 222 and 224 may communicate with base station 210; UEs 226 and 228 may communicate with base station 212; UEs 230 and 232 may communicate with base station 214 over RRH 216; UE 234 may communicate with base station 218; and UE 236 may communicate with mobile base station 220. In some examples, UEs 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, and/or 242 may be the same or similar to UE/scheduling entity 106 described above and shown in fig. 1. In some examples, UAV 220 (e.g., a quadrotor) may be a mobile network node and may be configured to function as a UE. For example, UAV 220 may operate within cell 202 by communicating with base station 210.

In another aspect of the RAN 200, side-link signals may be used between UEs without having to rely on scheduling or control information from the base station. For example, the side link communication may be used in a device-to-device (D2D) network, peer-to-peer (P2P) network, vehicle-to-vehicle (V2V) network, vehicle-to-everything (V2X) network, and/or other suitable side link network. For example, two or more UEs (e.g., UEs 238, 240, and 242) may communicate with each other using side link signals 237 without relaying the communication through a base station. In some examples, each of UEs 238, 240, and 242 may function as a scheduling entity or transmitting side link device and/or a scheduled entity or receiving side link device to schedule resources and transmit side link signals 237 therebetween without relying on scheduling or control information from a base station. In other examples, two or more UEs (e.g., UEs 226 and 228) within the coverage area of a base station (e.g., base station 212) may also transmit side link signal 227 on a direct link (side link) without transmitting the communication through base station 212. In this example, base station 212 may allocate resources to UEs 226 and 228 for side link communication.

Channel coding may be used in order to transmit over the air interface to achieve a low block error rate (BLER) while still achieving very high data rates. That is, wireless communication may generally use an appropriate error correction block code. In a typical block code, an information message or sequence is divided into Code Blocks (CBs), and an encoder (e.g., CODEC) at the transmitting device then mathematically adds redundancy to the information message. The use of such redundancy in encoding information messages may improve the reliability of the message, thereby enabling correction of any bit errors that may occur due to noise.

Data decoding may be implemented in a variety of ways. In the early 5G NR specifications, user data was decoded using quasi-cyclic Low Density Parity Check (LDPC) with two different base patterns: one base map is used for large code blocks and/or high code rates, while the other base map is used for other cases. The control information and Physical Broadcast Channel (PBCH) are decoded using Polar decoding based on nested sequences. For these channels, puncturing, shortening, and repetition are used for rate matching.

Aspects of the disclosure may be implemented using any suitable channel code. Various implementations of base stations and UEs may include appropriate hardware and capabilities (e.g., encoders, decoders, and/or CODECs) to utilize one or more of these channel codes for wireless communications.

In the RAN 200, the ability of a UE to communicate while moving, independent of the UE's location, is referred to as mobility. The various physical channels between the UE and the RAN 200 are typically established, maintained, and released under control of access and mobility management functions (AMFs). In some scenarios, the AMF may include a Security Context Management Function (SCMF) and a security anchor function (SEAF) that perform authentication. The SCMF may manage, in whole or in part, security contexts for both control plane and user plane functions.

In various aspects of the present disclosure, the RAN 200 may utilize DL-based mobility or UL-based mobility to implement mobility and handover (i.e., transfer a connection of a UE from one radio channel to another radio channel). In a network configured for DL-based mobility, a UE may monitor various parameters of signals from its serving cell and various parameters of neighboring cells during a call with a scheduling entity, or at any other time. Depending on the quality of these parameters, the UE may maintain communication with one or more of the neighboring cells. During this time, if the UE moves from one cell to another, or if the signal quality from the neighboring cell exceeds the signal quality from the serving cell within a given amount of time, the UE may make a handover (handover) or handoff (handover) from the serving cell to the neighboring (target) cell. For example, UE 224 may move from a geographic region corresponding to its serving cell 202 to a geographic region corresponding to neighboring cell 206. When the signal strength or quality from the neighboring cell 206 exceeds the signal strength or quality of its serving cell 202 for a given amount of time, the UE 224 may send a report message to its serving base station 210 indicating the condition. In response, UE 224 may receive the handover command and the UE may experience a handover to cell 206.

In a network configured for UL-based mobility, UL reference signals from each UE may be utilized by the network to select a serving cell for each UE. In some examples, base stations 210, 212, and 214/216 may broadcast unified synchronization signals (e.g., unified Primary Synchronization Signal (PSS), unified Secondary Synchronization Signal (SSS), and unified Physical Broadcast Channel (PBCH)). UEs 222, 224, 226, 228, 230, and 232 may receive the unified synchronization signal, derive carrier frequencies and slot timings from the synchronization signal, and transmit uplink pilot or reference signals in response to the derived timings. Uplink pilot signals transmitted by a UE (e.g., UE 224) may be received simultaneously by two or more cells (e.g., base stations 210 and 214/216) within RAN 200. Each of the cells may measure the strength of the pilot signal and the radio access network (e.g., one or more of the base stations 210 and 214/216 and/or a central node within the core network) may determine a serving cell for the UE 224. As UE 224 moves through RAN 200, RAN 200 may continue to monitor the uplink pilot signals transmitted by UE 224. When the signal strength or quality of the pilot signal measured by the neighbor cell exceeds the signal strength or quality measured by the serving cell, the RAN 200 may handover the UE 224 from the serving cell to the neighbor cell with or without informing the UE 224.

Although the synchronization signals transmitted by the base stations 210, 212, and 214/216 may be uniform, the synchronization signals may not identify a particular cell, but may identify a cell that operates on the same frequency and/or has multiple cells with the same timing. The use of zones in a 5G network or other next generation communication network enables an uplink-based mobility framework and simultaneously improves the efficiency of both the UE and the network, as the number of mobility messages that need to be exchanged between the UE and the network can be reduced.

In various implementations, the air interface in the radio access network 200 may utilize licensed spectrum, unlicensed spectrum, or shared spectrum. Licensed spectrum typically provides for exclusive use of portions of the spectrum by mobile network operators purchasing licenses from government regulators. Unlicensed spectrum provides shared use of portions of spectrum without the need for government-granted permissions. Access rights are generally available to any operator or device, although access to unlicensed spectrum is still generally required to adhere to some technical rules. The shared spectrum may fall between a licensed spectrum and an unlicensed spectrum, where technical rules or restrictions may be needed to access the spectrum, but the spectrum may still be shared by multiple operators and/or multiple Radio Access Technologies (RATs). For example, a licensee that licensed a portion of a spectrum may provide License Sharing Access (LSA) to share the spectrum with other parties, e.g., with appropriate license holder-determined conditions to gain access.

Devices communicating in radio access network 200 may utilize one or more multiplexing techniques and multiple access algorithms to enable simultaneous communication of the various devices. For example, the 5G NR specification provides multiple access for UL transmissions from UEs 222 and 224 to base station 210 using Orthogonal Frequency Division Multiplexing (OFDM) with a Cyclic Prefix (CP) and multiplexing for DL transmissions from base station 210 to one or more UEs 222 and 224. Further, for UL transmissions, the 5G NR specification provides support for discrete fourier transform spread OFDM (DFT-s-OFDM) with CP, also known as single carrier FDMA (SC-FDMA). However, it is within the scope of the present disclosure that multiplexing and multiple access are not limited to the above-described schemes, and may be provided using Time Division Multiple Access (TDMA), code Division Multiple Access (CDMA), frequency Division Multiple Access (FDMA), sparse Code Multiple Access (SCMA), resource Spread Multiple Access (RSMA), or other suitable multiple access schemes. Further, multiplexed DL transmissions from base station 210 to UEs 222 and 224 may be provided utilizing Time Division Multiplexing (TDM), code Division Multiplexing (CDM), frequency Division Multiplexing (FDM), orthogonal Frequency Division Multiplexing (OFDM), sparse Code Multiplexing (SCM), or other suitable multiplexing schemes.

Devices in radio access network 200 may also utilize one or more duplexing algorithms. Duplex is a point-to-point communication link in which two endpoints can communicate with each other in both directions. Full duplex means that two endpoints can communicate with each other at the same time. Half duplex means that only one endpoint can send information to the other endpoint at a time. Half-duplex emulation is often used for wireless links that utilize Time Division Duplexing (TDD). In TDD, time division multiplexing is used to separate transmissions in different directions on a given channel from each other. That is, in some scenarios, a channel is dedicated to transmissions in one direction, while at other times, the channel is dedicated to transmissions in another direction, where the direction may change very rapidly, e.g., several times per slot. In wireless links, full duplex channels typically rely on physical isolation of the transmitter and receiver and appropriate interference cancellation techniques. Full duplex emulation is often implemented for wireless links by utilizing Frequency Division Duplexing (FDD) or Space Division Duplexing (SDD). In FDD, transmissions in different directions may operate at different carrier frequencies (e.g., within a paired spectrum). In SDD, spatial Division Multiplexing (SDM) is used to separate transmissions in different directions on a given channel from each other. In other examples, full duplex communications may be implemented within unpaired spectrum (e.g., within a single carrier bandwidth), where transmissions in different directions occur within different sub-bands of the carrier bandwidth. This type of full duplex communication may be referred to herein as sub-band full duplex (SBFD), also referred to as flexible duplex.

Various aspects of the present disclosure will be described with reference to Orthogonal Frequency Division Multiplexing (OFDM) waveforms schematically illustrated in fig. 3. Those of ordinary skill in the art will appreciate that the various aspects of the present disclosure may be applied to SC-FDMA waveforms in substantially the same manner as described below. That is, while some examples of the present disclosure may focus on OFDM links for clarity, it should be understood that the same principles may also be applied to SC-FDMA waveforms.

Referring now to fig. 3, an expanded view of an exemplary subframe 302 is shown that illustrates an OFDM resource grid. However, as will be readily appreciated by those skilled in the art, the Physical (PHY) transmission structure for any particular application may differ from the examples described herein, depending on any number of factors. Here, time is in the horizontal direction, in units of OFDM symbols; the frequency is in the vertical direction, in units of subcarriers of the carrier.

The resource grid 304 may be used to schematically represent time-frequency resources for a given antenna port. That is, in a multiple-input multiple-output (MIMO) implementation with multiple available antenna ports, a corresponding multiple number of resource grids 304 may be used for communication. The resource grid 304 is divided into a plurality of Resource Elements (REs) 306. REs (which are 1 subcarrier x 1 symbol) are the smallest discrete part of the time-frequency grid and contain a single complex value representing data from a physical channel or signal. Each RE may represent one or more information bits, depending on the modulation used in a particular implementation. In some examples, the RE blocks may be referred to as Physical Resource Blocks (PRBs) or, more simply, resource Blocks (RBs) 308, which contain any suitable number of contiguous subcarriers in the frequency domain. In one example, the RB may include 12 subcarriers, the number of which is independent of the parameter set (numerology) used. In some examples, an RB may include any suitable number of consecutive OFDM symbols in the time domain, depending on the parameter set. In this disclosure, it is assumed that a single RB, such as RB 308, corresponds entirely to a single communication direction (transmission or reception for a given device).

A set of contiguous or non-contiguous resource blocks may be referred to herein as a Resource Block Group (RBG), a subband, or a bandwidth portion (BWP). A set of subbands or BWP may span the entire bandwidth. Scheduling of a scheduled entity (e.g., UE) for downlink, uplink, or side-link transmission involves scheduling one or more resource elements 306 within one or more subbands or bandwidth portions (BWP). Thus, the UE typically utilizes only a subset of the resource grid 304. In some examples, an RB may be the smallest resource unit that can be allocated to a UE. Thus, the more RBs scheduled for a UE and the higher the modulation scheme selected for the air interface, the higher the data rate of the UE. RBs may be scheduled by a base station (e.g., a gNB, eNB, etc.), or may be self-scheduled by a UE implementing D2D side-link communication.

In this illustration, RB 308 is shown to occupy less than the entire bandwidth of subframe 302, with some subcarriers shown above and below RB 308. In a given implementation, subframe 302 may have a bandwidth corresponding to any number of one or more RBs 308. Further, in this illustration, RB 308 is shown to occupy less than the entire duration of subframe 302, although this is merely one possible example.

Each 1ms subframe 302 may be comprised of one or more adjacent slots. In the example shown in fig. 3, one subframe 302 includes four slots 310 as an illustrative example. In some examples, a slot may be defined according to a specified number of OFDM symbols having a given Cyclic Prefix (CP) length. For example, one slot may include 7 or 14 OFDM symbols with a nominal CP. Additional examples may include minislots with shorter durations (e.g., one to three OFDM symbols), sometimes referred to as shortened Transmission Time Intervals (TTIs). In some cases, these minislots or shortened Transmission Time Intervals (TTIs) may be sent occupying resources scheduled for ongoing slot transmissions for the same or different UEs. Any number of resource blocks may be used within a subframe or slot.

An expanded view of one of the time slots 310 shows that the time slot 310 includes a control region 312 and a data region 314. In general, control region 312 may carry control channels, while data region 314 may carry data channels. Of course, one slot may contain all DL, all UL, or at least one DL portion and at least one UL portion. The structure shown in fig. 3 is merely exemplary in nature, different slot structures may be utilized, and may include one or more of each of the control region and the data region.

Although not shown in fig. 3, various REs 306 within an RB 308 may be scheduled to carry one or more physical channels, including control channels, shared channels, data channels, and the like. Other REs 306 within an RB 308 may also carry pilot or reference signals. These pilot or reference signals may be provided to a receiving device to perform channel estimation of the corresponding channel, which may enable coherent demodulation/detection of control and/or data channels within RB 308.

In some examples, the time slots 310 may be used for broadcast, multicast, or unicast communications. For example, broadcast, multicast, or multicast communication may refer to point-to-multipoint transmission by one device (e.g., a base station, UE, or other similar device) to another device. Here, broadcast communications are delivered to all devices, while multicast or multicast communications are delivered to a plurality of intended recipient devices. Unicast communication may refer to point-to-point transmission by one device to a single other device.

In an example of cellular communication over a cellular carrier via a Uu interface, a scheduling entity (e.g., a base station) may allocate one or more REs 306 (e.g., within a control region 312) for DL transmissions to carry DL control information including one or more DL control channels (e.g., physical Downlink Control Channels (PDCCHs)) to one or more scheduled entities (e.g., UEs). The PDCCH carries Downlink Control Information (DCI), including, but not limited to, power control commands (e.g., one or more open loop power control parameters and/or one or more closed loop power control parameters), scheduling information, grants, and/or assignments of REs for DL and UL transmissions. The PDCCH may also carry hybrid automatic repeat request (HARQ) feedback transmissions, such as Acknowledgements (ACKs) or Negative Acknowledgements (NACKs). HARQ is a technique well known to those of ordinary skill in the art, wherein the integrity of a packet transmission may be checked for accuracy at the receiving side, e.g., using any suitable integrity checking mechanism, such as a checksum or Cyclic Redundancy Check (CRC). If the integrity of the transmission is acknowledged, an ACK may be sent, and if not, a NACK may be sent. In response to the NACK, the transmitting device may transmit HARQ retransmissions, which may enable chase combining, incremental redundancy, etc.

The base station may further allocate one or more REs 306 (e.g., in the control region 312 or the data region 314) to carry other DL signals, such as demodulation reference signals (DM-RS); phase tracking reference signal (PT-RS); channel State Information (CSI) reference signals (CSI-RS); a Synchronization Signal Block (SSB). SSBs may be broadcast at regular intervals based on periodicity (e.g., 5, 10, 20, 40, 80, or 160 ms). SSBs include a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and a physical broadcast control channel (PBCH). The UE may implement radio frame, subframe, slot, and symbol synchronization in the time domain, identify the center of channel (system) bandwidth in the frequency domain, and identify the Physical Cell Identity (PCI) of the cell using PSS and SSS.

The PBCH in the SSB may further include a Master Information Block (MIB) including various system information and parameters for decoding the System Information Block (SIB). The SIB may be, for example, system information type 1 (SIB 1), which may include various additional system information. The MIB and SIB1 together provide minimum System Information (SI) for initial access. Examples of system information transmitted in the MIB may include, but are not limited to, subcarrier spacing (e.g., default downlink parameter set), system frame number, configuration of PDCCH control resource set (CORESET 0) (e.g., PDCCH CORESET 0), cell prohibit indicator, cell reselection indicator, raster offset, and search space for SIB 1. Examples of Remaining Minimum System Information (RMSI) transmitted in SIB1 may include, but are not limited to, random access search space, paging search space, downlink configuration information, and uplink configuration information. The base station may also transmit Other System Information (OSI).

In UL transmissions, a scheduled entity (e.g., a UE) may utilize one or more REs 306 to carry UL Control Information (UCI) including one or more UL control channels, such as a Physical Uplink Control Channel (PUCCH), to the scheduling entity. UCI may include various packet types and categories including pilot, reference signals, and information configured to enable or assist in decoding uplink data transmissions. Examples of the uplink reference signal may include a Sounding Reference Signal (SRS) and an uplink DM-RS. In some examples, UCI may include a Scheduling Request (SR), i.e., a request to schedule uplink transmissions for a scheduling entity. Here, in response to the SR transmitted on the UCI, the scheduling entity may transmit Downlink Control Information (DCI) which may schedule resources for uplink packet transmission. UCI may also include HARQ feedback, channel State Feedback (CSF), such as CSI reports, or any other suitable UCI.

In addition to control information, one or more REs 306 may be allocated for data traffic (e.g., within a data region 314). Such data traffic may be carried on one or more traffic channels, e.g., a Physical Downlink Shared Channel (PDSCH) for DL transmissions; or a Physical Uplink Shared Channel (PUSCH) for UL transmissions. In some examples, one or more REs 306 within the data region 314 may be configured to carry other signals, such as one or more SIBs and DM-RSs.

In an example of side link communication over a side link carrier via a proximity services (ProSe) PC5 interface, the control region 312 of the slot 310 may include a physical side link control channel (PSCCH) that includes side link control information (SCI) transmitted by an initiating (transmitting) side link device (e.g., a Tx V2X device or other Tx UE) to a set of one or more other receiving side link devices (e.g., an Rx V2X device or other Rx UE). The data region 314 of the slot 310 may include a Physical Sidelink Shared Channel (PSSCH) that includes sidelink data traffic transmitted by an originating (transmitting) sidelink device within resources reserved on a sidelink carrier by a transmitting sidelink device via SCI. Other information may be further transmitted on the various REs 306 within the time slot 310. For example, HARQ feedback information may be transmitted from a receiving side link device to a transmitting side link device in a physical side link feedback channel (PSFCH) within a time slot 310. Further, one or more reference signals, such as side link SSB, side link CSI-RS, side link SRS, and/or side link Positioning Reference Signals (PRS), may be transmitted within the slot 310.

These physical channels are typically multiplexed and mapped to transport channels for processing at the Medium Access Control (MAC) layer. The transport channel carries blocks of information called Transport Blocks (TBs). The Transport Block Size (TBS) may correspond to the number of bits of information and may be a controlled parameter based on the Modulation and Coding Scheme (MCS) and the number of RBs in a given transmission.

In some aspects of the disclosure, the scheduling entity and/or the scheduled entity may be configured for beamforming and/or multiple-input multiple-output (MIMO) techniques. Fig. 4 is a diagram illustrating an example of a wireless communication system 400 supporting beamforming and/or multiple-input multiple-output (MIMO) in accordance with some aspects. In a MIMO system, transmitter 402 includes a plurality of transmit antennas 404 (e.g., N transmit antennas) and receiver 406 includes a plurality of receive antennas 408 (e.g., M receive antennas). Thus, there are n×m signal paths 410 from the transmit antenna 404 to the receive antenna 408. The plurality of transmit antennas 404 and the plurality of receive antennas 408 may each be configured in a single-panel or multi-panel antenna array. Each of the transmitter 402 and the receiver 406 may be implemented, for example, within a scheduling entity (e.g., base station 108) as shown in fig. 1 and/or fig. 2, a scheduled entity (e.g., UE 106) as shown in fig. 1 or fig. 2, or any other suitable wireless communication device.

The use of such multiple antenna techniques enables the wireless communication system 400 to utilize the spatial domain to support spatial multiplexing, beamforming, and transmit diversity. Spatial multiplexing may be used to simultaneously transmit different data streams, also referred to as layers, on the same time-frequency resources. The data streams may be transmitted to a single UE to increase the data rate, or to multiple UEs to increase the overall system capacity, the latter being referred to as multi-user MIMO (MU-MIMO). This is achieved by spatially precoding each data stream (i.e., multiplying data streams with different weights and phase shifts) and then transmitting each spatially precoded stream through multiple transmit antennas on the downlink. The spatially precoded data streams arrive at the UEs with different spatial signatures, which enable each UE to recover one or more data streams destined for that UE. On the uplink, each UE transmits a spatially precoded data stream, which enables the base station to identify the source of each spatially precoded data stream.

The number of data streams or layers corresponds to the rank of transmission. In general, the rank of a MIMO system (e.g., MIMO-enabled wireless communication system 400) is limited by the number of transmit or receive antennas 404 or 408 (whichever is lower). In addition, channel conditions at the UE and other considerations (such as available resources at the base station) may also affect the transmission rank. For example, the rank (and thus the number of data streams) allocated to a particular UE on the downlink may be determined based on a Rank Indicator (RI) transmitted from the UE to the base station. RI may be determined based on the antenna configuration (e.g., the number of transmit antennas and receive antennas) and the measured signal-to-interference-plus-noise ratio (SINR) at each receive antenna. The RI may indicate, for example, the number of layers that may be supported under the current channel conditions. The base station may use the RI along with resource information (e.g., available resources and data amounts to be scheduled for the UE) to assign a transmission rank to the UE.

In a Time Division Duplex (TDD) system, UL and DL are reciprocal in that each uses a different time slot of the same frequency bandwidth. Thus, in a TDD system, a base station may allocate a rank of DL MIMO transmission based on UL SINR measurements (e.g., based on Sounding Reference Signals (SRS) or other pilot signals transmitted from a UE). Based on the assigned rank, the base station may then transmit a channel state information reference signal (CSI-RS) with a separate CSI-RS sequence for each layer to provide a multi-layer channel estimate. From the CSI-RS, the UE may measure channel quality across layers and resource blocks and feed back Channel Quality Indicator (CQI) and Rank Indicator (RI) values to the base station for updating the rank and allocating REs for future downlink transmissions.

In one example, as shown in fig. 4, a rank 2 spatially multiplexed transmission on a 2 x 2 MIMO antenna configuration will transmit one data stream from each transmit antenna 404. Each data stream follows a different one of the signal paths 410 to each of the receive antennas 408. The receiver 406 may then reconstruct the data stream using the signals received from each receive antenna 408.

Beamforming is a signal processing technique that may be used at either the transmitter 402 or the receiver 406 to shape or steer an antenna beam (e.g., a transmit/receive beam) along a spatial path between the transmitter 402 and the receiver 406. Beamforming may be implemented by combining signals transmitted via antennas 404 or 408 (e.g., antenna elements of an antenna array) such that some signals experience constructive interference and others experience destructive interference. To produce the desired constructive/destructive interference, the transmitter 402 or receiver 406 may apply an amplitude and/or phase offset to signals transmitted or received from each of the antennas 404 or 408 associated with the transmitter 402 or receiver 406.

A base station (e.g., a gNB) is typically able to communicate with UEs using transmit beams of different beamwidths (e.g., downlink transmit beams). For example, the base station may be configured to use a wider beam when communicating with a UE in motion and a narrower beam when communicating with a UE in rest. The UE may also be configured to receive signals from the base station using one or more downlink receive beams.

In some examples, to select one or more serving beams (e.g., one or more downlink transmit beams and one or more downlink receive beams) for communication with the UE, the base station may transmit a reference signal, such as a Synchronization Signal Block (SSB), a Tracking Reference Signal (TRS), or a channel state information reference signal (CSI-RS), on each of the plurality of beams (e.g., on each of the plurality of downlink transmit beams) in a beam scanning manner. The UE may measure a Reference Signal Received Power (RSRP) on each beam (e.g., measure RSRP on each of a plurality of downlink transmit beams) and send a beam measurement report to the base station indicating a layer 1RSRP (L-1 RSRP) of each measured beam. The base station may then select a serving beam(s) for communication with the UE based on the beam measurement report. In other examples, when the channel is reciprocal, the base station may derive the particular beam(s) (e.g., particular downlink beam (s)) in communication with the UE based on uplink measurements of one or more uplink reference signals, such as Sounding Reference Signals (SRS).

Similarly, uplink beams (e.g., uplink transmit beam(s) at the UE and uplink receive beam(s) at the base station) may be selected by measuring RSRP of received uplink reference signals (e.g., SRS) or downlink reference signals (e.g., SSB or CSI-RS) during uplink or downlink beam scanning. For example, the base station may determine the uplink beam by uplink beam management via SRS beam scanning in the case of measurement at the base station or by downlink beam management via SSB/CSI-RS beam scanning in the case of measurement at the UE. The selected uplink beam may be indicated by the selected SRS resource (e.g., time-frequency resource for transmission of SRS) when uplink beam management is implemented, or by the selected SSB/CSI-RS resource when downlink beam management is implemented. For example, the selected SSB/CSI-RS resources may have a spatial relationship with the selected uplink transmit beam (e.g., uplink transmit beams for PUCCH, SRS, and/or PUSCH). The resulting selected uplink transmit beam and uplink receive beam may form an uplink beam pair link.

In a 5G New Radio (NR) system, particularly for above 6GHz or millimeter wave (mmWave) systems, the beamformed signals may be used for downlink channels, including Physical Downlink Control Channels (PDCCHs) and Physical Downlink Shared Channels (PDSCH). Furthermore, for UEs configured with a beamforming antenna array module, the beamforming signals may also be used for uplink channels, including Physical Uplink Control Channel (PUCCH) and Physical Uplink Shared Channel (PUSCH). However, it should be appreciated that the beamformed signals may also be utilized by an enhanced mobile broadband (eMBB) gNB, for example, for sub-6 GHz systems.

Fig. 5 is a diagram illustrating an example of communication between a base station 504 and a UE 502 using beamforming in accordance with some aspects. The base station 504 may be any of the base stations (e.g., the gnbs) or scheduling entities shown in fig. 1, 2, or 4, and the UE 502 may be any of the UEs or scheduled entities shown in fig. 1, 2, or 4.

The base station 504 is typically capable of communicating with the UE 502 using one or more transmit beams and the UE 502 is also capable of communicating with the base station 504 using one or more receive beams. As used herein, the term transmit beam refers to a beam on the base station 504 that may be used for downlink or uplink communications with the UE 502. Further, the term receive beam refers to a beam on the UE 502 that may be used for downlink or uplink communications with the base station 504.

In the example shown in fig. 5, the base station 504 is configured to generate a plurality of transmit beams 506a, 506b, 506c, 506d, 506e, 506f, 506g, and 506h (506 a-506 h), each associated with a different spatial direction. Further, the UE 502 is configured to generate a plurality of receive beams 508a, 508b, 508c, 508d, and 508e (508 a-508 e), each beam being associated with a different spatial direction. It should be noted that while some of the beams are shown adjacent to each other, this arrangement may be different in different respects. For example, transmit beams 506a-506h transmitted during the same symbol may not be adjacent to each other. In some examples, the base station 504 and the UE 502 may each transmit more or less beams distributed in all directions (e.g., 360 degrees) and three dimensions. In addition, transmit beams 506a-506h may include beams having varying beamwidths. For example, base station 504 may transmit some signals (e.g., synchronization Signal Blocks (SSBs)) on a wider beam and other signals (e.g., CSI-RS) on a narrower beam.

The base station 504 and the UE 502 may select one or more transmit beams 506a-506h on the base station 504 and one or more receive beams 508a-508e on the UE 502 for transmitting uplink and downlink signals therebetween using a beam management procedure. In one example, during initial cell acquisition, the UE 502 may perform a P1 beam management procedure to scan a plurality of transmit beams 506a-506h using a plurality of receive beams 508a-508e to select a beam-to-link (e.g., one of the transmit beams 506a-506h and one of the receive beams 508a-508 e) for a Physical Random Access Channel (PRACH) procedure of an initial access cell. For example, periodic SSB beam scanning may be implemented at certain intervals (e.g., based on SSB periodicity) at base station 504. Thus, the base station 504 may be configured to scan or transmit SSBs on each of the plurality of wider transmit beams 506a-506h during a beam scanning interval. The UE 502 may measure the Reference Signal Received Power (RSRP) of each SSB transmitted on each transmit beam 506a-506h on each receive beam 508a-508e of the UE 502. The UE 502 may select a transmit beam and a receive beam based on the measured RSRP. In one example, the selected receive beam may be the receive beam on which the highest RSRP is measured, and the selected transmit beam may have the highest RSRP measured on the selected receive beam.

After completing the PRACH procedure, the base station 504 and the UE 502 may perform a P2 beam management procedure for beam refinement at the base station 504. For example, the base station 504 may be configured to scan or transmit CSI-RS on each of a plurality of narrower transmit beams 506a-506h. Each of the narrower CSI-RS beams may be a sub-beam (not shown) of the selected SSB transmit beam (e.g., in a spatial direction of the SSB transmit beam). The transmission of CSI-RS transmit beams may occur periodically (e.g., as configured via Radio Resource Control (RRC) signaling of the gNB), semi-continuously (e.g., as configured via RRC signaling of the gNB and activated/deactivated via medium access control-control element (MAC-CE) signaling), or aperiodically (e.g., as triggered by the gNB via Downlink Control Information (DCI)). The UE 502 may be configured to scan a plurality of CSI-RS transmit beams 506a-506h on a plurality of receive beams 508a-508 e. The UE 502 may then perform beam measurements (e.g., measurements of RSRP, SINR, etc.) of the received CSI-RS on each of the receive beams 508a-508e to determine a respective beam quality for each of the CSI-RS transmit beams 506a-506h measured on each of the receive beams 508a-508 e.

The UE 502 may then generate and transmit a layer 1 (L1) measurement report to the base station 504 that includes respective beam indices (e.g., CSI-RS resource indicators (CRI)) and beam measurements (e.g., RSRP or SINR) of CSI-RS transmit beams 506a-506h on one or more of the receive beams 508a-508 e. The base station 504 may then select one or more CSI-RS transmit beams on which to transmit downlink and/or uplink control and/or data with the UE 502. In some examples, the selected CSI-RS transmit beam(s) have the highest RSRP from the L1 measurement report. The transmission of the L1 measurement report may occur periodically (e.g., as configured via RRC signaling of the gNB), semi-continuously (e.g., as configured via RRC signaling of the gNB and activated/deactivated via MAC-CE signaling), or aperiodically (e.g., as triggered by the gNB via DCI).

The UE 502 may also select a corresponding receive beam on the UE 502 for each selected serving CSI-RS transmit beam to form a respective Beam Pair Link (BPL) for each selected CSI-RS transmit beam. For example, the UE 502 may utilize the beam measurements obtained in the P2 procedure, or perform a P3 beam management procedure to obtain new beam measurements for the selected CSI-RS transmit beams to select a corresponding receive beam for each selected transmit beam. In some examples, the selected receive beam paired with the particular CSI-RS transmit beam may be the receive beam on which the highest RSRP of the particular CSI-RS transmit beam is measured.

In some examples, in addition to performing CSI-RS beam measurements, base station 504 may configure UE 502 to perform SSB beam measurements and provide L1 measurement reports including beam measurements for SSB transmit beams 506a-506 h. For example, the base station 504 may configure the UE 502 to perform SSB beam measurements and/or CSI-RS beam measurements for Beam Fault Detection (BFD), beam Fault Recovery (BFR), cell reselection, beam tracking (e.g., for mobile UE 502 and/or base station 504), or other beam optimization purposes.

Further, when the channel is reciprocal, the transmit and receive beams may be selected using an uplink beam management scheme. In one example, the UE 502 may be configured to scan or transmit on each of a plurality of receive beams 508a-508 e. For example, UE 502 may transmit SRS on each beam in a different beam direction. Further, the base station 504 may be configured to receive uplink beam reference signals on a plurality of transmit beams 506a-506 h. The base station 504 may then perform beam measurements (e.g., RSRP, SINR, etc.) of the beam reference signals on each of the transmit beams 506a-506h to determine a respective beam quality for each of the receive beams 508a-508e measured on each of the transmit beams 506a-506 h.

The base station 504 may then select one or more transmit beams on which to communicate downlink and/or uplink control and/or data with the UE 502. In some examples, the selected transmit beam(s) may have the highest RSRP. The UE 502 may then select a corresponding receive beam for each selected serving transmit beam using, for example, a P3 beam management procedure to form a respective Beam Pair Link (BPL) for each selected serving transmit beam, as described above.

In one example, a single CSI-RS transmit beam (e.g., transmit beam 506 d) on base station 504 and a single receive beam (e.g., receive beam 508 c) on UE 502 may form a single BPL for communication between base station 504 and UE 502. In another example, multiple CSI-RS transmit beams (e.g., transmit beams 506c, 506d, and 506 e) on base station 504 and a single receive beam (e.g., receive beam 508 c) on UE 502 may form respective BPLs for communication between base station 504 and UE 502. In another example, multiple CSI-RS transmit beams (e.g., transmit beams 506c, 506d, and 506 e) on base station 504 and multiple receive beams (e.g., receive beams 508c and 508 d) on UE 502 may form multiple BPLs for communication between base station 504 and UE 502. In this example, the first BPL may include a transmit beam 506c and a receive beam 508c, the second BPL may include a transmit beam 508d and a receive beam 508d, and the third BPL may include a transmit beam 508e and a receive beam 508d.

The channels or carriers described herein are not necessarily all channels or carriers that may be used between the scheduling entity and the scheduled entity, and one of ordinary skill in the art will recognize that other channels or carriers may be used in addition to those shown, such as other traffic, control, and feedback channels.

High Speed Trains (HSTs) may utilize a Single Frequency Network (SFN) to facilitate wireless communications. User Equipment (UE) located within the HST may move in a predefined path or trajectory (e.g., where the train track defines a predefined path or trajectory) at speeds exceeding 300 kilometers per hour. Remote radio heads or Transmission and Reception Points (TRP) may be deployed along a predetermined path and associated with a base station. In an SFN, multiple TRPs may serve a single UE and transmit on the same time-frequency resource. Due to densification, SFNs can be used to provide spatial diversity gain, where adjacent TRPs transmit the same data in the same time-frequency resource to simultaneously provide signals (bearer data) from multiple TRPs to the UE. However, due to the different locations of the TRPs relative to the UE and the different paths based on the different beams, the transmission from each TRP may arrive at the UE at different times, which may increase delay spread, resulting in Inter Symbol Interference (ISI).

Fig. 6A is a graph of an uncompensated effective Power Delay Profile (PDP) 600 over time at a plurality of delay locations without beam-specific timing precompensation, according to some aspects. Fig. 6B is a graph of a precompensated effective Power Delay Profile (PDP) 601 over time at multiple delay locations with beam specific timing precompensation, according to some aspects. In the examples of fig. 6A and 6B, a Power Delay Profile (PDP) is shown along the vertical axis in units of power (e.g., mW, dBm), while a plurality of delay locations are shown along the horizontal axis in units of time (e.g., τ1, τ2, τ3, τ4). The uncompensated active PDP 600 and the timing precompensated active PDP 601 illustrate PDPs at the receiver of one UE. The first PDP trace 602 centered at τ1, the second PDP trace 604 centered at τ2, the third PDP trace 606 centered at τ3, and the fourth PDP trace 608 centered at τ4 correspond to the transmission of the same downlink channel (or the same signal) from four corresponding TRPs.

The shape of each PDP trace may be a function of the respective beam pair link characteristics (e.g., gain, width, etc.), where each respective beam pair link is directed between a respective TRP and UE. The shape of each PDP trace may also be a function of the beam weights used by the UE and TRP. Fig. 6A and 6B may represent large time domain windows (e.g., windows spanning less than τ1 to greater than τ4) that a UE may use to cover the entire time delay spread in an HSF-SFN scenario.

As shown in fig. 6A, uncompensated active PDP 600 (e.g., a composite of first PDP trace 602, second PDP trace 604, third PDP trace 606, and fourth PDP trace 608) exhibits nulls between component traces (e.g., nulls between τ1 and τ2, between τ2 and τ3, etc.). During the null value, there may be little or no energy corresponding to the desired information in the downlink channel (or signal) received at the UE from the corresponding TRP. During the null, the receiver of the UE may receive undesired interference (e.g., inter-symbol interference (ISI)) instead of the actual desired signal.

As shown in fig. 6B, a first PDP trace 602 (e.g., associated with a first TRP) that was previously pre-compensated for by a timing centered at τ1 may be delayed in time (i.e., shifted to the right along the time axis). This delay may allow the first PDP trace 602 to be more centered near τ2 (as shown) or even centered around it (not shown). Similarly, a third PDP trace 606 (e.g., associated with a third TRP) that was previously pre-compensated for by a τ3-centered timing may be advanced in time (i.e., moved to the left along the time axis). This advance may allow the third PDP trace 606 to be more centered near τ2 (as shown) or even centered around it (not shown). Similarly, a fourth PDP trace 608 (e.g., associated with a fourth TRP) that was previously pre-compensated for by τ4-centered timing may be advanced in time (i.e., moved to the left along the time axis). This advance (which in this example is greater than the advance applied to the third PDP trace 606) may allow the fourth PDP trace 608 to be more centered near τ2 (as shown) or even centered around it (not shown). In the example of fig. 6B, no beam-specific timing pre-compensation may be applied to the second PDP trace 604 (e.g., associated with the second TRP). Thus, the position in time of the second PDP trace 604 remains unchanged on the time axis. The effect of the time offset on the timing pre-compensated active PDP 601 is that the delay spread (in time) of the timing pre-compensated active PDP 601 of fig. 6B is narrowed compared to the uncompensated active PDP 600 of fig. 6A.

Of course, the time offset due to the beam specific timing precompensation in fig. 6B is exemplary and not limiting. Any combination of time offsets that results in a narrowing (in time) of the delay spread is within the scope of the present disclosure. For example, each of the first and second PDP traces 602 and 604 may be delayed in time so that their center points are closer to or coincide with the time between τ2 and τ3, while each of the third and fourth PDP traces 606 and 608 may be advanced in time so that their center points are closer to or coincide with the same time between τ3 and τ2. Further, pre-compensation (including pre-compensating only the first beam, pre-compensating only the second beam, or pre-compensating both the first beam and the second beam) may be applied to the beam pair links of any two or more TRPs. The precompensation applied to four TRPs (represented by four PDP traces in fig. 6A and 6B) in fig. 6B is exemplary and not limiting. Still further, two or more TRPs may or may not be adjacent to each other.

Based on the time offset attributable to the beam-specific timing precompensation as described herein, the overall delay spread of the active PDP can be reduced in time. As shown in this example, the entire delay spread in fig. 6A extends from a point earlier than τ1 on the time axis to a point later than τ4 on the time axis. In contrast, the entire delay spread in fig. 6B extends from a point on the time axis corresponding to τ1 to a point located midway between T3 and τ4. By using beam-specific timing precompensation, the narrowing of the overall delay spread time window may allow more of the desired signal in the channel to be received over the entire (narrowed compared to fig. 6B) delay spread, at least because the nulls between the corresponding PDP traces where the interference power may exceed the component of the signal power are narrowed and may even be eliminated (as shown). Furthermore, the narrowing of the overall delay spread time window may make it easier to handle an active PDP (i.e., a composite of corresponding PDP traces).

In some cases, extending the Cyclic Prefix (CP) duration (unlike the practice of beam-specific timing precompensation described herein) may reduce null values, thereby reducing interference (e.g., inter-symbol interference (ISI)). However, excessive delay spread of a received downlink signal or channel (e.g., such as the channel shown in the example of fig. 6A) may not be fully compensated for by extending the CP duration. In this case, compensation by extending the CP duration still results in reduced Receiver (RX) performance (e.g., due to noise, due to ISI). Furthermore, extending the CP duration undesirably increases transmission overhead. Extending CP duration and beam-specific timing pre-compensation as described herein is a different practice.

Further, and by way of example only, in accela type trains, UEs may apply timing advance to their uplink transmissions such that all different uplink transmissions received by the gNB from the UE may be aligned on a symbol level. In current practice of TA, the base station uses the downlink to indicate to the respective UEs the timing advance that each respective UE should apply to its respective uplink transmission. In contrast, in the practice of beam-specific timing precompensation, as described herein, the base station may use the downlink to inform the respective UE about the timing advance (or delay) of the respective downlink beam that the gNB has or is about to apply to the respective TRP.

In summary, the compensation technique for reducing delay spread of a PDP for a downlink signal or channel or an uplink signal or channel in an HST-SFN environment may be a function of parameters and beam weights for individual beams used by a single UE and multiple TRPs for the link. Excessive delay spread may undesirably reduce Receiver (RX) performance and may not be compensated for by extending the Cyclic Prefix (CP) duration. If the CP duration is extended to compensate for the delay spread, the transmission overhead may undesirably increase. In addition to beam-specific timing precompensation as described herein, current practice of extending CP duration in downlink transmissions and/or TAs (as exemplified in connection with Accella-type trains in uplink transmissions) may also be practiced.

Fig. 7 is a right side elevation view of a vehicle 714 (e.g., a high speed train car) in an environment illustrating an example of beam specific timing precompensation in a high speed train (HST-SFN) single frequency network (HST-SFN) 700, in accordance with some aspects. As shown in fig. 7, the HST-SFN 700 includes a base station 702 that includes a plurality of Transmission and Reception Points (TRPs) 704 deployed in a remote radio head configuration. In the example shown, the plurality of TRPs 704 includes a first TRP 706, a second TRP 708, a third TRP 710, and a fourth TRP 712; however, any number of TRPs is within the scope of the present disclosure. The HST-SFN 700 also includes a vehicle 714 (e.g., a high speed railcar) having a centerline located at a position marked by the letter X716. As shown in the example of fig. 7, the vehicle 714 moves along a path 720 (e.g., a high speed track) along the X-axis in the direction described by vector 718. The vehicle 714 may include a plurality of UEs 722.

The plurality of UEs 722 may include a first UE 724, a second UE 726, and a third UE 728. Any number of UEs, from one to a plurality, is within the scope of the present disclosure. The plurality of UEs 722 may include a mobile handset, a tablet, a mobile phone, customer Premise Equipment (CPE), and the like. The first UE 724 is offset from a centerline X716 of the vehicle 714; however, because the first UE 724 is located within the vehicle 714, the speed, acceleration, and direction of movement of the first UE 724 may be considered the same as the speed, acceleration, and direction of movement of the vehicle 714 when the vehicle 714 is moving.

As shown in fig. 7, a first UE 724 may communicate with a first TRP 706 via a first beam pair link 730. The first beam pair link may include a beam for downlink transmission and uplink reception (collectively, transmit beams) at the first TRP, and a beam for downlink reception and uplink transmission (collectively, receive beams) by the first UE 724. The first UE 724 may also communicate with a second TRP 708 via a second beam pair link 732. The first UE 724 may additionally or alternatively communicate with the third TRP 710 via a third beam pair link 734. Communication between the first UE 724 and two or more TRPs is within the scope of the present disclosure.

It should be appreciated that each of the plurality of UEs 722 may communicate with each of the plurality of TRPs 704 via a respective beam pair link. Although the description herein may use examples of communication between the first UE 724 and both the first TRP 706 and the second TRP 708 (via the first beam pair link 730 and the second beam pair link 732, respectively), or communication between the first UE 724 and the first TRP 706, the second TRP 708, and the third TRP 710 (via the first beam pair link 730, the second beam pair link 732, and the third beam pair link 734, respectively), the first UE 724 may use the respective beam pair links to communicate with any two or more of the plurality of TRPs 704 while implementing the concepts described herein. Further, each of the plurality of TRPs 704 may communicate with each of the plurality of UEs 722 via a respective beam pair link and implement the concepts described herein.

The first UE 724 may send one or more uplink transmissions for receipt by the base station 702 via the plurality of TRPs 704 including the first TRP 706, the second TRP 708, and/or the third TRP 710 (and/or additional TRPs including, but not limited to, the fourth TRP 712). The plurality of TRPs 704 may be located adjacent to the path 720 (e.g., mounted adjacent to one another on a wall of a tunnel through which the path 720 passes, or mounted on poles, towers, buildings, or overhead supports that are staggered along the length of the path 720). As described herein, the first UE 724 may move with the plurality of UEs 722 at the same speed, in the same direction, and along the same path 720 (e.g., defined by a train track) of the vehicle 714 relative to each of the plurality of TRPs 704 associated with the base station 702. In the example of fig. 7, the first UE 724 moves along the X-axis in the direction indicated by vector 718 (e.g., to the right). The plurality of UEs 722 may move at a constant speed or with acceleration.

The first UE 724 may transmit an uplink signal or channel in (e.g., uplink transmission) on the first beam-pair link 730 to the first TRP 706, on the second beam-pair link 732 to the second TRP 708, and/or on the third beam-pair link 734 to the third TRP 710. Examples of the uplink signal include a demodulation reference signal (DM-RS) (for PUSCH and PUCCH), a phase tracking reference signal (PT-RS) (for PUSCH), and a Sounding Reference Signal (SRS). Examples of uplink channels include a Physical Uplink Shared Channel (PUSCH), a Physical Uplink Control Channel (PUCCH), and a Physical Random Access Channel (PRACH). A signal or channel (e.g., uplink transmission) received by the first TRP 706 on the first beam pair link 730 may have a first delay 740 (e.g., delay between transmission from the first UE 724 and reception via the first TRP 706). The signal or channel received by the second TRP 708 on the second beam pair link 732 may have a second delay 742 (e.g., a delay between transmission from the first UE 724 and reception at the second TRP 708). The signal or channel received by the third TRP 710 on the third beam pair link 734 may have a third delay 744 (e.g., a delay between transmission from the first UE 724 and reception at the third TRP 710).

In a first scenario 701, where a signal or channel (e.g., an uplink transmission) is received by the first TRP706 and the second TRP 708, and the first TRP706 and the second TRP 708 are adjacent to each other, the first delay 740 may be longer than the second delay 742 (because in the example of fig. 7, the first UE 724 is closer to the first TRP 708 than it is to the first TRP 706). Thus, in the example of the first case 701 of fig. 7, the first delay 740 > the second delay 742. In a second scenario 703, wherein the signal or channel is received by the first TRP706, the second TRP 708, and the third TRP 710, wherein the first TRP706 is adjacent to the second TRP 708 and not adjacent to the third TRP 710 (i.e., the second TRP 708 is located between the first TRP706 and the third TRP 710), the third delay 744 may be longer than the first delay 740, and the first delay may be longer than the second delay 742 (because in the example of fig. 7 the first UE 724 is furthest from the third TRP 710, furthest from the first TRP706, and closest to the second TRP 708). Thus, in the example of the second case 703 of fig. 7, the third delay 744 > the first delay 740 > the second delay 742.

In the time span shown in fig. 7 (e.g., where the time span includes at least enough time for receiving uplink transmissions via the first TRP706, the second TRP 708, and/or the third TRP 710), a first distance corresponding to a first delay 740 between the first UE 724 and the first TRP706 is greater than a second distance corresponding to a second delay 742 between the first UE and the second TRP 708. A third distance corresponding to a third delay 744 between the first UE and the third TRP 710 is greater than both the first distance and the second distance. The first distance/delay, the second distance/delay, and the third distance/delay dynamically change as the vehicle 714 (e.g., a high speed train) moves along the path 720 (e.g., a train track). In the next time span, when the first UE 724 and the second TRP 708 (not shown) are parallel, the distance between the first UE 724 and the first TRP706 and between the first UE 724 and the third TRP 710 may be equal to and greater than the distance between the first UE 724 and the second TRP 708. The varying distance/delay is dynamic as long as the vehicle 714 is moving.

As an example regarding uplink transmissions (e.g., signals or channels), the base station 702 may trigger the first UE 724 to transmit a Sounding Reference Signal (SRS) or another (reference) signal on two or more of the first beam pair link 730, the second beam pair link 732, and/or the third beam pair link 734 as an uplink transmission from the first UE 724. The base station 702 can determine a timing difference between receiving SRS or other (reference) signals via the first TRP 706 on the first beam pair link 730, the second TRP 708 on the second beam pair link 732, and/or the third TRP 710 on the third beam pair link 734.

In some aspects, the base station 702 may obtain (e.g., estimate, calculate, determine, derive) a first beam-specific timing pre-compensation for a downlink transmit beam of the first beam-pair link 730, a second beam-specific timing pre-compensation for a downlink transmit beam of the second beam-pair link 732, and/or a third beam-specific timing pre-compensation for a downlink transmit beam of the third beam-pair link 734 based on the determined timing difference between receipt of SRS or other (reference) signals via the first TRP 706 on the first beam-pair link 730, the second TRP 708 on the second beam-pair link 732, and/or the third TRP 710 on the third beam-pair link 734.

The base station may apply a first beam-specific timing pre-compensation to the first beam-pair link 730, a second beam-specific timing pre-compensation to the second beam-pair link 732, and/or a third beam-specific timing pre-compensation to the three beam-pair link 734 in downlink transmissions of downlink channels or downlink signals sent to the first UE 724 via the first TRP 706, the second TRP 708, and/or the third TRP 710, respectively. The base station 702 may prevent or reduce interference (e.g., ISI) experienced at the first UE 724 due to, for example, a channel or downlink transmission of a signal received at a different time by applying first, second, and/or third beam-specific timing precompensations to the first, second, and/or third TRPs 706, 708, and/or 710, respectively.

In the HST-SFN 700 shown in fig. 7, the downlink transmissions of a given channel or signal from the first TRP 706, the second TRP 708, and/or the third TRP 710 may utilize the same time-frequency resources. Applying the first, second, and/or third beam-specific timing precompensations to the downlink transmissions of a given channel or signal on the first, second, and/or third beam-pair links 730, 732, 734, respectively, may reduce the total time-spread delay of the power delay profile of the respective transmissions by shifting one or more of the power delay profiles in time to or towards a predetermined time.

In some examples, the base station 702 may determine whether the first beam specific timing precompensation advances or delays the transmission time of the first beam to a downlink channel or signal on the link 730. Similarly, the base station 702 can determine whether the second beam specific timing precompensation advances or delays the time of the second beam to the downlink channel or signal on link 732. Similarly, the base station 702 may determine whether the third beam-specific timing precompensation advances or delays the transmission time of a downlink channel or signal on the third beam-pair link 734. In some examples, the base station 702 may determine that the first beam-specific timing precompensation does not affect the downlink channel or the transmission time of the signal on the first beam-pair link 730. Similarly, the base station 702 may determine that the second beam-specific timing precompensation does not affect the downlink channel or the transmission time of the signal on the second beam-pair link 732. Similarly, the base station 702 may determine that the third beam-specific timing precompensation does not affect the downlink channel or the time of transmission of the signal on the third beam pair link 734. The base station 702 may set the value of the beam-specific timing precompensation for the given beam to the link to zero so that any beam-specific timing precompensation does not affect the transmission time of the given beam to the downlink channel or signal on the link. In one example, for purposes of discussion and not limitation, the base station 702 may determine that the first beam-specific timing pre-compensation does not affect the transmission time of the first TRP 706 of the downlink channel or signal on the first beam-pair link 730 (i.e., set the first beam-specific timing pre-compensation to zero) while setting the second beam-specific timing pre-compensation and/or the third beam-specific timing pre-compensation to move the second PDP of the second TRP 708 and/or the third PDP of the third TRP 710 toward the first PDP of the first TRP 706.

In some aspects, obtaining the first, second, and/or third beam-specific timing precompensations may include determining a first, second, and/or third beam-specific timing precompensations for at least one of one or more signals, one or more UE-specific channels, or one or more common channels common to each of the plurality of UEs (e.g., the plurality of UEs 722). For example, as described herein, the first beam-specific timing pre-compensation, the second beam-specific timing pre-compensation, and/or the third beam-specific timing pre-compensation may be used to pre-compensate one or more signals (e.g., DM-RS, tracking Reference Signals (TRSs), etc.), one or more UE-specific channels (e.g., PDSCH or UE-specific DCI carried within PDCCH dedicated to a particular UE on the vehicle 714), or one or more common channels (e.g., common DCI carried within PDCCH) common to each of the plurality of UEs 722 on the vehicle 714.

The base station 702 may send an indication of at least one of the first beam-specific timing pre-compensation, the second beam-specific timing pre-compensation, or the third beam-specific timing pre-compensation to the first UE 724 (i.e., the base station sends the beam-specific timing pre-compensation to the first UE 724 for use by the base station 702 and/or to be used for downlink transmissions to the first UE 724). For example, an indication of at least one of the first beam-specific timing precompensation, the second beam-specific timing precompensation, or the third beam-specific timing precompensation may be transmitted to at least a first UE 724 of the plurality of UEs 722 using at least one of Downlink Control Information (DCI), a transmission configuration indication, a Medium Access Control (MAC) control element (MAC-CE), or RRC signaling. In some aspects, the indication of at least one of the first beam-specific timing pre-compensation, the second beam-specific timing pre-compensation, or the third beam-specific timing pre-compensation may be based on, for example, a speed of the first UE 724 (and/or the plurality of UEs 722) moving along the path 720, an acceleration of the first UE 724 (and/or the plurality of UEs 722) moving along the path 720, a position of at least one UE of the plurality of UEs 722 (e.g., the first UE 724) (where the position may be given by at least one of a geographic location such as latitude and longitude, a reference to a predetermined location on the path 720, a position relative to a departure or arrival time of the vehicle 714 at a given site or location along the path, etc.), or a direction of movement (travel) of the first UE 724 (and/or the plurality of UEs 722) along the path 720.

For example, as the speed of the vehicle 714 changes, the rate of change of the distance between each TRP (including the first TRP 706, the second TRP 708, and the third TRP 710) and the first UE 724 changes. To accommodate such a rate of change in distance, the base station 702 may modify or change one or more beam-specific timing precompensations for the link for each of the plurality of TRPs 704 located along the path 720, including, for example, a first beam-specific timing precompensation for the downlink transmit beam applied to the first beam-to-link 730, a second beam-specific timing precompensation for the downlink transmit beam applied to the second beam-to-link 732, and/or a third beam-specific timing precompensation for the downlink transmit beam applied to the third beam-to-link 734, which are associated with the first TRP 706, the second TRP 708, and/or the third TRP 710, respectively.

As another example, as the location of the vehicle 714 changes along the path 720, the location of the first UE 724 may also change along the path 720, resulting in a change in the distance between each of the plurality of TRPs 704 (including the first TRP 706, the second TRP 708, and the third TRP 710) and the plurality of UEs 722 (including the first UE 724, the second UE 726, and the third UE 728). The change in distance may cause the base station 702 to modify or change one or more beam-specific timing precompensations of the beam of each of the plurality of TRPs 704 located along the path 720, including, for example, a first beam-specific timing precompensation applied to the downlink transmit beam of the first beam-to-link 730, a second beam-specific timing precompensation applied to the downlink transmit beam of the second beam-to-link 732, and/or a third beam-specific timing precompensation applied to the downlink transmit beam of the third beam-to-link 734, which are associated with the first TRP 706, the second TRP 708, and/or the third TRP 710, respectively.

As yet another example, as the direction of movement of the vehicle 714 changes along the path 720, the direction of movement of the first UE 724 may change relative to each of the plurality of TRPs 704 (including the first TRP 706, the second TRP 708, and the third TRP 710) and the first UE 724. The change in direction of movement may cause the base station 702 to modify or change one or more beam-specific timing precompensations of the beam of each of the plurality of TRPs 704 located along path 720, including, for example, a first beam-specific timing precompensation applied to the downlink transmit beam of the first beam-to-link 730, a second beam-specific timing precompensation applied to the downlink transmit beam of the second beam-to-link 732, and/or a third beam-specific timing precompensation applied to the downlink transmit beam of the third beam-to-link 734, which are associated with the first TRP 706, the second TRP 708, and/or the third TRP 710, respectively.

Subsequently, the base station 702 can pre-compensate a first beam pair link 730 via the first TRP 706 according to a first beam specific timing, pre-compensate a second beam pair link 732 via the second TRP 708 according to a second beam specific timing, and/or transmit a Physical Downlink Shared Channel (PDSCH) transmission (or other downlink channel or signal) on one resource (e.g., time-frequency resource) via the third TRP 710 according to a third beam specific timing.

In some examples, each data layer of the PDSCH may be associated with multiple Transition Configuration Indication (TCI) states. For example, each data layer of PDSCH may be associated with a first TCI state indicating a downlink transmit beam of a first beam pair link 730 of a first TRP 706 and a second TCI state indicating a downlink transmit beam of a second beam pair link 732 of a second TRP 708. In some examples, each data layer of the PDSCH may be associated with a single composite TCI state representing multiple TCI states. For example, each data layer of the PDSCH may be associated with a single composite TCI state representing a first TCI state and a second TCI state.

Fig. 8 is a signaling diagram illustrating exemplary signaling 800 for beam-specific timing precompensation according to some aspects. In some examples, the example signaling 800 may be used in a Single Frequency Network (SFN). In some examples, the example signaling 800 may be used in a High Speed Train (HST) single frequency network (HST-SFN). In the example shown in fig. 8, a User Equipment (UE) 802 (e.g., a first UE 724 as shown and described above in connection with fig. 7) may be in wireless communication with a base station 804 (e.g., base station 702 as shown and described above in connection with fig. 7). Base station 804 may have multiple TRPs for use in a remote radio head configuration. In the example of fig. 8, a first TRP 805 and a second TRP 807 through an nth TRP 809 are depicted, where n is a positive integer (e.g., first TRP 706, second TRP 708, and/or third TRP 710 as shown and described above in connection with fig. 7). The UE 802 may communicate wirelessly with the base station 804 via two or more of the plurality of TRPs, including a first TRP 805 on a first beam pair link and a second TRP 807 on a second beam pair link (e.g., a first beam pair link 730 and a second beam pair link 732 as shown and described above in connection with fig. 7). The UE 802, the base station 804, the first TRP 805, and the second TRP 805 to the nth TRP 809 may correspond to similar named entities as shown and described above in connection with fig. 1, 2, 4, 5, and/or 7.

At 806, the UE 802 can send an uplink transmission on a first beam pair link (not shown) to a first TRP 805 associated with the base station 804 and on a second beam pair link (not shown) to a second TRP 807 associated with the base station 804. Accordingly, at 806, the first TRP 805 associated with the base station 804 and the second TRP 807 associated with the base station 804 may each receive uplink transmissions. Because the distance between the UE 802 and the first TRP 805 may not be equal to the spacing between the UE 802 and the second TRP 807, uplink transmissions may be received via the first TRP 805 and the second TRP 807 at different times. The base station 804 may determine a timing difference between receipt of the uplink transmission via the first TRP 805 and the second TRP 807.

At 808, the UE 802 may receive a downlink transmission via the first TRP 805 on a first beam pair link (not shown) having a first beam specific timing precompensation and a downlink transmission via the second TRP 807 on a second beam pair link having a second beam specific timing precompensation, each of which may be based on a determination by the base station 804 of a timing difference between receipt of the uplink transmission via the first TRP 805 and the second TRP 807.

Fig. 9 is a signaling diagram illustrating exemplary signaling 900 for beam-specific timing precompensation according to some aspects. In some examples, the example signaling 900 may be used in a Single Frequency Network (SFN). In some examples, the example signaling 900 may be used in a High Speed Train (HST) single frequency network (HST-SFN). In the example shown in fig. 9, a User Equipment (UE) 902 (e.g., a first UE 724 as shown and described above in connection with fig. 7) may be in wireless communication with a base station 904 (e.g., base station 702 as shown and described above in connection with fig. 7). Base station 904 may have multiple TRPs for use in remote radio head configuration. In the example of fig. 9, a first TRP 905 and a second TRP 907 to an nth TRP 909 are depicted, where n is a positive integer (e.g., first TRP 706, second TRP 708, and/or third TRP 710 as shown and described above in connection with fig. 7). The UE 902 may communicate wirelessly with the base station 904 via two or more of the plurality of TRPs, including a first TRP 905 on a first beam pair link and a second TRP 907 on a second beam pair link (e.g., a first beam pair link 730 and a second beam pair link 732 as shown and described above in connection with fig. 7). The UE 902, the base station 904, the first TRP 905, and the second TRP 907 to the nth TRP 909 may correspond to similar named entities as shown and described above in connection with fig. 1, fig. 2, fig. 4, fig. 5, and/or fig. 7.

At 906, an uplink transmission (e.g., an uplink channel or signal) may be sent from the UE 902 to the base station 904 via the respective TRP (e.g., via the first TRP 905 and the second TRP 907) on the respective receive beam of the respective beam-pair link. Accordingly, uplink transmissions may be received at base station 904 via respective transmit beams at respective TRPs (e.g., a first transmit beam of a first beam pair link at a first TRP 905 associated with base station 904 and a second transmit beam of a second beam pair link at a second TRP 907 associated with base station 904).

At 908, the base station 904 can determine a time difference between receipt of the uplink transmission via the first TRP 905 and the second TRP 907. At 910, the base station 904 can obtain (e.g., estimate, calculate, determine, derive) a first beam-specific timing pre-compensation and a second beam-specific timing pre-compensation based on the time difference to apply to respective transmit beams at the first TRP 905 and the second TRP 907, respectively.

At 912, the base station may transmit via the first TRP 905 and the second TRP 907 and the UE 902 may receive an indication of at least one of a first beam-specific timing precompensation or a second beam-specific timing precompensation that was or would be applied to the downlink transmission from the base station 904, respectively. At 914, the first TRP 905 and the second TRP 907 may transmit downlink transmissions from respective transmit beams of the first TRP 905 and the second TRP 907 according to the first beam specific timing precompensation and the second beam specific timing precompensation, respectively, and the UE 902 may receive the downlink transmissions. At 916, the base station 904 may transmit to the first TRP 905 and the second TRP 907, respectively, and the UE 902 may receive an indication of the respective timing advances to be applied by the UE 902 for subsequent uplink transmissions.

Fig. 10 is a signaling diagram illustrating exemplary signaling 1000 for beam-specific timing precompensation according to some aspects. In some examples, the exemplary signaling 1000 may be used in a Single Frequency Network (SFN). In some examples, the exemplary signaling 1000 may be used in a High Speed Train (HST) single frequency network (HST-SFN). In the example illustrated in fig. 10, a User Equipment (UE) 1002 is in wireless communication with a base station 1004 via one or more wireless communication links. In some aspects, the UE 1002 may wirelessly communicate with the base station 1004 via a plurality of Transmission and Reception Points (TRPs) including a first TRP 1005 and a second TRP 1007 associated with the base station 1004. Each of the UE 1002, the base station 1004, the first TRP 1005, and the second TRP 1007 to nth TRP 1009 may correspond to similar named entities as shown and described above in connection with fig. 1, fig. 2, fig. 4, fig. 5, and/or fig. 7.

At 1006, the UE 1002 may send one or more uplink transmissions for receipt by the base station 1004. In some aspects, the UE 1002 may move with one or more other UEs at the same speed and along the same path relative to the base station 1004. For example, when the UE 1002 travels in a direction along a path (e.g., along a train track), the UE 1002 may send one or more uplink transmissions to the plurality of TRPs, including a first TRP 1005 and a second TRP 1007 located at locations adjacent to the path, as shown in fig. 7. The UE 1002 may send an uplink transmission to a first TRP 1005 associated with the base station 1004 using a first uplink beam and to a second TRP 1007 associated with the base station 1004 using a second uplink beam. In some aspects, the one or more uplink transmissions may include a Sounding Reference Signal (SRS).

At 1008, the base station 1004 may obtain (e.g., estimate, calculate, determine, derive) a timing difference (e.g., delay, timing delay) between at least a first beam and a second beam based on the one or more uplink transmissions, wherein the first beam may be transmitted by a first TRP 1005 associated with the base station 1004 and the second beam may be transmitted by a second TRP1007 associated with the base station 1004. For example, the base station 1004 may obtain a timing difference between the reception of the first uplink beam by the first TRP 1005 and the reception of the second uplink beam by the second TRP 1007. The base station 1004 may estimate a timing difference between a first beam for transmission by the first TRP 1005 to the UE 1002 and a second beam for transmission by the second TRP1007 to the UE 1002 based on the timing difference between the one or more uplink transmissions received by the first TRP 1005 from the UE 1002 and the one or more uplink transmissions received by the second TRP 1007.

At 1010, the base station 1004 may obtain a first beam-specific timing pre-compensation (e.g., a first beam-specific timing pre-compensation) for the first beam and a second beam-specific timing pre-compensation (e.g., a second beam-specific timing pre-compensation) for the second beam based on the timing difference. In some aspects, to prevent or reduce inter-symbol interference (ISI) between transmissions of a downlink channel or signal utilizing a first beam from a first TRP 1005 and a second beam from a second TRP1007, the base station 1004 may obtain a first beam-specific timing pre-compensation for the first beam and a second beam-specific timing pre-compensation for the second beam based on the obtained timing difference between the first beam and the second beam. In some examples, the base station 1004 may determine whether the first beam specific timing precompensation is to advance or delay transmission of a downlink channel or signal (e.g., downlink transmission) on the first beam in time. Similarly, the base station 1004 can determine whether the second beam specific timing precompensation advances or delays transmission of a downlink channel or signal on the second beam in time. Alternatively, the base station 1004 may determine that the first beam specific timing precompensation does not affect the transmission time of the downlink channel or signal of the first TRP 1005 on the first beam. Similarly, the base station 1004 may determine that the second beam specific timing precompensation does not affect the transmission time of the downlink channel or signal of the second TRP1007 on the second beam.

In some aspects, obtaining the first and second beam-specific timing precompensations may include determining the first and second beam-specific timing precompensations for at least one of one or more signals, one or more UE-specific channels, or one or more common channels common to each of the plurality of UEs. For example, as described herein, the HST may include (e.g., carry, transmit in) a plurality of UEs including UE 1002, and the first beam-specific timing pre-compensation and the second beam-specific timing pre-compensation may be for one or more signals (e.g., DM-RS, TRS, etc.), one or more UE-specific channels (e.g., PDCCH or PDSCH), or one or more common channels (e.g., common control information carried in PDCCH) common to each of the plurality of UEs on the HST.

At 1012, the base station 1004 may transmit an indication of at least one of the first beam-specific timing precompensation or the second beam-specific timing precompensation for reception by the UE 1002. For example, an indication of at least one of the first beam-specific timing precompensation or the second beam-specific timing precompensation may be transmitted to at least one of the plurality of UEs using at least one of Downlink Control Information (DCI) or a Medium Access Control (MAC) control element (MAC-CE). In some aspects, the indication of at least one of the first beam-specific timing precompensation or the second beam-specific timing precompensation may vary over time based on a speed of one or more UEs moving along the path, a position of at least one of the one or more UEs, or a direction of movement of the one or more UEs along the path.

For example, when the speed of the HST changes, the rate at which the distance between each TRP including the first TRP 1005 and the second TRP 1007 and the UE 1002 changes. To accommodate such a rate of change in distance, the base station 1004 may modify or change one or more beam-specific timing precompensations of the beam of each of the plurality of TRPs located along the path, including a first beam-specific timing precompensation of a first beam of the first TRP 1005 and a second beam-specific timing precompensation of a second beam of the second TRP 1007. As another example, when the location of the HST changes along the path, the location of the UE 1002 may also change along the path, resulting in a change in the distance between each TRP including the first TRP 1005 and the second TRP 1007 and the UE 1002. The change in distance may cause the base station 1004 to modify or change one or more beam-specific timing precompensations of the beam of each of the one or more TRPs located along the path, including a first beam-specific timing precompensation of a first beam of the first TRP 1005 and a second beam-specific timing precompensation of a second beam of the second TRP 1007. As yet another example, when the movement direction of the HST changes along the path, the movement direction of the UE 1002 may change with respect to each TRP including the first TRP 1005 and the second TRP 1007 and the UE 1002. The change in direction of movement may cause the base station 1004 to modify or change one or more beam-specific timing precompensations of the beam of each of the plurality of TRPs located along the path, including a first beam-specific timing precompensation of a first beam of the first TRP 1005 and a second beam-specific timing precompensation of a second beam of the second TRP 1007.

At 1014, base station 1004 may transmit the same Physical Downlink Shared Channel (PDSCH) transmission (or other downlink channel or signal) via the first beam of first TRP 1005 and via the second beam of second TRP 1007 according to the first beam specific timing pre-compensation. The TRPs including the first TRP 1005 and the second TRP 1007 may each transmit PDSCH transmissions on the same resources (e.g., time-frequency resources) using their respective beams (e.g., first beam for the first TRP 1005, second beam for the second TRP 1007) adjusted according to their respective beam-specific timing precompensations. In some examples, each data layer of the PDSCH may be associated with multiple Transition Configuration Indication (TCI) states. For example, each data layer of the PDSCH may be associated with a first TCI state indicating a first beam on a first TRP 1005 and a second TCI state indicating a second beam on a second TRP 1007. In some examples, each data layer of the PDSCH may be associated with a single composite TCI state representing multiple TCI states. For example, each data layer of the PDSCH may be associated with a TCI state that represents a first TCI state and a second TCI state.

Fig. 11 is a block diagram illustrating an example of a hardware implementation of a base station 1100 employing a processing system 1114, according to some aspects. Base station 1100 may be any base station (e.g., scheduling entity, gNB, eNB) shown in any one or more of fig. 1, 2, 4, 5, and 7-10.

According to various aspects of the disclosure, an element, any portion of an element, or any combination of elements may be implemented with a processing system 1114 that includes one or more processors (such as processor 1104). Examples of processor 1104 include microprocessors, microcontrollers, digital Signal Processors (DSPs), field Programmable Gate Arrays (FPGAs), programmable Logic Devices (PLDs), state machines, gate logic, discrete hardware circuits, and other suitable hardware configured to perform the various functions described throughout this disclosure. In various examples, base station 1100 may be configured to perform any one or more of the functions described herein. That is, the processor 1104 as used in the base station 1100 may be used to implement any one or more of the methodologies or processes described and illustrated, for example, in fig. 8, 9, and/or 10.

Processor 1104 may be implemented via a baseband or modem chip in some cases, and in other implementations, processor 1104 may include multiple devices other than a baseband or modem (e.g., in situations that may work cooperatively to implement the examples discussed herein). As described above, various hardware arrangements and components other than baseband modem processors may be used in implementations, including RF chains, power amplifiers, modulators, buffers, interleavers, adders/summers, and the like.

In this example, the processing system 1114 may be implemented with a bus architecture, represented generally by the bus 1102. Bus 1102 may include any number of interconnecting buses and bridges depending on the specific application of processing system 1114 and the overall design constraints. Bus 1102 communicatively couples various circuitry including one or more processors (generally represented by processor 1104), memory 1105, and computer-readable media (generally represented by computer-readable media 1106). Bus 1102 may also link various other circuits well known in the art, such as timing sources, peripherals, voltage regulators, and power management circuits, and therefore, will not be described any further.

Bus interface 1108 provides an interface between bus 1102 and transceiver 1110. Transceiver 1110 may be, for example, a wireless transceiver. The transceiver 1110 provides a means for communicating with various other apparatus over a transmission medium, e.g., an air interface. Transceiver 1110 may be further coupled to one or more antennas/antenna arrays (not shown). Bus interface 1108 further provides an interface between bus 1102 and a user interface 1112 (e.g., keypad, display, touch screen, speaker, microphone, control features, etc.). Of course, such user interface 1112 may be omitted in some examples. In addition, bus interface 1108 further provides an interface between bus 1102 and a power source (not shown). Bus interface 1108 may also provide an interface between bus 1102 and a Transmit Receive Point (TRP) interface 1120. The TRP interface 1120 may provide an interface between the base station 1100 and a plurality of TRPs including a first TRP 1121, a second TRP 1122, and/or a third TRP 1123 to an nth TRP 1124, where n is a positive integer. The plurality of TRPs may be configured as remote radio heads of the base station 1100.

One or more processors (such as processor 1104) may be responsible for managing the bus 1102 and general processing, including the execution of software stored on the computer-readable medium 1106. Software should be construed broadly to mean instructions, instruction sets, code segments, program code, programs, subroutines, software modules, applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures/processes, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. The software may reside on a computer readable medium 1106. The software, when executed by the processor 1104, causes the processing system 1114 to perform the various processes and functions described herein for any particular apparatus.

Computer-readable medium 1106 may be non-transitory computer-readable medium and may be referred to as a computer-readable storage medium or non-transitory computer-readable medium. The non-transitory computer readable medium may store computer executable code (e.g., processor executable code). The computer-executable code may include code for causing a computer (e.g., a processor) to perform one or more of the functions described herein. Non-transitory computer readable media include, for example, magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips), optical disks (e.g., compact Disk (CD) or Digital Versatile Disk (DVD)), smart cards, flash memory devices (e.g., card, stick, or key drive), random Access Memory (RAM), read Only Memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically Erasable PROM (EEPROM), registers, removable disk, and any other suitable medium for storing software and/or instructions that can be accessed and read by a computer. The computer-readable medium 1106 may reside in the processing system 1114, external to the processing system 1114, or distributed across multiple entities including the processing system 1114. The computer-readable medium 1106 may be embodied in a computer program product or article of manufacture. For example, a computer program product or article of manufacture may comprise a computer readable medium in a packaging material. In some examples, computer-readable medium 1106 may be part of memory 1105. Those skilled in the art will recognize how best to implement the functionality described throughout this disclosure, depending on the particular application and the overall design constraints imposed on the overall system. The computer-readable medium 1106 and/or the memory 1105 may also be used for storing data that may be manipulated by the processor 1104 when executing software.

In some aspects of the disclosure, the processor 1104 may include communication and processing circuitry 1140 configured for various functions, including, for example, communication with a network core (e.g., a 5G core network), one or more scheduling entities, a scheduled entity, one or more TRPs (such as first TRP 1121, second TRP 1122, and/or third TRP 1123 through nth TRP 1124), and/or any other entity, e.g., a local infrastructure or an entity communicating with the base station 1100 via the internet, e.g., a network provider. According to some aspects, various functions of the communication and processing circuitry 1140 may be used to implement beam-specific timing precompensation as described herein.

In some examples, communications and processing circuitry 1140 may include one or more hardware components that provide physical structure to perform processes related to wireless communications (e.g., signal reception and/or signal transmission) and signal processing (e.g., processing received signals and/or processing signals for transmission) and to perform processes related to the beam-specific timing precompensation process described herein. Further, the communication and processing circuitry 1140 may be configured to receive and process downlink traffic and downlink control (e.g., similar to downlink traffic 112 and downlink control 114 of fig. 1), and to process and transmit uplink traffic and uplink control (e.g., similar to uplink traffic 116 and uplink control 118 of fig. 1). The communications and processing circuitry 1140 may also be configured to execute communications and processing software 1150 stored on the computer-readable medium 1106 to implement one or more functions described herein.

In some aspects, the processor 1104 may include circuitry configured for various other functions. For example, the processor 1104 may include receive circuitry 1141 configured to receive an uplink transmission via a first Transmit and Receive Point (TRP) associated with the base station 1100 on a first beam pair link (e.g., the first TRP 1121) and a second TRP associated with the base station 1100 on a second beam pair link (e.g., the second TRP 1122). In another example, the receive circuit 1141 may be configured to receive uplink transmissions on respective transmit beams (e.g., transmit beams of respective beam-to-link) via a first TRP associated with the base station 1100 (e.g., the first TRP 1121) and a second TRP associated with the base station 1100 (e.g., the second TRP 1122), respectively. In another example, the receive circuit 1141 may be configured to receive one or more uplink transmissions from one or more User Equipments (UEs), wherein each of the one or more UEs moves at the same speed and along the same path relative to the base station. The receive circuitry 1141 may be configured to execute the receive instructions 1151 stored in the computer readable medium 1106 to implement any one or more of the functions described herein.

The processor 1104 may also include a timing difference circuit 1142. In one example, the timing difference circuit 1142 may be configured to obtain (e.g., estimate, calculate, determine, derive) a timing difference between receiving the uplink transmission via the first TRP (e.g., the first TRP 1121) and the second TRP (e.g., the second TRP 1122). In another example, the timing difference circuit 1142 may be configured to obtain a timing difference between at least a first beam and a second beam based on one or more uplink transmissions, wherein the first beam may be transmitted by a first Transmission and Reception Point (TRP) of a plurality of TRPs associated with the base station 1100 (e.g., the first TRP 1121) and the second beam may be transmitted by a second TRP of the plurality of TRPs associated with the base station 1100 (e.g., the second TRP 1122). Timing difference circuit 1142 may be configured to execute timing difference instructions 1152 stored in computer readable medium 1106 to implement any one or more of the functions described herein.

The processor 1104 may also include a beam-specific timing precompensation circuit 1143. In one example, the beam-specific timing precompensation circuit 1143 may be configured to obtain (e.g., estimate, calculate, determine, derive) the first beam-specific timing precompensation and the second beam-specific timing precompensation based on a timing difference between reception of the uplink transmission via the first TRP (e.g., the first TRP 1121) and the second TRP (e.g., the second TRP 1122). The timing difference may be obtained by the base station 1100 using, for example, the timing difference circuit 1142 described above. In another example, the beam-specific timing precompensation circuit 1143 may be configured to obtain a first beam-specific timing precompensation and a second beam-specific timing precompensation for application to respective transmit beams at a first TRP (e.g., first TRP 1121) and a second TRP (e.g., second TRP 1122), respectively. Also, the first beam-specific timing precompensation and the second beam-specific timing precompensation may be based on the timing difference obtained by the timing difference circuit 1142. In another example, the beam-specific timing precompensation circuit 1143 may be configured to determine a first beam-specific timing precompensation (e.g., a first delay precompensation) for a first beam (e.g., a first transmit beam of a first beam-to-link) and a second beam-specific timing precompensation (e.g., a first delay precompensation) for a second beam (e.g., a second transmit beam of a second beam-to-link) based on the timing differences. The beam-specific timing precompensation circuit 1143 may be configured to execute the beam-specific timing precompensation instructions 1153 stored in the computer readable medium 1106 to implement any one or more of the functions described herein.

The processor 1104 may also include a transmit circuit 1144. The transmit circuit 1144, in combination with the TRP interface 1120 and the plurality of TRPs (e.g., including the first TRP 1121 and the second TRP 1122), may be configured to transmit downlink transmissions via the first TRP (e.g., the first TRP 1121) on a first beam pair link having a first beam specific timing pre-compensation and via the second TRP (e.g., the second TRP 1122) on a second beam pair link having a second beam specific timing pre-compensation. In some examples, the first beam-specific timing precompensation and the second beam-specific timing precompensation may be obtained from the beam-specific timing precompensation circuit 1143. In another example, the transmit circuit 1144 may be configured to transmit an indication of at least one of the first beam-specific timing precompensation or the second beam-specific timing precompensation to the UE. In another example, the transmit circuit 1144 may be configured to transmit downlink transmissions from respective transmit beams of the first TRP and the second TRP via the first TRP and the second TRP according to the first beam specific timing precompensation and the second beam specific timing precompensation, respectively. In another example, the transmit circuit 1144 may be configured to transmit, by the base station, an indication of respective timing advances to be applied by the UE for subsequent uplink transmissions to the first TRP and the second TRP, respectively. In yet another example, the transmit circuit 1144 may be configured to transmit an indication of at least one of the first beam-specific timing precompensation (e.g., the first delay precompensation) or the second beam-specific timing precompensation (e.g., the second delay precompensation) to at least one of the one or more UEs. The transmit circuit 1144 may be further configured to pre-compensate a first beam through a first TRP according to a first beam specific timing and to pre-compensate a second beam through a second TRP according to a second beam specific timing to transmit a Physical Downlink Shared Channel (PDSCH) transmission. The transmit circuitry 1144 may be configured to execute the transmit instructions 1154 stored in the computer readable medium 1106 to implement any one or more of the functions described herein.

Fig. 12 is a flow diagram of a method 1200 of wireless communication utilizing beam-specific timing precompensation, according to some aspects. In some examples, the wireless communication method 1200 may be used in a Single Frequency Network (SFN). In some examples, the wireless communication method 1200 may be used in a High Speed Train (HST) single frequency network (HST-SFN). As described below, in certain implementations within the scope of the present disclosure, some or all of the illustrated features may be omitted, and some of the illustrated features may not be required to implement all aspects. In some examples, wireless communication method 1200 may be performed by base station 1100, as described herein and shown in fig. 11, by a processor or processing system, or by any suitable means for performing the described functions.

At block 1202, the base station may receive an uplink transmission (e.g., channel, signal) on a first transmit beam of a first beam-pair link (e.g., a first beam of the first beam-pair link at a TRP for downlink or uplink communications and configured to receive the uplink at that moment) via a first Transmit and Receive Point (TRP) associated with the base station. At block 1204, the base station may receive an uplink transmission on a second transmit beam of a second beam pair link (e.g., a second beam for downlink or uplink communications and configured to receive the second beam pair link at the uplink TRP at the moment) via a second TRP associated with the base station. Uplink transmissions may be received (via the first TRP and the second TRP) from the UE. For example, the receive circuit 1141 shown and described above in connection with fig. 11, along with the TRP interface 1120, the first TRP 1121, and the second TRP 1122, may provide means for receiving uplink transmissions on a first transmit beam of a first beam pair link via a first Transmit and Receive Point (TRP) associated with a base station, and means for receiving uplink transmissions on a second transmit beam of a second beam pair link via a second TRP associated with the base station.

At block 1206, the base station may transmit a downlink transmission (e.g., channel, signal) via the first TRP on a first transmit beam (of the first beam-to-link) with a first beam-specific timing precompensation (e.g., for downlink or uplink communications and configured at this time to transmit the first beam-to-link first beam at the TRP of the downlink). At block 1208, the base station may transmit a downlink transmission on a second transmit beam (of a second beam pair link) having a second beam-specific timing pre-compensation (e.g., a second beam of the second beam pair link at the TRP for downlink or uplink communications and configured to transmit the downlink at the moment) via a second TRP, wherein the first beam-specific timing pre-compensation and the second beam-specific timing pre-compensation may be based on a timing difference between reception of the uplink transmission via the first TRP and reception of the uplink transmission via the second TRP.

The base station may obtain (e.g., estimate, calculate, determine, derive) a timing difference and may also obtain a first beam-specific timing precompensation and a second beam-specific timing precompensation based on the timing difference. For example, the transmit circuit 1144, along with the TRP interface 1120, the first TRP 1121, and the second TRP 1122, as shown and described above in connection with fig. 11, may provide means for transmitting downlink transmissions via the first TRP on a first transmit beam having a first beam specific timing pre-compensation, and may also provide means for transmitting downlink transmissions via the second TRP on a second transmit beam having a second beam specific timing pre-compensation. In addition, the timing difference circuit 1142 may provide means for obtaining a timing difference between reception of the uplink transmission via the first TRP and the second TRP. Further, the beam-specific timing precompensation circuit 1143 may provide means for obtaining the first beam-specific timing precompensation and the second beam-specific timing precompensation based on a timing difference between reception of the uplink transmission via the first TRP and reception of the uplink transmission via the second TRP.

According to some aspects, the uplink transmission may include a Sounding Reference Signal (SRS) or another reference signal. The base station may use the reference signal to obtain the timing difference. According to some aspects, the downlink transmission may include an indication of at least one of a first beam-specific timing precompensation or a second beam-specific timing precompensation. According to some aspects, the downlink transmission may include at least one of a signal, a UE-specific channel, or a common channel common to each of the plurality of UEs. According to some aspects, the downlink transmission may include at least one of Downlink Control Information (DCI) or a Medium Access Control (MAC) control element (MAC-CE) indicating at least one of the first beam-specific timing precompensation or the second beam-specific timing precompensation. According to some aspects, the downlink transmission may include a Physical Downlink Shared Channel (PDSCH), and each data layer of the PDSCH may be associated with at least one of a plurality of Transition Configuration Indication (TCI) states or a single composite TCI state representing a plurality of TCI states. In some examples, the base station may be further configured to send the downlink transmission on the same time-frequency resource within a Single Frequency Network (SFN) via the first TRP and the second TRP.

Fig. 13 is a flow diagram of a method 1300 of wireless communication utilizing beam-specific timing precompensation, according to some aspects. In some examples, the wireless communication method 1300 may be used in a Single Frequency Network (SFN). In some examples, the wireless communication method 1300 may be used in a High Speed Train (HST) single frequency network (HST-SFN). As described below, in certain implementations within the scope of the present disclosure, some or all of the illustrated features may be omitted, and some of the illustrated features may not be required to implement all aspects. In some examples, the wireless communication method 1300 may be performed by the base station 1100, as described herein and shown in fig. 11, by a processor or processing system, or by any suitable means for performing the described functions.

At block 1302, a base station may receive one or more uplink transmissions from one or more User Equipment (UEs). In some examples, each of the one or more UEs may move at the same speed and along the same path relative to the base station. For example, when the UE travels in a direction along a path (e.g., along a train track), the UE may send one or more uplink transmissions to the plurality of TRPs, including a first TRP and a second TRP located at locations adjacent to the path. The base station may receive uplink transmissions via the first TRP using a first transmit beam of the first beam pair link (e.g., a first beam of the first beam pair link at the TRP for downlink or uplink communications and configured to receive uplink transmissions from the UE at the moment), and may also receive uplink transmissions via the second TRP using a second transmit beam of the second beam pair link (e.g., a second beam of the second beam pair link at the TRP for downlink or uplink communications and configured to receive uplink transmissions from the UE at the moment). In some aspects, the one or more uplink transmissions may include a Sounding Reference Signal (SRS). As shown and described above in connection with fig. 11, the receive circuit 1141, along with the TRP interface 1120 and the first TRP 1121 and the second TRP 1122, may provide means for receiving one or more uplink transmissions from one or more User Equipments (UEs).

At block 1304, the base station may obtain (e.g., estimate, calculate, determine, derive) a timing difference between at least a first beam and a second beam based on one or more uplink transmissions, wherein the first beam may be transmitted by a first one of a plurality of TRPs associated with the base station and the second beam may be transmitted by a second one of the plurality of TRPs associated with the base station. For example, the base station may obtain a timing difference between receiving the first uplink beam by the first TRP and receiving the second uplink beam by the second TRP. In one example, the base station may estimate a timing difference between a first beam for transmitting by a first TRP to the UE and a second beam for transmitting by a second TRP to the UE based on a timing difference between one or more uplink transmissions received by the first TRP from the UE and one or more uplink transmissions received by the second TRP from the UE. For example, as shown and described above in connection with fig. 11, the timing difference circuit 1142 may provide means for obtaining a timing difference between at least the first beam and the second beam based on one or more uplink transmissions.

At block 1306, the base station may obtain a first beam-specific timing pre-compensation for the first beam and a second beam-specific timing pre-compensation for the second beam based on the timing difference. In some aspects, to prevent or reduce inter-symbol interference (ISI) between transmissions of a downlink channel or signal utilizing a first beam from a first TRP and a second beam from a second TRP, a base station may obtain a first beam-specific timing pre-compensation for the first beam and a second beam-specific timing pre-compensation for the second beam based on a timing difference between the first beam and the second beam. In some examples, the base station may determine whether the first beam specific timing precompensation advances or delays a downlink transmission time (e.g., of a downlink transmission, channel, or signal) on the first beam. Similarly, the base station may determine whether the second beam specific timing precompensation advances or delays transmission of a downlink transmission (e.g., channel or signal) on the second beam in time. Alternatively, the base station may determine that the first beam-specific timing precompensation does not affect a transmission time of the downlink transmission of the first TRP on the first beam. Similarly, the base station may determine that the second beam-specific timing precompensation does not affect a transmission time of the downlink transmission of the second TRP on the second beam.

In some aspects, determining the first and second beam-specific timing precompensations may include determining the first and second beam-specific timing precompensations for at least one of one or more signals, one or more UE-specific channels, or one or more common channels common to each of the plurality of UEs. For example, as described herein, the HST may include a plurality of UEs including the UE, and the first beam-specific timing pre-compensation and the second beam-specific timing pre-compensation may be for one or more signals (e.g., DM-RS, TRS, etc.), one or more UE-specific channels (e.g., PDCCH or PDSCH), or one or more common channels (e.g., common control information carried in PDCCH) common to each of the plurality of UEs included by the HST. The beam-specific timing precompensation circuit 1143 shown and described above in connection with fig. 11 may provide a means for obtaining a first beam-specific timing precompensation for a first beam and a second beam-specific timing precompensation for a second beam based on the timing differences.

At block 1308, the base station may transmit an indication of at least one of the first beam-specific timing precompensation or the second beam-specific timing precompensation to at least one of the one or more UEs. For example, an indication of at least one of the first beam-specific timing precompensation or the second beam-specific timing precompensation may be transmitted to at least one of the one or more UEs using at least one of Downlink Control Information (DCI) or a Medium Access Control (MAC) control element (MAC-CE). In some aspects, the indication of at least one of the first beam-specific timing precompensation or the second beam-specific timing precompensation may vary over time based on a speed of one or more UEs moving along a path (e.g., a path defined by a train track of the HST), a positioning of at least one of the one or more UEs, or a direction of movement of the one or more UEs along the path.

For example, when the speed of the HST changes, the rate at which the distance between each TRP including the first TRP and the second TRP and the UE changes varies. To accommodate such a rate of change in distance, the base station may modify or change one or more beam-specific timing precompensations of the beam of each of the plurality of TRPs located along the path, including a first beam-specific timing precompensation of a first beam of a first TRP and a second beam-specific timing precompensation of a second beam of a second TRP. As another example, when the location of the HST changes along the path, the location of the UE may also change along the path, resulting in a change in the distance between each TRP, including the first TRP and the second TRP, and the UE. The change in distance may cause the base station to modify or change one or more beam-specific timing precompensations of the beam of each of the one or more TRPs located along the path, including a first beam-specific timing precompensation of a first beam of the first TRP and a second beam-specific timing precompensation of a second beam of the second TRP. As yet another example, when the movement direction of the HST changes along the path, the movement direction of the UE may change with respect to each TRP including the first TRP and the second TRP and the UE. The change in the direction of movement may cause the base station to modify or change one or more beam-specific timing precompensations of the beam of each of the plurality of TRPs located along the path, including a first beam-specific timing precompensation of a first beam of the first TRP and a second beam-specific timing precompensations of a second beam of the second TRP. As shown and described above in connection with fig. 11, the transmit circuit 1144, along with the TRP interface 1120, the first TRP 1121, and the second TRP 1122, may provide means for transmitting an indication of at least one of the first beam specific timing precompensation or the second beam specific timing precompensation to at least one of the one or more UEs.

At block 1310, the base station may pre-compensate a first beam through a first TRP according to a first beam-specific timing and pre-compensate a second beam through a second TRP according to a second beam-specific timing to transmit a Physical Downlink Shared Channel (PDSCH) transmission. Each of the TRPs including the first TRP and the second TRP may be pre-compensated according to their respective beam specific timing, transmitting PDSCH transmissions on the same resources (e.g., time-frequency resources) using their respective beams (e.g., first beam for the first TRP, second beam for the second TRP). In some examples, each data layer of the PDSCH may be associated with multiple Transition Configuration Indication (TCI) states. For example, each data layer of the PDSCH may be associated with a first TCI state indicating a first beam on a first TRP and a second TCI state indicating a second beam on a second TRP. In some examples, each data layer of the PDSCH may be associated with a single composite TCI state representing multiple TCI states. For example, each data layer of the PDSCH may be associated with a TCI state that represents a first TCI state and a second TCI state. As shown and described above in connection with fig. 11, the transmit circuit 1144, along with the TRP interface 1120, the first TRP 1121, and the second TRP 1122, may provide means for pre-compensating a first beam through the first TRP according to a first beam specific timing and transmitting PDSCH transmissions through a second beam through the second TRP according to a second beam specific timing.

Fig. 14 is a block diagram illustrating an example of a hardware implementation of a User Equipment (UE) 1400 employing a processing system 1414 in accordance with some aspects. UE 1400 may be, for example, any UE, scheduling entity, or wireless communication device as shown in any one or more of fig. 1, 2, 4, 5, and/or 7-10. In accordance with various aspects of the disclosure, an element, any portion of an element, or any combination of elements may be implemented with a processing system 1414 including one or more processors (such as processor 1404). The processing system 1414 may be substantially the same as the processing system 1114 shown and described above in connection with fig. 11, including a bus interface 1408, a bus 1402, a memory 1405, a processor 1404, and a computer-readable medium 1406. Further, UE 1400 may include a user interface 1412, a transceiver 1410, and an antenna/antenna array (not shown), substantially similar to those described above in fig. 11. Therefore, their description will not be repeated for the sake of brevity.

In some aspects of the disclosure, the processor 1404 may include communication and processing circuitry 1440 configured for various functions, including, for example, communication with other UEs, TRPs, scheduling entities, or any other entity, e.g., a local infrastructure or an entity communicating with the UE 1400 via the internet, such as a network provider. In some examples, communication and processing circuitry 1440 may include one or more hardware components that provide physical structure to perform processes related to wireless communication (e.g., signal reception and/or signal transmission) and signal processing (e.g., processing received signals and/or processing signals for transmission). Further, communication and processing circuitry 1440 may be configured to receive and process downlink traffic and downlink control (e.g., similar to downlink traffic 142 and downlink control 144 of fig. 1), and to process and transmit uplink traffic and uplink control (e.g., similar to uplink traffic 146 and uplink control 148). The communication and processing circuitry 1440 may also be configured to execute the communication and processing software 1450 stored on the computer-readable medium 1406 to implement one or more of the functions described herein.

In some aspects of the disclosure, the processor 1404 may include other circuitry configured for various functions. For example, the processor 1404 may include a transmit circuit 1441 that may be configured to transmit uplink transmissions to a first Transmit and Receive Point (TRP) of a base station on a first receive beam of a first beam-pair link and to transmit uplink transmissions to a second TRP associated with the base station on a second receive beam of a second beam-pair link. In another example, the transmit circuit 1441 may be configured to transmit one or more uplink transmissions to at least a first TRP and a second TRP of the plurality of TRPs of the base station. In some examples, the UE may move with one or more other UEs at the same speed and along the same path relative to the first TRP and the second TRP. The transmit circuitry 1441 may be configured to execute transmit instructions 1451 stored in the computer-readable medium 1406 to implement any one or more of the functions described herein.

The processor 1404 may also include a receive circuit 1442. In one example, the receive circuit 1442 may be configured to receive downlink transmissions via a first TRP on a first receive beam having a first beam specific timing precompensation and receive downlink transmissions via a second TRP on a second receive beam having a second beam specific timing precompensation, the first and second beam specific timing precompensations being based on a timing difference between reception of uplink transmissions via the first and second TRPs. In another aspect, the receive circuitry 1442 may be configured to receive a downlink transmission indicating: a first beam specific timing pre-compensation applied to a first transmit beam of a first beam pair link and a second beam specific timing pre-compensation applied to a second transmit beam of a second beam pair link. In another example, the receive circuit 1442 may be configured to receive an indication of at least one of a first beam-specific timing pre-compensation for a first beam transmitted by a first TRP or a second beam-specific timing pre-compensation for a second beam transmitted by a second TRP. The indication of at least one of the first beam specific timing precompensation or the second beam specific timing precompensation may be stored, for example, in a beam specific timing precompensation value storage 1407 location in the memory 1405. In addition, the receive circuitry 1442 may be further configured to pre-compensate a first beam through a first TRP according to a first beam specific timing and to pre-compensate a second beam through a second TRP according to a second beam specific timing to receive a Physical Downlink Shared Channel (PDSCH) transmission. The receive circuitry 1442 may also be configured to execute the receive instructions 1452 stored in the computer readable medium 1406 to implement any one or more of the functions described herein.

Fig. 15 is a flow diagram of a wireless communication method 1500 that utilizes beam-specific timing precompensation in accordance with some aspects. In some examples, the wireless communication method 1500 may be used in a Single Frequency Network (SFN). In some examples, the wireless communication method 1500 may be used in a High Speed Train (HST) single frequency network (HST-SFN). As described below, in certain implementations within the scope of the present disclosure, some or all of the illustrated features may be omitted, and some of the illustrated features may not be required to implement all aspects. In some examples, the wireless communication method 1500 may be performed by a User Equipment (UE) 1400, as described herein and shown in fig. 14, by a processor or processing system, or by any suitable means for performing the described functions.

At block 1502, the UE may send an uplink transmission on a first receive beam of a first beam-to-link (e.g., for downlink or uplink communications and configured at the moment to send the first beam of the first beam-to-link at the UE of the uplink). At block 1504, the UE may send an uplink transmission on a second receive beam of a second beam-pair link (e.g., a second beam of the second beam-pair link at the UE for downlink or uplink communications and configured to send uplink at the moment). The uplink transmissions sent from the UE on the first and second receive beams may be simultaneous or substantially simultaneous. For example, an uplink transmission may be transmitted on a first receive beam of a first beam pair link to a first Transmit and Receive Point (TRP) associated with a base station and on a second receive beam of a second beam pair link to a second TRP associated with the base station. For example, as shown and described above in connection with fig. 14, the transmit circuitry 1441, along with the transceiver 1410, may provide means for transmitting uplink transmissions on a first receive beam of a first beam-pair link, and may also provide means for transmitting uplink transmissions on a second receive beam of a second beam-pair link.

At block 1506, the UE may receive a downlink transmission indicating: a first beam specific timing pre-compensation that may be applied to a first transmit beam of a first beam-to-link (e.g., a first beam of the first beam-to-link at a UE for downlink or uplink communications and configured to receive the downlink at that moment), and a second beam specific timing pre-compensation that may be applied to a second transmit beam of a second beam-to-link (e.g., a second beam of the second beam-to-link at a UE for downlink or uplink communications and configured to receive the downlink at that moment). The downlink transmission may be received, for example, from the base station or from a first TRP associated with the base station using a first beam pair link and a second TRP associated with the base station using a second beam pair link, respectively. For example, as shown and described above in connection with fig. 14, the receive circuitry 1442, along with the transceiver 1410, may provide means for receiving a downlink transmission indicating: the first beam-specific timing pre-compensation may be applied to a first transmit beam of a first beam-pair link and the second beam-specific timing pre-compensation may be applied to a second transmit beam of a second beam-pair link.

According to some aspects, the uplink transmission may include a Sounding Reference Signal (SRS) or another reference signal. The base station may use the reference signal to obtain a timing difference between receipt of an uplink transmission via the first TRP and receipt of a downlink transmission via the second TRP. According to some aspects, the first beam-specific timing pre-compensation and the second beam-specific timing pre-compensation (at the first TRP and the second TRP, respectively) are applied to at least one of: a signal, a UE-specific channel, or a common channel common to each of a plurality of UEs. According to some aspects, the downlink transmission indicating the first beam-specific timing pre-compensation and the second beam-specific timing pre-compensation is within at least one of Downlink Control Information (DCI) or a Medium Access Control (MAC) control element (MAC-CE). According to some aspects, the method may further comprise: downlink transmissions are received on a first receive beam of a first beam pair link according to a first beam-specific timing pre-compensation on a first time-frequency resource, and downlink transmissions are received on a second receive beam of a second beam pair link according to a second beam-specific timing pre-compensation on the first time-frequency resource.

In some examples, the method further comprises: downlink transmissions are received on a first receive beam of a first beam-pair link according to a first beam-specific timing pre-compensation on a first time-frequency resource, and downlink transmissions are received on a second receive beam of a second beam-pair link according to a second beam-specific timing pre-compensation on the first time-frequency resource (i.e., the same time-frequency resource).

In some examples, the method further comprises: a Physical Downlink Shared Channel (PDSCH) is received on a first receive beam of the first beam pair link according to the first beam-specific timing precompensation, and a PDSCH is received on a second receive beam of the second beam pair link according to the second beam-specific timing precompensation. According to one aspect, each data layer of the PDSCH may be associated with multiple Transition Configuration Indication (TCI) states. According to another aspect, each data layer of the PDSCH may be associated with a single composite TCI state representing multiple TCI states.

Fig. 16 is a flow diagram of a wireless communication method 1600 that utilizes beam-specific timing precompensation in accordance with some aspects. In some examples, the wireless communication method 1600 may be used in a Single Frequency Network (SFN). In some examples, the wireless communication method 1600 may be used in a High Speed Train (HST) single frequency network (HST-SFN). As described below, in certain implementations within the scope of the present disclosure, some or all of the illustrated features may be omitted, and some of the illustrated features may not be required to implement all aspects. In some examples, the wireless communication method 1600 may be performed by a User Equipment (UE) 1400, as described herein and shown in fig. 14, by a processor or processing system, or by any suitable means for performing the described functions.

At block 1602, the UE may send one or more uplink transmissions to at least a first Transmit and Receive Point (TRP) and a second TRP of a plurality of TRPs associated with a base station. In some aspects, the UE may move with one or more other UEs at the same speed and along the same path relative to the first TRP and the second TRP. For example, when the UE travels in a direction along a path (e.g., along a train track), the UE may send one or more uplink transmissions to the plurality of TRPs, including a first TRP and a second TRP located at locations adjacent to the path. The UE may transmit uplink transmissions to a first TRP associated with the base station using a first uplink beam (a first beam at the UE for downlink or uplink communications and configured to transmit uplink at the moment) and transmit uplink transmissions to a second TRP associated with the base station using a second uplink beam (a second beam at the UE for downlink or uplink communications and configured to transmit uplink at the moment). In some aspects, the one or more uplink transmissions may include a Sounding Reference Signal (SRS). As shown and described above in connection with fig. 14, the transmit circuitry 1441 may provide, in conjunction with the transceiver 1410, means for transmitting one or more uplink transmissions to at least a first Transmit and Receive Point (TRP) and a second TRP of a plurality of TRPs of a base station.

The base station may obtain (e.g., estimate, calculate, determine, derive) a timing difference between at least a first beam and a second beam based on one or more uplink transmissions, wherein the first beam may be received by a first TRP associated with the base station and the second beam may be received by a second TRP associated with the base station. For example, the base station may determine a timing difference between receiving the first uplink beam by the first TRP and receiving the second uplink beam by the second TRP.

The base station may determine a first beam-specific timing pre-compensation for the first beam and a second beam-specific timing pre-compensation for the second beam based on the timing differences. In some aspects, to prevent or reduce inter-symbol interference (ISI) between transmissions of a downlink channel or signal utilizing a first beam from a first TRP and a second beam from a second TRP, a base station may obtain a first beam-specific timing pre-compensation for the first beam and a second beam-specific timing pre-compensation for the second beam based on a timing difference between the first beam and the second beam. In some examples, the base station may determine whether the first beam specific timing precompensation advances or delays transmission of a downlink channel or signal on the first beam in time. Similarly, the base station may determine whether the second beam specific timing precompensation advances or delays transmission of a downlink channel or signal on the second beam in time. Alternatively, the base station may determine that the first beam specific timing precompensation does not affect the transmission time of the downlink channel or signal of the first TRP on the first beam. Similarly, the base station may determine that the second beam-specific timing precompensation does not affect the transmission time of the downlink channel or signal of the second TRP on the second beam.

In some aspects, determining the first and second beam-specific timing precompensations may include determining the first and second beam-specific timing precompensations for at least one of one or more signals, one or more UE-specific channels, or one or more common channels common to each of the plurality of UEs. For example, as described herein, the HST may include a plurality of UEs including the UE, and the first beam-specific timing pre-compensation and the second beam-specific timing pre-compensation may be for one or more signals (e.g., DM-RS, TRS, etc.), one or more UE-specific channels (e.g., PDCCH or PDSCH), or one or more common channels (e.g., common control information carried in PDCCH) common to each of the plurality of UEs included by the HST.

At block 1604, the UE may receive an indication of at least one of a first beam-specific timing pre-compensation for a first beam transmitted by a first TRP or a second beam-specific timing pre-compensation for a second beam transmitted by a second TRP. For example, an indication of at least one of the first beam-specific timing precompensation or the second beam-specific timing precompensation may be transmitted to at least one of the one or more UEs using at least one of Downlink Control Information (DCI) or a Medium Access Control (MAC) control element (MAC-CE). In some aspects, the indication of at least one of the first beam-specific timing precompensation or the second beam-specific timing precompensation may vary over time based on a speed of one or more UEs moving along the path, a position of at least one of the one or more UEs, or a direction of movement of the one or more UEs along the path.

For example, when the speed of the HST changes, the rate at which the distance between each TRP including the first TRP and the second TRP and the UE changes varies. To accommodate such a rate of change in distance, the base station may modify or change one or more beam-specific timing precompensations of the beam of each of the plurality of TRPs located along the path, including a first beam-specific timing precompensation of a first beam of a first TRP and a second beam-specific timing precompensation of a second beam of a second TRP. As another example, when the location of the HST changes along the path, the location of the UE may also change along the path, resulting in a change in the distance between each TRP, including the first TRP and the second TRP, and the UE. The change in distance may cause the base station to modify or change one or more beam-specific timing precompensations of the beam of each of the one or more TRPs located along the path, including a first beam-specific timing precompensation of a first beam of the first TRP and a second beam-specific timing precompensation of a second beam of the second TRP. As yet another example, when the movement direction of the HST changes along the path, the movement direction of the UE may change with respect to each TRP including the first TRP and the second TRP and the UE. The change in the direction of movement may cause the base station to modify or change one or more beam-specific timing precompensations of the beam of each of the plurality of TRPs located along the path, including a first beam-specific timing precompensation of a first beam of the first TRP and a second beam-specific timing precompensations of a second beam of the second TRP. As shown and described above in connection with fig. 14, the receive circuitry 1442 along with the transceiver 1410 may provide means for receiving an indication of at least one of a first beam-specific timing pre-compensation for a first beam transmitted by a first TRP or a second beam-specific timing pre-compensation for a second beam transmitted by a second TRP.

At block 1606, the UE may pre-compensate a first beam through a first TRP according to a first beam-specific timing and a second beam through a second TRP according to a second beam-specific timing to receive a Physical Downlink Shared Channel (PDSCH) transmission. Each of the TRPs including the first TRP and the second TRP may be pre-compensated according to their respective beam specific timing, transmitting PDSCH transmissions on the same resources (e.g., time-frequency resources) using their respective beams (e.g., first beam for the first TRP, second beam for the second TRP). In some examples, each data layer of the PDSCH may be associated with multiple Transition Configuration Indication (TCI) states. For example, each data layer of the PDSCH may be associated with a first TCI state indicating a first beam on a first TRP and a second TCI state indicating a second beam on a second TRP. In some examples, each data layer of the PDSCH may be associated with a single composite TCI state representing multiple TCI states. For example, each data layer of the PDSCH may be associated with a TCI state that represents a first TCI state and a second TCI state. As shown and described above in connection with fig. 11, the receive circuitry 1442 may provide with the transceiver 1410 means for pre-compensating a first beam through a first TRP according to a first beam-specific timing and receiving a Physical Downlink Shared Channel (PDSCH) transmission through a second beam through a second TRP according to a second beam-specific timing.

Fig. 17A and 17B are illustrations of a Single Frequency Network (SFN) configuration in accordance with some aspects. Fig. 17A shows a first SFN configuration 1700. Tracking reference signals, such as reference signal 1 (RS 1) 1702 and reference signal 2 (RS 2) 1704, may be transmitted in TRP-specific and/or non-SFN configurations. DM-RS and Physical Downlink Control Channel (PDCCH) and/or PDSCH from TRP may be transmitted in SFN configuration. For example, the TCI state associated with each of RS11702 and RS21704 may be used to transmit PDSCH transmissions. A first TCI state (e.g., a first beam) associated with RS11702 may be used to send a first PDSCH 1706 transmission over a first TRP and a second TCI state (e.g., a second beam) associated with RS21704 may be used to send a second PDSCH 1708 transmission over a second TRP. Additionally or alternatively, as shown in fig. 17A, the TCI states associated with RS11702 and RS21704 may be used together in an SFN to transmit SFN PDSCH 1710. In some aspects, each DM-RS port may be associated with both a first TCI state and a second TCI state. In some aspects, each data layer of the first PDSCH 1706, the second PDSCH 1708, and the SFN PDSCH 1710 may be associated with both a first TCI state and a second TCI state.

Fig. 17B illustrates a second SFN configuration 1750. The tracking reference signal and DM RS, such as RS11752 and RS21754, may be sent in TRP-specific and/or non SFN configurations. The PDCCH and PDSCH from the TRP may be transmitted in the SFN configuration. For example, the TCI state associated with each of RS11752 and RS21754 may be used to send PDSCH transmissions. A first TCI state (e.g., a first beam) associated with RS11752 may be used to transmit a first PDSCH transmission 1756 over a first TRP, and a second TCI state (e.g., a second beam) associated with RS21754 may be used to transmit a second PDSCH transmission 1758 over a second TRP. Additionally or alternatively, as shown in fig. 17B, the TCI states associated with RS11752 and RS21754 can be used in SFN such that the TCI states associated with RS11752 and RS21754 can be used to transmit SFN PDSCH 1760. Further, since the DM-RSs are transmitted in a non-SFN manner, the TRP may transmit separate DM-RSs, and each DM-RS may be associated with a different DM-RS port 1762, 1764. In some aspects, each DM-RS port 1762, 1764 may be associated with a first TCI state or a second TCI state. In some aspects, each data layer of the SFN PDSCH 1760 may be associated with both a first TCI state and a second TCI state.

Fig. 18 is an illustration of a single frequency network configuration 1800 in accordance with some aspects. As shown in fig. 18, a first TCI state (TCI state 1) associated with a first reference signal (RS 1) 1802 of a first TRP may be used to transmit a first PDSCH 1808 and a second TCI state (TCI state 2) associated with a second reference signal (RS 2) 1804 of a second TRP may be used to transmit a second PDSCH 1810. Additionally or alternatively, the TCI states associated with RS1 1802 and RS21804 may be combined into a composite TCI state (TCI state 3) associated with a Single Frequency Network (SFN) reference signal (SFN-RS) 1806 that represents a spatial combination of a first TCI state (e.g., a first beam on a first TRP) and a second TCI state (e.g., a second beam on a second TRP). The SFN-RS 1806 may be used to transmit the SFN PDSCH 1812. In some aspects, using this configuration, the UE may not know whether to use SFN signals and whether the third TCI state consists of two beams. In some aspects, additional SFN-RS resources (e.g., channel State Information (CSI) reference signals (CSI-RS) and Tracking Reference Signals (TRS)) may be configured for the UE with SFN (composite) configuration.

Of course, in the above examples, the circuitry included in processor 1104 and/or processor 1404 is provided as an example only, and other components for performing the described functions may be included within aspects of the disclosure, including but not limited to instructions stored in computer-readable medium 1106, 1406 or any other suitable device or component described in any of fig. 1, 2, 4, 5, 7-11, 14, 17A, 17B, and/or 18 and utilizing, for example, the processes and/or algorithms described herein with respect to fig. 6, 8, 9, 10, 12, 13, 15, and/or 16.

The following provides an overview of aspects of the disclosure:

aspect 1: a method of wireless communication at a base station, the method comprising: receiving, via a first Transmit and Receive Point (TRP) associated with the base station, an uplink transmission on a first transmit beam of a first beam-to-link; receiving, via a second TRP associated with the base station, an uplink transmission on a second transmit beam of a second beam pair link; transmitting a downlink transmission on a first transmit beam having a first beam-specific timing precompensation via a first TRP; and transmitting a downlink transmission via a second TRP on a second transmit beam having a second beam specific timing precompensation, wherein the first beam specific timing precompensation and the second beam specific timing precompensation are based on a timing difference between reception of the uplink transmission via the first TRP and reception of the uplink transmission via the second TRP.

Aspect 2: the method of aspect 1, wherein the uplink transmission comprises a Sounding Reference Signal (SRS).

Aspect 3: the method of aspect 1 or 2, wherein the downlink transmission comprises an indication of at least one of: the first beam specific timing precompensation or the second beam specific timing precompensation.

Aspect 4: a method according to any of aspects 1 to 3, wherein the downlink transmission comprises at least one of: a signal, a UE-specific channel, or a common channel common to each of a plurality of UEs.

Aspect 5: the method of any one of aspects 1 to 4, wherein the downlink transmission comprises at least one of: downlink Control Information (DCI) or Medium Access Control (MAC) control element (MAC-CE) indicating at least one of the first beam specific timing pre-compensation or the second beam specific timing pre-compensation.

Aspect 6: the method of any one of aspects 1 to 5, wherein the downlink transmission is a Physical Downlink Shared Channel (PDSCH), and each data layer of the PDSCH is associated with at least one of: multiple Transition Configuration Indication (TCI) states or a single composite TCI state representing multiple TCI states.

Aspect 7: the method of any one of aspects 1 to 6, wherein the downlink transmission is transmitted within a Single Frequency Network (SFN) on the same time-frequency resource via a first TRP and a second TRP.

Aspect 8: a base station for wireless communication, comprising: a memory and a processor communicatively coupled to the memory, the processor and the memory configured to: receiving, via a first Transmit and Receive Point (TRP) associated with the base station, an uplink transmission on a first transmit beam of a first beam-to-link; receiving, via a second TRP associated with the base station, an uplink transmission on a second transmit beam of a second beam pair link; transmitting a downlink transmission on a first transmit beam having a first beam-specific timing precompensation via a first TRP; and transmitting a downlink transmission via a second TRP on a second transmit beam having a second beam specific timing precompensation, wherein the first beam specific timing precompensation and the second beam specific timing precompensation are based on a timing difference between reception of the uplink transmission via the first TRP and reception of the uplink transmission via the second TRP.

Aspect 9: the base station of aspect 8, wherein the uplink transmission comprises a Sounding Reference Signal (SRS).

Aspect 10: the base station of aspect 8 or 9, wherein the downlink transmission comprises an indication of at least one of: the first beam specific timing precompensation or the second beam specific timing precompensation.

Aspect 11: the base station according to any of the aspects 8 to 10, wherein the downlink transmission comprises at least one of: a signal, a UE-specific channel, or a common channel common to each of a plurality of UEs.

Aspect 12: the base station according to any of the aspects 8 to 11, wherein the downlink transmission comprises at least one of: downlink Control Information (DCI) or Medium Access Control (MAC) control element (MAC-CE) indicating at least one of the first beam specific timing pre-compensation or the second beam specific timing pre-compensation.

Aspect 13: the base station of any of aspects 8 to 12, wherein the downlink transmission is a Physical Downlink Shared Channel (PDSCH), and each data layer of the PDSCH is associated with at least one of: multiple Transition Configuration Indication (TCI) states or a single composite TCI state representing multiple TCI states.

Aspect 14: the base station of any of aspects 8 to 13, wherein the downlink transmission is sent on the same time-frequency resource within a Single Frequency Network (SFN) via a first TRP and a second TRP.

Aspect 15: a method of wireless communication at a User Equipment (UE), the method comprising: transmitting an uplink transmission on a first receive beam of a first beam pair link; transmitting an uplink transmission on a second receive beam of the second beam pair link; and receiving a downlink transmission, the downlink transmission indicating: a first beam specific timing pre-compensation applied to a first transmit beam of a first beam pair link and a second beam specific timing pre-compensation applied to a second transmit beam of a second beam pair link.

Aspect 16: the method of aspect 15, wherein the uplink transmission includes a Sounding Reference Signal (SRS).

Aspect 17: the method of aspect 15 or 16, wherein the first beam-specific timing precompensation and the second beam-specific timing precompensation are applied to at least one of: a signal, a UE-specific channel, or a common channel common to each of a plurality of UEs.

Aspect 18: the method of any one of aspects 15 to 17, further comprising: receiving downlink transmissions indicating a first beam-specific timing precompensation and a second beam-specific timing precompensation within at least one of: downlink Control Information (DCI) or Medium Access Control (MAC) control element (MAC-CE).

Aspect 19: the method of any one of aspects 15 to 18, further comprising: receiving a downlink transmission on a first receive beam of a first beam-to-link according to a first beam-specific timing precompensation on a first time-frequency resource; and receiving a downlink transmission on a second receive beam of the second beam-to-link according to the second beam-specific timing precompensation on the first time-frequency resource.

Aspect 20: the method of any one of aspects 15 to 19, further comprising: a Physical Downlink Shared Channel (PDSCH) is received on a first receive beam of the first beam pair link according to the first beam-specific timing precompensation, and a PDSCH is received on a second receive beam of the second beam pair link according to the second beam-specific timing precompensation.

Aspect 21: the method of any one of aspects 15 to 20, wherein each data layer of the PDSCH is associated with a plurality of Transition Configuration Indication (TCI) states.

Aspect 22: the method of any one of aspects 15 to 21, wherein each data layer of the PDSCH is associated with a single composite TCI state representing multiple TCI states.

Aspect 23: a User Equipment (UE) for wireless communication, comprising: a transceiver, a memory, and a processor communicatively coupled to the transceiver and the memory, the processor and the memory configured to: transmitting an uplink transmission on a first receive beam of a first beam pair link; transmitting an uplink transmission on a second receive beam of the second beam pair link; and receiving a downlink transmission, the downlink transmission indicating: a first beam specific timing pre-compensation applied to a first transmit beam of a first beam pair link and a second beam specific timing pre-compensation applied to a second transmit beam of a second beam pair link.

Aspect 24: the UE of aspect 23, wherein the uplink transmission includes a Sounding Reference Signal (SRS).

Aspect 25: the UE of claim 23 or 24, wherein the first beam-specific timing precompensation and the second beam-specific timing precompensation are applied to at least one of: a signal, a UE-specific channel, or a common channel common to each of a plurality of UEs.

Aspect 26: the UE of any of claims 23 to 25, wherein the downlink transmission indicating the first beam-specific timing precompensation and the second beam-specific timing precompensation is received within at least one of: downlink Control Information (DCI) or Medium Access Control (MAC) control element (MAC-CE).

Aspect 27: the UE of any of aspects 23-26, wherein the processor and memory are further configured to: receiving a downlink transmission on a first receive beam of a first beam-to-link according to a first beam-specific timing precompensation on a first time-frequency resource; and receiving a downlink transmission on a second receive beam of the second beam-to-link according to the second beam-specific timing precompensation on the first time-frequency resource.

Aspect 28: the UE of any of aspects 23-27, wherein the processor and memory are further configured to: receiving a Physical Downlink Shared Channel (PDSCH) on a first receive beam of the first beam-pair link according to the first beam-specific timing precompensation; and receiving the PDSCH on a second receive beam of the second beam pair link in accordance with the second beam specific timing precompensation.

Aspect 29: the UE of any of aspects 23-28, wherein each data layer of the PDSCH is associated with a plurality of Transition Configuration Indication (TCI) states.

Aspect 30: the UE of any of aspects 23-29, wherein each data layer of the PDSCH is associated with a single composite TCI state representing multiple TCI states.

Aspect 31: an apparatus configured for wireless communication, comprising at least one means for performing the method of any one of aspects 1-7 or 15-22.

Aspect 32: a non-transitory computer-readable medium storing computer-executable code, comprising code for causing an apparatus to perform the method of any one of aspects 1-7 or 15-22.

Several aspects of a wireless communication network have been presented with reference to exemplary implementations. Those skilled in the art will readily appreciate that the various aspects described throughout this disclosure may be extended to other telecommunication systems, network architectures, and communication standards.

For example, various aspects may be implemented within other systems defined by 3GPP, such as Long Term Evolution (LTE), evolved Packet System (EPS), universal Mobile Telecommunications System (UMTS), and/or global system for mobile communications (GSM). Various aspects may also be extended to systems defined by third generation partnership project 2 (3 GPP 2), such as CDMA2000 and/or evolution data optimized (EV-DO). Other examples may be implemented within systems employing IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, ultra Wideband (UWB), bluetooth, and/or other suitable systems. The actual telecommunications standards, network architectures, and/or communication standards employed will depend on the particular application and the overall design constraints imposed on the system.

In this disclosure, the term "exemplary" is used to mean "serving as an example, instance, or illustration. Any implementation or aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects of the disclosure. Likewise, the term "aspect" does not require that all aspects of the disclosure include the discussed feature, advantage or mode of operation. The term "coupled" is used herein to refer to a direct or indirect coupling between two objects. For example, if object A physically contacts object B, and object B contacts object C, then objects A and C may still be considered coupled to each other even though they are not in direct physical contact with each other. For example, a first object may be coupled to a second object even though the first object is never in direct physical contact with the second object. The terms "circuitry" and "circuitry" are used broadly and are intended to encompass both hardware implementations of electrical devices and conductors, as well as software implementations of information and instructions, which, when connected and configured, can carry out the functions described in this disclosure, without limitation to the type of electronic circuitry, and which, when executed by a processor, can carry out the functions described in this disclosure.

One or more of the components, steps, features, and/or functions illustrated in fig. 1-18 may be rearranged and/or combined into a single component, step, feature, or function, or embodied in several components, steps, or functions. Additional elements, components, steps, and/or functions may also be added without departing from the novel features disclosed herein. The apparatus, devices, and/or components shown in fig. 1, 2, 4, 5, 7-11, 14, 17A, 17B, and/or 18 may be configured to perform one or more of the methods, features, or steps described herein. The novel algorithms described herein may also be implemented effectively in software and/or embedded in hardware.

It should be understood that the specific order or hierarchy of steps in the methods disclosed is an illustration of exemplary processes. It will be appreciated that in accordance with design preferences, the specific order or hierarchy of steps in the methods may be rearranged. The accompanying method claims present elements of the various steps in a sample order, but are not intended to be limited to the specific order or hierarchy presented, unless specifically recited therein.

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean "one and only one" unless specifically so stated, but rather "one or more". The term "some" means one or more unless specifically stated otherwise. The phrase referring to "at least one" in a list of items refers to any combination of those items that comprise a single member. For example, "at least one of a, b, or c" is intended to encompass: a, a; a and b; a and c; b and c; and a, b and c. Constructs a and/or B are intended to cover A, B as well as a and B. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element should be construed in accordance with chapter 112 (f) of the american code for standardization unless the element is explicitly expressed by the phrase "means for" or, in the case of method claims, by the phrase "step for.

Claims (17)

1. A method of wireless communication at a base station, the method comprising:

receiving an uplink transmission on a first transmit beam of a first beam-to-link via a first Transmit and Receive Point (TRP) associated with the base station;

receiving the uplink transmission on a second transmit beam of a second beam-pair link via a second TRP associated with the base station;

transmitting a downlink transmission via the first TRP on the first transmit beam with a first beam specific timing precompensation; and

transmitting the downlink transmission via the second TRP on the second transmit beam having a second beam specific timing precompensation,

wherein the first beam-specific timing precompensation and the second beam-specific timing precompensation are based on a timing difference between reception of the uplink transmission via the first TRP and reception of the uplink transmission via the second TRP.

2. The method of claim 1, wherein the uplink transmission comprises a Sounding Reference Signal (SRS).

3. The method of claim 1, wherein the downlink transmission comprises an indication of at least one of: the first beam specific timing precompensation or the second beam specific timing precompensation.

4. The method of claim 1, wherein the downlink transmission comprises at least one of: a signal, a UE-specific channel, or a common channel common to each of a plurality of UEs.

5. The method of claim 1, wherein the downlink transmission comprises at least one of: downlink Control Information (DCI) or Medium Access Control (MAC) control elements (MAC-CEs) indicating at least one of the first beam-specific timing precompensation or the second beam-specific timing precompensation.

6. The method of claim 1, wherein the downlink transmission is a Physical Downlink Shared Channel (PDSCH), and each data layer of the PDSCH is associated with at least one of: multiple Transition Configuration Indication (TCI) states or a single composite TCI state representing the multiple TCI states.

7. The method of claim 1 wherein the downlink transmission is sent within a Single Frequency Network (SFN) over the same time-frequency resources via the first TRP and the second TRP.

8. A base station for wireless communication, comprising:

a transceiver;

a memory; and

a processor communicatively coupled to the memory and the transceiver, the processor and the memory configured to:

Receiving an uplink transmission on a first transmit beam of a first beam-to-link via a first Transmit and Receive Point (TRP) associated with the base station;

receiving the uplink transmission on a second transmit beam of a second beam-pair link via a second TRP associated with the base station;

transmitting a downlink transmission via the first TRP on the first transmit beam with a first beam specific timing precompensation; and

transmitting the downlink transmission via the second TRP on the second transmit beam having a second beam specific timing precompensation,

wherein the first beam-specific timing precompensation and the second beam-specific timing precompensation are based on a timing difference between reception of the uplink transmission via the first TRP and reception of the uplink transmission via the second TRP.

9. A method of wireless communication at a User Equipment (UE), the method comprising:

transmitting an uplink transmission on a first receive beam of a first beam pair link;

transmitting the uplink transmission on a second receive beam of a second beam pair link; and

receiving a downlink transmission, the downlink transmission indicating:

A first beam-specific timing precompensation applied to a first transmit beam of said first beam-pair link, and

a second beam specific timing precompensation applied to a second transmit beam of the link is performed by the second beam.

10. The method of claim 9, wherein the uplink transmission comprises a Sounding Reference Signal (SRS).

11. The method of claim 9, wherein the first beam-specific timing precompensation and the second beam-specific timing precompensation are applied to at least one of: a signal, a UE-specific channel, or a common channel common to each of a plurality of UEs.

12. The method of claim 9, further comprising:

receiving the downlink transmission indicating the first beam-specific timing precompensation and the second beam-specific timing precompensation within at least one of: downlink Control Information (DCI) or Medium Access Control (MAC) control element (MAC-CE).

13. The method of claim 9, further comprising:

receiving the downlink transmission on the first receive beam of a first beam-to-link according to a first beam-specific timing precompensation on a first time-frequency resource; and

The downlink transmission is received on the second receive beam of the second beam-pair link according to the second beam-specific timing precompensation on the first time-frequency resource.

14. The method of claim 9, further comprising:

receiving a Physical Downlink Shared Channel (PDSCH) on the first receive beam of the first beam-pair link according to the first beam-specific timing precompensation, and

the PDSCH is received on the second receive beam of the second beam pair link according to the second beam specific timing precompensation.

15. The method of claim 14, wherein each data layer of the PDSCH is associated with a plurality of Transition Configuration Indication (TCI) states.

16. The method of claim 14, wherein each data layer of the PDSCH is associated with a single composite TCI state representing multiple TCI states.

17. A User Equipment (UE) for wireless communication, comprising:

a transceiver;

a memory; and

a processor communicatively coupled to the memory and the transceiver, the processor and the memory configured to:

transmitting an uplink transmission on a first receive beam of a first beam pair link;

Transmitting the uplink transmission on a second receive beam of a second beam pair link; and

receiving a downlink transmission, the downlink transmission indicating:

a first beam-specific timing precompensation applied to a first transmit beam of said first beam-pair link, and

a second beam specific timing precompensation applied to a second transmit beam of the link is performed by the second beam.