WO2021227057A1

WO2021227057A1 - Uplink transmission configuration supporting multiple antenna panels transmission

Info

Publication number: WO2021227057A1
Application number: PCT/CN2020/090640
Authority: WO
Inventors: Fang Yuan; Mostafa KHOSHNEVISAN; Wooseok Nam; Tao Luo; Jing Sun; Xiaoxia Zhang
Original assignee: Qualcomm Incorporated
Priority date: 2020-05-15
Filing date: 2020-05-15
Publication date: 2021-11-18

Abstract

A user equipment (UE) can use multiple transmit precoding matrix indicator (TPMI) configurations for different number of antenna ports in multi-panel uplink transmission for supporting coherent joint transmission (CJT) and non-coherent joint transmission (NCJT). The UE can use a first TPMI configuration for CJT and a second TPMI configuration for NCJT. A scheduling entity (e.g., a base station) can indicate multiple TPMIs in downlink control information (DCI) that is transmitted to a UE that is capable of performing CJT and NCJT.

Description

UPLINK TRANSMISSION CONFIGURATION SUPPORTING MULTIPLE ANTENNA PANELS TRANSMISSION

TECHNICAL FIELD

The technology discussed below relates generally to wireless communication systems, and more particularly, to a method and apparatus for configuring an uplink transmission in a wireless communication system supporting multi-antenna transmission.

BACKGROUND

In wireless communication systems, such as 5G New Radio (NR) systems, codebook-based transmission and non-codebook-based transmission schemes may be used for the uplink data channel. Codebook-based transmission is based on precoder indication from a base station. Therefore, codebook-based uplink (UL) transmission may be used even when channel reciprocity is not present. For codebook-based uplink transmission, a user equipment (UE) can transmit non-precoded sounding reference signals (SRSs) . The UE can transmit SRS using one or two SRS resources, and an SRS resource can have multiple antenna ports. The base station determines the precoder based on the received SRSs and sends precoder parameters to the UE. For example, precoder parameters may include an SRS resource indicator (SRI) , a transmit precoding matrix indicator (TPMI) , and a transmit rank indicator (TRI) . The SRI indicates the selected SRS resource, the TRI indicates the preferred transmission rank, and the TPMI indicates the preferred precoder over the ports in the selected resource. The UE can select the precoder from an uplink codebook. Then, the UE can perform the uplink transmission based on the precoder indication report from the base station.

BRIEF SUMMARY OF SOME EXAMPLES

The following presents a summary of one or more aspects of the present 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 neither to identify key or critical elements of all aspects of the disclosure nor to 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.

One aspect of the present disclosure provides a method of wireless communication at a user equipment (UE) . The UE receives, from a scheduling entity, downlink control information (DCI) comprising a first transmit precoding matrix indicator (TPMI) and a second TPMI. The UE determines a TPMI configuration based on the first TPMI and the second TPMI. The UE precodes uplink (UL) data for a coherent joint transmission (CJT) or a non-coherent joint transmission (NCJT) , based on the TPMI configuration. The UE transmits the precoded UL data for the CJT or the NCJT using a plurality of antenna panels, each antenna panel comprising a plurality of antennas.

Another aspect of the present disclosure provides a method of wireless communication at a scheduling entity. The scheduling entity prepares downlink control information (DCI) for scheduling a UE to transmit UL data using a plurality of antenna panels, the DCI comprising a first TPMI and a second TPMI configured to indicate a TPMI configuration for precoding the UL data. The scheduling entity transmits the DCI to the UE. The scheduling entity receives, from the UE, the UL data in a CJT or a NCJT based on the TPMI configuration.

Another aspect of the present disclosure provides a UE for wireless communication. The UE includes a plurality of antenna panels, a communication interface configured for wireless communication with a scheduling entity, a memory, and

a processor operatively coupled with the communication interface and the memory. The processor and the memory are configured to receive, from the scheduling entity, DCI comprising a first TPMI and a second TPMI. The processor and the memory are further configured to determine a TPMI configuration based on the first TPMI and the second TPMI. The processor and the memory are further configured to precode UL data for a CJT or a NCJT, based on the TPMI configuration. The processor and the memory are further configured to transmit the precoded UL data for the CJT or the NCJT using the communication interface and the plurality of antenna panels, each antenna panel comprising a plurality of antennas.

Another aspect of the present disclosure provides a scheduling entity for wireless communication. The scheduling entity includes a communication interface configured for wireless communication with a UE, a memory, and a processor operatively coupled to the communication interface and the memory. The processor and the memory are configured to prepare DCI for scheduling the UE to transmit UL data using a plurality of antenna panels, the DCI comprising a first TPMI and a second TPMI that are configured to indicate a TPMI configuration for precoding the UL data. The processor and the memory are further configured to transmit the DCI to the UE. The processor and the memory are further configured to receive, from the UE, the UL data in a CJT or a NCJT based on the TPMI configuration.

Another aspect of the present disclosure provides a UE for wireless communication. The UE includes means for receiving, from a scheduling entity, DCI comprising a first TPMI and a second TPMI. The UE further includes means for determining a TPMI configuration based on the first TPMI and the second TPMI. The UE further includes means for precoding UL data for a CJT or a NCJT, based on the TPMI configuration. The UE further includes means for transmitting the precoded UL data for the CJT or the NCJT using a plurality of antenna panels, each antenna panel comprising a plurality of antennas.

Another aspect of the present disclosure provides a scheduling entity for wireless communication. The scheduling entity includes means for preparing DCI for scheduling a UE to transmit UL data using a plurality of antenna panels. The DCI includes a first TPMI and a second TPMI configured to indicate a TPMI configuration for precoding the UL data. The scheduling entity further includes means for transmitting the DCI to the UE. The scheduling entity further includes means for receiving, from the UE, the UL data in a CJT or a NCJT based on the TPMI configuration.

Another aspect of the present disclosure provides an article of manufacture for use by a UE in a wireless communication network. The article includes a computer-readable medium having stored therein instructions executable by one or more processors of the UE. The instructions cause the UE to receive, from a scheduling entity, DCI comprising a first TPMI and a second TPMI. The instructions cause the UE to determine a TPMI configuration based on the first TPMI and the second TPMI. The instructions cause the UE to precode UL data for a CJT or a NCJT, based on the TPMI configuration. The instructions further cause the UE to transmit the precoded UL data for the CJT or the NCJT using a plurality of antenna panels. Each antenna panel includes a plurality of antennas.

Another aspect of the present disclosure provides an article of manufacture for use by a scheduling entity in a wireless communication network. The article includes a computer-readable medium having stored therein instructions executable by one or more processors of the scheduling entity. The instructions cause the scheduling entity to prepare DCI for scheduling a UE to transmit UL data using a plurality of antenna panels. The DCI includes a first TPMI and a second TPMI configured to indicate a TPMI configuration for precoding the UL data. The instructions cause the scheduling entity to transmit the DCI to the UE. The instructions further cause the scheduling entity to receive, from the UE, the UL data in a CJT or a NCJT based on the TPMI configuration.

These and other aspects of the invention will become more fully understood upon a review of the detailed description, which follows. Other aspects, features, and embodiments will become apparent to those of ordinary skill in the art, upon reviewing the following description of specific, exemplary embodiments in conjunction with the accompanying figures. While features may be discussed relative to certain embodiments and figures below, all embodiments can include one or more of the advantageous features discussed herein. In other words, while one or more embodiments may be discussed as having certain advantageous features, one or more of such features may also be used in accordance with the various embodiments discussed herein. In similar fashion, while exemplary embodiments may be discussed below as device, system, or method embodiments it should be understood that such exemplary embodiments can be implemented in various devices, systems, and methods.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a wireless communication system according to some aspects of the disclosure.

FIG. 2 is a conceptual illustration of an example of a radio access network according to some aspects of the disclosure.

FIG. 3 is a block diagram illustrating a wireless communication system supporting multiple-input multiple-output (MIMO) communication.

FIG. 4 is a schematic illustration of an organization of wireless resources in an air interface utilizing orthogonal frequency divisional multiplexing (OFDM) according to some aspects of the disclosure.

FIG. 5 is a drawing illustrating an example of non-coherent joint transmission (NCJT) techniques according to some aspects of the disclosure.

FIG. 6 is a diagram illustrating an example of coherent joint transmission (CJT) according to some aspects of the disclosure.

FIGs. 7 and 8 illustrate two exemplary tables of precoding information and number of layers for selecting a codebook based on the values indicated in downlink control information (DCI) fields.

FIG. 9 is a drawing conceptually illustrating a downlink control information (DCI) carrying two transmit precoding matrix indicators (TPMIs) according to some aspects of the disclosure.

FIG. 10 is a drawing illustrating an example of DCI codepoint and transmit precoding matrix indicator (TPMI) mappings for single-layer transmission using four antenna ports for coherent joint transmission (CJT) .

FIG. 11 is a drawing illustrating an example of DCI codepoints and TPMI mappings for single-layer transmission using two antenna ports for NCJT.

FIG. 12 is a drawing conceptually illustrating a DCI carrying two TPMIs and a non-coherent transmission indicator (NCTI) according to some aspects of the disclosure.

FIG. 13 is a block diagram conceptually illustrating an example of a hardware implementation for a scheduling entity according to some aspects of the disclosure.

FIG. 14 is a flow chart illustrating an exemplary process at a scheduling entity for uplink communication using two TPMIs according to some aspects of the disclosure.

FIG. 15 is a block diagram conceptually illustrating an example of a hardware implementation for a scheduled entity according to some aspects of the disclosure.

FIG. 16 is a flow chart illustrating an exemplary process at a scheduled entity for uplink communication using two TPMIs according to some aspects of the disclosure.

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 various concepts. However, it will be apparent to those skilled in the art that these 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 such concepts.

While aspects and embodiments are described in this application by illustration to some examples, those skilled in the art will understand that additional implementations and use cases may come about in many different arrangements and scenarios. Innovations described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, packaging arrangements. For example, embodiments and/or uses may come about via integrated chip embodiments and other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, AI-enabled devices, etc. ) . While some examples may or may not be specifically directed to use cases or applications, a wide assortment of applicability of described innovations may occur. Implementations may range a spectrum from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregate, distributed, or OEM devices or systems incorporating one or more aspects of the described innovations. In some practical settings, devices incorporating described aspects and features may also necessarily include additional components and features for implementation and practice of claimed and described embodiments. For example, transmission and reception of wireless signals necessarily includes a number of components for analog and digital purposes (e.g., hardware components including antenna, RF-chains, power amplifiers, modulators, buffer, processor (s) , interleaver, adders/summers, etc. ) . It is intended that innovations described herein may be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, end-user devices, etc. of varying sizes, shapes and constitution.

Aspects of the present disclosure provide an uplink transmission scheme that supports the use of multiple transmit precoding matrix indicator (TPMI) configurations for different number of antenna ports in multi-panel uplink transmission at a UE capable of coherent joint transmission (CJT) and non-coherent joint transmission (NCJT) . In one aspect, a first TPMI configuration can be used for CJT, and a second TPMI configuration can be used for NCJT. In one aspect, a scheduling entity (e.g., a base station) can indicate multiple TPMIs in downlink control information (DCI) that is sent to a user equipment (UE) capable of performing CJT and NCJT. In one aspect, the scheduling entity can indicate multiple TPMIs in the DCI that includes a field to indicate whether the indicated TPMIs are for CJT or NCJT.

The various concepts presented throughout this disclosure may be implemented across a broad variety of telecommunication systems, network architectures, and communication standards. Referring now to FIG. 1, as an illustrative example without limitation, various aspects of the present disclosure are illustrated with reference to a wireless communication system 100. The wireless communication system 100 includes three interacting domains: a core network 102, a radio access network (RAN) 104, and a user equipment (UE) 106. By virtue of the wireless communication system 100, the UE 106 may be enabled to carry out data communication with an external data network 110, such as (but not limited to) the Internet.

The RAN 104 may implement any suitable wireless communication technology or technologies to provide radio access to the UE 106. As one example, the RAN 104 may operate according to 3 ^rd Generation Partnership Project (3GPP) New Radio (NR) specifications, often referred to as 5G. As another example, the RAN 104 may operate under a hybrid of 5G NR and Evolved Universal Terrestrial Radio Access Network (eUTRAN) standards, often referred to as LTE. The 3GPP refers to this hybrid RAN as a next-generation RAN, or NG-RAN. Of course, many other examples may be utilized within the scope of the present disclosure.

As illustrated, the RAN 104 includes a plurality of base stations 108. Broadly, a base station is a network element in a radio access network responsible for radio transmission and reception in one or more cells to or from a UE. In different technologies, standards, or contexts, a base station may variously be referred to by those skilled in the art as a base transceiver station (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) , or some other suitable terminology.

The radio access network 104 is further illustrated supporting wireless communication for multiple mobile apparatuses. A mobile apparatus may be referred to as user equipment (UE) in 3GPP standards, 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 device, a wireless communications 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. A UE may be an apparatus (e.g., a mobile apparatus) that provides a user with access to network services.

Within the present document, a “mobile” apparatus need not necessarily have a capability to move, and may be stationary. The term mobile apparatus or mobile device broadly refers to a diverse array of devices and technologies. UEs may include a number of hardware structural components sized, shaped, and arranged to help in communication; such components can include antennas, antenna arrays, RF chains, amplifiers, one or more processors, etc. electrically coupled to each other. For example, some non-limiting examples of a mobile apparatus include a mobile, a cellular (cell) phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal computer (PC) , a notebook, a netbook, a smartbook, a tablet, a personal digital assistant (PDA) , and a broad array of embedded systems, e.g., corresponding to an “Internet of things” (IoT) . A mobile apparatus may additionally be an automotive or other transportation vehicle, a remote sensor or actuator, a robot or robotics device, a satellite radio, a global positioning system (GPS) device, an object tracking device, a drone, a multi-copter, a quad-copter, a remote control device, a consumer and/or wearable device, such as eyewear, 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, etc. A mobile apparatus may additionally be a digital home or smart home device such as a home audio, video, and/or multimedia device, an appliance, a vending machine, intelligent lighting, a home security system, a smart meter, etc. A mobile apparatus may additionally be a smart energy device, a security device, a solar panel or solar array, a municipal infrastructure device controlling electric power (e.g., a smart grid) , lighting, water, etc.; an industrial automation and enterprise device; a logistics controller; agricultural equipment; military defense equipment, vehicles, aircraft, ships, and weaponry, etc. Still further, a mobile apparatus may provide for connected medicine or telemedicine support, e.g., health care at a distance. Telehealth devices may include telehealth monitoring devices and telehealth administration devices, whose communication may be given preferential treatment or prioritized access over other types of information, e.g., in terms of prioritized access for transport of critical service data, and/or relevant QoS for transport of critical service data.

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

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

Base stations 108 are not the only entities that may function as scheduling entities. That is, in some examples, a UE may function as a scheduling entity, scheduling resources for one or more scheduled entities (e.g., one or more other UEs) .

As illustrated in FIG. 1, a scheduling entity 108 may broadcast downlink traffic 112 to one or more scheduled entities 106. Broadly, the scheduling entity 108 is a node or device responsible for scheduling traffic in a wireless communication network, including the downlink traffic 112 and, in some examples, uplink traffic 116 from one or more scheduled entities 106 to the scheduling entity 108. On the other hand, the scheduled entity 106 is a node or device that receives downlink control information 114, including but not limited to scheduling information (e.g., a grant) , synchronization or timing information, or other control information from another entity in the wireless communication network such as the scheduling entity 108.

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

The core network 102 may be a 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 5G standards (e.g., 5GC) . In other examples, the core network 102 may be configured according to a 4G evolved packet core (EPC) , or any other suitable standard or configuration.

FIG. 2 is a conceptual illustration of an example of a radio access network (RAN) 200 according to some aspects of the disclosure. In some examples, the RAN 200 may be the same as the RAN 104 described above and illustrated in FIG. 1. The geographic area covered by the RAN 200 may be divided into cellular regions (cells) that can be uniquely identified by a user equipment (UE) based on an identification broadcasted from one access point or base station. FIG. 2 illustrates

macrocells

202, 204, and 206, and a small cell 208, each of which may include one or more sectors (not shown) . A sector is a sub-area of a cell. All sectors within one cell are served by the same base station. A radio link within a sector can be identified by a single logical identification belonging to that sector. In a cell that is divided into sectors, the multiple sectors within a cell can be formed by groups of antennas with each antenna responsible for communication with UEs in a portion of the cell.

In FIG. 2, two

base stations

210 and 212 are shown in

cells

202 and 204; and a third base station 214 is shown controlling a remote radio head (RRH) 216 in cell 206. That is, a base station can have an integrated antenna or can be connected to an antenna or RRH by feeder cables. In the illustrated example, the

cells

202, 204, and 126 may be referred to as macrocells, as the

base stations

210, 212, and 214 support cells having a large size. Further, a base station 218 is shown in the small cell 208 (e.g., a microcell, picocell, femtocell, home base station, home Node B, home eNode B, etc. ) which may overlap with one or more macrocells. In this example, the cell 208 may be referred to as a small cell, as the base station 218 supports a cell having a relatively small size. Cell sizing can be done according to system design as well as component constraints.

It is to be understood that the radio access network 200 may include any number of wireless base stations and cells. Further, a relay node 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 a core network for any number of mobile apparatuses. In some examples, the

base stations

210, 212, 214, and/or 218 may be the same as the base station/scheduling entity 108 described above and illustrated in FIG. 1.

FIG. 2 further includes a quadcopter or drone 220, which may be configured to function as a base station. That is, in some examples, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a mobile base station such as the quadcopter 220.

Within the RAN 200, the cells may include UEs that may be in communication 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 a core network 102 (see FIG. 1) for all the UEs in the respective cells. For example,

UEs

222 and 224 may be in communication with base station 210;

UEs

226 and 228 may be in communication with base station 212;

UEs

230 and 232 may be in communication with base station 214 by way of RRH 216; UE 234 may be in communication with base station 218; and UE 236 may be in communication with mobile base station 220. In some examples, the

UEs

222, 224, 226, 228, 230, 232, 234, 236, 238, 240, and/or 242 may be the same as the UE/scheduled entity 106 described above and illustrated in FIG. 1.

In some aspects of the disclosure, one or more of the UEs can perform both coherent joint transmission (CJT) and non-coherent joint transmission (NCJT) using multiple panels of antennas. In CJT, the UE can transmit a same layer of data using multiple panels. In NCJT, the UE can transmit independent layers of data using respective different panels of antennas.

In some examples, a mobile network node (e.g., quadcopter 220) may be configured to function as a UE. For example, the quadcopter 220 may operate within cell 202 by communicating with base station 210.

In a further aspect of the RAN 200, sidelink signals may be used between UEs without necessarily relying on scheduling or control information from a base station. For example, two or more UEs (e.g., UEs 226 and 228) may communicate with each other using peer to peer (P2P) or sidelink signals 227 without relaying that communication through a base station (e.g., base station 212) . In a further example, UE 238 is illustrated communicating with

UEs

240 and 242. Here, the UE 238 may function as a scheduling entity or a primary sidelink device, and

UEs

240 and 242 may function as a scheduled entity or a non-primary (e.g., secondary) sidelink device. In still another example, a UE may function as a scheduling entity in a device-to-device (D2D) , peer-to-peer (P2P) , or vehicle-to-vehicle (V2V) network, and/or in a mesh network. In a mesh network example,

UEs

240 and 242 may optionally communicate directly with one another in addition to communicating with the scheduling entity 238. Thus, in a wireless communication system with scheduled access to time–frequency resources and having a cellular configuration, a P2P configuration, or a mesh configuration, a scheduling entity and one or more scheduled entities may communicate utilizing the scheduled resources.

In the radio access network 200, the ability for a UE to communicate while moving, independent of its location, is referred to as mobility. The various physical channels between the UE and the radio access network are generally set up, maintained, and released under the control of an access and mobility management function (AMF, not illustrated, part of the core network 102 in FIG. 1) , which may include a security context management function (SCMF) that manages the security context for both the control plane and the user plane functionality, and a security anchor function (SEAF) that performs authentication.

In various aspects of the disclosure, a radio access network 200 may utilize DL-based mobility or UL-based mobility to enable mobility and handovers (i.e., the transfer of a UE’s connection from one radio channel to another) . In a network configured for DL-based mobility, during a call with a scheduling entity, or at any other time, a UE may monitor various parameters of the signal from its serving cell as well as various parameters of neighboring cells. 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 signal quality from a neighboring cell exceeds that from the serving cell for a given amount of time, the UE may undertake a handoff or handover from the serving cell to the neighboring (target) cell. For example, UE 224 (illustrated as a vehicle, although any suitable form of UE may be used) may move from the geographic area corresponding to its serving cell 202 to the geographic area corresponding to a neighbor cell 206. When the signal strength or quality from the neighbor cell 206 exceeds that of its serving cell 202 for a given amount of time, the UE 224 may transmit a reporting message to its serving base station 210 indicating this condition. In response, the UE 224 may receive a handover command, and the UE may undergo a handover to the 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, the

base stations

210, 212, and 214/216 may broadcast unified synchronization signals (e.g., unified Primary Synchronization Signals (PSSs) , unified Secondary Synchronization Signals (SSSs) and unified Physical Broadcast Channels (PBCH) ) . The

UEs

222, 224, 226, 228, 230, and 232 may receive the unified synchronization signals, derive the carrier frequency and slot timing from the synchronization signals, and in response to deriving timing, transmit an uplink pilot or reference signal. The uplink pilot signal transmitted by a UE (e.g., UE 224) may be concurrently received by two or more cells (e.g.,

base stations

210 and 214/216) within the radio access network 200. Each of the cells may measure a 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 the UE 224 moves through the radio access network 200, the network may continue to monitor the uplink pilot signal transmitted by the UE 224. When the signal strength or quality of the pilot signal measured by a neighboring cell exceeds that of the signal strength or quality measured by the serving cell, the network 200 may handover the UE 224 from the serving cell to the neighboring cell, with or without informing the UE 224.

Although the synchronization signal transmitted by the

base stations

210, 212, and 214/216 may be unified, the synchronization signal may not identify a particular cell, but rather may identify a zone of multiple cells operating on the same frequency and/or with the same timing. The use of zones in 5G networks or other next generation communication networks enables the uplink-based mobility framework and improves the efficiency of both the UE and the network, since the number of mobility messages that need to be exchanged between the UE and the network may be reduced.

The air interface in the radio access network 200 may utilize one or more duplexing algorithms. Duplex refers to a point-to-point communication link where both endpoints can communicate with one another in both directions. Full duplex means both endpoints can simultaneously communicate with one another. Half duplex means only one endpoint can send information to the other at a time. In a wireless link, a full duplex channel generally relies on physical isolation of a transmitter and receiver, and suitable interference cancellation technologies. Full duplex emulation is frequently implemented for wireless links by utilizing frequency division duplex (FDD) or time division duplex (TDD) . In FDD, transmissions in different directions operate at different carrier frequencies. In TDD, transmissions in different directions on a given channel are separated from one another using time division multiplexing. That is, at some times the channel is dedicated for transmissions in one direction, while at other times the channel is dedicated for transmissions in the other direction, where the direction may change very rapidly, e.g., several times per slot.

In some aspects of the disclosure, the scheduling entity and/or scheduled entity (UE) may be configured for beamforming and/or multiple-input multiple-output (MIMO) technology. FIG. 3 illustrates an example of a wireless communication system 300 supporting MIMO. In a MIMO system, a transmitter 302 includes multiple transmit antennas 304 (e.g., N transmit antennas) and a receiver 306 includes multiple receive antennas 308 (e.g., M receive antennas) . Thus, there are N × M signal paths 310 from the transmit antennas 304 to the receive antennas 308. Each of the transmitter 302 and the receiver 306 may be implemented, for example, within a scheduling entity 108, a scheduled entity 106, or any other suitable wireless communication device. In some aspects, the transmitter and receiver may each include multiple panels of antennas. Each panel includes an array of antennas. The panels may be used separately or together for MIMO communication, for example, CJT and NCJT.

The use of such multiple antenna technology enables the wireless communication system to exploit the spatial domain to support spatial multiplexing, beamforming, and transmit diversity. Spatial multiplexing may be used to transmit different streams of data, also referred to as layers, simultaneously on the same time-frequency resource. The data streams may be transmitted to a single receiver (e.g., UE or scheduling entity) to increase the data rate or to multiple receivers (e.g., 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 the data streams with different weighting and phase shifting) and then transmitting each spatially precoded stream through multiple transmit antennas on the downlink/uplink. The spatially precoded data streams arrive at the receivers with different spatial signatures, which enables each of the receivers to recover the one or more data streams destined for that receiver. In an uplink example, each UE can transmit a spatially precoded data stream, which enables the base station to identify the source of each spatially precoded data stream. In some examples, the UE can transmit multiple data streams or layers using multiple panels of antennas in CJT or NCJT.

The number of data streams or layers corresponds to the rank of the transmission. In general, the rank of the MIMO system 300 is limited by the number of transmit or receive

antennas

304 or 308, whichever is lower. In addition, the channel conditions at the UE, as well as other considerations, such as the available resources at the base station, may also affect the transmission rank. For example, the rank (and therefore, the number of data streams) assigned to a particular UE on the downlink may be determined based on the rank indicator (RI) transmitted from the UE to the base station. The RI may be determined based on the antenna configuration (e.g., the number of transmit and receive antennas) and a measured signal-to-interference-and-noise ratio (SINR) on each of the receive antennas. 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., the available resources and amount of data to be scheduled for the UE) , to assign a transmission rank to the UE. Similar processes may be used for the uplink MIMO transmissions.

In Time Division Duplex (TDD) systems, the UL and DL are reciprocal, in that each uses different time slots of the same frequency bandwidth. Therefore, in TDD systems, the base station may assign the rank for DL MIMO transmissions based on UL SINR measurements (e.g., based on a Sounding Reference Signal (SRS) transmitted from the UE or other pilot signal) . Based on the assigned rank, the base station may then transmit the CSI-RS with separate C-RS sequences for each layer to provide for multi-layer channel estimation. From the CSI-RS, the UE may measure the channel quality across layers and resource blocks and feed back the CQI and RI values to the base station for use in updating the rank and assigning REs for future downlink transmissions. Similar processes may be used for the uplink MIMO transmissions.

In the simplest case, as shown in FIG. 3, a rank-2 spatial multiplexing transmission on a 2x2 MIMO antenna configuration will transmit one data stream (or layer) from each transmit antenna 304. Each data stream reaches each receive antenna 308 along a different signal path 310. The receiver 306 may then reconstruct the data streams using the received signals from each receive antenna 308.

The air interface in the radio access network 200 may utilize one or more multiplexing and multiple access algorithms to enable simultaneous communication of the various devices. For example, 5G NR specifications provide multiple access for UL transmissions from

UEs

222 and 224 to a base station 210, and for multiplexing for DL transmissions from a base station 210 to one or

more UEs

222 and 224, utilizing orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) . In addition, for UL transmissions, 5G NR specifications provide support for discrete Fourier transform-spread-OFDM (DFT-s-OFDM) with a CP (also referred to as single-carrier FDMA (SC-FDMA) ) . However, within the scope of the present disclosure, multiplexing and multiple access are not limited to the above schemes, and may be provided utilizing 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, multiplexing DL transmissions from the 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.

Various aspects of the present disclosure will be described with reference to an OFDM waveform, schematically illustrated in FIG. 4. It should be understood by those of ordinary skill in the art that the various aspects of the present disclosure may be applied to a DFT-s-OFDMA waveform in substantially the same way as described herein below. That is, while some examples of the present disclosure may focus on an OFDM link for clarity, it should be understood that the same principles may be applied as well to DFT-s-OFDMA waveforms.

Within the present disclosure, a frame refers to a duration of 10 ms for wireless transmissions, with each frame consisting of 10 subframes of 1 ms each. On a given carrier, there may be one set of frames in the UL, and another set of frames in the DL. Referring now to FIG. 4, an expanded view of an exemplary DL subframe 402 is illustrated, showing an OFDM resource grid 404. However, as those skilled in the art will readily appreciate, the PHY transmission structure for any particular application may vary from the example described here, depending on any number of factors. Here, time is in the horizontal direction with units of OFDM symbols; and frequency is in the vertical direction with units of subcarriers or tones.

The resource grid 404 may be used to schematically represent time–frequency resources for a given antenna port. That is, in a MIMO implementation with multiple antenna ports and/or panels available, a corresponding multiple number of resource grids 404 may be available for communication. The resource grid 404 is divided into multiple resource elements (REs) 406. An RE, which is 1 subcarrier × 1 symbol, is the smallest discrete part of the time–frequency grid, and contains a single complex value representing data from a physical channel or signal. Depending on the modulation utilized in a particular implementation, each RE may represent one or more bits of information. In some examples, a block of REs may be referred to as a physical resource block (PRB) or more simply a resource block (RB) 408, which contains any suitable number of consecutive subcarriers in the frequency domain. In one example, an RB may include 12 subcarriers, a number independent of the numerology used. In some examples, depending on the numerology, an RB may include any suitable number of consecutive OFDM symbols in the time domain. Within the present disclosure, it is assumed that a single RB such as the RB 408 entirely corresponds to a single direction of communication (either transmission or reception for a given device) .

A UE generally utilizes only a subset of the resource grid 404. An RB may be the smallest unit of resources that can be allocated to a UE. Thus, the more RBs scheduled for a UE, and the higher the modulation scheme chosen for the air interface, the higher the data rate for the UE.

In this illustration, the RB 408 is shown as occupying less than the entire bandwidth of the subframe 402, with some subcarriers illustrated above and below the RB 408. In a given implementation, the subframe 402 may have a bandwidth corresponding to any number of one or more RBs 408. Further, in this illustration, the RB 408 is shown as occupying less than the entire duration of the subframe 402, although this is merely one possible example.

Each subframe 402 (e.g., a 1ms subframe) may consist of one or multiple adjacent slots. In the example shown in FIG. 4, one subframe 402 includes four slots 410, as an illustrative example. In some examples, a slot may be defined according to a specified number of OFDM symbols with a given cyclic prefix (CP) length. For example, a slot may include 7 or 14 OFDM symbols with a nominal CP. Additional examples may include mini-slots having a shorter duration (e.g., 1, 2, 4, or 7 OFDM symbols) . These mini-slots may in some cases be transmitted occupying resources scheduled for ongoing slot transmissions for the same or for different UEs.

An expanded view of one of the slots 410 illustrates the slot 410 including a control region 412 and a data region 414. In general, the control region 412 may carry control channels (e.g., PDCCH) , and the data region 414 may carry data channels (e.g., PDSCH or PUSCH) . Of course, a slot may contain all DL, all UL, or at least one DL portion and at least one UL portion. The simple structure illustrated in FIG. 4 is merely exemplary in nature, and different slot structures may be utilized, and may include one or more of each of the control region (s) and data region (s) .

Although not illustrated in FIG. 4, the various REs 406 within an RB 408 may be scheduled to carry one or more physical channels, including control channels, shared channels, data channels, etc. Other REs 406 within the RB 408 may also carry pilots or reference signals. These pilots or reference signals may provide for a receiving device to perform channel estimation of the corresponding channel, which may enable coherent demodulation/detection of the control and/or data channels within the RB 408.

In a DL transmission, the transmitting device (e.g., the scheduling entity 108) may allocate one or more REs 406 (e.g., within a control region 412) to carry DL control information 114 including one or more DL control channels that generally carry information originating from higher layers, such as a physical broadcast channel (PBCH) , a physical downlink control channel (PDCCH) , etc., to one or more scheduled entities 106. In addition, DL REs may be allocated to carry DL physical signals that generally do not carry information originating from higher layers. These DL physical signals may include a primary synchronization signal (PSS) ; a secondary synchronization signal (SSS) ; demodulation reference signals (DM-RS) ; phase-tracking reference signals (PT-RS) ; channel-state information reference signals (CSI-RS) ; etc.

The synchronization signals PSS and SSS (collectively referred to as SS) , and in some examples, the PBCH, may be transmitted in an SS block that includes 4 consecutive OFDM symbols, numbered via a time index in increasing order from 0 to 3. In the frequency domain, the SS block may extend over 240 contiguous subcarriers, with the subcarriers being numbered via a frequency index in increasing order from 0 to 239. Of course, the present disclosure is not limited to this specific SS block configuration. Other nonlimiting examples may utilize greater or fewer than two synchronization signals; may include one or more supplemental channels in addition to the PBCH; may omit a PBCH; and/or may utilize nonconsecutive symbols for an SS block, within the scope of the present disclosure.

The PDCCH may carry downlink control information (DCI) for one or more UEs in a cell. This can include, but is not limited to, power control commands, scheduling information, a grant, and/or an assignment of REs for DL and UL transmissions.

In an UL transmission, a transmitting device (e.g., a scheduled entity 106) may utilize one or more REs 406 to carry UL control information 118 (UCI) . The UCI can originate from higher layers via one or more UL control channels, such as a physical uplink control channel (PUCCH) , a physical random access channel (PRACH) , etc., to the scheduling entity 108. Further, UL REs may carry UL physical signals that generally do not carry information originating from higher layers, such as demodulation reference signals (DM-RS) , phase-tracking reference signals (PT-RS) , sounding reference signals (SRS) , etc. In some examples, the control information 118 may include a scheduling request (SR) , i.e., a request for the scheduling entity 108 to schedule uplink transmissions. Here, in response to the SR transmitted on the control channel 118, the scheduling entity 108 may transmit downlink control information 114 that may schedule resources for uplink packet transmissions.

UL control information may also include hybrid automatic repeat request (HARQ) feedback such as an acknowledgment (ACK) or negative acknowledgment (NACK) , channel state information (CSI) , or any other suitable UL control information. HARQ is a technique well-known to those of ordinary skill in the art, wherein the integrity of packet transmissions may be checked at the receiving side for accuracy, e.g., utilizing any suitable integrity checking mechanism, such as a checksum or a cyclic redundancy check (CRC) . If the integrity of the transmission confirmed, an ACK may be transmitted, whereas if not confirmed, a NACK may be transmitted. In response to a NACK, the transmitting device may send a HARQ retransmission, which may implement chase combining, incremental redundancy, etc.

In addition to control information, one or more REs 406 (e.g., within the data region 414) may be allocated for user data or traffic data. Such traffic may be carried on one or more traffic channels, such as, for a DL transmission, a physical downlink shared channel (PDSCH) ; or for an UL transmission, a physical uplink shared channel (PUSCH) .

In order for a UE to gain initial access to a cell, the RAN may provide system information (SI) characterizing the cell. This system information may be provided utilizing minimum system information (MSI) , and other system information (OSI) . The MSI may be periodically broadcast over the cell to provide the most basic information required for initial cell access, and for acquiring any OSI that may be broadcast periodically or sent on-demand. In some examples, the MSI may be provided over two different downlink channels. For example, the PBCH may carry a master information block (MIB) , and the PDSCH may carry a system information block type 1 (SIB1) . In the art, SIB1 may be referred to as the remaining minimum system information (RMSI) .

OSI may include any SI that is not broadcast in the MSI. In some examples, the PDSCH may carry a plurality of SIBs, not limited to SIB1, discussed above. Here, the OSI may be provided in these SIBs, e.g., SIB2 and above.

The channels or carriers described above and illustrated in FIGs. 1 and 4 are not necessarily all the channels or carriers that may be utilized between a scheduling entity 108 and scheduled entities 106, and those of ordinary skill in the art will recognize that other channels or carriers may be utilized in addition to those illustrated, such as other traffic, control, and feedback channels.

These physical channels described above are generally multiplexed and mapped to transport channels for handling at the medium access control (MAC) layer. Transport channels carry blocks of information called transport blocks (TB) . The transport block size (TBS) , which may correspond to a number of bits of information, may be a controlled parameter, based on the modulation and coding scheme (MCS) and the number of RBs in a given transmission.

FIG. 5 is a diagram illustrating an example of non-coherent joint transmission (NCJT) techniques according to some aspects of the disclosure. In this example, a transmitter (e.g., UE 502) may have multiple panels of antennas for wireless communication. For example, a UE 502 has a first panel 504 of antennas (e.g., antenna ports Tx0 and Tx2) , and a second panel 506 of antennas (e.g., antenna ports Tx1 and Tx3) . Using NCJT techniques, the UE 502 can use the first panel 504 for a first transmission of layer 0 and layer 1 to a first transmit receive point (TRP) 508 (e.g., a gNB) , and use the second panel 506 for a second transmission of layer 2 and layer 3 to a second TRP 510. Here, the UE can use different antenna panels to transmit different layers using NCJT techniques.

FIG. 6 is a diagram illustrating an example of coherent joint transmission (CJT) according to some aspects of the disclosure. In this example, a transmitter (e.g., UE 602) may have multiple panels of antennas for wireless communication. For example, a UE 602 has a first panel 604 of antennas (e.g., antenna ports Tx0 and Tx1) , and a second panel 606 of antennas (e.g., antenna ports Tx2 and Tx3) . Using CJT techniques, the UE 602 can use the first panel 604 (e.g., antenna port Tx0) and second panel 606 (e.g., antenna port Tx2) for a first transmission of all the layers, i.e., layers 0, 1, 2, and 3 to a first TRP 608, and use both the first panel 604 (e.g., antenna port Tx1) and second panel 606 (e.g., antenna Tx3) for a second transmission of all the layers, i.e., layers 0, 1, 2, and 3 to a second TRP 610. Here, the UE can use multiple antenna panels to transmit the same layers of data using CJT techniques.

In some aspects of the disclosure, a UE can support both CJT and NCJT in UL transmission using multiple panels of antennas. In codebook-based UL transmissions, a UE can utilize one or more SRS resources to transmit one or more SRSs, and each SRS resource can be used to transmit a beam and can have multiple antenna ports. The scheduling entity (e.g., a gNB) can determine an uplink beam and precoder based on the received SRSs and provide the UE with the determined uplink beam and precoder report or indication. In some examples, the uplink beam and precoder indication may include various parameters such as an SRS resource indicator (SRI) and a transmit precoding matrix indicator (TPMI) . The SRI indicates the selected SRS resource and a beam for uplink transmission. The TPMI indicates the preferred precoder for UL transmission and also the rank associated with the precoder over the ports in the selected resource, where the precoder may be selected from an uplink codebook. The UE then performs the uplink transmission based on the uplink beam and precoder parameters. For example, the TPMI can indicate the precoder to be applied over the layers of PUSCH transmission, which is transmitted by a beam that corresponds to the SRS resource selected by the SRI when multiple SRS resources are configured. If a single SRS resource is configured, the TPMI indicates the precoder to be applied over the layers and that corresponds to the same SRS resource.

In one example, an SRS resource can correspond to one antenna panel, and the antenna ports within an SRS resource correspond to the antenna ports within the panel. The UE may use the respective SRS resources to transmit an SRS via the antenna panels. The ports within an SRS resource are mapped to the antenna ports in each panel. The scheduling entity evaluates the different precoding matrices in the codebook based on the received SRS, then determines the SRS resource, precoding matrix, and signals the corresponding SRI and TPMI to the UE in corresponding DCI fields. FIGs. 7 and 8 illustrate two exemplary tables of precoding information and numbers of layers used for selecting a codebook based on values (e.g., TPMI) indicated in the DCI fields. The UE can select the precoding matrix for an UL transmission based on the precoder parameters received from the scheduling entity.

For codebook-based transmission in an NR network, a UE can support one or more levels of coherence capabilities: full, partial, and non-coherent. A UE with full coherence capability can transmit coherently over all antenna ports. This means that the UE can control the relative phase between all Tx chains. A UE with partial coherence capability is able to transmit coherently over certain pairs of antenna ports. A non-coherent UE cannot transmit coherently over any antenna ports. An uplink codebook may include different parts adapted to the different UE coherence capabilities. The scheduling entity can configure the UE to use a subset of the entire codebook depending on its coherence capability. For example, the codebook may have a subset for full/partial/non-coherent use, a subset restricted for partial/non-coherent use, and a subset restricted for non-coherent use. Therefore, a UE with full coherent capability can use the entire uplink codebook, while a non-coherent UE can only use the non-coherent subset. The UE determines its codebook subset (s) based on the TPMI and other higher layer parameters, for example, codebookSubset in pusch-Config which may be configured with “fullyAndPartialAndNonCoherent, ” “partialAndNonCoherent, ” or “noncoherent” depending on the UE capability. The maximum transmission rank may be configured by the higher layer parameter maxRank in pusch-Config.

In some aspects of the disclosure, a scheduling entity can configure a UE with two TPMI configurations. Each TPMI configuration indicates the number of antenna ports, precoder codebook subset restriction type, and maximum rank. In some aspects, the TPMI configurations can configure the UE to use different numbers of antenna ports in multi-panel transmissions. In other aspects, a first TPMI configuration provides the TPMIs of a first length (or a first number of antenna ports) used for CJT, and a second TPMI configuration provides the TPMIs of a second length (or second number of antenna ports) used for NCJT. The first length is larger than the second length. That is, the first number of antenna ports are larger in number than the second number of antenna ports. For example, if a UE has two panels each of two antenna ports, a first TPMI configuration can include TPMIs of length 4 (or 4 antenna ports) for a CJT TPMI configuration, and a second TPMI configuration can include TPMIs of length 2 (or 2 antenna ports) for a NCJT TPMI configuration.

In one aspect, an exemplary precoder configuration for CJT is defined below. The precoder P may include two TPMI matrices corresponding to different layer sets.

P= [V ^TPMI1 V ^TPMI2]

The TPMI matrices (V ^TPMI1 and V ^TPMI2) each have a length of N1+N2, where Ni is the number of antenna ports for the i-th panel (i=1, 2) . For two panels each of two antenna ports, the lengths are N1=2 and N2=2. Each TPMI is for a layer set, and each layer in the layer set is associated or mapped with two panels of antennas. The rank of the precoder P is r1+r2, where the sub-rank ri of each TPMI matrix V ^TPMIi can be determined in the DCI indication of the corresponding TPMIi. Therefore, the dimension of the precoder P is (N1+N2) * (r1+r2) , which is of length N1+N2.

In one aspect, an exemplary precoder configuration for NCJT is shown below including two TPMIs matrices corresponding to different layer sets.

The TPMI matrices (V ^TPMI1 and V ^TPMI2) have lengths N1 and N2, respectively, where Ni is number of antenna ports for the i-th panel (i=1, 2) . Each TPMI is for a layer set, and the two layer sets are mapped or associated with different panels of antennas. In this case, the rank of the precoder P is r1+r2, where the sub-rank ri of V ^TPMIi can be determined in the DCI indication of TPMIi. Therefore, the dimension of the NCJT precoder P is (N1+N2) * (r1+r2) , which is of length N1+N2. The NCJT precoder and CJT precoder may have the same length of N1+N2. For example, the i-th TPMI is for the PUSCH transmission using the layer set associated with the i-th panel. The panel may be identified by a beam ID, a TCI ID, and/or an SRS resource ID received from the scheduling entity.

In some aspects of the disclosure, a scheduling entity (e.g., base station or gNB) can transmit one downlink control information (DCI) that can indicate the precoding information for multiple panels of antennas for CJT or NCJT when both transmission schemes are supported by the UE. FIG. 9 is a drawing conceptually illustrating a DCI 900 according to one aspect of the disclosure. In this example, a single DCI transmission carries two TPMIs 902 and 904 (TPMI 1 and TPMI 2) . However, in other examples, the DCI 900 may carry more than two TPMIs if supported by the UE.

In one aspect, if both

TPMIs

902 and 904 indicated by the DCI are of a length (e.g., a first length of 4) configured for CJT, the UE selects a precoder for CJT according to the TPMIs to perform UL CJT. FIG. 10 is a drawing illustrating exemplary DCI codepoints (e.g., codepoints y and y+1) mapped to two TPMIs for single-layer transmission using four antenna ports for CJT. In this example, the CJT TPMI configurations are for two panels each of two antenna ports, N1=2 and N2=2. The DCI may indicate two codepoints (e.g., y and y+1) in two DCI fields in the DCI, and each codepoint corresponds to a TPMI indication. For example, the TPMI 1 DCI field as shown in FIG. 9 can indicate a DCI codepoint value y that is mapped to the TPMI index 16, and the TPMI 2 DCI field as shown in FIG. 9 can indicate another DCI codepoint value y+1 that is mapped to the TPMI index 17 in the table shown in FIG. 10.

In one aspect, if both

TPMIs

902 and 904 indicated by the DCI are of a length (e.g., a second length of 2) configured for NCJT, the UE applies NCJT in an UL transmission using a precoder selected according to the TPMIs. FIG. 11 is a drawing illustrating exemplary DCI codepoints (e.g., codepoints x and x+1) mapped to two TPMIs for single-layer transmission using two antenna ports for NCJT. In this example, the NCJT TPMI configurations are for two panels each of two antenna ports, N1=2 and N2=2. For example, the DCI field TPMI 1 902 as shown in FIG. 9 can indicate a DCI codepoint value x that is mapped to the TPMI index 2, and the DCI field TPMI 2 904 as shown in FIG. 9 can indicate another DCI codepoint value x+1 that is mapped to the TPMI index 3 in the table shown in FIG. 11. In the case that the DCI indicates two TPMIs of different types (i.e., one CJT TPMI with a first length and one NCJT TPMI with a second length) , the UE considers that as an invalid indication and may ignore the TPMIs.

In some aspects of the disclosure, a scheduling entity can transmit a single DCI including fields for indicating two TPMIs and a dedicated field for indicating whether the indicated TPMIs are for CJT or NCJT. FIG. 12 is a drawing conceptually illustrating a DCI 1200 according to one aspect of the disclosure. In this example, the same DCI 1200 carries two DCI fields for TPMIs 1202 and 1204 (TPMI 1 and TPMI 2) and a field for non-coherent transmission indicator (NCTI) 1206. When the DCI field for the NCTI has a first value or codepoint that indicates NCJT, both

TPMIs

1202 and 1204 are of a second length (e.g., a length of 2) for a NCJT TPMI configuration. For example, when the DCI field for NCTI has a first value or codepoint that indicates NCJT, all DCI codepoints for the DCI fields of

TPMIs

1202 and 1204 are mapped to TPMIs of length 2 for two panels each of two antenna ports, with lengths N1=2 and N2=2. When the DCI field for the NCTI has a second value or codepoint that indicates CJT, both

TPMIs

1202 and 1204 are of a first length (e.g., a length of 4) for a CJT TPMI configuration. For example, when the DCI field for the NCTI has a second value or codepoint that indicates CJT, all DCI codepoints for the DCI fields of

TPMIs

1202 and 1204 are mapped to TPMIs of length 4 for two panels each of two antenna ports, with lengths N1+N2=4. Based on the DCI indicated NCTI value, the UE can select the precoding matrices using the TPMIs indicated by the DCI from the codebook in either NCJT or CJT TPMI configuration.

FIG. 13 is a block diagram illustrating an example of a hardware implementation for a scheduling entity 1300 employing a processing system 1314. For example, the scheduling entity 1300 may be a base station (e.g., gNB or TRP) as illustrated in any one or more of FIGs. 1, 2, 3, 5, and/or 6.

The scheduling entity 1300 may be implemented with a processing system 1314 that includes one or more processors 1304. Examples of processors 1304 include microprocessors, microcontrollers, digital signal processors (DSPs) , field programmable gate arrays (FPGAs) , programmable logic devices (PLDs) , state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. In various examples, the scheduling entity 1300 may be configured to perform any one or more of the functions described herein. That is, the processor 1304, as utilized in a scheduling entity 1300, may be used to implement any one or more of the processes and procedures described illustrated in FIG. 14.

In this example, the processing system 1314 may be implemented with a bus architecture, represented generally by the bus 1302. The bus 1302 may include any number of interconnecting buses and bridges depending on the specific application of the processing system 1314 and the overall design constraints. The bus 1302 communicatively couples together various circuits including one or more processors (represented generally by the processor 1304) , a memory 1305, and computer-readable media (represented generally by the computer-readable medium 1306) . The bus 1302 may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further. A bus interface 1308 provides an interface between the bus 1302 and a transceiver 1310. The transceiver 1310 provides a communication interface or means for communicating with various other apparatus over a transmission medium. Depending upon the nature of the apparatus, a user interface 1312 (e.g., keypad, display, speaker, microphone, joystick) may also be provided. Of course, such a user interface 1312 is optional, and may be omitted in some examples, such as a base station.

In some aspects of the disclosure, the processor 1304 may include circuitry configured for various functions, including, for example, UL communication control and configuration. For example, the circuitry may be configured to implement one or more of the functions described below in relation to FIG. 14.

The processor 1304 may include a control and scheduling circuit 1340 for controlling, configuring, and scheduling UL and DL communication with one or more UEs. The control and scheduling circuit 1340 may determine downlink control information (DCI) including two TPMIs for scheduling an UL transmission using CJT or NCJT as described above in relation to FIGs. 5–12. The processor 1304 may include an UL/DL communication circuit 1342 for performing various processes and functions used for UL and DL communication. In one example, the UL/DL communication circuit 1342 alone or in connection other circuits may perform scrambling, descrambling, modulation, demodulation, layer mapping, layer demapping, precoding, decoding, resource mapping, and resource demapping for UL/DL communication.

The processor 1304 is responsible for managing the bus 1302 and general processing, including the execution of software stored on the computer-readable medium 1306. The software, when executed by the processor 1304, causes the processing system 1314 to perform the various functions described below for any particular apparatus. The computer-readable medium 1306 and the memory 1305 may also be used for storing data that is manipulated by the processor 1304 when executing software.

One or more processors 1304 in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. The software may reside on a computer-readable medium 1306. The computer-readable medium 1306 may be a non-transitory computer-readable medium. A non-transitory computer-readable medium includes, by way of example, a magnetic storage device (e.g., hard disk, floppy disk, magnetic strip) , an optical disk (e.g., a compact disc (CD) or a digital versatile disc (DVD) ) , a smart card, a flash memory device (e.g., a card, a stick, or a key drive) , a random access memory (RAM) , a read only memory (ROM) , a programmable ROM (PROM) , an erasable PROM (EPROM) , an electrically erasable PROM (EEPROM) , a register, a removable disk, and any other suitable medium for storing software and/or instructions that may be accessed and read by a computer. The computer-readable medium 1306 may reside in the processing system 1314, external to the processing system 1314, or distributed across multiple entities including the processing system 1314. The computer-readable medium 1306 may be embodied in a computer program product. By way of example, a computer program product may include a computer-readable medium in packaging materials. Those skilled in the art will recognize how best to implement the described functionality presented throughout this disclosure depending on the particular application and the overall design constraints imposed on the overall system.

In one or more examples, the computer-readable storage medium 1306 may include software configured for various functions, including, for example, UL communication control and configuration. For example, the software may be configured to implement one or more of the functions described in relation to FIG. 14.

The software may include control and scheduling instructions 1352 for controlling, configuring, and scheduling UL and DL communication with one or more UEs. The control and scheduling instructions 1352 may determine a DCI that includes two TPMIs for scheduling an UL transmission using CJT or NCJT as described above in relation to FIGs. 5–12. The software may include UL/DL communication instructions 1354 for performing various processes and functions used for UL and DL communication. In one aspect, the UL/DL communication instructions 1354 may cause the processing system to perform scrambling, descrambling, modulation, demodulation, layer mapping, demapping, precoding, decoding, resource mapping, and demapping for UL/DL.

FIG. 14 is a flow chart illustrating an exemplary process 1400 for uplink communication in accordance with some aspects of the present disclosure. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all embodiments. In some examples, the process 1400 may be carried out by the scheduling entity 1300 illustrated in FIG. 13. In some examples, the process 1400 may be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At block 1402, the scheduling entity (e.g., a gNB) prepares downlink control information (DCI) for scheduling a UE to transmit UL data using a plurality of antenna panels. For example, the scheduling entity may use the control and scheduling circuit 1340 to prepare the DCI. The DCI may include various fields including a first transmit precoding matrix indicator (TPMI) and a second TPMI. The first and second TPMIs may be similar to those described above in relation to FIGs. 9 and 12. The first and second TPMIs may indicate a TPMI configuration for precoding the UL data for a coherent joint transmission (CJT) or a non-coherent joint transmission (NCJT) using the antenna panels.

At block 1404, the scheduling entity transmits the DCI to the UE. For example, the scheduling entity may use the UL/DL communication circuit 1342 to transmit the DCI to the UE via the transceiver 1310. The DCI includes the first and second TPMIs that together indicate the TPMI configuration for CJT or NCJT.

At block 1406, the scheduling entity receives the UL data from the UE in a CJT or a NCJT based on the TPMI configuration indicated by the DCI. The scheduling entity may use the UL/DL communication circuit 1342 to receive the UL data transmission via the transceiver 1310.

FIG. 15 is a conceptual diagram illustrating an example of a hardware implementation for an exemplary scheduled entity 1500 employing a processing system 1514. In accordance with various aspects of the disclosure, an element, or any portion of an element, or any combination of elements may be implemented with a processing system 1514 that includes one or more processors 1504. For example, the scheduled entity 1500 may be a user equipment (UE) as illustrated in any one or more of FIGs. 1, 2, 3, 5, and/or 6.

The processing system 1514 may be substantially the same as the processing system 1314 illustrated in FIG. 13, including a bus interface 1508, a bus 1502, memory 1505, a processor 1504, and a computer-readable medium 1506. Furthermore, the scheduled entity 1500 may include a user interface 1512 and a transceiver 1510 substantially similar to those described above in FIG. 13. The transceiver 1510 are coupled with a plurality of antenna panels 1520 for wireless communication. Each antenna panel includes an array of antennas for UL/DL communication using CJT and NCJT. The processor 1504, as utilized in a scheduled entity 1500, may be used to implement any one or more of the processes described and illustrated in FIG. 16.

In some aspects of the disclosure, the processor 1504 may include circuitry configured for various functions, including, for example, UL communication using CJT and NCJT. For example, the circuitry may be configured to implement one or more of the functions described below in relation to FIG. 16.

The processor 1504 may include a precoding circuit 1540 for precoding data for UL communication with one or more TRPs or base stations. The precoding circuit 1540 may select one or more precoding matrices from a codebook for precoding UL data for CJT or NCJT as described above in relation to FIGs. 5–12. The processor 1504 may include an UL/DL communication circuit 1542 for performing various processes and functions used for UL and DL communication. In one example, the UL/DL communication circuit 1542, alone or together with other circuits, may perform scrambling, descrambling, modulation, demodulation, layer mapping, demapping, precoding, decoding, resource mapping, and demapping for UL/DL communication via the transceiver 1510 and one or more antenna panels 1520.

FIG. 16 is a flow chart illustrating an exemplary process 1600 for UL communication in accordance with some aspects of the present disclosure. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all embodiments. In some examples, the process 1600 may be carried out by the scheduled entity 1500 illustrated in FIG. 15. In some examples, the process 1600 may be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At block 1602, a UE receives downlink control information (DCI) from a scheduling entity (e.g., gNB) . The DCI may include a first TPMI and a second TPMI. For example, the UE may use the UL/DL communication circuit 1542 to receive the DCI in a PDCCH via the transceiver 1510. The first and second TPMIs may be similar to those described above in relation to FIGs. 5–12.

At block 1604, the UE determines a TPMI configuration based on the first TPMI and second TPMI. For example, the UE may use precoding circuit 1540 to determine a TPMI configuration based on the first and second TPMIs. In one aspect, the TPMI configuration may be for an UL CJT. In another aspect, the TPMI configuration may be for an UL NCJT.

At block 1606, the UE precodes UL data for transmission using CJT or NCJT, based on the TPMI configuration. For example, the UE may use the precoding circuit 1540 to precode the UL data using precoding matrices selected based on the TPMI configuration. The precoding matrices may be indicated by the first and second TPMIs.

At block 1608, the UE transmits the precoded UL data using the CJT or NCJT. For example, the UE may use the transceiver 1510 to transmit the UL data via a plurality of antenna panels (e.g.,

panels

504, 506, 604, and 606 of FIGs. 5 and 6) . Each antenna panel may include an array of antennas. In CJT, the UE may transmit a set of layers of the UL data using a plurality of antenna panels. In NCJT, the UE may transmit different sets of layers of the UL data using respective antenna panels.

In one configuration, the apparatus 1300 for wireless communication includes means for performing UL communication with a UE using CJT or NCJT based on a TPMI configuration indicated by a DCI that includes multiple TPMIs. In one aspect, the aforementioned means may be the processor 1304 shown in FIG. 13 configured to perform the functions recited by the aforementioned means. In another aspect, the aforementioned means may be a circuit or any apparatus configured to perform the functions recited by the aforementioned means.

In one configuration, the apparatus 1500 for wireless communication includes means for performing UL communication with a scheduling entity using CJT or NCJT based on a TPMI configuration indicated by a DCI that includes multiple TPMIs. In one aspect, the aforementioned means may be the processor 1504 shown in FIG. 15 configured to perform the functions recited by the aforementioned means. In another aspect, the aforementioned means may be a circuit or any apparatus configured to perform the functions recited by the aforementioned means.

Of course, in the above examples, the circuitry included in the processor 1304/1504 is merely provided as an example, and other means for carrying out the described functions may be included within various aspects of the present disclosure, including but not limited to the instructions stored in the computer-readable storage medium 1306/1504, or any other suitable apparatus or means described in any one of the FIGs. 1, 2, 3, 5, and/or 6, and utilizing, for example, the processes and/or algorithms described herein in relation to FIGs. 5–12, 14, and/or 16.

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

By way of example, various aspects may be implemented within other systems defined by 3GPP, such as Long-Term Evolution (LTE) , the Evolved Packet System (EPS) , the Universal Mobile Telecommunication System (UMTS) , and/or the Global System for Mobile (GSM) . Various aspects may also be extended to systems defined by the 3 ^rd Generation Partnership Project 2 (3GPP2) , 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 telecommunication standard, network architecture, and/or communication standard employed will depend on the specific application and the overall design constraints imposed on the system.

Within the present disclosure, the word “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 “aspects” 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 the direct or indirect coupling between two objects. For example, if object A physically touches object B, and object B touches object C, then objects A and C may still be considered coupled to one another-even if they do not directly physically touch each other. For instance, a first object may be coupled to a second object even though the first object is never directly physically in contact with the second object. The terms “circuit” and “circuitry” are used broadly, and intended to include both hardware implementations of electrical devices and conductors that, when connected and configured, enable the performance of the functions described in the present disclosure, without limitation as to the type of electronic circuits, as well as software implementations of information and instructions that, when executed by a processor, enable the performance of the functions described in the present disclosure.

One or more of the components, steps, features and/or functions illustrated in FIGs. 1–16 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 novel features disclosed herein. The apparatus, devices, and/or components illustrated in FIGs. 1–16 may be configured to perform one or more of the methods, features, or steps described herein. The novel algorithms described herein may also be efficiently implemented in software and/or embedded in hardware.

It is to be understood that the specific order or hierarchy of steps in the methods disclosed is an illustration of exemplary processes. Based upon design preferences, it is understood that 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, and are not meant 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 are 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. ” Unless specifically stated otherwise, the term “some” refers to one or more. A phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover: a; b; c; a and b; a and c; b and c; and a, b and c. 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.

Claims

A method of wireless communication at a user equipment (UE) ,

comprising:

receiving, from a scheduling entity, downlink control information (DCI) comprising a first transmit precoding matrix indicator (TPMI) and a second TPMI;

determining a TPMI configuration based on the first TPMI and the second TPMI;

precoding uplink (UL) data for a coherent joint transmission (CJT) or a non-coherent joint transmission (NCJT) , based on the TPMI configuration; and

transmitting the precoded UL data for the CJT or the NCJT using a plurality of antenna panels, each antenna panel comprising a plurality of antennas.
The method of claim 1, wherein the first TPMI and the second TPMI are configured to indicate the UL data to be transmitted in the CJT or the NCJT.
The method of claim 1, wherein the first TPMI and the second TPMI correspond to different DCI fields, respectively.
The method of claim 1, wherein determining the TPMI configuration comprises:

determining a first TPMI configuration for the CJT when both the first TPMI and the second TPMI indicate the CJT; and

determining a second TPMI configuration for the NCJT when both the first TPMI and the second TPMI indicate the NCJT.
The method of claim 4, wherein the first TPMI configuration comprises a plurality of TPMIs of a first length, and the second TPMI configuration comprises a plurality of TPMIs of a second length that is smaller than the first length.
The method of claim 4, wherein the first TPMI configuration indicates a first number of antenna ports, and the second TPMI configuration indicates a second number of antenna ports that are fewer than the first number of antenna ports.
The method of claim 1, wherein the DCI further comprises an indicator field indicating that the first TPMI and the second TPMI correspond to the CJT or the NCJT.
The method of claim 1, wherein transmitting the precoded UL data comprises:

for the CJT, transmitting a first layer and a second layer of the precoded UL data using a same panel of the plurality of antenna panels; or

for the NCJT, transmitting the first layer using a first panel of the plurality of antenna panels, and the second layer using a second panel of the plurality of antenna panels.
The method of claim 1, wherein the TPMI configuration indicates a number of antenna ports, a precoder codebook subset restriction type, and a maximum rank for the CJT or NCJT.
A method of wireless communication at a scheduling entity, comprising:

preparing downlink control information (DCI) for scheduling a user equipment (UE) to transmit UL data using a plurality of antenna panels, the DCI comprising a first transmit precoding matrix indicator (TPMI) and a second TPMI configured to indicate a TPMI configuration for precoding the UL data;

transmitting the DCI to the UE; and

receiving, from the UE, the UL data in a coherent joint transmission (CJT) or a non-coherent joint transmission (NCJT) based on the TPMI configuration.
The method of claim 10, wherein the first TPMI and the second TPMI are configured to indicate the UL data to be transmitted in the CJT or the NCJT.
The method of claim 10, wherein the first TPMI and the second TPMI correspond to different DCI fields, respectively.
The method of claim 10, wherein receiving the UL data comprises:

receiving the UL data in the CJT according to a first TPMI configuration when both the first TPMI and the second TPMI indicate the CJT; or

receiving the UL data in the NCJT according to a second TPMI configuration when both the first TPMI and the second TPMI indicate the NCJT.
The method of claim 13, wherein the first TPMI configuration comprises a plurality of TPMIs of a first length, and the second TPMI configuration comprises a plurality of TPMIs of a second length that is smaller than the first length.
The method of claim 13, wherein the first TPMI configuration indicates a first number of antenna ports, and the second TPMI configuration indicates a second number of antenna ports that are fewer than the first number of antenna ports.
The method of claim 10, wherein the DCI further comprises an indicator field indicating that the first TPMI and the second TPMI correspond to the CJT or the NCJT.
The method of claim 10, wherein receiving the UL data comprises:

for the CJT, receiving a first layer and a second layer of the UL data from a same panel of the plurality of antenna panels; or

for the NCJT, receiving the first layer from a first panel of the plurality of antenna panels, and the second layer from a second panel of the plurality of antenna panels.
The method of claim 10, wherein the TPMI configuration indicates a number of antenna ports, a precoder codebook subset restriction type, and a maximum rank for the CJT or NCJT.
A user equipment (UE) for wireless communication, comprising:

a plurality of antenna panels;

a communication interface configured for wireless communication with a scheduling entity;

a memory; and

a processor operatively coupled with the communication interface and the memory,

wherein the processor and the memory are configured to:

receive, from the scheduling entity, downlink control information (DCI) comprising a first transmit precoding matrix indicator (TPMI) and a second TPMI;

determine a TPMI configuration based on the first TPMI and the second TPMI;

precode uplink (UL) data for a coherent joint transmission (CJT) or a non-coherent joint transmission (NCJT) , based on the TPMI configuration; and

transmit the precoded UL data for the CJT or the NCJT using the communication interface and the plurality of antenna panels, each antenna panel comprising a plurality of antennas.
The UE of claim 19, wherein the first TPMI and the second TPMI are configured to indicate the UL data to be transmitted in the CJT or the NCJT.
The UE of claim 19, wherein the first TPMI and the second TPMI correspond to different DCI fields, respectively.
The UE of claim 19, wherein the processor and the memory are further configured to:

determine a first TPMI configuration for the CJT when both the first TPMI and the second TPMI indicate the CJT; and

determine a second TPMI configuration for the NCJT when both the first TPMI and the second TPMI indicate the NCJT.
The UE of claim 22, wherein the first TPMI configuration comprises a plurality of TPMIs of a first length, and the second TPMI configuration comprises a plurality of TPMIs of a second length that is smaller than the first length.
The UE of claim 22, wherein the first TPMI configuration indicates a first number of antenna ports, and the second TPMI configuration indicates a second number of antenna ports that are fewer than the first number of antenna ports.
The UE of claim 19, wherein the DCI further comprises an indicator field indicating that the first TPMI and the second TPMI correspond to the CJT or the NCJT.
The UE of claim 19, wherein the processor and the memory are further configured to:

for the CJT, transmit a first layer and a second layer of the precoded UL data using a same panel of the plurality of antenna panels; or

for the NCJT, transmit the first layer using a first panel of the plurality of antenna panels, and the second layer using a second panel of the plurality of antenna panels.
The UE of claim 19, wherein the TPMI configuration indicates a number of antenna ports, a precoder codebook subset restriction type, and a maximum rank for the CJT or NCJT.
A scheduling entity comprising:

a communication interface configured for wireless communication with a user equipment (UE) ;

a memory; and

a processor operatively coupled to the communication interface and the memory,

wherein the processor and the memory are configured to:

prepare downlink control information (DCI) for scheduling the UE to transmit UL data using a plurality of antenna panels, the DCI comprising a first transmit precoding matrix indicator (TPMI) and a second TPMI configured to indicate a TPMI configuration for precoding the UL data;

transmit the DCI to the UE; and

receive, from the UE, the UL data in a coherent joint transmission (CJT) or a non-coherent joint transmission (NCJT) based on the TPMI configuration.
The scheduling entity of claim 28, wherein the first TPMI and the second TPMI are configured to indicate the UL data to be transmitted in the CJT or the NCJT.
The scheduling entity of claim 28, wherein the first TPMI and the second TPMI correspond to different DCI fields, respectively.
The scheduling entity of claim 28, wherein the processor and the memory are further configured to:

receive the UL data in the CJT according to a first TPMI configuration when both the first TPMI and the second TPMI indicate the CJT; or

receive the UL data in the NCJT according to a second TPMI configuration when both the first TPMI and the second TPMI indicate the NCJT.
The scheduling entity of claim 31, wherein the first TPMI configuration comprises a plurality of TPMIs of a first length, and the second TPMI configuration comprises a plurality of TPMIs of a second length that is smaller than the first length.
The scheduling entity of claim 31, wherein the first TPMI configuration indicates a first number of antenna ports, and the second TPMI configuration indicates a second number of antenna ports that are fewer than the first number of antenna ports.
The scheduling entity of claim 28, wherein the DCI further comprises an indicator field indicating that the first TPMI and the second TPMI correspond to the CJT or the NCJT.
The scheduling entity of claim 28, wherein the processor and the memory are further configured to:

for the CJT, receive a first layer and a second layer of the UL data from a same panel of the plurality of antenna panels; or

for the NCJT, receive the first layer from a first panel of the plurality of antenna panels, and the second layer from a second panel of the plurality of antenna panels.
The scheduling entity of claim 28, wherein the TPMI configuration indicates a number of antenna ports, a precoder codebook subset restriction type, and a maximum rank for the CJT or NCJT.
A user equipment (UE) for wireless communication, comprising:

means for receiving, from the scheduling entity, downlink control information (DCI) comprising a first transmit precoding matrix indicator (TPMI) and a second TPMI;

means for determining a TPMI configuration based on the first TPMI and the second TPMI;

means for precoding uplink (UL) data for a coherent joint transmission (CJT) or a non-coherent joint transmission (NCJT) , based on the TPMI configuration; and

means for transmitting the precoded UL data for the CJT or the NCJT using a plurality of antenna panels, each antenna panel comprising a plurality of antennas.
A scheduling entity for wireless communication, comprising:

means for preparing downlink control information (DCI) for scheduling the UE to transmit UL data using a plurality of antenna panels, the DCI comprising a first transmit precoding matrix indicator (TPMI) and a second TPMI configured to indicate a TPMI configuration for precoding the UL data;

means for transmitting the DCI to the UE; and

means for receiving, from the UE, the UL data in a coherent joint transmission (CJT) or a non-coherent joint transmission (NCJT) based on the TPMI configuration.
An article of manufacture for use by a user equipment (UE) in a wireless communication network, the article comprising:

a computer-readable medium having stored therein instructions executable by one or more processors of the UE to:

receive, from a scheduling entity, downlink control information (DCI) comprising a first transmit precoding matrix indicator (TPMI) and a second TPMI;

determine a TPMI configuration based on the first TPMI and the second TPMI;

precode uplink (UL) data for a coherent joint transmission (CJT) or a non-coherent joint transmission (NCJT) , based on the TPMI configuration; and

transmit the precoded UL data for the CJT or the NCJT using a plurality of antenna panels, each antenna panel comprising a plurality of antennas.
An article of manufacture for use by a scheduling entity in a wireless communication network, the article comprising:

a computer-readable medium having stored therein instructions executable by one or more processors of the scheduling entity to:

prepare downlink control information (DCI) for scheduling a user equipment (UE) to transmit UL data using a plurality of antenna panels, the DCI comprising a first transmit precoding matrix indicator (TPMI) and a second TPMI configured to indicate a TPMI configuration for precoding the UL data;

transmit the DCI to the UE; and

receive, from the UE, the UL data in a coherent joint transmission (CJT) or a non-coherent joint transmission (NCJT) based on the TPMI configuration.