WO2021114215A1

WO2021114215A1 - Uplink precoder grouping and tpmi feedback for subband precoding

Info

Publication number: WO2021114215A1
Application number: PCT/CN2019/125089
Authority: WO
Inventors: Liangming WU; Qiaoyu Li; Yu Zhang; Chenxi HAO; Hao Xu; Wanshi Chen
Original assignee: Qualcomm Incorporated
Priority date: 2019-12-13
Filing date: 2019-12-13
Publication date: 2021-06-17

Abstract

In a particular implementation, a method of wireless communication includes receiving, at a user equipment (UE) from a base station, a first downlink control information (DCI) transmission indicating information corresponding to a wideband transmitted precoding matrix indicator (TPMI). The method also includes receiving, at the UE from the base station, a second DCI transmission indicating information corresponding to subband TPMIs. The method further includes transmitting, from the UE to the base station, data in accordance with the subband TPMIs.

Description

UPLINK PRECODER GROUPING AND TPMI FEEDBACK FOR SUBBAND PRECODING

TECHNICAL FIELD

Aspects of the technology discussed below relate generally to wireless communication systems, and more particularly, to wireless communication systems that support subband precoding. Certain aspects of the technology discussed below can enable and provide transmitted precoding matrix indicators (TPMIs) on the subband level. The discussed techniques can help enable increased throughput and/or decreased latency.

INTRODUCTION

Wireless communication networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, and the like. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources. Such networks, which are usually multiple access networks, support communications for multiple users by sharing the available network resources.

A wireless communication network may include a number of base stations or node Bs that can support communication for a number of user equipments (UEs) . A UE may communicate with a base station via downlink and uplink. The downlink (or forward link) refers to the communication link from the base station to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the base station.

A base station may transmit data and control information on the downlink to a UE and/or may receive data and control information on the uplink from the UE. On the downlink, a transmission from the base station may encounter interference due to transmissions from neighbor base stations or from other wireless radio frequency (RF) transmitters. On the uplink, a transmission from the UE may encounter interference from uplink transmissions of other UEs communicating with the neighbor base stations or from other wireless RF transmitters. This interference may degrade performance on both the downlink and uplink.

As the demand for mobile broadband access continues to increase, the possibilities of interference and congested networks grows with more UEs accessing the long-range wireless communication networks and more short-range wireless systems being deployed in communities. Research and development continue to advance wireless technologies not only to meet the growing demand for mobile broadband access, but to advance and enhance the user experience with mobile communications.

To enable uplink communications, uplink precoding has been supported by wireless communication systems since the advent of long-term evolution (LTE) . In fifth generation new radio (5G-NR) , uplink precoding is also supported. The same, or very similar, codebook has been leveraged from LTE to 5G-NR, which supports rank less than or equal to four with wideband precoding. However, sometimes wideband precoding is insufficient to meet requirements of uplink data transmission in 5G-NR.

BRIEF SUMMARY OF SOME ASPECTS

The following summarizes some aspects of the present disclosure to provide a basic understanding of the discussed technology. 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 summary form as a prelude to the more detailed description that is presented later.

In one aspect of the disclosure, a method of wireless communication includes receiving, at a user equipment (UE) from a base station, a first downlink control information (DCI) transmission indicating information corresponding to a wideband transmitted precoding matrix indicator (TPMI) . The method also includes receiving, at the UE from the base station, a second DCI transmission indicating information corresponding to subband TPMIs. The method further includes transmitting, from the UE to the base station, data in accordance with the subband TPMIs.

In an additional aspect of the disclosure, an apparatus configured for wireless communication is disclosed. The apparatus includes at least one processor, and a memory coupled to the at least one processor. The at least one processor is configured to receive, at a user equipment (UE) from a base station, a first downlink control information (DCI) transmission indicating information corresponding to a wideband transmitted precoding matrix indicator (TPMI) . The at least one processor is also configured to receive, at the UE from the base station, a second DCI transmission indicating information corresponding to subband TPMIs. The at least one processor is further configured to initiate transmission, from the UE to the base station, of data in accordance with the subband TPMIs.

In an additional aspect of the disclosure, an apparatus configured for wireless communication is disclosed. The apparatus includes means for receiving, at a user equipment (UE) from a base station, a first downlink control information (DCI) transmission indicating information corresponding to a wideband transmitted precoding matrix indicator (TPMI) . The apparatus also includes means for receiving, at the UE from the base station, a second DCI transmission indicating information corresponding to subband TPMIs. The apparatus further includes means for transmitting, from the UE to the base station, data in accordance with the subband TPMIs.

In an additional aspect of the disclosure, a non-transitory computer-readable medium stores instructions that, when executed by a processor, cause the processor to perform operations including receiving, at a user equipment (UE) from a base station, a first downlink control information (DCI) transmission indicating information corresponding to a wideband transmitted precoding matrix indicator (TPMI) . The operations also include receiving, at the UE from the base station, a second DCI transmission indicating information corresponding to subband TPMIs. The operations further include initiating transmission, from the UE to the base station, of data in accordance with the subband TPMIs.

In an additional aspect of the disclosure, a method for wireless communication includes transmitting, from a base station to a user equipment (UE) , a first downlink control information (DCI) transmission indicating information corresponding to a wideband transmitted precoding matrix indicator (TPMI) . The method further includes transmitting, from the base station to the UE, a second DCI transmission indicating information corresponding to subband TPMIs.

In an additional aspect of the disclosure, an apparatus configured for wireless communication is disclosed. The apparatus includes at least one processor, and a memory coupled to the at least one processor. The at least one processor is configured to initiate transmission, from a base station to a user equipment (UE) , of a first downlink control information (DCI) transmission indicating information corresponding to a wideband transmitted precoding matrix indicator (TPMI) . The at least one processor is further configured to initiate transmission, from the base station to the UE, of a second DCI transmission indicating information corresponding to subband TPMIs.

In an additional aspect of the disclosure, an apparatus configured for wireless communication is disclosed. The apparatus includes means for transmitting, from a base station to a user equipment (UE) , a first downlink control information (DCI) transmission indicating information corresponding to a wideband transmitted precoding matrix indicator (TPMI) . The apparatus further includes means for transmitting, from the base station to the UE, a second DCI transmission indicating information corresponding to subband TPMIs.

In an additional aspect of the disclosure, a non-transitory computer-readable medium stores instructions that, when executed by a processor, cause the processor to perform operations including initiating transmission, from a base station to a user equipment (UE) , of a first downlink control information (DCI) transmission indicating information corresponding to a wideband transmitted precoding matrix indicator (TPMI) . The operations further include initiating transmission, from the base station to the UE, of a second DCI transmission indicating information corresponding to subband TPMIs.

In an additional aspect of the disclosure, a method of wireless communication includes receiving, at a user equipment (UE) from a base station, a downlink control information (DCI) transmission indicating first information corresponding to a wideband transmitted precoding matrix indicator (TPMI) and second information corresponding to subband TPMIs. The method further includes transmitting, from the UE to the base station, data in accordance with the subband TPMIs.

Other aspects, features, and embodiments of the present invention will become apparent to those of ordinary skill in the art, upon reviewing the following description of specific, exemplary embodiments of the present invention in conjunction with the accompanying figures. While features of the present invention may be discussed relative to certain embodiments and figures below, all embodiments of the present invention 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 of the invention discussed herein. In similar fashion, while exemplary embodiments may be discussed below as device, system, or method embodiments the exemplary embodiments can be implemented in various devices, systems, and methods.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the present disclosure may be realized by reference to the following drawings. In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.

FIG. 1 is a block diagram illustrating details of a wireless communication system according to some aspects.

FIG. 2 is a block diagram conceptually illustrating a design of a base station and a UE configured according to some aspects.

FIG. 3 is a block diagram illustrating details of a wireless communication system according to some aspects.

FIG. 4 is a diagram of communications, such as DCI and PUSCH transmissions, performed between a base station and a UE according to some aspects.

FIG. 5 is a diagram of communications, such as DCI and PUSCH transmissions, performed between a base station and a UE according to some aspects.

FIG. 6 is a flow diagram illustrating example blocks of a method executed by a UE according to some aspects.

FIG. 7 is a flow diagram illustrating example blocks of a method executed by a base station according to some aspects.

FIG. 8 is a block diagram conceptually illustrating an example design of a UE according to some aspects.

FIG. 9 is a block diagram conceptually illustrating an example design of a base station according to some aspects.

The Appendix provides further details regarding various embodiments of this disclosure and the subject matter therein forms a part of the specification of this application.

DETAILED DESCRIPTION

The detailed description set forth below, in connection with the appended drawings and appendix, is intended as a description of various configurations and is not intended to limit the scope of the disclosure. Rather, the detailed description includes specific details for the purpose of providing a thorough understanding of the inventive subject matter. It will be apparent to those skilled in the art that these specific details are not required in every case and that, in some instances, well-known structures and components are shown in block diagram form for clarity of presentation.

The systems, apparatus, computer-readable media, and methods described herein enable a wireless communication system that supports subband precoding. Subband precoding refers to precoding on the subband level, as compared to precoding on the wideband level. To enable subband precoding, the precoding matrix indicators (PMIs) of the fifth generation new radio (5G-NR) codebook are further grouped to support precoding of subbands. Information related to the subband precoding may be shared with a user equipment (UE) via a two-stage downlink control information (DCI) transmission. For example, a base station may transmit, to the UE, a first DCI transmission that indicates information corresponding to a wideband transmitted PMI (TPMI) . The base station may also transmit, to the UE, a second DCI transmission that indicates information corresponding to subband TPMIs. For example, the information in the second DCI transmission may indicate groupings of TPMIs to various subbands, as compared to a TPMI for wideband. The UE may transmit, to the base station, data in accordance with the subband TPMIs. Although two DCI transmissions are described, in other implementations, an entirety of the information may be communicated within a single DCI transmission. In this manner, uplink subband precoding may be supported between the UE and the base station. Enabling precoding at the subband level (e.g., at a finer granularity) may improve the speed and reliability of uplink data transmissions, thereby improving throughput and reducing latency in the wireless communication system.

This disclosure relates generally to providing or participating in communication as between two or more wireless devices in one or more wireless communications systems, also referred to as wireless communications networks. In various embodiments, the techniques and apparatus may be used for wireless communication networks such as code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) networks, single-carrier FDMA (SC-FDMA) networks, LTE networks, GSM networks, 5 ^th Generation (5G) or new radio (NR) networks (sometimes referred to as “5G NR” networks/systems/devices) , as well as other communications networks. As described herein, the terms “networks” and “systems” may be used interchangeably.

A CDMA network, for example, may implement a radio technology such as universal terrestrial radio access (UTRA) , cdma2000, and the like. UTRA includes wideband-CDMA (W-CDMA) and low chip rate (LCR) . CDMA2000 covers IS-2000, IS-95, and IS-856 standards.

A TDMA network may, for example implement a radio technology such as GSM. 3GPP defines standards for the GSM EDGE (enhanced data rates for GSM evolution) radio access network (RAN) , also denoted as GERAN. GERAN is the radio component of GSM/EDGE, together with the network that joins the base stations (for example, the Ater and Abis interfaces) and the base station controllers (Ainterfaces, etc. ) . The radio access network represents a component of a GSM network, through which phone calls and packet data are routed from and to the public switched telephone network (PSTN) and Internet to and from subscriber handsets, also known as user terminals or user equipments (UEs) . A mobile phone operator's network may comprise one or more GERANs, which may be coupled with Universal Terrestrial Radio Access Networks (UTRANs) in the case of a UMTS/GSM network. An operator network may also include one or more LTE networks, and/or one or more other networks. The various different network types may use different radio access technologies (RATs) and radio access networks (RANs) .

An OFDMA network may implement a radio technology such as evolved UTRA (E-UTRA) , IEEE 802.11, IEEE 802.16, IEEE 802.20, flash-OFDM and the like. UTRA, E-UTRA, and Global System for Mobile Communications (GSM) are part of universal mobile telecommunication system (UMTS) . In particular, long term evolution (LTE) is a release of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE are described in documents provided from an organization named “3rd Generation Partnership Project” (3GPP) , and cdma2000 is described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2) . These various radio technologies and standards are known or are being developed. For example, the 3rd Generation Partnership Project (3GPP) is a collaboration between groups of telecommunications associations that aims to define a globally applicable third generation (3G) mobile phone specification. 3GPP long term evolution (LTE) is a 3GPP project which was aimed at improving the universal mobile telecommunications system (UMTS) mobile phone standard. The 3GPP may define specifications for the next generation of mobile networks, mobile systems, and mobile devices. The present disclosure is concerned with the evolution of wireless technologies from LTE, 4G, 5G, NR, and beyond with shared access to wireless spectrum between networks using a collection of new and different radio access technologies or radio air interfaces.

5G networks contemplate diverse deployments, diverse spectrum, and diverse services and devices that may be implemented using an OFDM-based unified, air interface. To achieve these goals, further enhancements to LTE and LTE-A are considered in addition to development of the new radio technology for 5G NR networks. The 5G NR will be capable of scaling to provide coverage (1) to a massive Internet of things (IoTs) with an ultra-high density (e.g., ～1M nodes/km ²) , ultra-low complexity (e.g., ～10s of bits/sec) , ultra-low energy (e.g., ～10+ years of battery life) , and deep coverage with the capability to reach challenging locations; (2) including mission-critical control with strong security to safeguard sensitive personal, financial, or classified information, ultra-high reliability (e.g., ～99.9999%reliability) , ultra-low latency (e.g., ～ 1 ms) , and users with wide ranges of mobility or lack thereof; and (3) with enhanced mobile broadband including extreme high capacity (e.g., ～ 10 Tbps/km ²) , extreme data rates (e.g., multi-Gbps rate, 100+ Mbps user experienced rates) , and deep awareness with advanced discovery and optimizations.

5G NR devices, networks, and systems may be implemented to use optimized OFDM-based waveform features. These features may include scalable numerology and transmission time intervals (TTIs) ; a common, flexible framework to efficiently multiplex services and features with a dynamic, low-latency time division duplex (TDD) /frequency division duplex (FDD) design; and advanced wireless technologies, such as massive multiple input, multiple output (MIMO) , robust millimeter wave (mmWave) transmissions, advanced channel coding, and device-centric mobility. Scalability of the numerology in 5G NR, with scaling of subcarrier spacing, may efficiently address operating diverse services across diverse spectrum and diverse deployments. For example, in various outdoor and macro coverage deployments of less than 3GHz FDD/TDD implementations, subcarrier spacing may occur with 15 kHz, for example over 1, 5, 10, 20 MHz, and the like bandwidth. For other various outdoor and small cell coverage deployments of TDD greater than 3 GHz, subcarrier spacing may occur with 30 kHz over 80/100 MHz bandwidth. For other various indoor wideband implementations, using a TDD over the unlicensed portion of the 5 GHz band, the subcarrier spacing may occur with 60 kHz over a 160 MHz bandwidth. Finally, for various deployments transmitting with mmWave components at a TDD of 28 GHz, subcarrier spacing may occur with 120 kHz over a 500MHz bandwidth.

The scalable numerology of 5G NR facilitates scalable TTI for diverse latency and quality of service (QoS) requirements. For example, shorter TTI may be used for low latency and high reliability, while longer TTI may be used for higher spectral efficiency. The efficient multiplexing of long and short TTIs to allow transmissions to start on symbol boundaries. 5G NR also contemplates a self-contained integrated subframe design with uplink/downlink scheduling information, data, and acknowledgement in the same subframe. The self-contained integrated subframe supports communications in unlicensed or contention-based shared spectrum, adaptive uplink/downlink that may be flexibly configured on a per-cell basis to dynamically switch between uplink and downlink to meet the current traffic needs.

For clarity, certain aspects of the apparatus and techniques may be described below with reference to exemplary LTE implementations or in an LTE-centric way, and LTE terminology may be used as illustrative examples in portions of the description below; however, the description is not intended to be limited to LTE applications. Indeed, the present disclosure is concerned with shared access to wireless spectrum between networks using different radio access technologies or radio air interfaces, such as those of 5G NR.

Moreover, it should be understood that, in operation, wireless communication networks adapted according to the concepts herein may operate with any combination of licensed or unlicensed spectrum depending on loading and availability. Accordingly, it will be apparent to one of skill in the art that the systems, apparatus and methods described herein may be applied to other communications systems and applications than the particular examples provided.

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/or 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 from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregated, distributed, or OEM devices or systems incorporating one or more described aspects. 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. It is intended that innovations described herein may be practiced in a wide variety of implementations, including both large/small devices, chip-level components, multi-component systems (e.g. RF-chain, communication interface, processor) , distributed arrangements, end-user devices, etc. of varying sizes, shapes, and constitution.

FIG. 1 shows wireless network 100 for communication according to some embodiments. Wireless network 100 may, for example, comprise a 5G wireless network. As appreciated by those skilled in the art, components appearing in FIG. 1 are likely to have related counterparts in other network arrangements including, for example, cellular-style network arrangements and non-cellular-style-network arrangements (e.g., device to device or peer to peer or ad hoc network arrangements, etc. ) .

Wireless network 100 illustrated in FIG. 1 includes a number of base stations 105 and other network entities. A base station may be a station that communicates with the UEs and may also be referred to as an evolved node B (eNB) , a next generation eNB (gNB) , an access point, and the like. Each base station 105 may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to this particular geographic coverage area of a base station and/or a base station subsystem serving the coverage area, depending on the context in which the term is used. In implementations of wireless network 100 herein, base stations 105 may be associated with a same operator or different operators (e.g., wireless network 100 may comprise a plurality of operator wireless networks) , and may provide wireless communications using one or more of the same frequencies (e.g., one or more frequency bands in licensed spectrum, unlicensed spectrum, or a combination thereof) as a neighboring cell. In some examples, an individual base station 105 or UE 115 may be operated by more than one network operating entity. In other examples, each base station 105 and UE 115 may be operated by a single network operating entity.

A base station may provide communication coverage for a macro cell or a small cell, such as a pico cell or a femto cell, and/or other types of cell. A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell, such as a pico cell, would generally cover a relatively smaller geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell, such as a femto cell, would also generally cover a relatively small geographic area (e.g., a home) and, in addition to unrestricted access, may also provide restricted access by UEs having an association with the femto cell (e.g., UEs in a closed subscriber group (CSG) , UEs for users in the home, and the like) . A base station for a macro cell may be referred to as a macro base station. A base station for a small cell may be referred to as a small cell base station, a pico base station, a femto base station or a home base station. In the example shown in FIG. 1,

base stations

105d and 105e are regular macro base stations, while base stations 105a-105c are macro base stations enabled with one of 3 dimension (3D) , full dimension (FD) , or massive MIMO. Base stations 105a-105c take advantage of their higher dimension MIMO capabilities to exploit 3D beamforming in both elevation and azimuth beamforming to increase coverage and capacity. Base station 105f is a small cell base station which may be a home node or portable access point. A base station may support one or multiple (e.g., two, three, four, and the like) cells.

Wireless network 100 may support synchronous or asynchronous operation. For synchronous operation, the base stations may have similar frame timing, and transmissions from different base stations may be approximately aligned in time. For asynchronous operation, the base stations may have different frame timing, and transmissions from different base stations may not be aligned in time. In some scenarios, networks may be enabled or configured to handle dynamic switching between synchronous or asynchronous operations.

UEs 115 are dispersed throughout the wireless network 100, and each UE may be stationary or mobile. It should be appreciated that, although a mobile apparatus is commonly referred to as user equipment (UE) in standards and specifications promulgated by the 3rd Generation Partnership Project (3GPP) , such apparatus 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. Within the present document, a “mobile” apparatus or UE need not necessarily have a capability to move, and may be stationary. Some non-limiting examples of a mobile apparatus, such as may comprise embodiments of one or more of UEs 115, include a mobile, a cellular (cell) phone, a smart phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a laptop, a personal computer (PC) , a notebook, a netbook, a smart book, a tablet, gaming devices, reality modification devices (e.g., extended reality (XR) , augmented reality (AR) , virtual reality (VR) ) , entertainment devices, and a personal digital assistant (PDA) . A mobile apparatus may additionally be an “Internet of things” (IoT) or “Internet of everything” (IoE) device such as an automotive or other transportation vehicle, a satellite radio, a global positioning system (GPS) device, a logistics controller, a drone, a multi-copter, a quad-copter, a smart energy or security device, a solar panel or solar array, municipal lighting, water, or other infrastructure; industrial automation and enterprise devices; consumer and wearable devices, such as eyewear, a wearable camera, a smart watch, a health or fitness tracker, a mammal implantable device, gesture tracking device, medical device, a digital audio player (e.g., MP3 player) , a camera, a game console, etc.; and digital home or smart home devices such as a home audio, video, and multimedia device, an appliance, a sensor, a vending machine, intelligent lighting, a home security system, a smart meter, etc. In one aspect, a UE may be a device that includes a Universal Integrated Circuit Card (UICC) . In another aspect, a UE may be a device that does not include a UICC. In some aspects, UEs that do not include UICCs may also be referred to as IoE devices. UEs 115a-115d of the embodiment illustrated in FIG. 1 are examples of mobile smart phone-type devices accessing wireless network 100 A UE may also be a machine specifically configured for connected communication, including machine type communication (MTC) , enhanced MTC (eMTC) , narrowband IoT (NB-IoT) and the like. UEs 115e-115k illustrated in FIG. 1 are examples of various machines configured for communication that access wireless network 100.

A mobile apparatus, such as UEs 115, may be able to communicate with any type of the base stations, whether macro base stations, pico base stations, femto base stations, relays, and the like. In FIG. 1, a lightning bolt (e.g., communication link) indicates wireless transmissions between a UE and a serving base station, which is a base station designated to serve the UE on the downlink and/or uplink, or desired transmission between base stations, and backhaul transmissions between base stations. Backhaul communication between base stations of wireless network 100 may occur using wired and/or wireless communication links.

In operation at wireless network 100, base stations 105a-105c serve

UEs

115a and 115b using 3D beamforming and coordinated spatial techniques, such as coordinated multipoint (CoMP) or multi-connectivity. Macro base station 105d performs backhaul communications with base stations 105a-105c, as well as small cell, base station 105f. Macro base station 105d also transmits multicast services which are subscribed to and received by

UEs

115c and 115d. Such multicast services may include mobile television or stream video, or may include other services for providing community information, such as weather emergencies or alerts, such as Amber alerts or gray alerts.

Wireless network 100 can support mission critical communications with ultra-reliable and redundant links for mission critical devices, such UE 115e, which is a drone. Redundant communication links with UE 115e include from

macro base stations

105d and 105e, as well as small cell base station 105f. Other machine type devices, such as UE 115f (thermometer) , UE 115g (smart meter) , and UE 115h (wearable device) may communicate through wireless network 100 either directly with base stations, such as small cell base station 105f, and macro base station 105e, or in multi-hop configurations by communicating with another user device which relays its information to the network, such as UE 115f communicating temperature measurement information to the smart meter, UE 115g, which is then reported to the network through small cell base station 105f. Wireless network 100 may also provide additional network efficiency through dynamic, low-latency TDD/FDD communications, such as in a vehicle-to-vehicle (V2V) mesh network between UEs 115i-115k communicating with macro base station 105e.

FIG. 2 shows a block diagram of a design of a base station 105 and a UE 115, which may be any of the base stations and one of the UEs in FIG. 1. For a restricted association scenario (as mentioned above) , base station 105 may be small cell base station 105f in FIG. 1, and UE 115 may be UE 115c or 115D operating in a service area of base station 105f, which in order to access small cell base station 105f, would be included in a list of accessible UEs for small cell base station 105f. Base station 105 may also be a base station of some other type. As shown in FIG. 2, base station 105 may be equipped with antennas 234a through 234t, and UE 115 may be equipped with antennas 252a through 252r for facilitating wireless communications.

At the base station 105, a transmit processor 220 may receive data from a data source 212 and control information from a controller/processor 240. The control information may be for the physical broadcast channel (PBCH) , physical control format indicator channel (PCFICH) , physical hybrid-ARQ (automatic repeat request) indicator channel (PHICH) , physical downlink control channel (PDCCH) , enhanced physical downlink control channel (EPDCCH) , MTC physical downlink control channel (MPDCCH) , etc. The data may be for the PDSCH, etc. The transmit processor 220 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. The transmit processor 220 may also generate reference symbols, e.g., for the primary synchronization signal (PSS) and secondary synchronization signal (SSS) , and cell-specific reference signal. Transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to modulators (MODs) 232a through 232t. Each modulator 232 may process a respective output symbol stream (e.g., for OFDM, etc. ) to obtain an output sample stream. Each modulator 232 may additionally or alternatively process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. Downlink signals from modulators 232a through 232t may be transmitted via the antennas 234a through 234t, respectively.

At the UE 115, the antennas 252a through 252r may receive the downlink signals from the base station 105 and may provide received signals to the demodulators (DEMODs) 254a through 254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM, etc. ) to obtain received symbols. MIMO detector 256 may obtain received symbols from demodulators 254a through 254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. Receive processor 258 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE 115 to a data sink 260, and provide decoded control information to a controller/processor 280.

On the uplink, at the UE 115, a transmit processor 264 may receive and process data (e.g., for the physical uplink shared channel (PUSCH) ) from a data source 262 and control information (e.g., for the physical uplink control channel (PUCCH) ) from the controller/processor 280. Transmit processor 264 may also generate reference symbols for a reference signal. The symbols from the transmit processor 264 may be precoded by TX MIMO processor 266 if applicable, further processed by the modulators 254a through 254r (e.g., for SC-FDM, etc. ) , and transmitted to the base station 105. At base station 105, the uplink signals from UE 115 may be received by antennas 234, processed by demodulators 232, detected by MIMO detector 236 if applicable, and further processed by receive processor 238 to obtain decoded data and control information sent by UE 115. Receive processor 238 may provide the decoded data to data sink 239 and the decoded control information to controller/processor 240.

Controllers/

processors

240 and 280 may direct the operation at base station 105 and UE 115, respectively. Controller/processor 240 and/or other processors and modules at base station 105 and/or controller/processor 280 and/or other processors and modules at UE 115 may perform or direct the execution of various processes for the techniques described herein, such as to perform or direct the execution illustrated in FIGS. 6 and 7, and/or other processes for the techniques described herein.

Memories

242 and 282 may store data and program codes for base station 105 and UE 115, respectively. Scheduler 244 may schedule UEs for data transmission on the downlink and/or uplink.

Wireless communications systems operated by different network operating entities (e.g., network operators) may share spectrum. In some instances, a network operating entity may be configured to use an entirety of a designated shared spectrum for at least a period of time before another network operating entity uses the entirety of the designated shared spectrum for a different period of time. Thus, in order to allow network operating entities use of the full designated shared spectrum, and in order to mitigate interfering communications between the different network operating entities, certain resources (e.g., time) may be partitioned and allocated to the different network operating entities for certain types of communication.

For example, a network operating entity may be allocated certain time resources reserved for exclusive communication by the network operating entity using the entirety of the shared spectrum. The network operating entity may also be allocated other time resources where the entity is given priority over other network operating entities to communicate using the shared spectrum. These time resources, prioritized for use by the network operating entity, may be utilized by other network operating entities on an opportunistic basis if the prioritized network operating entity does not utilize the resources. Additional time resources may be allocated for any network operator to use on an opportunistic basis.

Access to the shared spectrum and the arbitration of time resources among different network operating entities may be centrally controlled by a separate entity, autonomously determined by a predefined arbitration scheme, or dynamically determined based on interactions between wireless nodes of the network operators.

In some cases, UE 115 and base station 105 may operate in a shared radio frequency spectrum band, which may include licensed or unlicensed (e.g., contention-based) frequency spectrum. In an unlicensed frequency portion of the shared radio frequency spectrum band, UEs 115 or base stations 105 may traditionally perform a medium-sensing procedure to contend for access to the frequency spectrum. For example, UE 115 or base station 105 may perform a listen before talk (LBT) procedure such as a clear channel assessment (CCA) prior to communicating in order to determine whether the shared channel is available. A CCA may include an energy detection procedure to determine whether there are any other active transmissions. For example, a device may infer that a change in a received signal strength indicator (RSSI) of a power meter indicates that a channel is occupied. Specifically, signal power that is concentrated in a certain bandwidth and exceeds a predetermined noise floor may indicate another wireless transmitter. A CCA also may include detection of specific sequences that indicate use of the channel. For example, another device may transmit a specific preamble prior to transmitting a data sequence. In some cases, an LBT procedure may include a wireless node adjusting its own backoff window based on the amount of energy detected on a channel and/or the acknowledge/negative-acknowledge (ACK/NACK) feedback for its own transmitted packets as a proxy for collisions.

Precoding improves the reliability of messages on the downlink and the uplink. One way to further improve the reliability of messages is to support subband precoding. Subband precoding refers to precoding on the subband level, as compared to precoding on the wideband level. To enable subband precoding, the precoding matrix indicators (PMIs) of the fifth generation new radio (5G-NR) codebook are further grouped to support precoding of subbands. Information related to the subband precoding may be shared with a user equipment (UE) via a two-stage downlink control information (DCI) transmission. For example, a base station may transmit, to the UE, a first DCI transmission that indicates information corresponding to a wideband transmitted PMI (TPMI) . The base station may also transmit, to the UE, a second DCI transmission that indicates information corresponding to subband TPMIs. For example, the information in the second DCI transmission may indicate groupings of TPMIs to various subbands, as compared to a TPMI for wideband. The UE may transmit, to the base station, data in accordance with the subband TPMIs. In this manner, uplink subband precoding may be supported between the UE and the base station. Enabling precoding at the subband level (e.g., at a finer granularity) may improve the speed and reliability of uplink data transmissions, thereby improving throughput and reducing latency in the wireless communication system.

FIG. 3 is a block diagram of an example wireless communications system 300 configured to support subband precoding. In some examples, wireless communications system 300 may implement aspects of wireless network 100. For example, wireless communications system 300 may include UE 115 and the base station 105. Although one UE and one base station are illustrated, in other implementations, wireless communications system 300 may include multiple UEs 115, multiple base stations 105, or both.

UE 115 can include a variety of components (e.g., structural, hardware components) used for carrying out one or more functions described herein. For example, these components can include a processor 302, a memory 304, a transmitter 306, and a receiver 308. Processor 302 may be configured to execute instructions stored at memory 304 to perform the operations described herein. In some implementations, processor 302 includes or corresponds to controller/processor 280, and memory 304 includes or corresponds to memory 282.

Transmitter 306 is configured to transmit data to one or more other devices, and receiver 308 is configured to receive data from one or more other devices. For example, transmitter 306 may transmit data, and receiver 318 may receive data, via a network, such as a wired network, a wireless network, or a combination thereof. For example, UE 115 may be configured to transmit or receive data via a direct device-to-device connection, a local area network (LAN) , a wide area network (WAN) , a modem-to-modem connection, the Internet, intranet, extranet, cable transmission system, cellular communication network, any combination of the above, or any other communications network now known or later developed within which permits two or more electronic devices to communicate. In some implementations, transmitter 306 and receiver 308 may be replaced with a transceiver. Additionally, or alternatively, transmitter 306, receiver 308, or both may include or correspond to one or more components of UE 115 described with reference to FIG. 2.

Base station 105 can include a variety of components (e.g., structural, hardware components) used for carrying out one or more functions described herein. For example, these components can include processor 312, memory 314, transmitter 316, and receiver 318. Processor 312 may be configured to execute instructions stored at memory 314 to perform the operations described herein. In some implementations, processor 312 includes or corresponds to controller/processor 240, and memory 314 includes or corresponds to memory 242.

Transmitter 316 is configured to transmit data to one or more other devices, and receiver 318 is configured to receive data from one or more other devices. For example, transmitter 316 may transmit data, and receiver 318 may receive data, via a network, such as a wired network, a wireless network, or a combination thereof. For example, base station 105 may be configured to transmit or receive data via a direct device-to-device connection, a LAN, a WAN, a modem-to-modem connection, the Internet, intranet, extranet, cable transmission system, cellular communication network, any combination of the above, or any other communications network now known or later developed within which permits two or more electronic devices to communicate. In some implementations, transmitter 316 and receiver 318 may be replaced with a transceiver. Additionally, or alternatively, transmitter 316, receiver, 318, or both may include or correspond to one or more components of base station 105 described with reference to FIG. 2.

In a particular implementation, wireless communications system 300 includes a fifth generation (5G) network. For example, base station 105 may be a 5G base station (e.g., configured to operate in accordance with a 5G standard) . Additionally, UE 115 may include a 5G UE (e.g., a UE configured to operate in accordance with a 5G network) .

During operation of wireless communication system 300, base station 105 transmits a two-stage DCI transmission to UE 115. For example, base station 105 transmits a first DCI transmission 320 to UE 115, and UE 115 receives first DCI transmission. First DCI transmission 320 indicates information, such as wideband TPMI information 322, that corresponds to a wideband TPMI. In some implementations, wideband TPMI information 322 may include or indicate an identifier, a codebook entry, or a table entry for a particular TPMI, and the matrix values for the particular TPMI may be obtained or retrieved based on the identifier. As another example, wideband TPMI information 322 may include one or more TPMIs. To illustrate, wideband TPMI information 322 may include or indicate the matrix values of one or more TPMIs. First DCI transmission 320 also indicates a first modulation and coding scheme (MCS) 324. Optionally, first DCI transmission 320 may include an indicator 325, as further described herein.

Wideband TPMI information 322 may include or indicate TPMIs associated with a wideband. In some implementations, wideband TPMI information 322 includes or indicates the wideband TPMI in accordance with a wireless standard, such as a 3 ^rd Generation Partnership Project (3GPP) standard or an Institute of Electrical and Electronics Engineers (IEEE) standard, as non-limiting examples. Some examples of TPMIs in accordance with a 3GPP standard are given by Tables 1-7 below.

Table 1 –Precoding matrix W for single-layer transmission using two antenna ports

Table 2 –Precoding matrix W for single-layer transmission using four antenna ports with transform precoding enabled

Table 3 –Precoding matrix W for single-layer transmission using four antenna ports with transform precoding disabled

Table 4 –Precoding matrix W for two-layer transmission using two antenna ports with transform precoding disabled

Table 5 –Precoding matrix W for two-layer transmission using four antenna ports with transform precoding disabled

Table 6 –Precoding matrix W for three-layer transmission using four antenna ports with transform precoding disabled

Table 7 –Precoding matrix W for four-layer transmission using four antenna ports with transform precoding disabled

In some of the examples in Tables 1-7 above, various types of TPMI information are provided. In some implementations, for indices 0-3, non-coherent TPMIs are given. For indices 4-11, partial coherent TPMIs are given. For indices 12-27, full coherent TPMIs are given. To support subband TPMIs, the partial coherent TPMIs or the full coherent TPMIs are grouped. The groups can be divided based on the orthogonality between the TPMIs. For example, there may be four orthogonal groups with indices {12, 14, 20, 22} , {13, 15, 21, 23} , {16, 18, 24, 26} and {17, 19, 25, 27} . A first option is to group non-orthogonal TPMIs in the same group. A second option is to group orthogonal TPMIs in the same group. A third option is to switch between the first option and the second option. For instance, some of the TPMIs can be orthogonal, and some of the TPMIs can be non-orthogonal.

To indicate the groupings of TPMIs to subbands, a second DCI transmission may be used. To illustrate, base station 105 transmits a second DCI transmission 326 to UE 115, and UE 115 receives second DCI transmission 326. Second DCI transmission 326 indicates information, such as subband TPMI information 328, that corresponds to subband TPMIs. Second DCI transmission 326 may also indicate second MCS 329, as further described herein. Subband TPMI information 328 may indicate groupings of TPMIs, relations between TPMIs and subbands, and/or other information that enables subband precoding.

There are multiple ways to divide the information between first DCI transmission 320 and second DCI transmission 326. In some implementations, first DCI transmission 320 indicates the wideband TPMI in accordance with a wireless standard (e.g., the same as existing TPMI in the codebook) . The wireless standard may be a 3GPP standard, as a non-limiting example. Additionally, second DCI transmission 326 may indicate a set of selected subband TPMIs from the wideband TPMI. For example, subband TPMI information 328 may indicate a group of TPMIs selected from the wideband TPMI. The group may be non-orthogonal TPMIs or orthogonal TPMIs, as non-limiting examples. In some such implementations, second DCI transmission 326 indicates a selected set of TPMIs from the group of TPMIs, or the set of TPMIs are selected based on pre-defined rules. For example, subband TPMI information 328 may indicate a correspondence between subbands and TPMIs of the group of TPMIs, such that a TPMI for a selected subband is indicated. As an example, wideband index 12 may correspond to indices {12, 13, 15, 16} , and second DCI transmission 326 (e.g., subband TPMI information 328) may be used to further select TPMIs within the group.

In some other implementations, first DCI transmission 320 includes group information of a group of TPMIs from the wideband TPMI. For example, wideband TPMI information 322 may include information indicating that four groups are divided based on an orthogonality property of the TPMIs. In some such implementations, second DCI transmission 326 indicates a set of selected subband TPMIs from the group of TPMIs. For example, subband TPMI information 328 may indicate a set of selected subband TPMIs from the group of TPMIs indicated by wideband TPMI information 322 and/or the set of subband TPMIs may be selected based on a set of pre-defined rules. The selected set of TPMIs may correspond to a subband TPMIs. For example, a subband TPMI may be down selected from the group of TPMIs indicated by wideband TPMI information 322.

In some implementations, the subband TPMIs indicated by second DCI transmission 326 (e.g., subband TPMI information 328) are subbands that overlap with resource allocation. For example, if an entire bandwidth (e.g., a wideband) includes four subbands subband 0, subband 1, subband 2, and subband 3, only the subbands which are allocated resources may be indicated by second DCI transmission 326. To illustrate, if resources are allocated to subband 0, subband 2, and subband 3, only those three subbands (and not subband 1) may have TPMIs indicated by second DCI transmission 326 (e.g., by subband TPMI information 328) . This example is provided for illustration only, and in other implementations, other numbers of subbands, and other subbands, may be allocated and indicated.

In some implementations, in addition to indicating TPMI-related information, the DCI transmissions also indicate MCSs. To illustrate, first DCI transmission 320 may indicate a first MCS and second DCI transmission 326 may indicate a second MCS. For example, first DCI transmission 320 may indicate first MCS 324, and second DCI transmission 326 may indicate second MCS 329. First MCS 324 may be different from second MCS 329. In some implementations, second MCS 329 is a differential MCS. For example, second MCS 329 may only indicate an offset (e.g., a difference) between first MCS 324 and second MCS 329, when subband TPMI is enabled. Transmitting a differential MCS may reduce the overall size of second DCI transmission 326 as compared to transmitting a full MCS indicator. In some implementations, first DCI transmission 320 indicates the number of allocated resources, the number of subbands is derived accordingly, and the payload of second DCI transmission 326 (which is related to the number of subbands) is therefore derived, which can reduce blind decoding complexity at base station 105.

In some implementations, a subband size of the subbands corresponds to a resource allocation in first DCI transmission 320. Additionally, or alternatively, the subband size may correspond to a configured subband size from a radio resource control (RRC) message or higher layer signaling. A payload size of second DCI transmission 326 may also be based on the resource allocation, or other information within, first DCI transmission 320.

After receiving first DCI transmission 320 and second DCI transmission 326, UE 115 may transmit data 330 to base station 105 in accordance with the subband TPMIs. For example, UE 115 may precode data 330 based on the subband (s) allocated to transmission of data 330. The precoding may be based on particular TPMIs indicated by second DCI transmission 326. Additionally, data 330 may be transmitted in accordance with second MCS 329.

Base station 105 may receive data 330 from UE 115 and perform blind decoding on data 330. Blind decoding refers to attempting to decode data 330 based on multiple (e.g., different) MCSs because base station 105 does not have knowledge of which MCS was used by UE 115. For example, base station 105 may decode data 330 based on first MCS 324. If data 330 is decoded successfully based on first MCS 324, base station 105 determines that first MCS 324 was used by UE 115, and that second DCI transmission 326 may have failed decoding at UE 115. If data 330 is not decoded (e.g., based on failing to decode data 330 based on first MCS 324) , base station 105 may decode data 330 based on second MCS 329. If data 330 is successfully decoded based on second MCS 329, base station 105 may determine that UE 115 successfully decoded second DCI transmission 326. Thus, if data 330 is successfully decoded using either first MCS 324 or second MCS 329, base station 105 identifies the MCS that was used by UE 115 (and potentially, whether or not one or more of first DCI transmission 320 and second DCI transmission 326 were successfully decoded at UE 115) .

If data 330 is unsuccessfully decoded based on first MCS 324 and second MCS 329, base station 105 may transmit, to UE 115, second scheduling information (e.g., based on the unsuccessful decoding of data 330) . The second scheduling information may be transmitted as a second two stage DCI transmission, such as a third DCI transmission (e.g., a first DCI transmission of the second two stage DCI transmission) and a fourth DCI transmission (e.g., a second DCI transmission of the second two stage DCI transmission) . In some implementations, base station 105 may configure different TPMIs for uplink precoding in the second two stage DCI transmission, but the same MCS from the first two stage DCI transmission (e.g., first DCI transmission 320 and second DCI transmission 326) may be used for retransmitting the data, even if one or both of the third and fourth DCI transmissions are decoded successfully.

Base station 105 may receive, from UE 115, a retransmission of data 330 at a time indicated by the second scheduling information. Base station 105 may again perform blind decoding on the retransmission of data 330. For example, base station 105 may decode data 330 based on first MCS 324. If the decoding is successful, data 330 is processed, and base station 105 determines that second DCI transmission 326 was not decoded successfully at UE 115. If data 330 is not successfully decoded based on first MCS 324, base station 105 decodes data 330 based on second MCS 329. If the decoding is successful, data 330 is processed, and base station 105 determines that second DCI transmission 326 was decoded successfully at UE 115. If the decoding is unsuccessful, base station 105 schedules another transmission opportunity for UE 115.

On the UE side, UE 115 receives first DCI transmission 320 and second DCI transmission 326 and attempts to decode the respective DCI transmissions. As an example, UE 115 may successfully decode first DCI transmission 320 but unsuccessfully decode second DCI transmission 326. In this example, UE 115 transmits data 330 in accordance with wideband TPMI information 322 and first MCS 324. If base station 105 fails to decode data 330 using blind decoding, as described above, UE 115 receives, from base station 105, second scheduling information. The second scheduling information may be received as a second two-stage DCI transmission (e.g., a third DCI transmission and a fourth DCI transmission) . UE 115 may retransmit data 330 to base station 105 during a time indicated by the second scheduling information. Data 330 may be retransmitted in accordance with first MCS 324 in this example, because second DCI transmission 326 failed to decode, regardless of whether either the third or fourth DCI transmissions are successfully decoded.

As another example, UE 115 may successfully decode both first DCI transmission 320 and second DCI transmission 326. However, for other reasons, data 330 may not be successfully decoded at base station 105. Thus, UE 115 receives, from base station 105, second scheduling information. The second scheduling information may be received as a second two-stage DCI transmission (e.g., a third DCI transmission and a fourth DCI transmission) . UE 115 may retransmit data 330 to base station 105 during a time indicated by the second scheduling information. Data 330 may be retransmitted in accordance with second MCS 329 in this example, because second DCI transmission 326 was successfully decoded, regardless of whether either the third or fourth DCI transmissions are successfully decoded.

In some implementations, first DCI transmission 320 includes indicator 325. Indicator 325 corresponds to subband precoding and indicates that subband precoding is enabled. Indicator 325 also indicates that there is a second DCI transmission (e.g., second DCI transmission 326) to be received at UE 115. In such implementations, if UE 115 successfully decodes first DCI transmission 320 (and processes indicator 325) but fails to decode (or receive) second DCI transmission 326, UE 115 determines that an error has occurred. In such implementations, UE 115 will refrain from transmitting data 330 at the designated time. Refraining from transmitting data 330 will communicate to base station 105 that transmission of at least one of first DCI transmission 320 and second DCI transmission 326 has failed.

In such implementations, on the base station side, base station 105 monitors a wireless channel for data 330 from UE 115 at a time designated for data transmission. If base station 105 does not receive data 330 from UE 115 during the designated time, base station 105 determines that first DCI transmission 320 and/or second DCI transmission 326 has failed. In response to determining the failure, base station 105 may second a second two-stage DCI transmission (e.g., a third DCI transmission and a fourth DCI transmission) to UE 115 to trigger retransmission of data 330.

Although described as receiving two DCI transmissions, in some implementations, the relevant information is communicated from base station 105 to UE 115 using a single DCI transmission. For example, a single DCI transmission may include wideband TPMI information 322 and subband TPMI information 328. As in the implementations described above, the wideband TPMI (e.g., wideband TPMI information 322) may be indicated in accordance with a wireless standard. Additionally, a payload size of the single DCI transmission may be dynamic. For example, the payload size may be based on a number of resources allocated in the DCI transmission. In some such implementations, the single DCI transmission may indicate a set of selected subband TPMIs from a group of TPMIs indicated by the single DCI transmission. Additionally, or alternatively, a number of subbands may correspond to a number of resources allocated in the DCI transmission.

Thus, FIG. 3 describes wireless communication system 300 that enables subband precoding. For example, base station 105 may transmit a two-stage DCI transmission including first DCI transmission 320 and second DCI transmission 326 to UE 115. First DCI transmission 320 includes wideband TPMI information 322 that includes information about TPMIs for a wideband. In some implementations, wideband TPMI information 322 may include information indicating groupings of TPMIs. Second DCI transmission 326 includes subband TPMI information 328 that includes information about grouping TPMIs, and about specific TPMIs for subbands. Enabling UE 115 to use TPMIs for subbands that are allocated for data transmission improves the reliability and speed of the data transmissions, which increases throughput and decreases latency within wireless communication system 300.

Referring to FIG. 4, a diagram of communications between devices of a wireless communication system 400 is shown. Wireless communication system 400 includes base station 105 and UE 115. FIG. 4 illustrates one example of communications between base station 105 and UE 115. To illustrate, base station 105 transmits two DCI transmissions, a first DCI transmission ( “DCI-1” ) and a second DCI transmission ( “DCI-2” ) . In some implementations, DCI-1 and DCI-2 may include or correspond to first DCI transmission 320 and second DCI transmission 326, respectively.

As illustrated in FIG. 4, DCI-1 is successfully received and decoded at UE 115. However, DCI-2 is unsuccessfully received and decoded at UE 115 (as indicated by the hatching lines of DCI-2) . Because DCI-2 is not successfully decoded, information about a second MCS is not received by UE 115. Thus, uplink data sent via the physical uplink shared channel (PUSCH) is sent in accordance with a first MCS indicated by DCI-1.

In the example of FIG. 4, reception of the data fails at base station 105. Thus, base station 105 schedules a second transmission time. To indicate the second transmission time, base station 105 transmits a second set of DCI transmissions to UE 115. As illustrated in FIG. 4, UE 115 successfully receives and decodes the second set of DCI transmissions. However, UE 115 transmits the uplink data (via the PUSCH) in accordance with the MCS of the first DCI transmission in the first set of transmissions, regardless of the successful decoding of the second set of DCI transmissions. Additionally, the data may be transmit in accordance with the subband TPMIs indicated by the fourth DCI transmission. This enables base station 105 to successfully decode the received data.

Referring to FIG. 5, a diagram of communications between devices of a wireless communication system 500 is shown. Wireless communication system 500 includes base station 105 and UE 115. FIG. 5 illustrates one example of communications between base station 105 and UE 115. To illustrate, base station 105 transmits two DCI transmissions, a first DCI transmission ( “DCI-1” ) and a second DCI transmission ( “DCI-2” ) . In some implementations, DCI-1 and DCI-2 may include or correspond to first DCI transmission 320 and second DCI transmission 326, respectively.

As illustrated in FIG. 5, DCI-1 is successfully received and decoded at UE 115. DCI-2 is also successfully received and decoded at UE 115. Because DCI-2 is successfully decoded, information about a second MCS is received by UE 115. Thus, uplink data sent via the PUSCH is sent in accordance with the second MCS indicated by DCI-2.

In the example of FIG. 5, reception of the data fails at base station 105. Thus, base station 105 schedules a second transmission time. To indicate the second transmission time, base station 105 transmits a second set of DCI transmissions to UE 115. As illustrated in FIG. 5, UE 115 successfully receives and decodes the first DCI transmission of the second set of DCI transmissions. However, UE 115 does not successfully receive the second DCI transmission of the second set of DCI transmissions (as indicated by the hatch lines) . Thus, UE 115 transmits the uplink data (via the PUSCH) in accordance with the second MCS of the second DCI transmission in the first set of transmissions, regardless of the successful decoding of one or more of the second set of DCI transmissions. Additionally, the data is transmitted in accordance with TPMIs indicated by the third DCI transmission. This enables base station 105 to successfully decode the received data.

FIG. 6 is a block diagram illustrating example blocks executed to implement one aspect of the present disclosure. The example blocks will also be described with respect to UE 115 as illustrated in FIG. 8. FIG. 8 is a block diagram illustrating UE 115 configured according to one aspect of the present disclosure. UE 115 includes the structure, hardware, and components as illustrated for UE 115 of FIG. 2. For example, UE 115 includes controller/processor 280, which operates to execute logic or computer instructions stored in memory 282, as well as controlling the components of UE 115 that provide the features and functionality of UE 115. UE 115, under control of controller/processor 280, transmits and receives signals via wireless radios 801a-r and antennas 252a-r. Wireless radios 801a-r includes various components and hardware, as illustrated in FIG. 2 for UE 115, including modulator/demodulators 254a-r, MIMO detector 256, receive processor 258, transmit processor 264, and TX MIMO processor 266.

At block 600, the UE receives, from a base station, a first downlink control information (DCI) transmission indicating information corresponding to a wideband transmitted precoding matrix indicator (TPMI) . The UE 115 may execute, under control of controller/processor 280, DCI receiving logic 802 stored in memory 282. The execution environment of DCI receiving logic 802 provides the functionality to receive a first DCI transmission from the base station. The first DCI transmission includes wideband TPMI information 803, which in some implementations includes or corresponds to wideband TPMI information 322 of FIG. 3. Wideband TPMI information 803 includes information corresponding to wideband TPMIs.

At block 601, the UE receives, from the base station, a second DCI transmission indicating information corresponding to subband TPMIs. The UE 115 may execute, under control of controller/processor 280, DCI receiving logic 802 stored in memory 282. The execution environment of DCI receiving logic 802 provides the functionality to receive a second DCI transmission from the base station. The second DCI transmission includes subband TPMI information 804, which in some implementations includes or corresponds to subband TPMI information 328 of FIG. 3. Subband TPMI information 804 includes information that indicates groups of TPMIs and/or divides the groups of TPMIs into TPMIs allocated to various subbands.

At block 602, the UE transmits, to the base station, data in accordance with the subband TPMIs. The UE 115 may execute, under control of controller/processor 280, data transmission logic 805. The execution environment of data transmission logic 805 provides the functionality to transmit data, to the base station, in accordance with the subband TPMIs. For example, the data may be transmit in accordance with subband TPMI information 804.

In some implementations, the first DCI transmission also includes first MCS 806, and the second DCI transmission also includes second MCS 807. In some such implementations, second MCS 807 is a differential MCS of first MCS 806. If only the first DCI transmission is successfully received and decoded, the data may be transmit to the base station in accordance with first MCS 806. If the second DCI transmission is successfully received and decoded, the data may be transmitted to the base station in accordance with second MCS 807.

FIG. 7 is a block diagram illustrating example blocks executed to implement one aspect of the present disclosure. The example blocks will also be described with respect to base station 105 as illustrated in FIG. 9. FIG. 9 is a block diagram illustrating base station 105 configured according to one aspect of the present disclosure. Base station 105 includes the structure, hardware, and components as illustrated for base station 105 of FIG. 2. For example, base station 105 includes controller/processor 240, which operates to execute logic or computer instructions stored in memory 242, as well as controlling the components of base station 105 that provide the features and functionality of base station 105. Base station 105, under control of controller/processor 240, transmits and receives signals via wireless radios 901a-t and antennas 234a-t. Wireless radios 901a-t includes various components and hardware, as illustrated in FIG. 2 for base station 105, including modulator/demodulators 232a-t, MIMO detector 236, receive processor 238, transmit processor 220, and TX MIMO processor 230.

At block 700, a base station transmits, to a UE, a first downlink control information (DCI) transmission indicating information corresponding to a wideband transmitted precoding matrix indicator (TPMI) . Base station 105 may execute, under control of controller/processor 240, DCI transmission logic 902 stored in memory 242. The execution environment of DCI transmission logic 902 provides the functionality to transmit a first DCI transmission to the UE. The first DCI transmission includes wideband TPMI information 903, which in some implementations includes or corresponds to wideband TPMI information 322 of FIG. 3. Wideband TPMI information 903 includes information corresponding to wideband TPMIs.

At block 701, the base station transmits, to the UE, a second DCI transmission indicating information corresponding to subband TPMIs. Base station 105 may execute, under control of controller/processor 240, DCI transmission logic 902 stored in memory 242. The execution environment of DCI transmission logic 902 provides the functionality to transmit a second DCI transmission to the UE. The second DCI transmission includes subband TPMI information 904, which in some implementations includes or corresponds to subband TPMI information 328 of FIG. 3. Subband TPMI information 904 includes information that indicates groups of TPMIs and/or divides the groups of TPMIs into TPMIs allocated to various subbands.

Thus, a wireless communication system may support subband precoding. For example, a base station may transmit a two-stage DCI transmission. A first DCI transmission includes or indicates information about TPMIs for a wideband. In some implementations, the wideband TPMI information may include information indicating groupings of TPMIs. A second DCI transmission includes or indicates information about grouping TPMIs, and about specific TPMIs for subbands. Enabling a UE to use TPMIs for subbands that are allocated for data transmission improves the reliability and speed of the data transmissions, which increases throughput and decreases latency within wireless communication system.

In some implementations, the first DCI transmission also includes first MCS 905, and the second DCI transmission also includes second MCS 906. In some such implementations, second MCS 906 is a differential MCS of first MCS 905. Base station 105 may blindly decode data received from the UE based on first MCS 905 and/or second MCS 906. For example, base station 105 may first attempt to decode the data based on first MCS 905. If the decoding fails, base station 105 may attempt to decode the data based on second MCS 906. Thus, if at least one of the first DCI transmission and the second DCI transmission is successfully received and decoded at the UE, the data should be decodable at base station 105 through blind decoding.

Configuration or use of subband TPMIs may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein. In such aspects, a UE may receive, from a base station, a first downlink control information (DCI) transmission indicating information corresponding to a wideband transmitted precoding matrix indicator (TPMI) . The UE may receive, from the base station, a second DCI transmission indicating information corresponding to subband TPMIs. The UE may transmit, to the base station, data in accordance with the subband TPMIs.

In a first aspect, the first DCI transmission indicates the wideband TPMI in accordance with a wireless standard.

In a second aspect, alone or in combination with the first aspect, a group of TPMIs is associated with the wideband TPMI.

In a third aspect, alone or in combination with the second aspect, the second DCI transmission indicates a set of selected subband TPMIs of the group of TPMIs.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the first DCI transmission includes group information of a group of TPMIs from the wideband TPMI.

In a fifth aspect, alone or in combination with the fourth aspect, the second DCI transmission indicates a set of selected subband TPMIs of the group of TPMIs.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspecst, the a subband size corresponds to a resource allocation in the first DCI transmission and a configured subband size from a radio resource control (RRC) message or higher layer signaling.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the first DCI transmission indicates a first modulation and coding scheme (MCS) , and wherein the second DCI transmission indicates a differential MCS.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the UE successfully decodes the first DCI transmission, the UE unsuccessfully decodes the second DCI transmission, the UE receives, from the base station, second scheduling information, and the UE transmits, to the base station, the data during a time indicated by the second scheduling information in accordance with a modulation and coding scheme (MCS) indicated by the first DCI transmission.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the UE successfully decodes the first DCI transmission, the UE successfully decodes the second DCI transmission, the UE receives, from the base station, second scheduling information, and the UE transmits, to the base station, the data during a time indicated by the second scheduling information in accordance with a modulation and coding scheme (MCS) indicated by the second DCI transmission.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the first DCI transmission includes an indicator, the indicator corresponding to subband precoding.

In an eleventh aspect, alone or in combination with the tenth aspect, the UE successfully decodes the first DCI transmission, the UE unsuccessfully decodes the second DCI transmission, and the UE refrains from transmitting the data based on the unsuccessful decoding of the second DCI transmission.

In some aspects, configuration and/or use of subband TPMIs may include a base station transmitting, to a user equipment (UE) , a first downlink control information (DCI) transmission indicating information corresponding to a wideband transmitted precoding matrix indicator (TPMI) . Configuration and/or use of subband TPMIs may also include the base station transmitting, to the UE, a second DCI transmission indicating information corresponding to subband TPMIs.

In a twelfth aspect, the first DCI transmission indicates the wideband TPMI in accordance with a wireless standard.

In a thirteenth aspect, alone or in combination with the twelfth aspect, a group of TPMIs is associated with the wideband TPMI.

In a fourteenth aspect, alone or in combination with the thirteenth aspect, the second DCI transmission indicates a set of selected subband TPMIs from the group of TPMIs.

In a fifteenth aspect, alone or in combination with one or more of the twelfth through fourteenth aspects, the first DCI transmission includes group information of a group of TPMIs from the wideband TPMI.

In a sixteenth aspect, alone or in combination with the fifteenth aspect, the second DCI transmission indicates a set of selected subband TPMIs from the group of TPMIs.

In a seventeenth aspect, alone or in combination with one or more of the twelfth through sixteenth aspects, a subband size corresponds to a resource allocation in the first DCI transmission and a configured subband size from a radio resource control (RRC) message or higher layer signaling.

In an eighteenth aspect, alone or in combination with one or more of the twelfth through seventeenth aspects, the first DCI transmission indicates a first modulation and coding scheme (MCS) , and wherein the second DCI transmission indicates a differential MCS.

In a nineteenth aspect, alone or in combination with one or more of the twelfth through eighteenth aspects, the base station receives, from the UE, data, the base station decodes the data based on a first modulation and coding scheme (MCS) indicated by the first DCI transmission, based on failing to decode the data based on the first MCS, the base station decodes the data based on a second MCS indicated by the second DCI transmission, and the base station identifies which MCS is used by the UE based on successful decoding of the data based on the first MCS or the second MCS.

In a twentieth aspect, alone or in combination with the nineteenth aspect, the base station transmits, to the UE, second scheduling information to the base station based on unsuccessful decoding of the data based on the second MCS.

In a twenty-first aspect, alone or in combination with the twentieth aspect, the base station receives, from the UE, the data during a time indicated by the second scheduling information and decodes the data based on the first MCS.

In a twenty-second aspect, alone or in combination with the twenty-first aspect, the base station, based on failing to decode the data based on the first MCS, decodes the data based on the second MCS.

In a twenty-third aspect, alone or in combination with one or more of the twelfth through twenty-second aspects, the first DCI transmission includes an indicator, the indicator corresponding to subband precoding.

In a twenty-fourth aspect, alone or in combination with the twenty-third aspect, the base station monitors a wireless channel for data from the UE at a time indicated by the first DCI transmission and determines that either the first DCI transmission or the second DCI transmission was unsuccessfully decoded at the UE based on failure to receive the data during the time.

In some aspects, configuration and/or use of subband TPMIs may include a user equipment (UE) receiving, from a base station, a downlink control information (DCI) transmission indicating first information corresponding to a wideband transmitted precoding matrix indicator (TPMI) and second information corresponding to subband TPMIs. The UE may transmit, to the base station, data in accordance with the subband TPMIs.

In a twenty-fifth aspect, the DCI transmission indicates the wideband TPMI in accordance with a wireless standard.

In a twenty-sixth aspect, alone or in combination with the twenty-fifth aspect, a payload size of the DCI transmission is dynamic based on a number of resources allocated in the DCI transmission.

In a twenty-seventh aspect, alone or in combination with one or more of the twenty-fifth through twenty-sixth aspects, a number of subbands corresponds to a number of resources allocated in the DCI transmission.

In a twenty-eighth aspect, alone or in combination with one or more of the twenty-fifth through twenty-seventh aspects, the second information indicates a set of selected subband TPMIs from a group of TPMIs indicated by the first information.

Those of skill in the art would understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The functional blocks and modules described herein (e.g., the functional blocks and modules in FIG. 2) may comprise processors, electronics devices, hardware devices, electronics components, logical circuits, memories, software codes, firmware codes, etc., or any combination thereof. In addition, features discussed herein relating to FIGS. 1-9 may be implemented via specialized processor circuitry, via executable instructions, and/or combinations thereof.

Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps (e.g., the logical blocks in FIGS. 6 and 7) described in connection with the disclosure herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure. Skilled artisans will also readily recognize that the order or combination of components, methods, or interactions that are described herein are merely examples and that the components, methods, or interactions of the various aspects of the present disclosure may be combined or performed in ways other than those illustrated and described herein.

The various illustrative logical blocks, modules, and circuits described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a digital signal processor (DSP) , an application specific integrated circuit (ASIC) , a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The steps of a method or algorithm described in connection with the disclosure herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal.

In one or more exemplary designs, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. Computer-readable storage media may be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, a connection may be properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, or digital subscriber line (DSL) , then the coaxial cable, fiber optic cable, twisted pair, or DSL, are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD) , laser disc, optical disc, digital versatile disc (DVD) , hard disk, solid state disk, and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

As used herein, including in the claims, the term “and/or, ” when used in a list of two or more items, means that any one of the listed items can be employed by itself, or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and/or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination. Also, as used herein, including in the claims, “or” as used in a list of items prefaced by “at least one of” indicates a disjunctive list such that, for example, a list of “at least one of A, B, or C” means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) or any of these in any combination thereof.

The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

A method of wireless communication, the method comprising:

receiving, at a user equipment (UE) from a base station, a first downlink control information (DCI) transmission indicating information corresponding to a wideband transmitted precoding matrix indicator (TPMI) ;

receiving, at the UE from the base station, a second DCI transmission indicating information corresponding to subband TPMIs; and

transmitting, from the UE to the base station, data in accordance with the subband TPMIs.
The method of claim 1, wherein the first DCI transmission indicates the wideband TPMI in accordance with a wireless standard.
The method of claim 2, wherein a group of TPMIs is associated with the wideband TPMI.
The method of claim 3, wherein the second DCI transmission indicates a set of selected subband TPMIs from the group of TPMIs.
The method of claim 1, wherein the first DCI transmission includes group information of a group of TPMIs from the wideband TPMI.
The method of claim 5, wherein the second DCI transmission indicates a set of selected subband TPMIs from the group of TPMIs.
The method of claim 1, wherein a subband size corresponds to a resource allocation in the first DCI transmission and a configured subband size from a radio resource control (RRC) message or higher layer signaling.
The method of claim 1, wherein the first DCI transmission indicates a first modulation and coding scheme (MCS) , and wherein the second DCI transmission indicates a differential MCS.
The method of claim 1, further comprising:

successfully decoding, at the UE, the first DCI transmission;

unsuccessfully decoding, at the UE, the second DCI transmission;

receiving, at the UE from the base station, second scheduling information; and

transmitting, from the UE to the base station, the data during a time indicated by the second scheduling information in accordance with a modulation and coding scheme (MCS) indicated by the first DCI transmission.
The method of claim 1, further comprising:

successfully decoding, at the UE, the first DCI transmission;

successfully decoding, at the UE, the second DCI transmission;

receiving, at the UE from the base station, second scheduling information; and

transmitting, from the UE to the base station, the data during a time indicated by the second scheduling information in accordance with a modulation and coding scheme (MCS) indicated by the second DCI transmission.
The method of claim 1, wherein the first DCI transmission includes an indicator, the indicator corresponding to subband precoding.
The method of claim 11, further comprising:

successfully decoding the first DCI transmission;

unsuccessfully decoding the second DCI transmission; and

refraining from transmitting the data based on the unsuccessful decoding of the second DCI transmission.
An apparatus configured for wireless communication, the apparatus comprising:

at least one processor; and

a memory coupled to the at least one processor, wherein the at least one processor is configured to:

receive, at a user equipment (UE) from a base station, a first downlink control information (DCI) transmission indicating information corresponding to a wideband transmitted precoding matrix indicator (TPMI) ;

receive, at the UE from the base station, a second DCI transmission indicating information corresponding to subband TPMIs; and

initiate transmission, from the UE to the base station, of data in accordance with the subband TPMIs.
The apparatus of claim 13, wherein the first DCI transmission indicates the wideband TPMI in accordance with a wireless standard.
The apparatus of claim 14, wherein a group of TPMIs is associated with the wideband TPMI.
The apparatus of claim 15, wherein the second DCI transmission indicates a set of selected subband TPMIs from the group of TPMIs.
The apparatus of claim 13, wherein the first DCI transmission includes group information of a group of TPMIs from the wideband TPMI.
The apparatus of claim 17, wherein the second DCI transmission indicates a set of selected subband TPMIs from the group of TPMIs.
The apparatus of claim 13, wherein a subband size corresponds to a resource allocation in the first DCI transmission and a configured subband size from a radio resource control (RRC) message or higher layer signaling.
The apparatus of claim 13, wherein the first DCI transmission indicates a first modulation and coding scheme (MCS) , and wherein the second DCI transmission indicates a differential MCS.
The apparatus of claim 13, wherein the at least one processor is further configured to:

successfully decode, at the UE, the first DCI transmission;

unsuccessfully decode, at the UE, the second DCI transmission;

receive, at the UE from the base station, second scheduling information; and

initiate transmission, from the UE to the base station, of the data during a time indicated by the second scheduling information in accordance with a modulation and coding scheme (MCS) indicated by the first DCI transmission.
The apparatus of claim 13, wherein the at least one processor is further configured to:

successfully decode, at the UE, the first DCI transmission;

successfully decode, at the UE, the second DCI transmission;

receive, at the UE from the base station, second scheduling information; and

initiate transmission, from the UE to the base station, of the data during a time indicated by the second scheduling information in accordance with a modulation and coding scheme (MCS) indicated by the second DCI transmission.
The apparatus of claim 13, wherein the first DCI transmission includes an indicator, the indicator corresponding to subband precoding.
The apparatus of claim 23, wherein the at least one processor is further configured to:

successfully decode the first DCI transmission;

unsuccessfully decode the second DCI transmission; and

refrain from initiating transmission of the data based on the unsuccessful decoding of the second DCI transmission.
An apparatus configured for wireless communication, comprising:

means for receiving, at a user equipment (UE) from a base station, a first downlink control information (DCI) transmission indicating information corresponding to a wideband transmitted precoding matrix indicator (TPMI) ;

means for receiving, at the UE from the base station, a second DCI transmission indicating information corresponding to subband TPMIs; and

means for transmitting, from the UE to the base station, data in accordance with the subband TPMIs.
The apparatus of claim 25, wherein a group of TPMIs is associated with the wideband TPMI.
The apparatus of claim 26, wherein the second DCI transmission indicates a set of selected subband TPMIs from the group of TPMIs.
A non-transitory computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform operations comprising:

receiving, at a user equipment (UE) from a base station, a first downlink control information (DCI) transmission indicating information corresponding to a wideband transmitted precoding matrix indicator (TPMI) ;

receiving, at the UE from the base station, a second DCI transmission indicating information corresponding to subband TPMIs; and

initiating transmission, from the UE to the base station, of data in accordance with the subband TPMIs.
The non-transitory computer-readable medium of claim 28, wherein the first DCI transmission includes group information of a group of TPMIs from the wideband TPMI.
The non-transitory computer-readable medium of claim 29, wherein the second DCI transmission indicates a set of selected subband TPMIs from the group of TPMIs.
A method of wireless communication, the method comprising:

transmitting, from a base station to a user equipment (UE) , a first downlink control information (DCI) transmission indicating information corresponding to a wideband transmitted precoding matrix indicator (TPMI) ; and

transmitting, from the base station to the UE, a second DCI transmission indicating information corresponding to subband TPMIs.
The method of claim 31, wherein the first DCI transmission indicates the wideband TPMI in accordance with a wireless standard.
The method of claim 32, wherein a group of TPMIs is associated with the wideband TPMI.
The method of claim 33, wherein the second DCI transmission indicates a set of selected subband TPMIs from the group of TPMIs.
The method of claim 31, wherein the first DCI transmission includes group information of a group of TPMIs from the wideband TPMI.
The method of claim 35, wherein the second DCI transmission indicates a set of selected subband TPMIs from the group of TPMIs.
The method of claim 31, wherein a subband size corresponds to a resource allocation in the first DCI transmission and a configured subband size from a radio resource control (RRC) message or higher layer signaling.
The method of claim 31, wherein the first DCI transmission indicates a first modulation and coding scheme (MCS) , and wherein the second DCI transmission indicates a differential MCS.
The method of claim 31, further comprising:

receiving, at the base station from the UE, data;

decoding the data based on a first modulation and coding scheme (MCS) indicated by the first DCI transmission;

based on failing to decode the data based on the first MCS, decoding the data based on a second MCS indicated by the second DCI transmission; and

identifying which MCS is used by the UE based on successful decoding of the data based on the first MCS or the second MCS.
The method of claim 39, further comprising transmitting, from the base station to the UE, second scheduling information based on unsuccessful decoding of the data based on the second MCS.
The method of claim 40, further comprising:

receiving, at the base station from the UE, the data during a time indicated by the second scheduling information; and

decoding the data based on the first MCS.
The method of claim 41, further comprising, based on failing to decode the data based on the first MCS, decoding the data based on the second MCS.
The method of claim 31, wherein the first DCI transmission includes an indicator, the indicator corresponding to subband precoding.
The method of claim 43, further comprising:

monitoring a wireless channel for data from the UE at a time indicated by the first DCI transmission; and

determining that either the first DCI transmission or the second DCI transmission was unsuccessfully decoded at the UE based on failure to receive the data during the time.
An apparatus configured for wireless communication, the apparatus comprising:

at least one processor; and

a memory coupled to the at least one processor, wherein the at least one processor is configured to:

initiate transmission, from a base station to a user equipment (UE) , of a first downlink control information (DCI) transmission indicating information corresponding to a wideband transmitted precoding matrix indicator (TPMI) ; and

initiate transmission, from the base station to the UE, of a second DCI transmission indicating information corresponding to subband TPMIs.
The apparatus of claim 45, wherein the first DCI transmission indicates the wideband TPMI in accordance with a wireless standard.
The apparatus of claim 46, wherein a group of TPMIs is associated with the wideband TPMI.
The apparatus of claim 47, wherein the second DCI transmission indicates a set of selected subband TPMIs of the group of TPMIs.
The apparatus of claim 45, wherein the first DCI transmission includes group information of a group of TPMIs from the wideband TPMI.
The apparatus of claim 49, wherein the second DCI transmission indicates a set of selected subband TPMIs from the group of TPMIs.
The apparatus of claim 45, wherein a subband size corresponds to a resource allocation in the first DCI transmission and a configured subband size from a radio resource control (RRC) message or higher layer signaling.
The apparatus of claim 45, wherein the first DCI transmission indicates a first modulation and coding scheme (MCS) , and wherein the second DCI transmission indicates a differential MCS.
The apparatus of claim 45, wherein the at least one processor is further configured to:

receive, at the base station from the UE, data;

decode the data based on a first modulation and coding scheme (MCS) indicated by the first DCI transmission;

based on failing to decode the data based on the first MCS, decode the data based on a second MCS indicated by the second DCI transmission; and

identify which MCS is used by the UE based on successful decoding of the data based on the first MCS or the second MCS.
The apparatus of claim 53, wherein the at least one processor is further configured to initiate transmission, from the base station to the UE, of second scheduling information based on unsuccessful decoding of the data based on the second MCS.
The apparatus of claim 54, wherein the at least one processor is further configured to:

receive, at the base station from the UE, the data during a time indicated by the second scheduling information; and

decode the data based on the first MCS.
The apparatus of claim 55, wherein the at least one processor is further configured to, based on failing to decode the data based on the first MCS, decode the data based on the second MCS.
The apparatus of claim 45, wherein the first DCI transmission includes an indicator, the indicator corresponding to subband precoding.
The apparatus of claim 57, wherein the at least one processor is further configured to:

monitor a wireless channel for data from the UE at a time indicated by the first DCI transmission; and

determine that either the first DCI transmission or the second DCI transmission was unsuccessfully decoded at the UE based on failure to receive the data during the time.
An apparatus configured for wireless communication, comprising:

means for transmitting, from a base station to a user equipment (UE) , a first downlink control information (DCI) transmission indicating information corresponding to a wideband transmitted precoding matrix indicator (TPMI) ; and

means for transmitting, from the base station to the UE, a second DCI transmission indicating information corresponding to subband TPMIs.
The apparatus of claim 59, wherein a group of TPMIs is associated with the wideband TPMI.
The apparatus of claim 60, wherein the second DCI transmission indicates a set of selected subband TPMIs from the group of TPMIs.
A non-transitory computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform operations comprising:

initiating transmission, from a base station to a user equipment (UE) , of a first downlink control information (DCI) transmission indicating information corresponding to a wideband transmitted precoding matrix indicator (TPMI) ; and

initiating transmission, from the base station to the UE, of a second DCI transmission indicating information corresponding to subband TPMIs.
The non-transitory computer-readable medium of claim 62, wherein the first DCI transmission includes group information of a group of TPMIs from the wideband TPMI.
The non-transitory computer-readable medium of claim 63, wherein the second DCI transmission indicates a set of selected subband TPMIs from the group of TPMIs.
A method of wireless communication, the method comprising:

receiving, at a user equipment (UE) from a base station, a downlink control information (DCI) transmission indicating first information corresponding to a wideband transmitted precoding matrix indicator (TPMI) and second information corresponding to subband TPMIs; and

transmitting, from the UE to the base station, data in accordance with the subband TPMIs.
The method of claim 65, wherein the DCI transmission indicates the wideband TPMI in accordance with a wireless standard.
The method of claim 65, wherein a payload size of the DCI transmission is dynamic based on a number of resources allocated in the DCI transmission.
The method of claim 65, wherein a number of subbands corresponds to a number of resources allocated in the DCI transmission.
The method of claim 65, wherein in the second information indicates a set of selected subband TPMIs from a group of TPMIs indicated by the first information.