WO2021167790A1

WO2021167790A1 - Configuration of large-scale properties relations across reference signals

Info

Publication number: WO2021167790A1
Application number: PCT/US2021/016443
Authority: WO
Inventors: Alexandros MANOLAKOS; Muhammad Sayed Khairy Abdelghaffar; Hwan Joon Kwon; Yeliz Tokgoz; Krishna Kiran Mukkavilli; Naga Bhushan
Original assignee: Qualcomm Incorporated
Priority date: 2020-02-21
Filing date: 2021-02-03
Publication date: 2021-08-26

Abstract

Configuration of large scale properties across multiple reference signals is disclosed. User equipments (UEs) receive properties relation information that identifies a relationship between the large scale properties of two or more reference signals from different transmission/reception points (TRPs). When receiving downlink transmission with the reference signals the UEs may determine the frequency properties of the TRPs based on the large scale properties of the multiple reference signals determined using the properties relation information. The UEs may then generate a combined frequency property of the two or more reference signals to apply to the channel estimate of the downlink transmissions. With the property channel estimate, the UEs may decode and receive of the downlink transmission.

Description

CONFIGURATION OF LARGE-SCALE PROPERTIES RELATIONS ACROSS

REFERENCE SIGNALS

BACKGROUND

Cross-Reference To Related Applications

[0001] This application claims the benefit of Greek Patent Application No. 20200100094, entitled, “CONFIGURATION OF LARGE-SCALE PROPERTIES RELATIONS ACROSS REFERENCE SIGNALS,” filed on February 21, 2020, which is expressly incorporated by reference herein in its entirety.

Field

[0002] Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to configuration of large-scale properties relations across reference signals.

Background

[0003] 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. One example of such a network is the Universal Terrestrial Radio Access Network (UTRAN). The UTRAN is the radio access network (RAN) defined as a part of the Universal Mobile Telecommunications System (UMTS), a third generation (3G) mobile phone technology supported by the 3rd Generation Partnership Project (3GPP). Examples of multiple-access network formats include Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, and Single-Carrier FDMA (SC-FDMA) networks.

[0004] 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.

[0005] 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.

[0006] 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.

SUMMARY

[0007] In one aspect of the disclosure, a method of wireless communication includes receiving, by a user equipment (UE), properties relation information identifying a relationship between large scale properties of two or more downlink reference signals, receiving, by the UE, the two or more downlink reference signals from two or more transmission-reception points (TRPs), receiving, by the UE, an indication comprising the two or more downlink reference signals being a quasi-co-location (QCL) source of a downlink transmission, estimating, by the UE, large scale properties of the two or more downlink reference signals, calculating, by the UE, a channel estimate of the downlink transmission at least based on the estimated large scale properties and the properties relation information, and decoding, by the UE, the downlink channel in accordance with the channel estimate.

[0008] In an additional aspect of the disclosure, a method of wireless communication includes determining, by a TRP, properties relation information identifying a relationship between large scale properties of a downlink reference signal transmitted by the TRP and one or more additional downlink reference signals transmitted by one or more neighboring TRPs, transmitting, by the TRP, the properties relation information to a served UE, and transmitting, by the TRP, a downlink transmission including the downlink reference signal.

[0009] In an additional aspect of the disclosure, an apparatus configured for wireless communication includes means for receiving, by a UE, properties relation information identifying a relationship between large scale properties of two or more downlink reference signals, means for receiving, by the UE, the two or more downlink reference signals from two or more TRPs, means for receiving, by the UE, an indication comprising the two or more downlink reference signals being QCL source of a downlink transmission, means for estimating, by the UE, large scale properties of the two or more downlink reference signals, means for calculating, by the UE, a channel estimate of the downlink transmission at least based on the estimated large scale properties and the properties relation information, and means for decoding, by the UE, the downlink channel in accordance with the channel estimate.

[0010] In an additional aspect of the disclosure, an apparatus configured for wireless communication includes means for determining, by a TRP, properties relation information identifying a relationship between large scale properties of a downlink reference signal transmitted by the TRP and one or more additional downlink reference signals transmitted by one or more neighboring TRPs, means for transmitting, by the TRP, the properties relation information to a served UE, and means for transmitting, by the TRP, a downlink transmission including the downlink reference signal.

[0011] In an additional aspect of the disclosure, a non-transitory computer-readable medium having program code recorded thereon. The program code further includes code to receive, by a UE, properties relation information identifying a relationship between large scale properties of two or more downlink reference signals, code to receive, by the UE, the two or more downlink reference signals from two or more TRPs, code to receive, by the UE, an indication comprising the two or more downlink reference signals being QCL source of a downlink transmission, code to estimate, by the UE, large scale properties of the two or more downlink reference signals, code to calculate, by the UE, a channel estimate of the downlink transmission at least based on the estimated large scale properties and the properties relation information, and code to decode, by the UE, the downlink channel in accordance with the channel estimate.

[0012] In an additional aspect of the disclosure, a non-transitory computer-readable medium having program code recorded thereon. The program code further includes code to determine, by a TRP, properties relation information identifying a relationship between large scale properties of a downlink reference signal transmitted by the TRP and one or more additional downlink reference signals transmitted by one or more neighboring TRPs, code to transmit, by the TRP, the properties relation information to a served UE, and code to transmit, by the TRP, a downlink transmission including the downlink reference signal.

[0013] 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 processor. The processor is configured to receive, by a UE, properties relation information identifying a relationship between large scale properties of two or more downlink reference signals, to receive, by the UE, the two or more downlink reference signals from two or more TRPs, to receive, by the UE, an indication comprising the two or more downlink reference signals being QCL source of a downlink transmission, to estimate, by the UE, large scale properties of the two or more downlink reference signals, to calculate, by the UE, a channel estimate of the downlink transmission at least based on the estimated large scale properties and the properties relation information, and to decode, by the UE, the downlink channel in accordance with the channel estimate.

[0014] 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 processor. The processor is configured to determine, by a TRP, properties relation information identifying a relationship between large scale properties of a downlink reference signal transmitted by the TRP and one or more additional downlink reference signals transmitted by one or more neighboring TRPs, to transmit, by the TRP, the properties relation information to a served UE, and to transmit, by the TRP, a downlink transmission including the downlink reference signal.

[0015] The foregoing has outlined rather broadly the features and technical advantages of examples according to the disclosure in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter. The conception and specific examples disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. Characteristics of the concepts disclosed herein, both their organization and method of operation, together with associated advantages will be better understood from the following description when considered in connection with the accompanying figures. Each of the figures is provided for the purpose of illustration and description, and not as a definition of the limits of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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.

[0017] FIG. l is a block diagram illustrating details of a wireless communication system.

[0018] FIG. 2 is a block diagram illustrating a design of a base station and a UE configured according to one aspect of the present disclosure. [0019] FIGs. 3A-3B are block diagrams illustrating multiple schemes for transmissions between multiple TRPs and a UE.

[0020] FIGs. 4A and 4B are block diagrams illustrating example blocks executed to implement aspects of the present disclosure.

[0021] FIG. 5 is a block diagram illustrating an SFN deployment having a UE deployed in a high speed usage scenario in communication with TRP0-3, each of UE 115 and TRP0-3 configured according to one aspect of the present disclosure.

[0022] FIG. 6 is a block diagram illustrating an example UE configured according to one aspect of the present disclosure.

[0023] FIG. 7 is a block diagram illustrating a base station configured according to one aspect of the present disclosure.

[0024] 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

[0025] 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.

[0026] This disclosure relates generally to providing or participating in authorized shared access between two 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, as well as other communications networks. As described herein, the terms “networks” and “systems” may be used interchangeably.

[0027] 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. 3 GPP 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.

[0028] In particular, 5G networks contemplate diverse deployments, diverse spectrum, and diverse services and devices that may be implemented using an OFDM-based unified, air interface. In order 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/km²), 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/km²), extreme data rates (e.g., multi-Gbps rate, 100+ Mbps user experienced rates), and deep awareness with advanced discovery and optimizations.

[0029] The 5G NR may be implemented to use optimized OFDM-based waveforms with scalable numerology and transmission time interval (TTI); having 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 with 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 3 GHz 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 500 MHz bandwidth.

[0030] The scalable numerology of the 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.

[0031] Various other aspects and features of the disclosure are further described below. It should be apparent that the teachings herein may be embodied in a wide variety of forms and that any specific structure, function, or both being disclosed herein is merely representative and not limiting. Based on the teachings herein one of an ordinary level of skill in the art should appreciate that an aspect disclosed herein may be implemented independently of any other aspects and that two or more of these aspects may be combined in various ways. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, such an apparatus may be implemented or such a method may be practiced using other structure, functionality, or structure and functionality in addition to or other than one or more of the aspects set forth herein. For example, a method may be implemented as part of a system, device, apparatus, and/or as instructions stored on a computer readable medium for execution on a processor or computer. Furthermore, an aspect may comprise at least one element of a claim.

[0032] FIG. 1 is a block diagram illustrating an example of a wireless communications system 100 that supports the configuration of large scale properties across multiple reference signals, such as tracking reference signals (TRS), channel state information-reference signals (CSI-RS), etc., in accordance with aspects of the present disclosure. The wireless communications system 100 includes base stations 105, UEs 115, and a core network 130. In some examples, the wireless communications system 100 may be a Long Term Evolution (LTE) network, an LTE- Advanced (LTE-A) network, an LTE-A Pro network, or NR network. In some cases, wireless communications system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, or communications with low-cost and low-complexity devices. In operations according to the aspects of the present disclosure, UEs 115 receive properties relation information that identifies a relationship between the large scale properties of two or more reference signals. When receiving downlink transmission with the reference signals UEs 115 may determine the frequency offsets of the reference signals based on the large scale properties determined using the properties relation information. UEs 115 may then generate a combined frequency offset of the two or more reference signals to apply to the channel estimate of the downlink transmissions.

[0033] Base stations 105 may wirelessly communicate with UEs 115 via one or more base station antennas. Base stations 105 described herein may include or may be referred to by those skilled in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next-generation NodeB or giga-NodeB (either of which may be referred to as a gNB), a Home NodeB, a Home eNodeB, or some other suitable terminology. Wireless communications system 100 may include base stations 105 of different types (e.g., macro or small cell base stations). The UEs 115 described herein may be able to communicate with various types of base stations 105 and network equipment including macro eNBs, small cell eNBs, gNBs, relay base stations, and the like.

[0034] Each base station 105 may be associated with a particular geographic coverage area 110 in which communications with various UEs 115 is supported. Each base station 105 may provide communication coverage for a respective geographic coverage area 110 via communication links 125, and communication links 125 between a base station 105 and a UE 115 may utilize one or more carriers. Communication links 125 shown in wireless communications system 100 may include uplink transmissions from a UE 115 to a base station 105, or downlink transmissions from a base station 105 to a UE 115. Downlink transmissions may also be referred to as forward link transmissions while uplink transmissions may also be referred to as reverse link transmissions.

[0035] The geographic coverage area 110 for a base station 105 may be divided into sectors making up a portion of the geographic coverage area 110, and each sector may be associated with a cell. For example, each base station 105 may provide communication coverage for a macro cell, a small cell, a hot spot, or other types of cells, or various combinations thereof. In some examples, a base station 105 may be movable and, therefore, provide communication coverage for a moving geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, and overlapping geographic coverage areas 110 associated with different technologies may be supported by the same base station 105 or by different base stations 105. The wireless communications system 100 may include, for example, a heterogeneous LTE/LTE-A/LTE-A Pro or NR network in which different types of base stations 105 provide coverage for various geographic coverage areas 110.

[0036] The term “cell” refers to a logical communication entity used for communication with a base station 105 (e.g., over a carrier), and may be associated with an identifier for distinguishing neighboring cells (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID)) operating via the same or a different carrier. In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., machine- type communication (MTC), narrowband Internet-of-things (NB-IoT), enhanced mobile broadband (eMBB), or others) that may provide access for different types of devices. In some cases, the term “cell” may refer to a portion of a geographic coverage area 110 (e.g., a sector) over which the logical entity operates.

[0037] UEs 115 may be dispersed throughout the wireless communications system 100, and each UE 115 may be stationary or mobile. A UE 115 may also be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” may also be referred to as a unit, a station, a terminal, or a client. A UE 115 may also be a personal electronic device such as a cellular phone (UE 115a), a personal digital assistant (PDA), a wearable device (UE 115d), a tablet computer, a laptop computer (UE 115g), or a personal computer. In some examples, a UE 115 may also refer to a wireless local loop (WLL) station, an Internet-of-things (IoT) device, an Internet-of- everything (IoE) device, an MTC device, or the like, which may be implemented in various articles such as appliances, vehicles (UE 115e and UE 115f), meters (UE 115b and UE 115c), or the like.

[0038] Some UEs 115, such as MTC or IoT devices, may be low cost or low complexity devices, and may provide for automated communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC may refer to data communication technologies that allow devices to communicate with one another or a base station 105 without human intervention. In some examples, M2M communication or MTC may include communications from devices that integrate sensors or meters to measure or capture information and relay that information to a central server or application program that can make use of the information or present the information to humans interacting with the program or application. Some UEs 115 may be designed to collect information or enable automated behavior of machines. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based business charging.

[0039] Some UEs 115 may be configured to employ operating modes that reduce power consumption, such as half-duplex communications (e.g., a mode that supports one-way communication via transmission or reception, but not transmission and reception simultaneously). In some examples, half-duplex communications may be performed at a reduced peak rate. Other power conservation techniques for UEs 115 include entering a power saving “deep sleep” mode when not engaging in active communications, or operating over a limited bandwidth (e.g., according to narrowband communications). In other cases, UEs 115 may be designed to support critical functions (e.g., mission critical functions), and a wireless communications system 100 may be configured to provide ultra-reliable communications for these functions.

[0040] In certain cases, a UE 115 may also be able to communicate directly with other UEs 115 (e.g., using a peer-to-peer (P2P) or device-to-device (D2D) protocol). One or more of a group of UEs 115 utilizing D2D communications may be within the geographic coverage area 110 of a base station 105. Other UEs 115 in such a group may be outside the geographic coverage area 110 of a base station 105, or be otherwise unable to receive transmissions from a base station 105. In some cases, groups of UEs 115 communicating via D2D communications may utilize a one-to-many (1:M) system in which each UE 115 transmits to every other UE 115 in the group. In some cases, a base station 105 may facilitate the scheduling of resources for D2D communications. In other cases, D2D communications may be carried out between UEs 115 without the involvement of a base station 105.

[0041] Base stations 105 may communicate with the core network 130 and with one another. For example, base stations 105 may interface with the core network 130 through backhaul links 132 (e.g., via an SI, N2, N3, or other interface). Base stations 105 may communicate with one another over backhaul links 134 (e.g., via an X2, Xn, or other interface) either directly (e.g., directly between base stations 105) or indirectly (e.g., via core network 130).

[0042] The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC), which may include at least one mobility management entity (MME), at least one serving gateway (S-GW), and at least one packet data network (PDN) gateway (P-GW). The MME may manage non-access stratum (e.g., control plane) functions such as mobility, authentication, and bearer management for UEs 115 served by base stations 105 associated with the EPC. User IP packets may be transferred through the S-GW, which itself may be connected to the P-GW. The P-GW may provide IP address allocation as well as other functions. The P-GW may be connected to the network operators IP services. The operators IP services may include access to the Internet, Intranet(s), an IP multimedia subsystem (IMS), or a packet-switched (PS) streaming service.

[0043] At least some of the network devices, such as a base station 105, may include subcomponents such as an access network entity, which may be an example of an access node controller (ANC). Each access network entity may communicate with UEs 115 through a number of other access network transmission entities, which may be referred to as a radio head, a smart radio head, or a transmission/reception point (TRP). In some configurations, various functions of each access network entity or base station 105 may be distributed across various network devices (e.g., radio heads and access network controllers) or consolidated into a single network device (e.g., a base station 105).

[0044] Wireless communications system 100 may operate using one or more frequency bands, typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Generally, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band, since the wavelengths range from approximately one decimeter to one meter in length. UHF waves may be blocked or redirected by buildings and environmental features. However, the waves may penetrate structures sufficiently for a macro cell to provide service to UEs 115 located indoors. Transmission of UHF waves may be associated with smaller antennas and shorter range (e.g., less than 100 km) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz.

[0045] Wireless communications system 100 may also operate in a super high frequency (SHF) region using frequency bands from 3 GHz to 30 GHz, also known as the centimeter band. The SHF region includes bands such as the 5 GHz industrial, scientific, and medical (ISM) bands, which may be used opportunistically by devices that may be capable of tolerating interference from other users.

[0046] Wireless communications system 100 may also operate in an extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz), also known as the millimeter band. In some examples, wireless communications system 100 may support millimeter wave (mmW) communications between UEs 115 and base stations 105, and EHF antennas of the respective devices may be even smaller and more closely spaced than UHF antennas. In some cases, this may facilitate use of antenna arrays within a UE 115. However, the propagation of EHF transmissions may be subject to even greater atmospheric attenuation and shorter range than SHF or UHF transmissions. Techniques disclosed herein may be employed across transmissions that use one or more different frequency regions, and designated use of bands across these frequency regions may differ by country or regulating body.

[0047] Wireless communications system 100 may include operations by different network operating entities (e.g., network operators), in which each network operator 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.

[0048] 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.

[0049] 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.

[0050] In various implementations, wireless communications system 100 may use both licensed and unlicensed radio frequency spectrum bands. For example, wireless communications system 100 may employ license assisted access (LAA), LTE-unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band (NR-U), such as the 5 GHz ISM band. In some cases, UE 115 and base station 105 of the wireless communications system 100 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.

[0051] A CCA may include an energy detection procedure to determine whether there are any other active transmissions on the shared channel. 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 message 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.

[0052] In general, four categories of LBT procedure have been suggested for sensing a shared channel for signals that may indicate the channel is already occupied. In a first category (CAT 1 LBT), no LBT or CCA is applied to detect occupancy of the shared channel. A second category (CAT 2 LBT), which may also be referred to as an abbreviated LBT, a single-shot LBT, or a 25-ps LBT, provides for the node to perform a CCA to detect energy above a predetermined threshold or detect a message or preamble occupying the shared channel. The CAT 2 LBT performs the CCA without using a random back-off operation, which results in its abbreviated length, relative to the next categories.

[0053] A third category (CAT 3 LBT) performs CCA to detect energy or messages on a shared channel, but also uses a random back-off and fixed contention window. Therefore, when the node initiates the CAT 3 LBT, it performs a first CCA to detect occupancy of the shared channel. If the shared channel is idle for the duration of the first CCA, the node may proceed to transmit. However, if the first CCA detects a signal occupying the shared channel, the node selects a random back-off based on the fixed contention window size and performs an extended CCA. If the shared channel is detected to be idle during the extended CCA and the random number has been decremented to 0, then the node may begin transmission on the shared channel. Otherwise, the node decrements the random number and performs another extended CCA. The node would continue performing extended CCA until the random number reaches 0. If the random number reaches 0 without any of the extended CCAs detecting channel occupancy, the node may then transmit on the shared channel. If at any of the extended CCA, the node detects channel occupancy, the node may re-select a new random back-off based on the fixed contention window size to begin the countdown again.

[0054] A fourth category (CAT 4 LBT), which may also be referred to as a full LBT procedure, performs the CCA with energy or message detection using a random back-off and variable contention window size. The sequence of CCA detection proceeds similarly to the process of the CAT 3 LBT, except that the contention window size is variable for the CAT 4 LBT procedure.

[0055] Use of a medium-sensing procedure to contend for access to an unlicensed shared spectrum may result in communication inefficiencies. This may be particularly evident when multiple network operating entities (e.g., network operators) are attempting to access a shared resource. In wireless communications system 100, base stations 105 and UEs 115 may be operated by the same or different network operating entities. 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. Requiring each base station 105 and UE 115 of different network operating entities to contend for shared resources may result in increased signaling overhead and communication latency.

[0056] In some cases, operations in unlicensed bands may be based on a carrier aggregation configuration in conjunction with component carriers operating in a licensed band (e.g., LAA). Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, peer-to-peer transmissions, or a combination of these. Duplexing in unlicensed spectrum may be based on frequency division duplexing (FDD), time division duplexing (TDD), or a combination of both.

[0057] In some examples, base station 105 or UE 115 may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. For example, wireless communications system 100 may use a transmission scheme between a transmitting device (e.g., a base station 105) and a receiving device (e.g., a UE 115), where the transmitting device is equipped with multiple antennas and the receiving device is equipped with one or more antennas. MIMO communications may employ multipath signal propagation to increase the spectral efficiency by transmitting or receiving multiple signals via different spatial layers, which may be referred to as spatial multiplexing. The multiple signals may, for example, be transmitted by the transmitting device via different antennas or different combinations of antennas. Likewise, the multiple signals may be received by the receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream, and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams. Different spatial layers may be associated with different antenna ports used for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO) where multiple spatial layers are transmitted to the same receiving device, and multiple-user MIMO (MU-MIMO) where multiple spatial layers are transmitted to multiple devices.

[0058] Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station 105 or a UE 115) to shape or steer an antenna beam (e.g., a transmit beam or receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining the signals communicated via antenna elements of an antenna array such that signals propagating at particular orientations with respect to an antenna array experience constructive interference while others experience destructive interference. The adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying certain amplitude and phase offsets to signals carried via each of the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation).

[0059] In one example, a base station 105 may use multiple antennas or antenna arrays to conduct beamforming operations for directional communications with a UE 115. For instance, some signals (e.g. synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a base station 105 multiple times in different directions, which may include a signal being transmitted according to different beamforming weight sets associated with different directions of transmission. Transmissions in different beam directions may be used to identify (e.g., by the base station 105 or a receiving device, such as a UE 115) a beam direction for subsequent transmission and/or reception by the base station 105.

[0060] Some signals, such as data signals associated with a particular receiving device, may be transmitted by a base station 105 in a single beam direction (e.g., a direction associated with the receiving device, such as a UE 115). In some examples, the beam direction associated with transmissions along a single beam direction may be determined based at least in in part on a signal that was transmitted in different beam directions. For example, a UE 115 may receive one or more of the signals transmitted by the base station 105 in different directions, and the UE 115 may report to the base station 105 an indication of the signal it received with a highest signal quality, or an otherwise acceptable signal quality. Although these techniques are described with reference to signals transmitted in one or more directions by a base station 105, a UE 115 may employ similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE 115), or transmitting a signal in a single direction (e.g., for transmitting data to a receiving device).

[0061] A receiving device (e.g., a UE 115, which may be an example of a mmW receiving device) may try multiple receive beams when receiving various signals from the base station 105, such as synchronization signals, reference signals, beam selection signals, or other control signals. For example, a receiving device may try multiple receive directions by receiving via different antenna subarrays, by processing received signals according to different antenna subarrays, by receiving according to different receive beamforming weight sets applied to signals received at a plurality of antenna elements of an antenna array, or by processing received signals according to different receive beamforming weight sets applied to signals received at a plurality of antenna elements of an antenna array, any of which may be referred to as “listening” according to different receive beams or receive directions. In some examples a receiving device may use a single receive beam to receive along a single beam direction (e.g., when receiving a data signal). The single receive beam may be aligned in a beam direction determined based at least in part on listening according to different receive beam directions (e.g., a beam direction determined to have a highest signal strength, highest signal-to-noise ratio, or otherwise acceptable signal quality based at least in part on listening according to multiple beam directions).

[0062] In certain implementations, the antennas of a base station 105 or UE 115 may be located within one or more antenna arrays, which may support MIMO operations, or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co located at an antenna assembly, such as an antenna tower. In some cases, antennas or antenna arrays associated with a base station 105 may be located in diverse geographic locations. A base station 105 may have an antenna array with a number of rows and columns of antenna ports that the base station 105 may use to support beamforming of communications with a UE 115. Likewise, a UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations.

[0063] In additional cases, UEs 115 and base stations 105 may support retransmissions of data to increase the likelihood that data is received successfully. HARQ feedback is one technique of increasing the likelihood that data is received correctly over a communication link 125. HARQ may include a combination of error detection (e.g., using a cyclic redundancy check (CRC)), forward error correction (FEC), and retransmission (e.g., automatic repeat request (ARQ)). HARQ may improve throughput at the MAC layer in poor radio conditions (e.g., signal-to- noise conditions). In some cases, a wireless device may support same-slot HARQ feedback, where the device may provide HARQ feedback in a specific slot for data received in a previous symbol in the slot, while in other cases, the device may provide HARQ feedback in a subsequent slot, or according to some other time interval.

[0064] Time intervals in LTE or NR may be expressed in multiples of a basic time unit, which may, for example, refer to a sampling period of T_s = 1/30,720,000 seconds. Time intervals of a communications resource may be organized according to radio frames each having a duration of 10 milliseconds (ms), where the frame period may be expressed as Tf = 307,200 T_s. The radio frames may be identified by a system frame number (SFN) ranging from 0 to 1023. Each frame may include 10 subframes numbered from 0 to 9, and each subframe may have a duration of 1 ms. A subframe may be further divided into 2 slots each having a duration of 0.5 ms, and each slot may contain 6 or 7 modulation symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period). Excluding the cyclic prefix, each symbol period may contain 2048 sampling periods. In some cases, a subframe may be the smallest scheduling unit of the wireless communications system 100, and may be referred to as a transmission time interval (TTI). In other cases, a smallest scheduling unit of the wireless communications system 100 may be shorter than a subframe or may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs) or in selected component carriers using sTTIs).

[0065] In some wireless communications systems, a slot may further be divided into multiple mini slots containing one or more symbols. In some instances, a symbol of a mini-slot or a mini slot may be the smallest unit of scheduling. Each symbol may vary in duration depending on the subcarrier spacing or frequency band of operation, for example. Further, some wireless communications systems may implement slot aggregation in which multiple slots or mini-slots are aggregated together and used for communication between a UE 115 and a base station 105.

[0066] The term “carrier,” as may be used herein, refers to a set of radio frequency spectrum resources having a defined physical layer structure for supporting communications over a communication link 125. For example, a carrier of a communication link 125 may include a portion of a radio frequency spectrum band that is operated according to physical layer channels for a given radio access technology. Each physical layer channel may carry user data, control information, or other signaling. A carrier may be associated with a pre-defmed frequency channel (e.g., an evolved universal mobile telecommunication system terrestrial radio access (E-UTRA) absolute radio frequency channel number (EARFCN)), and may be positioned according to a channel raster for discovery by EIEs 115. Carriers may be downlink or uplink (e.g., in an FDD mode), or be configured to carry downlink and uplink communications (e.g., in a TDD mode). In some examples, signal waveforms transmitted over a carrier may be made up of multiple sub-carriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT- S-OFDM)).

[0067] The organizational structure of the carriers may be different for different radio access technologies (e.g., LTE, LTE-A, LTE-A Pro, NR). For example, communications over a carrier may be organized according to TTIs or slots, each of which may include user data as well as control information or signaling to support decoding the user data. A carrier may also include dedicated acquisition signaling (e.g., synchronization signals or system information, etc.) and control signaling that coordinates operation for the carrier. In some examples (e.g., in a carrier aggregation configuration), a carrier may also have acquisition signaling or control signaling that coordinates operations for other carriers.

[0068] Physical channels may be multiplexed on a carrier according to various techniques. A physical control channel and a physical data channel may be multiplexed on a downlink carrier, for example, using time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. In some examples, control information transmitted in a physical control channel may be distributed between different control regions in a cascaded manner (e.g., between a common control region or common search space and one or more UE-specific control regions or UE-specific search spaces).

[0069] A carrier may be associated with a particular bandwidth of the radio frequency spectrum, and in some examples the carrier bandwidth may be referred to as a “system bandwidth” of the carrier or the wireless communications system 100. For example, the carrier bandwidth may be one of a number of predetermined bandwidths for carriers of a particular radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz). In some examples, each served UE 115 may be configured for operating over portions or all of the carrier bandwidth. In other examples, some UEs 115 may be configured for operation using a narrowband protocol type that is associated with a predefined portion or range (e.g., set of subcarriers or RBs) within a carrier (e.g., “in-band” deployment of a narrowband protocol type).

[0070] In a system employing MCM techniques, a resource element may consist of one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme). Thus, the more resource elements that a UE 115 receives and the higher the order of the modulation scheme, the higher the data rate may be for the UE 115. In MIMO systems, a wireless communications resource may refer to a combination of a radio frequency spectrum resource, a time resource, and a spatial resource (e.g., spatial layers), and the use of multiple spatial layers may further increase the data rate for communications with a UE 115.

[0071] Devices of the wireless communications system 100 (e.g., base stations 105 or UEs 115) may have a hardware configuration that supports communications over a particular carrier bandwidth, or may be configurable to support communications over one of a set of carrier bandwidths. In some examples, the wireless communications system 100 may include base stations 105 and/or UEs 115 that support simultaneous communications via carriers associated with more than one different carrier bandwidth.

[0072] Wireless communications system 100 may support communication with a UE 115 on multiple cells or carriers, a feature which may be referred to as carrier aggregation or multi-carrier operation. A UE 115 may be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used with both FDD and TDD component carriers.

[0073] In some cases, wireless communications system 100 may utilize enhanced component carriers (eCCs). An eCC may be characterized by one or more features including wider carrier or frequency channel bandwidth, shorter symbol duration, shorter TTI duration, or modified control channel configuration. In certain instances, an eCC may be associated with a carrier aggregation configuration or a dual connectivity configuration (e.g., when multiple serving cells have a suboptimal or non-ideal backhaul link). An eCC may also be configured for use in unlicensed spectrum or shared spectrum (e.g., where more than one operator is allowed to use the spectrum, such as NR-shared spectrum (NR-SS)). An eCC characterized by wide carrier bandwidth may include one or more segments that may be utilized by UEs 115 that are not capable of monitoring the whole carrier bandwidth or are otherwise configured to use a limited carrier bandwidth (e.g., to conserve power). [0074] In additional cases, an eCC may utilize a different symbol duration than other component carriers, which may include use of a reduced symbol duration as compared with symbol durations of the other component carriers. A shorter symbol duration may be associated with increased spacing between adjacent subcarriers. A device, such as a UE 115 or base station 105, utilizing eCCs may transmit wideband signals (e.g., according to frequency channel or carrier bandwidths of 20, 40, 60, 80 MHz, etc.) at reduced symbol durations (e.g., 16.67 microseconds). A TTI in eCC may consist of one or multiple symbol periods. In some cases, the TTI duration (that is, the number of symbol periods in a TTI) may be variable.

[0075] Wireless communications system 100 may be an NR system that may utilize any combination of licensed, shared, and unlicensed spectrum bands, among others. The flexibility of eCC symbol duration and subcarrier spacing may allow for the use of eCC across multiple spectrums. In some examples, NR shared spectrum may increase spectrum utilization and spectral efficiency, specifically through dynamic vertical (e.g., across the frequency domain) and horizontal (e.g., across the time domain) sharing of resources.

[0076] FIG. 2 shows a block diagram of a design of a base station 105 and a UE 115, which may be one of the base station and one of the UEs in FIG. 1. At 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 PBCH, PCFICH, PHICH, PDCCH, EPDCCH, 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 PSS, SSS, and cell-specific reference signal. A 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 the 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 further 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.

[0077] At 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. A MIMO detector 256 may obtain received symbols from all the demodulators 254a through 254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor 258 may process (e.g., demodulate, 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.

[0078] On the uplink, at the UE 115, a transmit processor 264 may receive and process data (e.g., for the PUSCH) from a data source 262 and control information (e.g., for the PUCCH) from the controller/processor 280. The transmit processor 264 may also generate reference symbols for a reference signal. The symbols from the transmit processor 264 may be precoded by a 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 the base station 105, the uplink signals from the UE 115 may be received by the antennas 234, processed by the demodulators 232, detected by a MIMO detector 236 if applicable, and further processed by a receive processor 238 to obtain decoded data and control information sent by the UE 115. The processor 238 may provide the decoded data to a data sink 239 and the decoded control information to the controller/processor 240.

[0079] The controllers/processors 240 and 280 may direct the operation at the base station 105 and the UE 115, respectively. The controller/processor 240 and/or other processors and modules at the base station 105 may perform or direct the execution of various processes for the techniques described herein. The controllers/processor 280 and/or other processors and modules at the UE 115 may also perform or direct the execution of the functional blocks illustrated in FIGs. 4A and 4B, and/or other processes for the techniques described herein. The memories 242 and 282 may store data and program codes for the base station 105 and the UE 115, respectively. A scheduler 244 may schedule UEs for data transmission on the downlink and/or uplink.

[0080] With the increased deployment and use scenarios that become available in the 5G NR operations, considerations for enhancing support for various evolving deployment scenarios have included leveraging difference quasi-colocation (QCL) assumption or QCL-like relationships. For example in high speed deployments, such as automobile, airplane, unmanned drone, high speed train, and the like, UEs within these high speed deployments may leverage transmissions from multiple base station or transmission/reception points (TRPs) in order to improve quality of service (QoS). Enhancement to support such high speed deployment scenarios include identifying and specifying solution(s) on various QCL assumptions for demodulation reference signals (DMRS), e.g. multiple QCL assumptions for the same DMRS port(s), targeting downlink-only transmissions.

[0081] Within the 3GPP Release 16 (Rel. 16) discussions, different schemes for multi-TRP based ultra-reliable, low-latency communication (URLLC) scheduled by single downlink control indicator (DCI) at least, have been considered. The underlying assumption for such Rel. 16 schemes provides for spatial division multiplex (SDM), with a predetermined number of transmission configuration indicator (TCI) states within a single slot, with overlapped time and frequency resource allocation. In the scheme agreed to in Rel. 16, each transmission occasion may be a layer or a set of layers of the same transport block (TB), with each layer or layer set being associated with one TCI and one set of DMRS port(s). In this agreed scheme, a single codeword with one redundancy version (RV) may be used across all spatial layers or layer sets. From the UE perspective, different coded bits may be mapped to different layers or layer sets using the same mapping rule as in prior 3 GPP releases.

[0082] In a second proposed scheme discussed that was not agreed to in Rel. 16, each transmission occasion may also be a layer or a set of layers of the same TB, with each layer or layer set associated with one TCI and one set of DMRS port(s). In this second discussed scheme, a single codeword with one RV would be used for each spatial layer or layer set. The RVs corresponding to each spatial layer or layer set may be the same or different. In such second discussed scheme, there was no decision on any codeword-to-layer mapping when the total number of layers was set less than or equal to four.

[0083] In a third discussed scheme that was not agreed to in Rel. 16, one transmission occasion is associated to one layer of the same TB with one DMRS port associated with multiple TCI state indices, or one layer of the same TB with multiple DMRS ports may be associated with multiple TCI state indices one by one. The various aspects of the present disclosure provide for different optional aspects to address multi-TRP -based URLLC using this third proposed scheme.

[0084] FIGs 3A-3B are block diagrams illustrating multiple schemes for transmissions between multiple TRPsl-2 and UE 115a. As illustrated in FIG. 3 A, TRPl and TRP2 transmit separate reference signals, RSI and RS2, in which RSI is associated with PDSCH1 in a first TCI state, TCI state 1, RS2 is associated with PDSCH2 in a second TCI state, TCI state 2, and a third TCI state, TCI state 3 accommodates a single frequency network (SFN) joint transmission of TRPl and TRP2 in SFN’ed RS associated with SFN’ed PDSCH. In the transmission of SFN’ed RS, each of TRPl and TRP2 transmit the same reference signal. The transmission by two TRPs is transparent to UE 115a, which must detect and decode each instance of SFN’ed RS without the knowledge that SFN’ed RS is transmitted by multiple TRPs. [0085] As illustrated in FIG. 3B, TRP1 and TRP2 transmit separate reference signals, RSI and RS2, associated with PDSCH1 and PDSCH2 in TCI states 1 and 2, respectively. RSI and RS2 are also jointly associated with SFN’ed PDSCH across both TCI states 1 and 2. UE 115a receives the TCI state configuration information which informs UE 115a that multiple TRPs transmit multiple reference signals that may be associated with the single SFN’ed PDSCH. Accordingly, UE 115a detects and decodes RSI and RS2 with the knowledge that they are transmitted by separate TRPs and that they are associated with SFN’ed PDSCH.

[0086] As illustrated in FIG. 3C, TRPl and TRP2 also transmit separate reference signals, RSI and RS2, associated with PDSCH1 and PDSCH2 in TCI states 1 and 2, respectively. RSI and RS2 are also jointly associated with SFN’ed PDSCH across TCI states 1 and 2. According to the illustrated scheme, each TCI state is associated with a separate DMRS antenna port group, DMRS1 and DMRS2, respectively, within SFN’ed PDSCH. Again, UE 115a receives the TCI state configuration information which informs UE 115a that multiple TRPs transmit multiple reference signals that may be associated with individual DMRS antenna port groups with the single SFN’ed PDSCH. Accordingly, UE 115a again detects and decodes RSI and RS2 with the knowledge that they are transmitted by separate TRPs.

[0087] It should be noted that, within the schemes illustrated by FIGs. 3B and 3C, UE 115a can separately estimate frequency offsets for the two TRPs, TRPl and TRP2, based on the two indicated reference signals, RSI and RS2. Based on these two estimated frequency offsets, UE 115a may then calculate a combined frequency offset to compensate for the channel estimation on the DMRS port(s), (e.g., DMRS 1 and DMRS 2) within the SFN’ed PDSCH of FIGs. 3B and 3C. With the scheme illustrated by FIG. 3A, the SFN transmission, SFN’ed PDSCH, from multiple TRPs, TRPl and TRP2, according to a single TCI state, TCI state 3, the same reference signal, SFN’ed RS, configured according to TCI state 3, is transmitted by the two coordinated TRPs, TRPl andTRP2, simultaneously. UE 115a would calculate a combined frequency offset based on the combined reference signal. The combined frequency offset based on the combined reference signal may provide a less accurate estimate of the frequency offset than the combined frequency offset determined using the per channel frequency offsets obtained by UE 115a in accordance with the schemes illustrated in FIGs. 3B and 3C, which may perform an optimized estimation of the Doppler parameters on a “sparse” Doppler profile.

[0088] FIG. 4A 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 FIGs. 2 and 6. FIG. 6 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 600a-r and antennas 252a-r. Wireless radios 600a-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.

[0089] At block 400, a UE receives properties relation information identifying a relationship between large scale properties of two or more downlink reference signals. A UE, such as UE 115, receives signaling from a TRP via antennas 252a-r and wireless radios 600a-r. UE 115 may store, under control of controller/processor 280, the properties relation information in memory 282 at properties relation information 601. As will be described in greater detail below, the properties relation information provide a relationship between the large scale properties of two or more downlink reference signals. It may identify a basic relationship, such as higher or lower, positive or negative sign, and the like, or may identify a more complex relationship, such as a rate of change over time or distance.

[0090] At block 401, the UE receives the two or more downlink reference signals from two or more TRPs. UE 115 receives the two or more downlink reference signals in a downlink transmission via antennas 252a-r and wireless radios 600a-r.

[0091] At block 402, the UE receives an indication comprising the two or more downlink reference signals being a quasi-codocation (QCL) source of a downlink transmission. Along with the receipt of the reference signals, UE 115 receives and indication that the reference signals represent a QCL source of the downlink transmission. This indication prompts UE 115, under control of controller/processor 280 to execute QCL relation logic 602, stored in memory 282. The features and functionality resulting from execution of the steps and instructions of QCL relation logic 602 (referred to as “the execution environment” of QCL relation logic 602), allow UE 115 to know that the two or more downlink reference signals are both associated with the downlink transmission.

[0092] At block 403, the UE estimates large scale properties of the two or more downlink reference signals. Within the execution environment of QCL relation logic 602, UE 115 estimates the large scale properties of the two or more downlink reference signals.

[0093] At block 404, the UE calculates a channel estimate of the downlink transmission at least based on the estimated large scale properties and the properties relation information. Further within the execution environment of QCL relation logic 602, UE 115, under control of controller/processor 280, executes channel estimation 603, stored in memory 282. Channel estimation 603 uses the properties relation information to adjust the estimated large scale properties of the two or more reference signals. The resulting modification provides a more accurate channel estimation.

[0094] At block 405, the UE decodes the downlink channel in accordance with the channel estimate. With the downlink transmission received via antennas 252a-r and wireless radios 600a-r, once UE 115 has the channel estimate, it may trigger execution of coding/decoding process 605, stored in memory 282, under control of controller/processor 280. The execution environment of coding/decoding process 605 uses the more accurate channel estimate to decode the downlink transmission.

[0095] FIG. 4B 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 FIGs. 2 and 7. FIG. 7 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 700a-t and antennas 234a-t. Wireless radios 700a-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.

[0096] At block 410, a TRP determines properties relation information identifying a relationship between large scale properties of a downlink reference signal transmitted by the TRP and one or more additional downlink reference signals transmitted by one or more neighboring TRPs. A TRP, such as base station 105, may determine the properties relation information between multiple reference signals from different TRPs by using various information about the served UEs or reporting information from the UEs. For example, in memory 242, base station 105 may store information on the served UEs’ individual location and velocity, stored at UE statistics 701. Memory 701 may further include UE reporting 702, which stores information reported from the served UEs on the large scale properties of various reference signals that it observes and receives. Under control of controller/processor 240, base station 105 may execute measurement logic 703. Within the execution environment of measurement logic 703, base station 105 uses the information in one or both of UE statistics 701 and UE reporting 702 to calculate a relationship between large scale properties of various reference signals.

[0097] At block 411, the TRP transmits the properties relation information to a served UE. Under control of controller/processor 240, base station 105 transmits the properties relation information to the corresponding UE via wireless radios 700a-t and antennas 234a-t.

[0098] At block 412, the TRP transmits a downlink transmission including the reference signal. Once the properties relation information is transmitted, base station 105 may perform its downlink transmissions with other neighboring TRPs. The properties relation information may then not only indicate that the two or more reference signals received by the UE from different TRPs is associated with the downlink transmission, but also provide the UE with information to more accurately determine the large scale properties of the different reference signals for determining a more accurate channel estimate and downlink decoding.

[0099] FIG. 5 is a block diagram illustrating an SFN deployment 50 having UE 115 deployed in a high speed usage scenario in communication with TRPO-3, each of UE 115 and TRPO-3 configured according to one aspect of the present disclosure. The high speed usage scenario includes SFN deployment 50 in which UE 115 is located on high speed train 500 traveling at a high rate of speed. Any number of TRPs may be distributed along the track of high speed train 500. As illustrated in FIG. 5, UE 115 connects to the four nearest TRPs, TRPO-3, that share the same cell ID. UE 115 moves along the track in high speed train 500 and experiences different Doppler shifts and path delays at different locations, as illustrated in Doppler graph 501.

[00100] QCL relations among various reference signals are defined by type, which identifies the particular large scale properties or parameters associated with the reference signal. For example, a “QCL-TypeA” may include the large scale properties of Doppler shift, Doppler spread, average delay, delay spread. A “QCL-TypeB” may include the large scale properties of Doppler shift and Doppler spread. A “QCL-TypeC” may include the large scale properties of Doppler shift and average delay, while a “QCL-TypeD” may include the large scale property of a spatial receive parameter. UE 115 receives the TCI state configuration that identifies the number of reference signals and the QCL type associated with the reference signal. For example, UE 115 may receive a TCI state configuration that identifies TRS0-3 as QCL-TypeB. Accordingly, UE 115 would configure Doppler shift and Doppler spread as the large scale properties for TRS0-3. It should be noted that the assignment of QCL-TypeB to TRSO-3 was made solely as an example. TRS0-3 may be assigned to any of the available QCL types.

[00101] According to the illustrated aspect of FIG. 5, when two or more reference signals are used as reference for a DMRS, additional properties relation information may be signaled to UE 115 that identifies a relationship between the large scale properties of TRS0-3. At point 502, UE 115 receives TRS0-3 from TRPO-3, respectively. However, because of the location and speed of UE 115 within high speed train 500, the large scale properties (e.g., Doppler shift, path delay, etc.) of each of TRS0-3 are detected in different relative locations along Doppler graph 501. The additional properties relation information allows UE 115 to locate TRS0-3 more easily by giving a relationship between the large scale properties of the reference signals.

[00102] It should be noted that different types of relations may be transmitted as the properties relation information. For example, the properties relation information may include any of a Doppler shifts relation that identifies a gap or scaling factor between the Doppler shifts of TRS0-3, a Doppler spreads relation that identifies a gap or scaling factor of the Doppler spreads between TRS0-3, an average delay relation that identifies a gap or scaling factor between the average delays of TRS0-3, a delay spread relation that identifies a gap or scaling factor between the spread of average delays of TRS0-3, or a combination of such relations. UE 115 uses the relation to locate and determine the large scale properties of each TRS.

[00103] The network may signal, via one or more TRPs, such properties relation information to UE 115 using multiple different resources. For example, the network may signal the properties relation information using higher-layer signaling, such as radio resource control (RRC) signaling or TCI state signaling. In a first optional aspect, each of TRS0-3 may correspond to a CSI-RS resource set, which may be configured by the network with the expected or estimated large scale properties (e.g., Doppler shift and/or Doppler spread, and/or average delay, and/or delay spread). UE 115 may use the expected/estimated large scale properties to determine the relationship between each reference signal. In a second optional aspect of higher layer signaling, in a TCI state that uses multiple TRSs, additional parameters are signaled with the TCI state configuration which correspond to the properties relation information (e.g., the relative gap or scaling factor between the corresponding large scale properties) of TRSO-3. In a third optional aspect of higher layer signaling, for each TCI state that is associated with one of TRS0-3, an additional field in RRC messaging may be provided which provides a pair-wise relative gap or scaling factor between the corresponding large scale properties of 2 TRSs.

[00104] The network may further signal the properties relation information using other types of signaling, such as medium access control -control element (MAC-CE) signaling or downlink control indicator (DCI) signaling. In the optional aspect that uses MAC-CE signaling, the MAC-CE may update the “expected value” of a large scale parameter, or the relative gap or scaling factor between any of TRS0-3 or between TCI states. As an update to the expected value, the MAC-CE signaling may be used in conjunction with the higher-layer signaling options, in which the expected values are provided by the higher-layer signaling, and the MAC- CE provides updates to those values. In the optional aspect that uses DCI signaling, special antenna port fields are added to the antenna port table within a typical DCI in which several rows with, for example, port 0 may provide configured relationships of their associated TRSs, such as TRS0-3.

[00105] On the network side, the relation between TRS0-3 can be estimated using information of the position and/or velocity of UE 115. Additionally, UEs, such as UEs 115x and 115y, may be configured to report the large scale properties values (either absolute or relative). In such a high speed scenario, UEs 115x and 115y also exist inside high speed train 500 and experience similar channels to UE 115. The network may configure TRS0-3 or the TCI states accordingly. For example, if UE 115x has reported that TRS0 is at FcO, TRS1 is at Fcl, TRS2 is at Fc2, TRS3 is at Fc3, and TRP2 may decide to serve the UE 115 with TRS1 and TRS3, and can inform UE 115 of the expected or estimated values of the large scale properties or relations between the large scale properties of TRS0-3.

[00106] It should be noted that the properties relation information can be very coarse, such as, for example, a 1-bit signaling which identifies a simple relationship between large scale properties of TRSO-3, such as equal or not, same sign (positive/negative) or different, positive or negative, and the like. In practice, a 1-bit signal may indicate that TRS0 and TRS1 have the same sign (e.g., a negative Doppler shift), or a 1-bit signal may indicate that TRS1 and TRS2 have a different signed relationship (e.g., a negative Doppler shift of TRS1 and a positive Doppler shift of TRS2).

[00107] Alternatively, the network may provide more advanced information, such as information on how the relation between the large scale properties of TRS0-3 changes across time. For example, the network may provide a rate of change for how the Doppler shift of the TRS are expected to change across time. Then, based on its knowledge of its location/velocity, UE 115 may determine the large scale property (e.g., Doppler spread or Doppler shift) of TRS0, or any other the other TRS1-3, at 503 and then use the rate of change to calculate the estimated large scale property (e.g., Doppler spread or Doppler shift) of TRS0 at both 502 and 504. Further, the network may provide a look-up table that lists the large scale relations/associations between TRS0-3 and a positioning indicator, which may include a time-stamp, time-tag, location tag, or the like, for each element or entry of the look-up table. This way, UE 115 receives the look-up table at a time prior to 503, and based on the positioning indicator, UE 115 may look-up the relationship between the large scale properties of any of TRS0-3 at 503, 502, and 504 and would know when to update or re-calibrate the large scale properties. [00108] It should be noted that, when providing such a look-up table, the table may itself be updated at a certain rate or period (e.g., every 100 frames, 200 frames, etc.).

[00109] 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.

[00110] The functional blocks and modules in FIGs. 4A and 4B may comprise processors, electronics devices, hardware devices, electronics components, logical circuits, memories, software codes, firmware codes, etc., or any combination thereof.

[00111] Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps 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.

[00112] 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. [00113] The various different aspects of the present disclosure may be implemented as methods, processes, non-transitory computer-readable media that include code that, when executed by a computer or one or more processors provides functionality, or in configurations of one or more processors to implement functionality in various components and hardware. For example, a first aspect may include receiving, by a user equipment (UE), properties relation information identifying a relationship between large scale properties of two or more downlink reference signals, receiving, by the UE, the two or more downlink reference signals from two or more transmission-reception points (TRPs), receiving, by the UE, an indication comprising the two or more downlink reference signals being a quasi-co-location (QCL) source of a downlink transmission, estimating, by the UE, large scale properties of the two or more downlink reference signals, calculating, by the UE, a channel estimate of the downlink transmission at least based on the estimated large scale properties and the properties relation information, and decoding, by the UE, the downlink channel in accordance with the channel estimate.

[00114] A second aspect, based on the first aspect, wherein the estimating the large scale properties, by the UE, includes estimating a combined frequency offset combining frequency offsets for each of the two or more TRPs.

[00115] A third aspect, based on the first aspect, wherein the determining the combined frequency offset includes determining the large scale properties of each of the two or more downlink reference signals of the two or more TRPs using the properties relation information, calculating a frequency offset for each of the two or more TRPs based on a corresponding one of the large scale properties determined for the two or more downlink reference signals, and generating the combined frequency offset based on a combination of the frequency offset for each of the two or more downlink reference signals.

[00116] A fourth aspect, based on the third aspect, further includes determining, by the UE, a set of properties relation information between the large scale properties determined for each of the two or more downlink reference signals, and reporting, by the UE, one of: the large scale properties of each of the two or more downlink reference signals or the set of properties relation information for each of the two or more downlink reference signals.

[00117] A fifth aspect, based on the first aspect, further includes receiving, at the UE, a transmission configuration indicator (TCI) state configuration that identifies the two or more downlink reference signals and a QCL type that identifies one or more large scale parameters of the large scale properties.

[00118] A sixth aspect, based on the fifth aspect, wherein the QCL type includes one of: a first QCL type identifying a Doppler shift, a Doppler spread, an average delay, and a delay spread as the one or more large scale properties, a second QCL type identifying the Doppler shift and the Doppler spread as the one or more large scale properties, a third QCL type identifying the Doppler shift and an average delay as the one or more large scale properties, or a fourth QCL type identifying a spatial reception parameter as the one or more large scale properties.

[00119] A seventh aspect based on the first aspect, wherein the properties relation information includes one or more of: a Doppler shifts relation identifying one of: a gap or scaling factor between the Doppler shift of the two or more downlink reference signals, a Doppler spreads relation identifying one of: the gap or the scaling factor between the Doppler spread of the two or more downlink reference signals, an average delay relation identifying one of: the gap or the scaling factor between the average delay of the two or more downlink reference signals, and a delay spread relation identifying one of: the gap or the scaling factor between an average spread of the average delay of the two or more downlink reference signals.

[00120] An eighth aspect, based on the first aspect, wherein the receiving the properties relation information includes one or more of: receiving an indication of the properties relation information via higher-layer signaling, receiving the indication of the properties relation information via medium access control (MAC) control element (CE) signaling, and receiving the indication of the properties relation information via downlink control indicator (DCI) signaling.

[00121] A ninth aspect, based on the eight aspect, wherein the higher-layer signaling includes one of: a radio resource control (RRC) channel state information-resource signal (CSI-RS) configuration message including estimated large scale properties associated with a set of CSI- RS, wherein the two or more downlink reference signals include the set of CSI-RS and wherein the properties relation information is determined based on a relation between the estimated large scale properties, an RRC transmission configuration indicator (TCI) state configuration message of the two or more downlink reference signals including the properties relation information associated with the two or more downlink reference signals, and the RRC TCI state configuration message including an additional field for each TCI state associated with one reference signal of the two or more downlink reference signals, wherein the additional field includes a pair-wise property relation information for each TCI state associated with each reference signal of the two or more downlink reference signals.

[00122] A tenth aspect, based on the ninth aspect, wherein the MAC-CE signaling includes an updated value for the UE to apply to one of: the estimated large scale properties received in the RRC CSI-RS configuration message, the properties relation information received in the RRC TCI state configuration message, or the pair-wise property relation information received in the RRC TCI state configuration message.

[00123] An eleventh aspect, based on the eighth aspect, wherein the DCI signaling includes: a plurality of additional special antenna port fields within a DCI antenna port table, wherein the plurality of additional special antenna port fields include the properties relation information associated with a corresponding reference sign of the two or more downlink reference signals.

[00124] A twelfth aspect, based on the first aspect, wherein the properties relation information includes one of: a coarse indication of the relationship between the large scale properties of the two or more downlink reference signals, a timing indication identifying a change of the large scale properties of the two or more downlink reference signals over time, or a look-up table of a list of property relation information entries of the two or more downlink reference signals indexed according to a positioning tag.

[00125] A thirteenth aspect, based on the twelfth aspect, wherein the look-up table is updated at a pre-defmed period.

[00126] A fourteenth aspect, based on the first aspect, wherein the downlink transmission includes one of: a downlink data channel, or a downlink control channel, and wherein the downlink transmission is configured with a single demodulation reference signal (DMRS) port.

[00127] A fifteenth aspect that may be combination of the first through the fourteenth aspects.

[00128] A sixteenth aspect may include determining, by a transmission-reception point (TRP), properties relation information identifying a relationship between large scale properties of a downlink reference signal transmitted by the TRP and one or more additional downlink reference signals transmitted by one or more neighboring TRPs, transmitting, by the TRP, the properties relation information to a served user equipment (UE), and transmitting, by the TRP, a downlink transmission including the downlink reference signal.

[00129] A seventeenth aspect, based on the sixteenth aspect, wherein the determining the properties relation information includes one of: determining the properties relation information based on one or more of: a position and a velocity of the served UE in relation to positions of the TRP and the one or more neighboring TRPs, or calculating the properties relation information based on one of: large scale properties of the reference signal and the one or more additional downlink reference signals or a set of properties relation information between the downlink reference signal and the one or more additional downlink reference signals received from one or more other served UEs neighboring the served UE.

[00130] An eighteenth aspect, based on the sixteenth aspect, further includes signaling, by the TRP, the served UE a transmission configuration indicator (TCI) state configuration that identifies the downlink reference signal and the one or more additional downlink reference signals and a quasi-co-location (QCL) type that identifies one or more large scale parameters of the large scale properties.

[00131] A nineteenth aspect, based on the eighteenth aspect, wherein the QCL type includes one of: a first QCL type identifying a Doppler shift, a Doppler spread, an average delay, and a delay spread as the one or more large scale properties, a second QCL type identifying the Doppler shift and the Doppler spread as the one or more large scale properties, a third QCL type identifying the Doppler shift and an average delay as the one or more large scale properties, or a fourth QCL type identifying a spatial reception parameter as the one or more large scale properties.

[00132] A twentieth aspect, based on the sixteenth aspect, wherein the properties relation information includes one or more of: a Doppler shifts relation identifying one of: a gap or scaling factor between the Doppler shift of the downlink reference signal and the one or more additional downlink reference signals, a Doppler spreads relation identifying one of: the gap or the scaling factor between the Doppler spread of the downlink reference signal and the one or more additional downlink reference signals, an average delay relation identifying one of: the gap or the scaling factor between the average delay of the downlink reference signal and the one or more additional downlink reference signals, and a delay spread relation identifying one of: the gap or the scaling factor between an average spread of the average delay of the downlink reference signal and the one or more additional downlink reference signals.

[00133] A twenty-first aspect, based on the sixteenth aspect, wherein the transmitting the properties relation information includes one or more of: transmitting an indication of the properties relation information via higher-layer signaling, transmitting the indication of the properties relation information via medium access control (MAC) control element (CE) signaling, and transmitting the indication of the properties relation information via downlink control indicator (DCI) signaling.

[00134] A twenty-second aspect, based on the twenty-first aspect, wherein the higher-layer signaling includes one of: a radio resource control (RRC) channel state information-resource signal (CSI-RS) configuration message including estimated large scale properties associated with a set of CSI-RS, wherein the downlink reference signal and the one or more additional downlink reference signals include the set of CSI-RS and wherein the properties relation information is determined based on a relation between the estimated large scale properties, an RRC transmission configuration indicator (TCI) state configuration message of the downlink reference signal and the one or more additional downlink reference signals including the properties relation information associated with the downlink reference signal and the one or more additional downlink reference signals, and the RRC TCI state configuration message including an additional field for each TCI state associated with one downlink reference signal of the downlink reference signal and the one or more additional downlink reference signals, wherein the additional field includes a pair-wise property relation information for each TCI state associated with each downlink reference signal of the downlink reference signal and the one or more additional downlink reference signals.

[00135] A twenty-third aspect, based on the twenty-second aspect, wherein the MAC-CE signaling includes an updated value for the UE to apply to one of: the estimated large scale properties received in the RRC CSI-RS configuration message, the properties relation information received in the RRC TCI state configuration message, or the pair-wise property relation information received in the RRC TCI state configuration message.

[00136] A twenty-fourth aspect, based on the twenty-first aspect, wherein the DCI signaling includes: a plurality of additional special antenna port fields within a DCI antenna port table, wherein the plurality of additional special antenna port fields include the properties relation information associated with a corresponding reference sign of the downlink reference signal and the one or more additional downlink reference signals.

[00137] A twenty-fifth aspect, based on the sixteenth aspect, wherein the properties relation information includes one of: a coarse indication of the relationship between the large scale properties of the downlink reference signal and the one or more additional downlink reference signals, a timing indication identifying a change of the large scale properties of the downlink reference signal and the one or more additional downlink reference signals over time, or a look up table of a list of property relation information entries of the downlink reference signal and the one or more additional downlink reference signals indexed according to a positioning tag.

[00138] A twenty-sixth aspect, based on the twenty-fifth aspect, further includes updating, by the TRP, the look-up table at a pre-defmed period.

[00139] A twenty-seventh aspect, based on the sixteenth aspect, wherein the downlink transmission includes one of: a downlink data channel, or a downlink control channel, and wherein the downlink transmission is configured with a single demodulation reference signal (DMRS) port.

[00140] A twenty-eighth aspect, based on any combination of the sixteenth through twenty- seventh aspects.

[00141] 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.

[00142] 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), floppy 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.

[00143] 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.

[00144] 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

CLAIMS WHAT IS CLAIMED IS:

1. A method of wireless communication, comprising: receiving, by a user equipment (UE), properties relation information identifying a relationship between large scale properties of two or more downlink reference signals; receiving, by the UE, the two or more downlink reference signals from two or more transmission-reception points (TRPs); receiving, by the UE, an indication comprising the two or more downlink reference signals being a quasi-co-location (QCL) source of a downlink transmission; estimating, by the UE, large scale properties of the two or more downlink reference signals; calculating, by the UE, a channel estimate of the downlink transmission at least based on the estimated large scale properties and the properties relation information; and decoding, by the UE, the downlink channel in accordance with the channel estimate.

2. The method of claim 1, wherein the estimating the large scale properties, by the UE, includes estimating a combined frequency property combining frequency properties for each of the two or more TRPs

3. The method of claim 1, wherein the determining the combined frequency property includes: determining the large scale properties of each of the two or more downlink reference signals of the two or more TRPs using the properties relation information; calculating a frequency property for each of the two or more TRPs based on a corresponding one of the large scale properties determined for the two or more downlink reference signals; generating the combined frequency property based on a combination of the frequency property for each of the two or more downlink reference signals.

4. The method of claim 3, further including: determining, by the UE, a set of properties relation information between the large scale properties determined for each of the two or more downlink reference signals; and reporting, by the UE, one of: the large scale properties of each of the two or more downlink reference signals or the set of properties relation information for each of the two or more downlink reference signals.

5. The method of claim 1, further including: receiving, at the UE, a transmission configuration indicator (TCI) state configuration that identifies the two or more downlink reference signals and a QCL type that identifies one or more large scale parameters of the large scale properties.

6. The method of claim 5, wherein the QCL type includes one of: a first QCL type identifying a Doppler shift, a Doppler spread, an average delay, and a delay spread as the one or more large scale properties; a second QCL type identifying the Doppler shift and the Doppler spread as the one or more large scale properties; a third QCL type identifying the Doppler shift and an average delay as the one or more large scale properties; or a fourth QCL type identifying a spatial reception parameter as the one or more large scale properties.

7. The method of claim 1, wherein the properties relation information includes one or more of: a Doppler shifts relation identifying one of: a gap or scaling factor between the Doppler shift of the two or more downlink reference signals; a Doppler spreads relation identifying one of: the gap or the scaling factor between the Doppler spread of the two or more downlink reference signals; an average delay relation identifying one of: the gap or the scaling factor between the average delay of the two or more downlink reference signals; and a delay spread relation identifying one of: the gap or the scaling factor between an average spread of the average delay of the two or more downlink reference signals.

8. The method of claim 1, wherein the receiving the properties relation information includes one or more of: receiving an indication of the properties relation information via higher-layer signaling; receiving the indication of the properties relation information via medium access control (MAC) control element (CE) signaling; and receiving the indication of the properties relation information via downlink control indicator (DCI) signaling.

9. The method of claim 8, wherein the higher-layer signaling includes one of: a radio resource control (RRC) channel state information-resource signal (CSI-RS) configuration message including estimated large scale properties associated with a set of CSI- RS, wherein the two or more downlink reference signals include the set of CSI-RS and wherein the properties relation information is determined based on a relation between the estimated large scale properties; an RRC transmission configuration indicator (TCI) state configuration message of the two or more downlink reference signals including the properties relation information associated with the two or more downlink reference signals; and the RRC TCI state configuration message including an additional field for each TCI state associated with one reference signal of the two or more downlink reference signals, wherein the additional field includes a pair-wise property relation information for each TCI state associated with each reference signal of the two or more downlink reference signals.

10. The method of claim 9, wherein the MAC-CE signaling includes an updated value for the UE to apply to one of: the estimated large scale properties received in the RRC CSI-RS configuration message; the properties relation information received in the RRC TCI state configuration message; or the pair-wise property relation information received in the RRC TCI state configuration message.

11. The method of claim 8, wherein the DCI signaling includes: a plurality of additional special antenna port fields within a DCI antenna port table, wherein the plurality of additional special antenna port fields include the properties relation information associated with a corresponding reference sign of the two or more downlink reference signals.

12. The method of claim 1, wherein the properties relation information includes one of: a coarse indication of the relationship between the large scale properties of the two or more downlink reference signals; a timing indication identifying a change of the large scale properties of the two or more downlink reference signals over time; or a look-up table of a list of property relation information entries of the two or more downlink reference signals indexed according to a positioning tag.

13. The method of claim 12, wherein the look-up table is updated at a pre-defmed period.

14. The method of claim 1, wherein the downlink transmission includes one of: a downlink data channel; or a downlink control channel, and wherein the downlink transmission is configured with a single demodulation reference signal (DMRS) port.

15. The method of any combination of claims 1-14.

16. A method of wireless communication, comprising: determining, by a transmission-reception point (TRP), properties relation information identifying a relationship between large scale properties of a downlink reference signal transmitted by the TRP and one or more additional downlink reference signals transmitted by one or more neighboring TRPs; transmitting, by the TRP, the properties relation information to a served user equipment (UE); and transmitting, by the TRP, a downlink transmission including the downlink reference signal.

17. The method of claim 16, wherein the determining the properties relation information includes one of: determining the properties relation information based on one or more of: a position and a velocity of the served UE in relation to positions of the TRP and the one or more neighboring TRPs; or calculating the properties relation information based on one of: large scale properties of the reference signal and the one or more additional downlink reference signals or a set of properties relation information between the downlink reference signal and the one or more additional downlink reference signals received from one or more other served UEs neighboring the served UE.

18. The method of claim 16, further including: signaling, by the TRP, the served UE a transmission configuration indicator (TCI) state configuration that identifies the downlink reference signal and the one or more additional downlink reference signals and a quasi-co-location (QCL) type that identifies one or more large scale parameters of the large scale properties.

19. The method of claim 18, wherein the QCL type includes one of: a first QCL type identifying a Doppler shift, a Doppler spread, an average delay, and a delay spread as the one or more large scale properties; a second QCL type identifying the Doppler shift and the Doppler spread as the one or more large scale properties; a third QCL type identifying the Doppler shift and an average delay as the one or more large scale properties; or a fourth QCL type identifying a spatial reception parameter as the one or more large scale properties.

20. The method of claim 16, wherein the properties relation information includes one or more of: a Doppler shifts relation identifying one of: a gap or scaling factor between the Doppler shift of the downlink reference signal and the one or more additional downlink reference signals; a Doppler spreads relation identifying one of: the gap or the scaling factor between the Doppler spread of the downlink reference signal and the one or more additional downlink reference signals; an average delay relation identifying one of: the gap or the scaling factor between the average delay of the downlink reference signal and the one or more additional downlink reference signals; and a delay spread relation identifying one of: the gap or the scaling factor between an average spread of the average delay of the downlink reference signal and the one or more additional downlink reference signals.

21. The method of claim 16, wherein the transmitting the properties relation information includes one or more of: transmitting an indication of the properties relation information via higher-layer signaling; transmitting the indication of the properties relation information via medium access control (MAC) control element (CE) signaling; and transmitting the indication of the properties relation information via downlink control indicator (DCI) signaling.

22. The method of claim 21, wherein the higher-layer signaling includes one of: a radio resource control (RRC) channel state information-resource signal (CSI-RS) configuration message including estimated large scale properties associated with a set of CSI- RS, wherein the downlink reference signal and the one or more additional downlink reference signals include the set of CSI-RS and wherein the properties relation information is determined based on a relation between the estimated large scale properties; an RRC transmission configuration indicator (TCI) state configuration message of the downlink reference signal and the one or more additional downlink reference signals including the properties relation information associated with the downlink reference signal and the one or more additional downlink reference signals; and the RRC TCI state configuration message including an additional field for each TCI state associated with one downlink reference signal of the downlink reference signal and the one or more additional downlink reference signals, wherein the additional field includes a pair-wise property relation information for each TCI state associated with each downlink reference signal of the downlink reference signal and the one or more additional downlink reference signals.

23. The method of claim 22, wherein the MAC-CE signaling includes an updated value for the UE to apply to one of: the estimated large scale properties received in the RRC CSI-RS configuration message; the properties relation information received in the RRC TCI state configuration message; or the pair-wise property relation information received in the RRC TCI state configuration message.

24. The method of claim 21, wherein the DCI signaling includes: a plurality of additional special antenna port fields within a DCI antenna port table, wherein the plurality of additional special antenna port fields include the properties relation information associated with a corresponding reference sign of the downlink reference signal and the one or more additional downlink reference signals.

25. The method of claim 16, wherein the properties relation information includes one of: a coarse indication of the relationship between the large scale properties of the downlink reference signal and the one or more additional downlink reference signals; a timing indication identifying a change of the large scale properties of the downlink reference signal and the one or more additional downlink reference signals over time; or a look-up table of a list of property relation information entries of the downlink reference signal and the one or more additional downlink reference signals indexed according to a positioning tag.

26. The method of claim 16, wherein the downlink transmission includes one of: a downlink data channel; or a downlink control channel, and wherein the downlink transmission is configured with a single demodulation reference signal (DMRS) port

27. The method of any combination of claims 16-26.

28. 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 perform each of the steps of any one of the method claims 1-27.

29. An apparatus configured for wireless communication, comprising means for implementing each of the steps of any one of the method claims 1-27.

30. A non-transitory computer-readable medium having program code recorded thereon, the program code comprising instructions executable by a processor to cause the processor to perform each of the steps of any one of the method claims 1-27.