Combined port selection for multiple transmit and receive points

Abstract

A method includes: receiving, by a user equipment (UE) device, a joint transmission of a channel state information (CSI) reference signal (CSI-RS) from a first transmit and receive point (TRP) associated with a wireless network and at least a second TRP associated with the wireless network. The method further includes: determining a joint rank parameter associated with the joint transmission, and accessing a rank-to-port mapping codebook based on the joint rank parameter to determine a port index parameter. The method further includes: after determining the port index parameter, communicating with one or more of the first TRP or the second TRP through the UE device. Other aspects and features are also claimed and described.

Description

Technical Field

[0001] In general, aspects of the present disclosure relate to wireless communication systems, and more particularly, to port selection in wireless communication systems. Certain aspects of the techniques discussed below may enable and provide joint selection of ports of multiple transmit and receive points (TRPs) of a wireless communication system. Background Art

[0002] Wireless communication networks are widely deployed to provide various types of communication services such as voice, video, packet data, messaging, broadcast, etc. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources. Such networks (usually multiple-access networks) support communications for multiple users by sharing the available network resources.

[0003] A wireless communication network may include multiple base stations or Node Bs that may support communications for multiple user devices (UEs). A UE may communicate with a base station via a downlink and an uplink. A downlink (or forward link) refers to a communication link from a base station to a UE, and an uplink (or reverse link) refers to a communication link from a UE to a base station.

[0004] The base station may send data and control information to the UE on the downlink, and / or may receive data and control information from the UE on the uplink. On the downlink, the transmission from the base station may encounter interference caused by transmissions from neighboring base stations or from other wireless radio frequency (RF) transmitters. On the uplink, the transmission from the UE may encounter interference from uplink transmissions of other UEs communicating with the neighboring base stations or from other wireless RF transmitters. This interference may degrade the performance on both the downlink and uplink.

[0005] As the demand for mobile broadband access continues to grow, the potential for interference and congested networks increases as more UEs access long-range wireless communication networks and more short-range wireless systems are deployed in communities. Research and development continues to advance wireless technologies to not only meet the growing need for mobile broadband access, but also to facilitate and enhance the user experience with wireless communications. Summary of the invention

[0006] The following summarizes some aspects of the present disclosure in order to provide a basic understanding of the technology discussed. This summary is not a general review of all expected features of the present disclosure, and is neither intended to identify key or important elements of all aspects of the present disclosure, nor is it intended to describe the scope of any or all aspects of the present disclosure. Its sole purpose is to provide some concepts of one or more aspects of the present disclosure in the form of an overview as a prelude to a more detailed description given later.

[0007] In one aspect of the present disclosure, a method includes: receiving, by a user equipment (UE) device, a joint transmission of a channel state information (CSI) reference signal (CSI-RS) from a first transmit and receive point (TRP) associated with a wireless network and at least a second TRP associated with the wireless network. The method further includes: determining a joint rank parameter associated with the joint transmission, and accessing a rank-to-port mapping codebook based on the joint rank parameter to determine a port index parameter. The method further includes: after determining the port index parameter, communicating with one or more of the first TRP or the second TRP through the UE device.

[0008] In an additional aspect of the present disclosure, a method includes: sending, by a first transmit and receive point (TRP) associated with a wireless network, a first channel state information (CSI) report configuration message including a rank-to-port mapping codebook. The method further includes: sending, by the first TRP, a CSI reference signal (CSI-RS). The method further includes: receiving a CSI report message from a user equipment (UE) device in response to sending the CSI-RS and the CSI report configuration message. The method further includes: determining a joint selection of ports of a first TRP and a second TRP associated with the wireless network based on the CSI report message.

[0009] In an additional aspect of the present disclosure, a non-temporary computer-readable medium has a program code recorded thereon. The program code includes a program code executable by a computer for causing a computer to receive a joint transmission of a channel state information (CSI) reference signal (CSI-RS) from a first transmit and receive point (TRP) associated with a wireless network and at least a second TRP associated with the wireless network at a user equipment (UE) device. The program code further includes a program code executable by a computer for causing a computer to determine a joint rank parameter associated with the joint transmission. The program code further includes a program code executable by a computer for causing a computer to access a rank-to-port mapping codebook based on the joint rank parameter to determine a port index parameter. The program code further includes a program code executable by a computer for causing a computer to communicate with one or more of the first TRP or the second TRP after determining the port index parameter.

[0010] In an additional aspect of the present disclosure, a non-temporary computer-readable medium has a program code recorded thereon. The program code includes: a program code executable by a computer for causing a computer to send a first channel state information (CSI) report configuration message including a rank-to-port mapping codebook through a first transmission and reception point (TRP) associated with a wireless network. The program code further includes: a program code executable by a computer for causing a computer to send a CSI reference signal (CSI-RS) through a first TRP. The program code further includes: a program code executable by a computer for causing a computer to receive a CSI report message from a user equipment (UE) device in response to sending a CSI-RS and a CSI report configuration message. The program code further includes: a program code executable by a computer for causing a computer to determine a joint selection of ports of a first TRP and a second TRP associated with a wireless network based on a CSI report message.

[0011] In an additional aspect of the present disclosure, a device configured for wireless communication is disclosed. The device includes: at least one processor, and a memory coupled to the processor. The processor is configured to receive a joint transmission of a channel state information (CSI) reference signal (CSI-RS) from a first transmit and receive point (TRP) associated with a wireless network and at least a second TRP associated with the wireless network through a user equipment (UE) device. The processor is further configured to determine a joint rank parameter associated with the joint transmission and access a rank-to-port mapping codebook based on the joint rank parameter to determine a port index parameter. The processor is further configured to communicate with one or more of the first TRP or the second TRP after determining the port index parameter.

[0012] In an additional aspect of the present disclosure, a device configured for wireless communication is disclosed. The device includes: at least one processor, and a memory coupled to the processor. The processor is configured to send a first channel state information (CSI) report configuration message including a rank-to-port mapping codebook through a first transmit and receive point (TRP) associated with a wireless network. The processor is further configured to send a CSI reference signal (CSI-RS) through the first TRP. The processor is further configured to receive a CSI report message from a user equipment (UE) device in response to sending the CSI-RS and the CSI report configuration message. The processor is further configured to determine a joint selection of ports of a first TRP and a second TRP associated with the wireless network based on the CSI report message.

[0013] In an additional aspect of the present disclosure, a device configured for wireless communication is disclosed. The device includes: a unit for receiving a joint transmission of a channel state information (CSI) reference signal (CSI-RS) from a first transmit and receive point (TRP) associated with a wireless network and at least a second TRP associated with the wireless network by a user equipment (UE) device. The device further includes: a unit for determining a joint rank parameter associated with the joint transmission and a unit for accessing a rank-to-port mapping codebook based on the joint rank parameter to determine a port index parameter. The device further includes: a unit for communicating with one or more of the first TRP or the second TRP after determining the port index parameter.

[0014] In an additional aspect of the present disclosure, a device configured for wireless communication is disclosed. The device includes: a first channel state information (CSI) report configuration message including a rank-to-port mapping codebook is sent through a first transmit and receive point (TRP) associated with a wireless network, and a unit for sending a CSI reference signal (CSI-RS) through the first TRP. The device further includes: a unit for receiving a CSI report message from a user equipment (UE) device in response to sending the CSI-RS and the CSI report configuration message. The device further includes: a unit for determining a joint selection of ports of a first TRP and a second TRP associated with the wireless network based on the CSI report message.

[0015] After reading the following description of specific exemplary embodiments in conjunction with the accompanying drawings, other aspects, features and embodiments will become apparent to those of ordinary skill in the art. Although features may be discussed with respect to certain embodiments and drawings below, all embodiments may include one or more of the advantageous features discussed herein. In other words, although one or more embodiments may be discussed as having certain advantageous features, one or more of such features may also be used according to various embodiments. Similarly, although exemplary embodiments are discussed below as device, system or method embodiments, these exemplary embodiments may be implemented in various devices, systems and methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] A further understanding of the nature and advantages of the present disclosure may be achieved by reference to the following drawings. In the drawings, similar components or features may have the same reference numerals. Further, individual components of the same type may be distinguished by following the reference numeral with a dash and a second reference numeral that distinguishes the similar components. If only the first reference numeral is used in the specification, the description applies to any of the similar components having the same first reference numeral, regardless of the second reference numeral.

[0017] Figure 1 is a block diagram illustrating details of a wireless communication system configured for joint port selection using multiple transmit and receive points (TRPs) in accordance with some aspects of the present disclosure.

[0018] Figure 2 is a block diagram illustrating a design of a base station and a UE configured to perform joint port selection using multiple TRPs according to some aspects of the present disclosure.

[0019] Figure 3 is a block diagram illustrating an example of a wireless communication system configured for joint port selection using multiple TRPs according to some aspects of the present disclosure.

[0020] Figure 4 is a block diagram of an example of a joint transmission that can be sent using a TRP of a wireless communication system in accordance with some aspects of the present disclosure.

[0021] Figure 5 is a block diagram of another example of a joint transmission that can be sent using a TRP of a wireless communication system in accordance with some aspects of the present disclosure.

[0022] Figure 6 is an example of a rank-to-port mapping codebook according to some aspects of the present disclosure and that can be sent and used within a wireless communication system.

[0023] Figure 7 is another example of a rank-to-port mapping codebook according to some aspects of the present disclosure and that can be sent and used within a wireless communication system.

[0024] Figure 8 is a diagram illustrating some examples of operations that may be performed within a wireless communication system in accordance with some aspects of the present disclosure.

[0025] Fig. 9 is a flow chart of a method of wireless communication that may be performed by a user equipment (UE) device of a wireless communication system according to some aspects of the present disclosure.

[0026] Fig.10 is a flow chart of a method of wireless communication that may be performed by a base station of a wireless communication system according to some aspects of the present disclosure.

[0027] Fig.11 is a block diagram conceptually illustrating a design of a UE configured to perform port selection using multiple TRPs in accordance with some aspects of the present disclosure.

[0028] Fig.12is a block diagram conceptually illustrating a design of a base station configured to perform port selection using multiple TRPs in accordance with some aspects of the present disclosure.

[0029] The appendices provide further details on various aspects of the disclosure and the subject matter therein constitutes a part of the specification of this application. DETAILED DESCRIPTION

[0030] The detailed description set forth below in conjunction with the accompanying drawings and appendices is intended as a description of various configurations and is not intended to limit the scope of the present disclosure. On the contrary, the detailed description includes specific details in order to provide a thorough understanding of the subject matter of the invention. It will be apparent to those skilled in the art that these specific details are not required in every case, and in some instances, well-known structures and components are shown in block diagram form for clarity of presentation.

[0031] In some wireless communication systems, multiple transmit and receive points (TRPs) are used. For example, a particular base station or cell may include multiple TRPs that transmit signals to one or more user equipment (UE) devices and receive signals from one or more UE devices. The TRPs may be geographically distributed throughout the cell area to improve the coverage associated with the base station. The use of multiple TRPs may improve system performance by improving the reliability and coverage of UE devices.

[0032] The use of multiple TRPs may result in increased power consumption in some wireless communication systems. For example, as the number of TRPs in a cell increases, the amount of power used to generate and amplify the transmitted signal may also increase. Further, in some cases, the use of multiple TRPs may include increasing the amount of processing of received signals, which may also increase power consumption. In addition, the use of multiple TRPs may increase the number of signals present in the wireless communication system, which may result in increased noise or interference in some cases. In some networks, such as some 5th generation (5G) or new radio (NR) networks, the number of TRPs in a cell may be relatively large, which may involve a large amount of signal amplification, transmission, processing, and other operations.

[0033] According to one aspect of the present disclosure, certain port selection operations are performed on a joint basis for multiple TRPs. Performing port selection operations on a joint basis can reduce the number of signals sent within a wireless communication network compared to certain conventional techniques, such as techniques in which port selection operations are performed individually for each of the multiple TRPs.

[0034] For example, a rank-to-port mapping codebook may be used by a UE device and by a base station communicating with the UE device using multiple TRPs. The UE device may determine a rank parameter (RI) associated with communication with the base station (e.g., by determining the number of spatial streams received from the multiple TRPs). The UE device may provide the RI to the base station, such as by sending a channel state information (CSI) report message to the base station to indicate the RI.

[0035] In some examples, the RI is used to perform a lookup operation on a rank-to-port mapping codebook for selection of ports of multiple TRPs. For example, for multiple values ​​of the RI, the rank-to-port mapping codebook may indicate corresponding selections of ports of multiple TRPs. After port selection, one or more ports may be used for communication between a UE device and a base station, such as by using a port to send a non-coherent joint transmission (NCJT) of a CSI reference signal (CSI-RS).

[0036] The joint port selection described herein can improve communication efficiency in a communication system. For example, by using a single RI to select ports of multiple TRPs, the number of messages sent within a wireless communication network is reduced, compared to other techniques that use multiple messages to individually select ports of multiple TRPs. As a result, power consumption, noise, and interference can be reduced.

[0037] To further illustrate, in general, the present disclosure relates to providing or participating in communication between two or more wireless devices in one or more wireless communication systems (also referred to as wireless communication networks). In various embodiments, the techniques and apparatus can 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, 5th generation (5G) or new radio (NR) networks (sometimes referred to as "5G NR" networks / systems / devices), and other communication networks. As described herein, the terms "network" and "system" can be used interchangeably.

[0038] For example, a CDMA network may implement a radio technology such as Universal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includes Wideband-CDMA (W-CDMA) and Low Chip Rate (LCR). CDMA2000 covers IS-2000, IS-95, and IS-856 standards.

[0039] TDMA networks can, for example, implement radio technologies such as GSM. 3GPP defines standards for GSM EDGE (Enhanced Data Rate GSM Evolution) radio access networks (RANs) (also denoted as GERAN). GERAN, and networks connecting base stations (e.g., Ater and Abis interfaces) with base station controllers (A interfaces, etc.) are the radio components of GSM / EDGE. The radio access network represents a component of the GSM network, through which calls and packet data are routed from the public switched telephone network (PSTN) and the Internet to user mobile phones (also referred to as user terminals or user equipment (UE)) and from user mobile phones to the PSTN and the Internet. The network of a mobile phone operator may include one or more GERANs, and in the case of a UMTS / GSM network, the operator's network may be coupled to a universal terrestrial radio access network (UTRAN). The operator network may also include one or more LTE networks, and / or one or more other networks. Various network types may use different radio access technologies (RATs) and radio access networks (RANs).

[0040] OFDMA networks can implement radio technologies such as Evolved UTRA (E-UTRA), IEEE 802.11, IEEE 802.16, IEEE802.20, flash-OFDM, etc. UTRA, E-UTRA, and Global System for Mobile Communications (GSM) are part of Universal Mobile Telecommunications System (UMTS). Specifically, Long Term Evolution (LTE) is a version of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS, and LTE are described in documents 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 all known or under development. For example, the 3rd Generation Partnership Project (3GPP) is a collaboration between telecommunications association groups to define globally applicable third generation (3G) mobile phone specifications. 3GPP Long Term Evolution (LTE) is a 3GPP plan to improve the Universal Mobile Telecommunications System (UMTS) mobile phone standard. 3GPP may define specifications for next generation mobile networks, mobile systems, and mobile devices. The present disclosure is about the evolution of wireless technology from LTE, 4G, 5G, NR and higher generations in terms of shared access to wireless spectrum between networks employing some new and different radio access technologies or radio air interfaces.

[0041] 5G networks are expected to enable diverse deployments, diverse spectrum, and diverse services and devices using a unified OFDM-based air interface. To achieve these goals, in addition to developing new radio technologies for 5G NR networks, further enhancements to LTE and LTE-A are also being considered. 5G NR will be able to scale to provide coverage for: (1) the massive Internet of Things (IoT) with ultra-high density (e.g., ~1M nodes / km2), ultra-low complexity (e.g., ~10s of bits / second), ultra-low energy (e.g., ~10+ years of battery life), and deep coverage with the ability to reach challenging locations; (2) mission-critical controls including strong security to protect sensitive personal, financial, or classified information, ultra-high reliability (e.g., ~99.9999% reliability), ultra-low latency (e.g., ~1ms), and users with wide mobility range or lack of mobility range; and (3) deep awareness with enhanced mobile broadband, including extremely high capacity (e.g., ~10Tbps / km2), extreme data rates (e.g., multi-Gbps rates, 100+Mbp user experience rates), and advanced discovery and optimization.

[0042] 5G NR devices, networks, and systems can be implemented to use optimized OFDM-based waveform features. These features can include scalable digital schemes and transmission time intervals (TTIs); a common, flexible framework to efficiently multiplex services and features through dynamic, low-latency time division duplex (TDD) / frequency division duplex (FDD) designs; and advanced wireless technologies such as massive multiple-input multiple-output (MIMO), robust millimeter wave (mmWave) transmission, advanced channel coding, and device-centric mobility. The scalability of the digital scheme in 5G NR can efficiently handle diverse services in diverse spectrums and diverse deployments by adopting scaling of subcarrier spacing. For example, in various outdoor and macro coverage deployments of FDD / TDD implementations below 3GHz, a subcarrier spacing of 15kHz can be adopted on bandwidths such as 1, 5, 10, 20MHz, and the like. For other various outdoor and small cell coverage deployments of TDD above 3GHz, a subcarrier spacing of 30kHz can appear on 80 / 100MHz bandwidth. For various other indoor broadband implementations, this can occur with 60kHz subcarrier spacing over 160MHz bandwidth using TDD on the unlicensed portion of the 5GHz bandwidth. Finally, for various deployments transmitting via mmWave components at 28GHz TDD, this can occur with 120kHz subcarrier spacing over 500MHz bandwidth.

[0043] 5G NR's scalable digital scheme facilitates scalable TTI for diverse latency and quality of service (QoS) requirements. For example, shorter TTIs can be used for low latency and high reliability, while longer TTIs can be used for higher spectral efficiency. Efficient multiplexing of long TTIs and short TTIs allows transmissions to start on symbol boundaries. 5G NR also anticipates a self-contained integrated subframe design with uplink / downlink scheduling information, data, and acknowledgment in the same subframe. The self-contained integrated subframe supports communications in unlicensed or contention-based shared spectrum, and can be flexibly configured on a cell-by-cell basis to dynamically switch between uplink and downlink to meet current business needs. Adaptive uplink / downlink.

[0044] For clarity, certain aspects of the apparatus and techniques may be described below with reference to exemplary LTE implementations or in an LTE-centric manner, and in portions of the description below, LTE terminology may be used as an illustrative example; however, the description is not intended to be limited to LTE applications. In fact, the present disclosure relates to shared access to wireless spectrum between networks employing different radio access technologies or radio air interfaces (such as the radio access technologies or radio air interfaces of 5G NR).

[0045] Furthermore, it should be understood that in operation, a wireless communication network adapted in accordance with the concepts herein may operate using any combination of licensed or unlicensed spectrum (depending on load and availability). Thus, it will be apparent to those skilled in the art that the systems, apparatuses, and methods described herein may be applied to other communication systems and applications beyond the specific examples provided.

[0046] Although various aspects and embodiments are described in this application by illustrations of some examples, it will be understood by those skilled in the art that additional implementations and use cases will be generated in many other arrangements and scenarios. The innovations described herein can be implemented across many different platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, embodiments and / or uses can be generated via integrated chip embodiments and / or other devices based on non-module components (such as, end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail / purchasing equipment, medical devices, AI-enabled devices, etc.). Although some examples may be specifically for use cases or applications or may not be specifically for use cases or applications, a variety of applicability of the innovations may also occur. The range of implementations can range from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregated, distributed or OEM devices or systems incorporating one or more of the aspects. In some practical settings, the devices incorporating the aspects and features may also necessarily include additional components and features for the implementations and practices of the claimed and described embodiments. It is intended that the innovations described herein may be practiced in a wide variety of implementations, including large / small devices of varying sizes, shapes, and compositions, chip-level components, multi-component systems (e.g., RF chains, communication interfaces, processors), distributed arrangements, end-user devices, etc.

[0047] Figure 1 A wireless network 100 for joint port selection between multiple TRPs according to some embodiments is shown. The wireless network 100 may, for example, include a 5G wireless network. As will be appreciated by those skilled in the art, Figure 1 Components appearing in are likely to have related corresponding components in other network arrangements, including, for example, cellular-style network arrangements and non-cellular-style network arrangements (eg, device-to-device or peer-to-peer or ad hoc network arrangements, etc.).

[0048] Figure 1The wireless network 100 shown in includes a plurality of base stations 105 and other network entities. A base station may be a station communicating with a UE, and may also be referred to as an evolved Node B (eNB), a next generation eNB (gNB), an access point, etc. Each base station 105 may provide communication coverage for a specific geographical area. In 3GPP, the term "cell" may refer to the specific geographical coverage area of ​​a base station and / or a base station subsystem serving the coverage area, depending on the context in which the term is used. In the implementation of the wireless network 100 herein, the base station 105 may be associated with the same operator or different operators (e.g., the wireless network 100 may include multiple operating line wireless networks), and may provide wireless communications using one or more of the same frequencies (e.g., one or more frequency bands in a licensed spectrum, an unlicensed spectrum, or a combination thereof) as neighboring cells. In some examples, a separate base station 105 or UE 115 may be operated by more than one network operating entity. In other examples, each base station 105 or UE 115 may be operated by a single network operating entity.

[0049] A base station may provide communication coverage for a macro cell or a small cell (e.g., a pico cell or a femto cell) and / or other types of cells. A macro cell generally covers a relatively large geographic area (e.g., a radius of several kilometers) and may allow unrestricted access by a UE with a service subscription with a network provider. A small cell, such as a pico cell, generally covers a relatively small geographic area and may allow unrestricted access by a UE with a service subscription with a network provider. A small cell, such as a femto cell, generally also covers a relatively small geographic area (e.g., a residence) and, in addition to unrestricted access, may also provide restricted access by UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs for users in a residence, etc.). A base station for a macro cell may be referred to as a macro base station. A base station for a small cell may be referred to as a small cell base station, a pico base station, a femto base station, or a home base station. In Figure 1 In the example shown, base stations 105d and 105e are conventional macro base stations, while base stations 105a-105c are macro base stations with one of three-dimensional (3D), full-dimensional (FD), or massive MIMO. Base stations 105a-105c utilize their higher-dimensional MIMO capabilities to utilize 3D beamforming in elevation and azimuth beamforming to improve coverage and capacity. Base station 105f is a small cell base station, which can be a home node or a portable access point. The base station can support one or more (e.g., 2, 3, 4, etc.) cells.

[0050] Wireless network 100 may support synchronous or asynchronous operation. For synchronous operation, base stations may have similar frame timing, and transmissions from different base stations may be approximately aligned in time. For asynchronous operation, base stations may have different frame timing, and transmissions from different base stations may not be aligned in time. In some cases, the network may be enabled or configured to handle dynamic switching between synchronous or asynchronous operation.

[0051] UE 115 is distributed throughout the wireless network 100, and each UE can be stationary or mobile. It should be appreciated that although mobile devices are generally referred to as user equipment (UE) in the standards and specifications issued by the 3rd Generation Partnership Project (3GPP), such devices may also be referred to as mobile stations (MS), user stations, mobile units, user units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile user stations, access terminals (AT), mobile terminals, wireless terminals, remote terminals, mobile phones, terminals, user agents, mobile clients, clients or some other suitable terms by those skilled in the art. In this document, a "mobile" device or UE does not necessarily need to have the ability to move, and may be fixed. Some non-limiting examples of mobile devices, such as embodiments that may include one or more UE 115, include mobile, cellular phones, smart phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, laptop computers, personal computers (PCs), notebooks, netbooks, smart books, tablet computers, and personal digital assistants (PDAs). The mobile device may also be an "Internet of Things" (IoT) or "Internet of Everything" (IoE) device, such as a car or other transportation vehicle, a satellite radio, a global positioning system (GPS) device, a logic controller, a drone, a multi-rotor helicopter, a quad-rotor helicopter, a smart energy or security device, a solar panel or solar array, municipal lighting, water or other infrastructure; industrial automation and enterprise equipment; consumer and wearable devices, such as glasses, wearable cameras, smart watches, health or fitness trackers, mammal implants, gesture tracking devices, medical devices, digital audio players (e.g., MP3 players), cameras, game controllers, etc.; and digital home or smart home devices, such as home audio, video and multimedia devices, home appliances, sensors, vending machines, smart lighting, home security systems, smart meters, etc. In one aspect, the UE may be a device including a universal integrated circuit card (UICC). In another aspect, the UE may be a device that does not include a UICC. In some aspects, a UE that does not include a UICC may also be referred to as an IoE device. Figure 1The UEs 115a-115d of the embodiment shown in the figure are examples of mobile smart phone type devices accessing the wireless network 100. The UE may also be a machine specifically configured for connected communications (including machine type communications (MTC), enhanced MTC (eMTC), narrowband IoT (NB-IoT), etc.). Figure 1 The UEs 115e-115k shown in FIG. 1 are examples of various machines configured for communication that access the wireless network 100.

[0052] A mobile device, such as UE 115, may be able to communicate with any type of base station, whether macro, pico, femto, repeater, etc. Figure 1 In the present invention, lightning (e.g., communication link) indicates wireless transmission between the UE and the serving base station (the serving base station is a base station designated to serve the UE on the downlink and / or uplink), or expected transmission between base stations, and backhaul transmission between base stations. Backhaul transmission between base stations of the wireless network 100 can occur when using wired and / or wireless communication links.

[0053] In operation, at the wireless network 100, base stations 105a-105c use 3D beamforming and collaborative spatial techniques (e.g., coordinated multipoint (CoMP) or multi-connectivity) to serve UEs 115a and 115b. Macro base station 105d performs backhaul communications with base stations 105a-105c and small cell base station 105f. Macro base station 105d also sends multicast services, which are subscribed to and received by UEs 115c and 115d. Such multicast services may include mobile TV or streaming video, or may include other services for providing community information, such as weather emergencies or alerts (e.g., Amber Alerts or Gray Alerts).

[0054] The wireless network 100 of an embodiment supports mission-critical communications through ultra-reliable and redundant links for mission-critical devices such as UE 115e (which is a drone). The redundant communication links with UE 115e include from macro base stations 105d and 105e, and small cell base station 105f. Other machine-type devices, such as UE 115f (thermometer), UE 115g (smart meter), and UE 115h (wearable device) can communicate directly with base stations (such as small cell base station 105f and macro base station 105e) through the wireless network 100, or in a multi-hop configuration by communicating with another user device that relays its information to the network, for example, UE 115f transmits temperature measurement information to smart meter UE 115g, and then UE 115g reports it to the network through small cell base station 105f. The wireless network 100 may also provide additional network efficiency through dynamic, low-latency TDD / FDD communications, such as in a vehicle-to-vehicle (V2V) mesh network between UEs 115i-115k communicating with a macro base station 105e.

[0055] Figure 2 A block diagram shows a design of a base station 105 and a UE 115, which may be Figure 1 For a restricted association scenario (as described above), base station 105 may be any one of the base stations in the UE and one of the UEs. Figure 1 The small cell base station 105f in the example of FIG. 105 is a small cell base station 105f, and the UE 115 may be a UE 115c or 115D operating in the service area of ​​the base station 105f. In order to access the small cell base station 105f, the UE 115 is included in the list of accessible UEs of the small cell base station 105f. The base station 105 may also be some other type of base station. Figure 2 As shown in FIG. 1 , the base station 105 may be equipped with antennas 234a through 234t and the UE 115 may be equipped with antennas 252a through 252r for facilitating wireless communication.

[0056] At the base station 105, the transmit processor 220 may receive data from the data source 212 and control information from the controller / processor 240. The control information may be for a physical broadcast channel (PBCH), a physical control format indicator channel (PCFICH), a physical hybrid-ARQ (automatic repeat request) indicator channel (PHICH), a physical downlink control channel (PDCCH), an enhanced physical downlink control channel (EPDCCH), an MTC physical downlink control channel (MPDCCH), etc. The data may be for a PDSCH, etc. The transmit processor 220 may process (e.g., encode and symbol map) the data and the control information to obtain data symbols and control symbols, respectively. The transmit processor 220 may also generate reference symbols, such as for a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a cell-specific reference signal. If applicable, the transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on ​​the data symbols, control symbols, and / or reference symbols, and may provide output symbol streams to modulators (MODs) 232a to 232t. Each modulator 232 may process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 may additionally or alternatively process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. The downlink signals from modulators 232a to 232t may be transmitted via antennas 234a to 234t, respectively.

[0057] At the UE 115, antennas 252a to 252r may receive downlink signals from the base station 105 and may provide received signals to demodulators (DEMODs) 254a to 254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) the respective received signals 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 the demodulators 254a to 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.

[0058] On the uplink, at the UE 115, a transmit processor 264 may receive and process data from a data source 262 (e.g., for a physical uplink shared channel (PUSCH)) and control information from a controller / processor 280 (e.g., for a physical uplink control channel (PUCCH)). 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 modulators 232a through 232t (e.g., for SC-FDM, etc.), and transmitted to the base station 105. At the base station 105, the uplink signal from the UE 115 may be received by the antenna 234, processed by the demodulator 254, detected by the MIMO detector 236 (if applicable), and further processed by the receive processor 238 to obtain decoded data and control information transmitted by the UE 115. Processor 238 may provide decoded data to data sink 239 and decoded control information to controller / processor 240 .

[0059] 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 and / or the controller / processor 28 and / or other processors or modules at the UE 115 may perform or direct the execution of various processes for the techniques described herein (e.g., to perform or direct the execution of various processes). Fig. 9 10), and / or execution of other processes for the techniques described herein. Memories 242 and 282 may store data and program codes for base station 105 and UE 115, respectively. Scheduler 244 may schedule UEs for data transmission on the downlink and / or uplink.

[0060] Wireless communication systems operated by different network operating entities (e.g., network operators) may share spectrum. In some instances, a network operating entity may be configured to use the entire designated shared spectrum for at least one time period before another network operating entity uses the entire designated shared spectrum for a different time period. Thus, to allow network operating entities to use the entire designated shared spectrum and to reduce interfering communications between different network operating entities, certain resources (e.g., time) may be divided and allocated to different network operating entities for specific types of communications.

[0061] For example, a network operating entity may be allocated specific time resources reserved for dedicated communications by network operating entities using the entire shared spectrum. A network operating entity may also be allocated other time resources where an 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 to any network operator for use on an opportunistic basis.

[0062] Access to the shared spectrum and arbitration of time resources between different network operating entities can be centrally controlled by a separate entity, autonomously determined through a predetermined arbitration scheme, or dynamically determined based on interactions between wireless nodes of the network operator.

[0063] In some cases, the UE 115 and the base station 105 may operate in a shared radio frequency band, which may include a licensed or unlicensed (e.g., contention-based) spectrum. In the unlicensed frequency portion of the shared radio frequency band, the UE 115 or the base station 105 may traditionally perform a medium sensing process to compete for access to the spectrum. For example, the UE 115 or the base station 105 may perform a listen-before-talk (LBT) process (e.g., clear channel assessment (CCA)) before communicating to determine whether the shared channel is available. CCA may include an energy detection process to determine whether there are any other active transmissions. For example, the device may infer that a change in the received signal strength indicator (RSSI) of the power meter indicates that the channel is occupied. Specifically, a signal power concentrated in a certain bandwidth and exceeding a predetermined noise floor may indicate another wireless transmitter. CCA may also include detection of a specific sequence indicating channel use. For example, another device may send a specific preamble before sending a data sequence. In some cases, the LBT process may include the wireless node adjusting its own backoff window based on the amount of energy detected on the channel and / or acknowledgement / negative acknowledgement (ACK / NACK) feedback for its own transmitted packets (as a proxy for collisions).

[0064] Figure 3 is a block diagram of an exemplary wireless communication system 300 that performs joint port selection for multiple transmit and receive points (TRPs). In some examples, the wireless communication system 300 may implement Figure 1 1. For example, the wireless communication system 300 may include a base station 105. As another example, the base station 105 may include a UE 115. Figure 3 One UE and one base station are shown in FIG. 3 , but in other implementations, the wireless communication system 300 may include multiple UEs 115 , multiple base stations 105 , or both.

[0065] Figure 3 The base station 105 is shown to include a controller 302 (e.g., controller / processor 240) and a multipoint network 320 including a first TRP 322 and at least a second TRP 324. The controller 302 is coupled to the first TRP 322 and to the second TRP 324. Figure 3 The example shows two TRPs 322, 324, but in other implementations, the multipoint network 320 may include more than 2 TRPs.

[0066] Figure 3 UE 115 is also shown to include a processor 362 and a memory 368. Processor 362 is coupled to memory 368. In some examples, processor 362 corresponds to controller / processor 280, and memory 368 corresponds to memory 282. Processor 362 can be configured to retrieve instructions 364 from memory 368 and execute instructions 364 to perform, initiate, or control one or more operations described herein. Similarly, controller 302 can include a memory storing instructions and a processor configured to execute instructions to perform, initiate, or control one or more operations described herein.

[0067] During operation, the base station may communicate with the UE 115 using the multipoint network 320. For example, each TRP 322, 324 may transmit one or more spatial streams (also referred to herein as layers) using one or more ports. As used herein, a port may refer to an antenna port, which may be a virtual antenna or a logical antenna (rather than a physical antenna). For example, in Figure 3 In the non-limiting example of , the first TRP 322 includes ports P0, P1, P2, and P3. Figure 3 The example also shows that the second TRP 324 includes ports P4, P5, P6, and P7. In other examples, a different number of ports may be implemented.

[0068] The UE 115 may be configured to determine a rank parameter associated with spatial streams received from the first TRP 322, the second TRP 324, or both. For example, the UE 115 may be configured to determine a first rank parameter indicating a first number of spatial streams received from the first TRP 322. As another example, the UE 115 may be configured to determine a second rank parameter indicating a second number of spatial streams received from the second TRP 324. As an additional example, the UE 115 may be configured to determine a joint rank parameter indicating a combined number of spatial streams received from the first TRP 322 and the second TRP 324.

[0069] The base station 105 is configured to receive or determine a rank-to-port mapping codebook 304. The rank-to-port mapping codebook 304 may also be referred to as a port-to-rank mapping codebook. The rank-to-port mapping codebook 304 indicates a mapping of ports of TRPs 322, 324 to rank parameters. The rank-to-port mapping codebook 304 may indicate a single TRP parameter 306 (e.g., for communication, where one of the first TRP 322 or the second TRP 324 is used to communicate with the UE 115). For example, the single TRP parameter 306 may include a representative rank parameter 308 and a representative port index parameter 310. The rank-to-port mapping codebook 304 includes multiple TRP parameters 312 (e.g., for communication, where both the first TRP 322 and the second TRP 324 are used to communicate with the UE 115). For example, the multiple TRP parameters 312 may include a representative joint rank parameter 314 and a representative port index parameter 316.

[0070] The base station 105 may provide the rank-to-port mapping codebook 304 to the UE 115. In one example, the base station 105 sends a channel state information (CSI) report configuration message 330 including the rank-to-port mapping codebook 304 to the UE 115. In some examples, after receiving the rank-to-port mapping codebook 304 from the base station 105, the UE 115 stores the rank-to-port mapping codebook 304 to the memory 368.

[0071] In some examples, the rank-to-port mapping codebook 304 is specific to a particular base station 105. For example, in some implementations, Figure 1 Each base station 105 shown in FIG. 1 is associated with a respective rank-to-port mapping codebook 304, which is provided to a UE device such as UE 115. In another example, the rank-to-port mapping codebook 304 may be associated with multiple base stations 105.

[0072] UE 115 is configured to communicate data with base station 105 based on CSI report configuration message 330 and rank-to-port mapping codebook 304. To illustrate, CSI report configuration message 330 may specify one or more operations performed by UE 115 related to generating CSI report message 350.

[0073] In one example, the UE 115 is configured to receive one or more CSI reference signals (CSI-RS) from the base station 105. For example, the first TRP 322 and the second TRP 324 may transmit a joint transmission 340, which includes a first CSI-RS 342 transmitted by the first TRP 322 and further includes a second CSI-RS 344 transmitted by the second TRP 324. The joint transmission 340 may correspond to a non-coherent joint transmission (NCJT) (e.g., where the first CSI-RS 342 is or may be non-coherent with respect to the second CSI-RS 344).

[0074] The UE 115 may be configured to determine CSI data 366 based on the first CSI-RS 342 and the second CSI-RS 344. In one example, the UE 115 is configured to determine a joint rank parameter related to the joint transmission 340, such as the joint rank parameter 314. The joint rank parameter 314 may indicate a first number of spatial streams received from the first TRP 322, a second number of spatial streams received from the second TRP 324, and a combined number of spatial streams received from the multipoint network 320 via the joint transmission 340.

[0075] The UE 115 may be configured to access the rank-to-port mapping codebook 304 based on the joint rank parameter 314 to determine a port index parameter, such as the port index parameter 316. For example, the processor 362 may be configured to perform a lookup operation on the rank-to-port mapping codebook 304 based on the joint rank parameter 314 to identify the port index parameter 316.

[0076] The port index parameter 316 may indicate the configuration of the ports of the multipoint network 320. For example, the port index parameter 316 may indicate one or more of the ports P0, P1, P2, and P3 of the first TRP 322, and may further indicate one or more of the ports P4, P5, P6, and P7 of the second TRP 324.

[0077] UE 115 is configured to communicate with base station 105 based on joint rank parameter 314 and based on port index parameter 316. For example, UE 115 may send a CSI report message 350 to base station 105, and CSI report message 350 includes a rank indicator (RI) 352 corresponding to or based on joint rank parameter 314. For example, joint rank parameter 314 may include an RI 352 for each TRP (e.g., one RI 352 for a single TRP mode, two RIs 352 for two TRP modes, etc.). In some examples, CSI report message 350 includes CSI-RS resource indicator (CRI) 354.

[0078] The RI 352 may indicate the selection of one or more of the ports P0-P7 by the base station 105 or may be used by the base station 105 to determine. For example, the UE 115 may provide the RI 352 to the TRPs 322, 324 using the CSI report message 350, and the base station 105 may perform a lookup operation (e.g., to identify the port indicated by the port index parameter 316) based on the RI 352. Providing the RI 352 and the CRI 354 to the base station 105 to indicate the selection of the ports of the TRPs 322, 324 may be referred to as a multi-TRP port selection operation.

[0079] In some examples, the base station 105 sends one or more signals to the UE 115 using the selected port. For example, the base station 105 can tune the transmitter based on the selected port to initiate a multi-TRP beamforming operation. The multi-TRP beamforming operation can include selectively activating a TRP (or antenna elements of one or more TRPs) to send one or more beams in a specific direction toward the UE 115. The one or more beams can include certain signals (such as CSI-RS 342, 344), one or more other signals (e.g., data signals), or a combination thereof. In some examples, the selected port is associated with a specific precoder, a specific beam pattern, or a combination thereof.

[0080] As another example, the UE 115 may use the port index parameter 316 to determine one or more parameters for communicating with the base station 105, such as by tuning a receiver to receive a signal (e.g., a CSI-RS 342, 344 or other signal) from a TRP 322, 324 based on the port indicated by the port index parameter 316. As another example, a particular port may be associated with a beam having a particular directivity, and the UE 115 may selectively activate an antenna element of the UE 115 to receive the beam.

[0081] Reference Figure 3 One or more aspects described can improve communication efficiency in a communication system. For example, by using a single RI to select ports of multiple TRPs, the number of messages sent within a wireless communication network is reduced, compared to other techniques that use multiple messages to individually select ports of multiple TRPs. As a result, power consumption, noise, and interference can all be reduced.

[0082] Figure 4 A first example of a joint transmission 340 is shown. Figure 4In the example of , a first CSI-RS 342 transmitted by a first TRP 322 is multiplexed within the same CSI-RS resource 402 as a second CSI-RS 344 transmitted by a second TRP 324. In some implementations, the CSI-RS 342, 344 are multiplexed within the same CSI-RS resource 402 when the number of ports associated with the CSI-RS 342, 344 is relatively small (e.g., less than a threshold number of ports).

[0083] Figure 5 A second example of a joint transmission 340 is shown. Figure 5 In the example of , the first CSI-RS 342 is transmitted within a first CSI-RS resource 502, and the second CSI-RS 344 is transmitted within a second CSI-RS resource 504 that is different from the first CSI-RS resource 502. In some implementations, when the number of ports associated with the CSI-RSs 342, 344 is relatively large (e.g., greater than or equal to a threshold number of ports), the CSI-RSs 342, 344 are transmitted using separate CSI-RS resources 502, 504.

[0084] Therefore, in some examples, the selection may be based on the specific characteristics of the communication system. Figure 4 or Figure 5 For example, the number of ports associated with CSI-RS 342, 344 may be selected. Figure 4 or Figure 5 Implementation method.

[0085] Figure 6 A specific example of the rank-to-port mapping codebook 304 is shown. In some examples, in conjunction with reference to Figure 4 The described implementation utilizes Figure 6 A rank-to-port mapping codebook 304 (eg, where multiple CSI-RSs are multiplexed within a common CSI-RS resource).

[0086] exist Figure 6 In , a single TRP parameter 306 includes multiple rank parameters, each rank parameter is associated with a corresponding port index parameter. Figure 6In the example of , each port index parameter includes a port selection bit map of bits B0, B1, B2, and B3. Each bit can correspond to a respective TRP port. To illustrate, in one example, bits B0, B1, B2, and B3 can correspond to ports P0, P1, P2, and P3, respectively, or to ports P4, P5, P6, and P7, respectively. The specific value of the bit can indicate whether the port is selected. For example, a value of "0" for bit B0 can indicate that a particular port (e.g., port P0 or port P5) is not selected, and a value of "1" for bit B0 can indicate that the particular port is selected.

[0087] In the single TRP parameters 306, rank 1 may indicate that a single spatial stream is received from a single TRP (e.g., the first TRP 322 or the second TRP 324), and the corresponding port selection bitmap may indicate selection of a first set of one or more ports of the single TRP (e.g., one or more of ports P0, P1, P2, and P3, or one or more of ports P4, P5, P6, and P7). As additional examples, ranks 2, 3, or 4 may indicate that two, three, or four spatial streams are received from a single TRP, and the corresponding port selection bitmap may indicate selection of a second, third, or fourth set of one or more ports of the single TRP, respectively.

[0088] The multi-TRP parameters 312 include multiple joint rank parameters, each of which is associated with a corresponding port index parameter. Figure 6 In the example of , each port index parameter includes a port selection bit map of bits B0, B1, B2, B3, B4, B5, B6, and B7. Each bit can correspond to a respective TRP port. To illustrate, in one example, bits B0, B1, B2, and B3 can correspond to ports P0, P1, P2, and P3, respectively, and bits B4, B5, B6, and B7 can correspond to ports P4, P5, P6, and P7, respectively. A specific value of a bit can indicate whether a port is selected. For example, a value of "0" for bit B0 can indicate that a specific port (e.g., port P0) is not selected, and a value of "1" for a specific B0 can indicate that the specific port is selected.

[0089] In the multi-TRP parameters 312, rank 1+1 may indicate that a single spatial stream is received from one TRP (e.g., the first TRP 322) and a single spatial stream is received from another TRP (e.g., the second TRP 324), and the corresponding port selection bitmap may indicate the selection of a first set of one or more ports of the TRP (e.g., one or more of ports P0, P1, P2, P3, P4, P5, P6, and P7). As another example, rank 1+2 may indicate that a single spatial stream is received from one TRP (e.g., the first TRP 322) and two spatial streams are received from another TRP (e.g., the second TRP 324), and the corresponding port selection bitmap may indicate the selection of a second set of one or more ports of the TRP (e.g., one or more of ports P0, P1, P2, P3, P4, P5, P6, and P7). As an additional example, rank 2+1 may indicate that two spatial streams are received from one TRP (e.g., the first TRP 322) and one spatial stream is received from another TRP (e.g., the second TRP 324), and the corresponding port selection bitmap may indicate selection of a third set of one or more ports of the TRP (e.g., one or more of ports P0, P1, P2, P3, P4, P5, P6, and P7). As a further example, rank 2+2 may indicate that two spatial streams are received from one TRP (e.g., the first TRP 322) and two spatial streams are received from another TRP (e.g., the second TRP 324), and the corresponding port selection bitmap may indicate selection of a fourth set of one or more ports of the TRP (e.g., one or more of ports P0, P1, P2, P3, P4, P5, P6, and P7).

[0090] Therefore, in Figure 6 In, each joint rank parameter may be based on a first number of spatial streams (e.g., 1 or 2) received from the first TRP 322 and a second number of spatial streams (e.g., 1 or 2) received from the second TRP 324. In addition, Figure 6 In , for multiple combinations of the first number and the second number of values, the rank-to-port mapping codebook 304 indicates the corresponding port selection bit mapping of the port index parameter. Figure 6 In the example, multiple combinations include 1+1, 1+2, 2+1 and 2+2. For further illustration, Table 1 describes Figure 6 An example of a rank-to-port mapping codebook 304:

[0091] Table 1

[0092] Rank 1 / 8 PortIndex8 Rank 2 / 8 SEQUENCE(SIZE(2))OF PortIndex8 Rank 3 / 8 SEQUENCE(SIZE(3))OF PortIndex8 Rank 4 / 8 SEQUENCE(SIZE(4))OF PortIndex8 Rank 1+1 / 8 SEQUENCE(SIZE(2))OF PortIndex8 Rank 1+2 / 8 SEQUENCE(SIZE(3))OF PortIndex8 Rank 2+1 / 8 SEQUENCE(SIZE(3))OF PortIndex8 Rank 2+2 / 8 SEQUENCE(SIZE(4))OF PortIndex8

[0093] In Table 1, the entries in the left column can correspond to Figure 6 For example, "rank 1 / 8" may correspond to rank parameter 308, and "rank 1+1 / 8" may correspond to joint rank parameter 314. The entries in the right column of Table 1 may correspond to Figure 6 For example, “PortIndex8” may correspond to port index parameter 310 , and “SEQUENCE(SIZE(2))OFPortIndex8” may correspond to port index parameter 316 .

[0094] It should be noted that reference is provided Figure 6 Certain examples described are for illustration and are not limiting. For example, Figure 6 It is described with reference to an eight-port configuration. In other examples, other configurations are within the scope of the present disclosure (eg, four ports, six ports, or other numbers of ports).

[0095] Figure 7 Another example of a rank-to-port mapping codebook 304 is shown. In some examples, in conjunction with reference to Figure 7 The described implementation utilizes Figure 7 A rank-to-port mapping codebook 304 (eg, where multiple CSI-RSs are transmitted using multiple corresponding CSI-RS resources).

[0096] exist Figure 7 In , the rank-to-port mapping codebook 304 includes (for each of the multiple values ​​of CRI 354) multiple rank-to-port mappings. Figure 6 , the multiple values ​​of CRI 354 include 0, 1, and 2. The multiple rank-to-port mappings may include rank-to-port mapping 702 (corresponding to the value 0 of CRI 354), rank-to-port mapping 704 (corresponding to the value 1 of CRI 354), and rank-to-port mapping 706 (corresponding to the value 2 of CRI 354).

[0097] In addition, Figure 6 In the example 1, the rank-to-port mapping 706 includes a plurality of rank pairs for a specific value (e.g., 2) of the plurality of values ​​of the CRI 354. For example, for a value of 2 of the CRI 354, the plurality of rank pairs include rank 1+1, rank 1+2, rank 2+1, and rank 2+2. To further illustrate, Example 1 depicts a method that can be used with Figure 7 The pseudo code of the lookup table corresponding to the example of the rank-to-port mapping codebook 304 is:

[0098] Example 1

[0099]

[0100] In Example 1, the parameter "CRI=0" may correspond to Figure 7 Rank-to-port mapping 702. Further, parameters "CRI=1" and "CRI=2" may correspond to rank-to-port mapping 704 and rank-to-port mapping 706, respectively.

[0101] In some examples, including multiple rank-to-port mappings 702, 704, and 706 can enable the UE 115 to "down-select" from a multi-TRP operation mode (e.g., where the UE 115 communicates with both the first TRP 322 and the second TRP 324) to a single TRP operation mode (e.g., where the UE 115 communicates with one of the first TRP 322 or the second TRP 324). As an example, the UE 115 can initiate the down-select in response to detecting that the energy difference between a signal from one TRP and a signal from another TRP satisfies a threshold energy difference. In this example, the UE 115 can initiate the down-select to avoid interference from a signal from one TRP to a signal from another TRP that may occur in some cases.

[0102] For example, see Figure 8 , the UE 115 may set the value of CRI 354 to 2 to select a multi-TRP mode of operation (e.g., to communicate with both TRPs 322, 324). The UE 115 may use the RI 352 and the CRI 354 to select a port (or indicate a preferred selection of ports) for the TRPs 322, 324 (e.g., by indicating the RI 352 and the CRI 354 to the base station 105 using the CSI report message 350). For example, the UE 115 may provide the RI 352 to the TRPs 322, 324 using the CSI report message 350, and the base station 105 may perform a lookup operation based on the RI 352 (e.g., to identify the port indicated by the port index parameter 316). Providing the RI 352 and the CRI 354 to the base station 105 to indicate the selection of the port of the TRP 322, 324 may be referred to as a multi-TRP port selection operation 806.

[0103] To down-select from the multi-TRP operation mode to the single TRP operation mode, the UE 115 may set the value of the CRI 354 to 0 or 1 to select the single TRP operation mode (e.g., to communicate with one of the TRPs 322, 324 but not both). For example, the UE 115 may send a message (e.g., a CSI report message 350) indicating that the value of the CRI 354 is 0 to initiate the down-selection from the multi-TRP transmission mode to the single TRP transmission mode. Setting the value of the CRI 354 to 0 may cause the base station 105 to communicate with the UE 115 using one of the TRPs 322, 324 but not both. Modifying the value of the CRI 354 from 2 to 0 may be referred to as a down-selection operation 802.

[0104] As another example, the UE 115 may send a message (e.g., CSI report message 350) indicating that the value of CRI 354 is 1 to initiate a down-selection from the multi-TRP transmission mode to the single-TRP transmission mode. Setting the value of CRI 354 to 1 may cause the base station 105 to communicate with the UE 115 using one (rather than both) of TRPs 322, 324. Modifying the value of CRI 354 from 2 to 1 may be referred to as a down-selection operation 804.

[0105] Thus, down-selecting from the multi-TRP transmission mode to the single TRP transmission mode includes setting a specific value of the CRI 354 (e.g., by adjusting the value from 2 to 1 or 0). As a result, the UE 115 can effectively change operation from the multi-TRP transmission mode to the single TRP transmission mode.

[0106] Fig. 9 1 is a block diagram illustrating example blocks that may be executed by a UE device (e.g., UE 115) to implement one aspect of the present disclosure. The example blocks will also be described with respect to Fig.11 The description will be made using the UE 115 shown in FIG. Fig.11 1 is a block diagram illustrating a UE 115 configured according to one aspect of the present disclosure. The UE 115 includes a Figure 2 1. The UE 115 of the present invention is shown in FIG. 1. For example, the UE 115 includes a controller / processor 280 that operates to execute logic or computer instructions stored in a memory 282 and controls the components of the UE 115 that provide the features and functions of the UE 115. Under the control of the controller / processor 280, the UE 115 sends and receives signals via wireless radio units 1101a-r and antennas 252a-r. The wireless radio units 1101a-r include the following: Figure 2The various components and hardware shown in for UE 115 include modulators / demodulators 254a-r, MIMO detector 256, receive processor 258, transmit processor 264, and TX MIMO processor 266.

[0107] The memory 282 is configured to store instructions, data, or other information that implements joint port selection for multiple TRPs. For example, the memory 282 may store measurement logic 1102 that is executable by the controller / processor 280 to perform one or more network measurements, such as measurements that generate information including the CSI report message 350. As a specific example, the measurement logic 1102 may be executable by the controller / processor 280 to determine the joint rank parameter 314. Fig.11 The memory 282 is also shown to be configured to store a CSI report generator 1103. The CSI report generator 1103 may be executable by the controller / processor 280 to generate the CSI report message 350. Fig.11 The memory 282 is further depicted storing a rank-to-port mapping codebook 304 .

[0108] Reference Fig. 9 , an example flow chart of a method 900 of operation of a UE for wireless communication is shown. As shown at block 902, the method 900 includes receiving, by a UE device, a joint transmission of a CSI-RS from a first TRP associated with a wireless network and at least a second TRP associated with the wireless network. For example, the UE 115 may receive a joint transmission 340 of a first CSI-RS 342 and a second CSI-RS 344 from a first TRP 322 and a second TRP 324.

[0109] At block 904 , the method 900 further includes determining a joint rank parameter associated with the joint transmission. For example, the UE 115 may determine any joint rank parameter of the rank-to-port mapping codebook 304 , such as the joint rank parameter 314 .

[0110] At block 906 , the method 900 further includes accessing the rank-to-port mapping codebook by the UE device based on the joint rank parameter to determine the port index parameter. For example, the UE 115 may perform a lookup operation on the rank-to-port mapping codebook 304 based on the joint rank parameter 314 to identify the port index parameter 316 .

[0111] At block 908, after determining the port index parameter, the method 900 further includes: communicating, by the UE device, with one or more of the first TRP or the second TRP. As a specific example, the UE 115 may send a CSI report message 350 indicating the RI 352 and the CRI 354.

[0112] In a first aspect, the communication includes sending, by a UE device, a CSI report message including a rank indicator (RI) corresponding to a joint rank parameter.

[0113] In a second aspect, the port index parameter includes a port selection bit map indicating selection of ports of the first TRP and the second TRP, and the port selection bit map includes multiple bits for each of multiple values ​​of the joint rank parameter, each of the multiple bits having a value indicating whether the corresponding port is selected.

[0114] In a third aspect, the joint rank parameter is based on a first number of spatial streams received from a first TRP and a second number of spatial streams received from a second TRP.

[0115] In a fourth aspect, for multiple combinations of values ​​of the first number and the second number, the rank-to-port mapping codebook indicates corresponding bit mappings of the port index parameter.

[0116] In the fifth aspect, the first CSI-RS sent by the first TRP is multiplexed within the same CSI-RS resource as the second CSI-RS sent by the second TRP.

[0117] In the sixth aspect, the first CSI-RS sent by the first TRP is sent using a first CSI-RS resource, and the second CSI-RS sent by the second TRP is sent using a second CSI-RS resource different from the first CSI-RS resource.

[0118] In a seventh aspect, a rank-to-port mapping codebook includes multiple rank-to-port mappings for each of multiple values ​​of a CSI-RS resource indicator (CRI), and the multiple rank-to-port mappings include multiple rank pairs for specific values ​​of the multiple values ​​of the CRI.

[0119] In an eighth aspect, method 900 further comprises down-selecting from a multi-TRP transmission operation mode to a single TRP transmission operation mode.

[0120] In a ninth aspect, down-selecting from a multi-TRP transmission mode to a single TRP transmission mode includes setting a specific value of a CSI-RS resource indicator (CRI).

[0121] Fig.10 is a block diagram illustrating example blocks that are executed to implement one aspect of the present disclosure. The example blocks will also be described with respect to Fig.12 The description will be made with reference to the base station 105 shown in FIG. Fig.12 1 is a block diagram illustrating a base station 105 configured according to one aspect of the present disclosure. The base station 105 includes Figure 21. The structure, hardware, and components of the base station 105 are shown in FIG. 1. For example, the base station 105 includes a controller / processor 240 that operates to execute logic or computer instructions stored in a memory 242 and controls components of the base station 105 that provide the features and functions of the base station 105. Under the control of the controller / processor 240, the base station 105 transmits and receives signals via wireless radios 1201a-t and antennas 234a-t. The wireless radios 1201a-t include, for example, Figure 2 The various components and hardware for base station 105 shown in , include modulator / demodulators 232a - t , MIMO detector 236 , receive processor 238 , transmit processor 220 , and TX MIMO processor 230 .

[0122] The memory 242 is configured to store instructions, data, or other information that implements joint port selection for multiple TRPs. For example, the memory 242 may store a port selector 903 that is executable by the controller / processor 240 to select one or more of the ports P0-P7 of the TRPs 322, 324 for a joint transmission (such as NCJT). Fig.12 The memory 282 is also shown configured to store a CSI-RS generator 905. The CSI-RS generator 905 may be executable by the controller / processor 240 to generate the first CSI-RS 342, the second CSI-RS 344, or both. Fig.11 The memory 282 is further depicted storing a rank-to-port mapping codebook 304 .

[0123] Reference Fig.10 , illustrates an example flow chart of a method 1000 of operating a base station for wireless communication. As shown at block 1002, the method 1000 includes: sending, by a first TRP associated with a wireless network, a CSI report configuration message including a rank-to-port mapping codebook. For example, the first TRP 322 may send a CSI report configuration message 330 including the rank-to-port mapping codebook 304.

[0124] At block 1004, the method 1000 further includes: transmitting, by the first TRP, a first CSI-RS. For example, the first TRP 322 may transmit the first CSI-RS 342.

[0125] At block 1006 , the method 1000 further includes receiving a CSI report message from the UE device in response to sending the CSI-RS and CSI report configuration message. For example, the base station 105 may receive the CSI report message 350 from the UE 115 .

[0126] At block 1008, the method 1000 further includes determining a joint selection of ports of a first TRP and a second TRP associated with the wireless network based on the CSI report message. For example, the controller 302 may perform a lookup operation on the rank-to-port mapping codebook 304 to determine the selection of ports P0-P7. As a specific illustrative example, the CSI report message 350 may indicate the RI 352, and the controller 302 may perform a lookup operation based on the RI 352 to determine the port index parameter 316. The port index parameter 316 may indicate the selection of ports P0-P7.

[0127] In a tenth aspect, the joint selection of ports indicates ports across a single CSI-RS resource for non-coherent joint transmission (NCJT) between a first TRP and a second TRP.

[0128] In an eleventh aspect, the joint selection of ports indicates ports across multiple CSI-RS resources for non-coherent joint transmission (NCJT) between a first TRP and a second TRP.

[0129] In a twelfth aspect, determining a joint selection of ports comprises accessing a port selection bitmap of a rank-to-port mapping codebook.

[0130] In a thirteenth aspect, the CSI report message includes a rank indicator (RI), and the port selection bitmap is accessed based on the RI.

[0131] In a fourteenth aspect, a rank-to-port mapping codebook comprises, for each of a plurality of values ​​of a joint rank parameter, a plurality of bits each having a value indicating whether a corresponding port is selected.

[0132] In a fifteenth aspect, the joint rank parameter is based on a first number of spatial streams received from a first TRP and a second number of spatial streams received from a second TRP.

[0133] In a sixteenth aspect, for multiple combinations of values ​​of the first number and the second number, the rank-to-port mapping codebook indicates a corresponding bit mapping of the port index parameter.

[0134] In a seventeenth aspect, a rank-to-port mapping codebook includes multiple rank-to-port mappings for each of multiple values ​​of a CSI-RS resource indicator (CRI), and the multiple rank-to-port mappings include multiple rank pairs for specific values ​​of the multiple values ​​of the CRI.

[0135] In the eighteenth aspect, the method 1000 further includes: receiving a message from the UE device to initiate a down-selection from a multi-TRP transmission operation mode to a single TRP transmission operation mode.

[0136] In a nineteenth aspect, the message includes a CSI-RS resource indicator (CRI) that initiates a down-selection from a multi-TRP transmission mode to a single TRP transmission mode.

[0137] Those skilled in the art will appreciate that information and signals may be expressed using a variety of different technologies and methods. For example, voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or optical particles, or any combination thereof may be used to represent the data, instructions, commands, information, signals, bits, symbols, and chips mentioned in the entire above description.

[0138] The functional blocks and modules described herein (eg, Figure 2 The functional blocks and modules in the codebook 304 may include processors, electronic devices, hardware devices, electronic components, logic circuits, memories, software codes, firmware codes, etc., or any combination thereof. In addition, certain features discussed herein are implemented via specialized processor circuits, via executable instructions, and / or combinations thereof. For example, a lookup operation to access the rank-to-port mapping codebook 304 may be implemented via specialized circuits, via executable instructions, or a combination thereof.

[0139] Those skilled in the art will further recognize that various illustrative logical blocks, modules, circuits, and algorithm steps (e.g., Fig. 9 and 10 The logic blocks in the embodiment of the present invention can be implemented as electronic hardware, computer software or a combination thereof. In order to clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits and steps have been generally described in terms of their functionality. Whether this functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the entire system. The technician can implement the described functions in different ways for each specific application, but such implementation decisions should not be considered as causing a departure from the scope of the present disclosure. The technician will also easily recognize that the order or combination of components, methods or interactions described herein are merely examples, and the components, methods or interactions of various aspects of the present disclosure can be combined or performed in a manner other than that illustrated and described herein.

[0140] Various illustrative logical blocks, modules, and circuits associated with the disclosure herein may be implemented or performed by 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 for performing the functions described herein. A general purpose processor may be a microprocessor, but in an alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors and a DSP core, or any other such configuration.

[0141] The steps of the method or algorithm related to the disclosure herein can be directly implemented in hardware, software modules executed by a processor, or a combination thereof. The software module can be located in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a 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 so that the processor can read information from the storage medium and write information to the storage medium. In an alternative, the storage medium can be integrated into the processor. The processor and the storage medium can be located in an ASIC. The ASIC can be located in a user terminal. In an alternative, the processor and the storage medium can be located in a user terminal as discrete components.

[0142] In one or more exemplary designs, the functions may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored or transmitted as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media and communication media, and communication media include any media that facilitates the transfer of computer programs 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, but not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM, or any optical disk storage, disk storage, or other magnetic storage device, or any other medium that can be used to carry or store the required program code units in the form of instructions or data structures, and any other medium that can be accessed by a general-purpose or special-purpose computer or a general-purpose or special-purpose processor. In addition, the connection may be appropriately referred to as a computer-readable medium. For example, if a coaxial cable, fiber optic cable, twisted pair, or digital subscriber line (DSL) is used to transmit software from a website, server, or other remote source, the coaxial cable, fiber optic cable, twisted pair, or DSL is included in the definition of the medium. As used herein, disks include compact disks (CDs), laser disks, optical disks, digital versatile disks (DVDs), hard disks, solid state disks, and Blu-ray disks, some of which typically reproduce data magnetically and some of which reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0143] As used herein, including in the claims, when the term "and / or" is used in a list of two or more items, it means that any one of the listed items can be taken by itself, or any combination of two or more of the listed items can be taken. For example, if a composition is described as comprising components A, B, and / or C, the composition can comprise A alone; B alone; C alone; a combination of A and B; a combination of A and C; a combination of B and C; or a combination of A, B, and C. Furthermore, as used herein, including in the claims, "or" used in a list of items ending with "at least one of" indicates a disjunctive list, so 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 combination thereof.

[0144] The foregoing of the present disclosure is provided so that those skilled in the art can make or use the present disclosure. It will be apparent to those skilled in the art that various modifications are made to the present disclosure, and the general principles described herein can be used for other variations without departing from the scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the examples and designs described herein, but should be given the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method of wireless communication, comprising: receiving, by a user equipment (UE) device, a joint transmission of a channel state information (CSI) reference signal (CSI-RS) from a first transmit and receive point (TRP) associated with a wireless network and at least a second TRP associated with the wireless network; determining a joint rank parameter associated with the joint transmission; performing, by the UE device, a lookup in a rank-to-port mapping codebook to determine a port index parameter based on the joint rank parameter, wherein the rank-to-port mapping codebook comprises a plurality of rank-to-port mappings for each of a plurality of values ​​of a CSI-RS resource indicator (CRI), and wherein the plurality of rank-to-port mappings comprises a plurality of rank pairs for a particular value of the plurality of values ​​of the CRI; and After determining the port index parameter, the UE device communicates with one or more of the first TRP or the second TRP.

2. The method according to claim 1, wherein: The communication includes: sending, by the UE device, a CSI report message including a rank indicator (RI) corresponding to the joint rank parameter.

3. The method according to claim 1, wherein: The port index parameter includes a port selection bit map indicating selection of ports of the first TRP and the second TRP, and wherein the port selection bit map includes a plurality of bits for each of a plurality of values ​​of the joint rank parameter, each of the plurality of bits having a value indicating whether the corresponding port is selected.

4. The method according to claim 1, wherein: The joint rank parameter is based on a first number of spatial streams received from the first TRP and a second number of spatial streams received from the second TRP.

5. The method according to claim 4, wherein: The rank-to-port mapping codebook indicates corresponding bit mappings of the port index parameter for multiple combinations of values ​​of the first number and the second number.

6. The method according to claim 1, further comprising: Downselect from the multi-TRP transmission operation mode to the single TRP transmission operation mode.

7. The method according to claim 6, wherein: Selecting down from the multi-TRP transmission mode to the single TRP transmission mode includes: setting a specific value of the CSI-RS resource indicator (CRI).

8. A method of wireless communication, comprising: transmitting, by a first transmit and receive point (TRP) associated with a wireless network, a first channel state information (CSI) report configuration message comprising a rank-to-port mapping codebook, wherein the rank-to-port mapping codebook comprises a plurality of rank-to-port mappings for each of a plurality of values ​​of a CSI-RS resource indicator (CRI), and wherein the plurality of rank-to-port mappings comprises a plurality of rank pairs for a particular value of the plurality of values ​​of the CRI; The first TRP is used to send a CSI reference signal (CSI-RS); In response to sending the CSI-RS and the CSI report configuration message, receiving a CSI report message; and A joint selection of ports of the first TRP and the second TRP associated with the wireless network is determined based on the CSI report message.

9. The method according to claim 8, wherein: Determining the joint selection of the ports includes accessing a port selection bitmap of the rank-to-port mapping codebook.

10. The method according to claim 9, wherein: The CSI report message includes a rank indicator (RI), and wherein the port selection bitmap is accessed based on the RI.

11. The method according to claim 8, wherein: The rank-to-port mapping codebook includes a plurality of bits for each of a plurality of values ​​of a joint rank parameter, each of the plurality of bits having a value indicating whether a corresponding port is selected.

12. The method according to claim 11, wherein: The joint rank parameter is based on a first number of spatial streams received from the first TRP and a second number of spatial streams received from the second TRP.

13. The method according to claim 12, wherein: The rank-to-port mapping codebook indicates corresponding bit mappings of port index parameters for multiple combinations of values ​​of the first number and the second number.

14. The method according to claim 8, further comprising: Receive a message initiating a downselect from a multi-TRP transmission mode of operation to a single TRP transmission mode of operation.

15. The method according to claim 14, wherein: The message includes a CSI-RS resource indicator (CRI) that initiates the down-selection from the multi-TRP transmission mode to the single TRP transmission mode.

16. A non-transitory computer readable medium having program code recorded thereon, the program code comprising: program code executable by a computer to cause the computer to receive, at a user equipment (UE) device, a joint transmission of a channel state information (CSI) reference signal (CSI-RS) from a first transmit and receive point (TRP) associated with a wireless network and at least a second TRP associated with the wireless network; program code executable by the computer for causing the computer to determine a joint rank parameter associated with the joint transmission; program code executable by the computer for causing the computer to perform a lookup in a rank-to-port mapping codebook to determine a port index parameter based on the joint rank parameter, wherein the rank-to-port mapping codebook comprises a plurality of rank-to-port mappings for each of a plurality of values ​​of a CSI-RS resource indicator (CRI), and wherein the plurality of rank-to-port mappings comprises a plurality of rank pairs for a particular value of the plurality of values ​​of the CRI; and Program code executable by the computer for causing the computer to communicate with one or more of the first TRP or the second TRP after determining the port index parameter.

17. The non-transitory computer readable medium of claim 16, wherein: The communication includes sending, by the UE device, a CSI report message including a rank indicator (RI) corresponding to the joint rank parameter.

18. The non-transitory computer readable medium of claim 16, wherein: The port index parameter includes a port selection bit map indicating selection of ports of the first TRP and the second TRP, and wherein the port selection bit map includes a plurality of bits for each of a plurality of values ​​of the joint rank parameter, each of the plurality of bits having a value indicating whether the corresponding port is selected.

19. The non-transitory computer readable medium of claim 16, wherein: The joint rank parameter is based on a first number of spatial streams received from the first TRP and a second number of spatial streams received from the second TRP.

20. The non-transitory computer readable medium of claim 19, wherein: The rank-to-port mapping codebook indicates corresponding bit mappings of port index parameters for multiple combinations of values ​​of the first number and the second number.

21. The non-transitory computer readable medium of claim 16, further comprising: Program code executable by the computer for causing the computer to down-select from a multi-TRP transmission mode of operation to a single TRP transmission mode of operation.

22. The non-transitory computer readable medium of claim 21, wherein: Selecting down from the multi-TRP transmission mode to the single TRP transmission mode includes: setting a specific value of the CSI-RS resource indicator (CRI).

23. A non-transitory computer readable medium having program code recorded thereon, the program code comprising: Program code executable by a computer for causing the computer to transmit, through a first transmit and receive point (TRP) associated with a wireless network, a first channel state information (CSI) report configuration message comprising a rank-to-port mapping codebook, wherein the rank-to-port mapping codebook comprises a plurality of rank-to-port mappings for each of a plurality of values ​​of a CSI-RS resource indicator (CRI), and wherein the plurality of rank-to-port mappings comprises a plurality of rank pairs for a particular value of the plurality of values ​​of the CRI; program code executable by the computer for causing the computer to transmit a CSI reference signal (CSI-RS) through the first TRP; program code executable by the computer for causing the computer to receive a CSI report message in response to sending the CSI-RS and the CSI report configuration message; and Program code executable by the computer for causing the computer to determine a joint selection of ports of the first TRP and the second TRP associated with the wireless network based on the CSI report message.

24. The non-transitory computer readable medium of claim 23, wherein: Determining the joint selection of the ports includes accessing a port selection bitmap of the rank-to-port mapping codebook.

25. The non-transitory computer readable medium of claim 24, wherein: The CSI report message includes a rank indicator (RI), and wherein the port selection bitmap is accessed based on the RI.

26. The non-transitory computer readable medium of claim 23, wherein: The rank-to-port mapping codebook includes a plurality of bits for each of a plurality of values ​​of a joint rank parameter, the plurality of bits each having a value indicating whether a corresponding port is selected.

27. The non-transitory computer readable medium of claim 26, wherein: The joint rank parameter is based on a first number of spatial streams received from the first TRP and a second number of spatial streams received from the second TRP.

28. The non-transitory computer readable medium of claim 27, wherein: The rank-to-port mapping codebook indicates corresponding bit mappings of port index parameters for multiple combinations of values ​​of the first number and the second number.

29. The non-transitory computer readable medium of claim 23, further comprising: Program code executable by the computer for causing the computer to receive a message initiating a down-selection from a multiple TRP transmission mode of operation to a single TRP transmission mode of operation.

30. The non-transitory computer readable medium of claim 29, wherein: The message includes: a CSI-RS resource indicator (CRI) that initiates the downward selection from the multi-TRP transmission mode to the single TRP transmission mode.

31. An apparatus configured for wireless communication, the apparatus comprising: at least one processor; as well as a memory coupled to the at least one processor, Wherein, the at least one processor is configured to: receiving, by a user equipment (UE) device, a joint transmission of a channel state information (CSI) reference signal (CSI-RS) from a first transmit and receive point (TRP) associated with a wireless network and at least a second TRP associated with the wireless network; determining a joint rank parameter associated with the joint transmission; performing, by the UE device, a lookup in a rank-to-port mapping codebook to determine a port index parameter based on the joint rank parameter, wherein the rank-to-port mapping codebook comprises a plurality of rank-to-port mappings for each of a plurality of values ​​of a CSI-RS resource indicator (CRI), and wherein the plurality of rank-to-port mappings comprises a plurality of rank pairs for a particular value of the plurality of values ​​of the CRI; and After determining the port index parameter, communicate with one or more of the first TRP or the second TRP through the UE device.

32. The device according to claim 31, wherein The at least one processor is further configured to initiate, by the UE device, sending a CSI report message including a rank indicator (RI) corresponding to the joint rank parameter.

33. The device according to claim 31, wherein The port index parameter includes a port selection bit map indicating selection of ports of the first TRP and the second TRP, and wherein the port selection bit map includes a plurality of bits for each of a plurality of values ​​of the joint rank parameter, each of the plurality of bits having a value indicating whether the corresponding port is selected.

34. The device according to claim 31, wherein The joint rank parameter is based on a first number of spatial streams received from the first TRP and a second number of spatial streams received from the second TRP.

35. The device according to claim 34, wherein The rank-to-port mapping codebook indicates corresponding bit mappings of the port index parameter for multiple combinations of values ​​of the first number and the second number.

36. The device according to claim 31, wherein The at least one processor is also configured to down-select from a multi-TRP transmission mode of operation to a single TRP transmission mode of operation.

37. The device according to claim 36, wherein The at least one processor is also configured to down-select to the single TRP transmission mode by setting a specific value of a CSI-RS resource indicator (CRI).

38. An apparatus configured for wireless communication, the apparatus comprising: at least one processor; as well as a memory coupled to the at least one processor, Wherein, the at least one processor is configured to: transmitting, by a first transmit and receive point (TRP) associated with a wireless network, a first channel state information (CSI) report configuration message including a rank-to-port mapping codebook, wherein the rank-to-port mapping codebook includes a plurality of rank-to-port mappings for each of a plurality of values ​​of a CSI-RS resource indicator (CRI), and wherein the plurality of rank-to-port mappings includes a plurality of rank pairs for a particular value of the plurality of values ​​of the CRI; Sending a CSI reference signal (CSI-RS) through the first TRP; In response to sending the CSI-RS and the CSI report configuration message, receiving a CSI report message; and A joint selection of ports of the first TRP and the second TRP associated with the wireless network is determined based on the CSI report message.

39. The device according to claim 38, wherein The at least one processor is further configured to determine the joint selection of the ports by accessing a port selection bitmap of the rank-to-port mapping codebook.

40. The device according to claim 39, wherein The CSI report message includes a rank indicator (RI), and wherein the port selection bitmap is accessed based on the RI.

41. The apparatus of claim 38, wherein: The rank-to-port mapping codebook includes a plurality of bits for each of a plurality of values ​​of a joint rank parameter, the plurality of bits each having a value indicating whether a corresponding port is selected.

42. The device according to claim 41, wherein The joint rank parameter is based on a first number of spatial streams received from the first TRP and a second number of spatial streams received from the second TRP.

43. The device according to claim 42, wherein: The rank-to-port mapping codebook indicates corresponding bit mappings of port index parameters for multiple combinations of values ​​of the first number and the second number.

44. The apparatus of claim 38, wherein: The at least one processor is also configured to receive a message initiating a down-selection from a multiple TRP transmission mode of operation to a single TRP transmission mode of operation.

45. The device according to claim 44, wherein The message includes: a CSI-RS resource indicator (CRI) that initiates the downward selection from the multi-TRP transmission mode to the single TRP transmission mode.

46. ​​An apparatus configured for wireless communication, comprising: means for receiving, by a user equipment (UE) device, a joint transmission of a channel state information (CSI) reference signal (CSI-RS) from a first transmit and receive point (TRP) associated with a wireless network and at least a second TRP associated with the wireless network; means for determining a joint rank parameter associated with the joint transmission and for performing a lookup in a rank-to-port mapping codebook based on the joint rank parameter to determine a port index parameter, wherein the rank-to-port mapping codebook comprises a plurality of rank-to-port mappings for each of a plurality of values ​​of a CSI-RS resource indicator (CRI), and wherein the plurality of rank-to-port mappings comprises a plurality of rank pairs for a particular value of the plurality of values ​​of the CRI; and A unit for communicating with one or more of the first TRP or the second TRP after determining the port index parameter.

47. The device according to claim 46, wherein The means for communicating is configured to send, by the UE device, a CSI report message including a rank indicator (RI) corresponding to the joint rank parameter.

48. The apparatus of claim 46, wherein: The port index parameter includes a port selection bit map indicating selection of ports of the first TRP and the second TRP, and wherein the port selection bit map includes a plurality of bits for each of a plurality of values ​​of the joint rank parameter, each of the plurality of bits having a value indicating whether the corresponding port is selected.

49. The apparatus of claim 46, wherein: The joint rank parameter is based on a first number of spatial streams received from the first TRP and a second number of spatial streams received from the second TRP.

50. The apparatus of claim 49, wherein: The rank-to-port mapping codebook indicates corresponding bit mappings of the port index parameter for multiple combinations of values ​​of the first number and the second number.

51. The apparatus of claim 46, wherein: The unit for determining is configured to initiate a down-selection from a multi-TRP transmission operation mode to a single TRP transmission operation mode.

52. The apparatus of claim 51, wherein: The downward selection includes: setting a specific value of a CSI-RS resource indicator (CRI).

53. An apparatus configured for wireless communication, comprising: means for transmitting, through a first transmit and receive point (TRP) associated with a wireless network, a first channel state information (CSI) report configuration message comprising a rank-to-port mapping codebook, and means for transmitting, through the first TRP, a CSI reference signal (CSI-RS), wherein the rank-to-port mapping codebook comprises a plurality of rank-to-port mappings for each of a plurality of values ​​of a CSI-RS resource indicator (CRI), and wherein the plurality of rank-to-port mappings comprises a plurality of rank pairs for a particular value of the plurality of values ​​of the CRI; means for receiving a CSI report message in response to sending the CSI-RS and the CSI report configuration message; and A unit for determining a joint selection of ports of the first TRP and the second TRP associated with the wireless network based on the CSI report message.

54. The apparatus of claim 53, wherein: The means for determining is configured to determine the joint selection of the ports by accessing a port selection bitmap of the rank-to-port mapping codebook.

55. The apparatus of claim 54, wherein: The CSI report message includes a rank indicator (RI), and wherein the port selection bitmap is accessed based on the RI.

56. The apparatus of claim 53, wherein: The rank-to-port mapping codebook includes a plurality of bits for each of a plurality of values ​​of a joint rank parameter, the plurality of bits each having a value indicating whether a corresponding port is selected.

57. The apparatus of claim 56, wherein: The joint rank parameter is based on a first number of spatial streams received from the first TRP and a second number of spatial streams received from the second TRP.

58. The apparatus of claim 57, wherein: The rank-to-port mapping codebook indicates corresponding bit mappings of port index parameters for multiple combinations of values ​​of the first number and the second number.

59. The apparatus of claim 53, wherein: The unit for receiving is configured to receive a message initiating a down-selection from a multi-TRP transmission operation mode to a single TRP transmission operation mode.

60. The apparatus of claim 59, wherein: The message includes a CSI-RS resource indicator (CRI) that initiates the down-selection from the multi-TRP transmission mode to the single TRP transmission mode.

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