Method and apparatus for reporting delay for joint transmission

Abstract

The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. A method performed by a user equipment (UE) includes receiving information about a report, the information indicating antenna groups, determining, based on the information, a reference antenna group and determining, based on the information and the reference antenna group, for each antenna group, a first delay value and a second delay value. The method further includes transmitting the report including a first indicator indicating the reference antenna group, a second indicator indicating, for each antenna group, an interval to which the first delay value belongs, and a third indicator indicating, for each antenna group, whether the second delay value is inside or outside a pre-defined range via a 1-bit indicator.

Description

METHOD AND APPARATUS FOR REPORTING DELAY FOR JOINT TRANSMISSION

[0001] The present disclosure relates generally to wireless communication systems and, more specifically, the present disclosure is related to apparatuses and methods for delay and frequency reporting for coherent joint transmission.

[0002] 5G mobile communication technologies define broad frequency bands such that high transmission rates and new services are possible, and may be implemented not only in "Sub 6GHz" bands such as 3.5GHz, but also in "Above 6GHz" bands referred to as mmWave including 28GHz and 39GHz. In addition, it has been considered to implement 6G mobile communication technologies (referred to as Beyond 5G systems) in terahertz bands (for example, 95GHz to 3THz bands) in order to accomplish transmission rates fifty times faster than 5G mobile communication technologies and ultra-low latencies one-tenth of 5G mobile communication technologies.

[0003] At the beginning of the development of 5G mobile communication technologies, in order to support services and to satisfy performance requirements in connection with enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), there has been ongoing standardization regarding beamforming and massive MIMO for mitigating radio-wave path loss and increasing radio-wave transmission distances in mmWave, supporting numerologies (for example, operating multiple subcarrier spacings) for efficiently utilizing mmWave resources and dynamic operation of slot formats, initial access technologies for supporting multi-beam transmission and broadbands, definition and operation of BWP (BandWidth Part), new channel coding methods such as a LDPC (Low Density Parity Check) code for large amount of data transmission and a polar code for highly reliable transmission of control information, L2 pre-processing, and network slicing for providing a dedicated network specialized to a specific service.

[0004] Currently, there are ongoing discussions regarding improvement and performance enhancement of initial 5G mobile communication technologies in view of services to be supported by 5G mobile communication technologies, and there has been physical layer standardization regarding technologies such as V2X (Vehicle-to-everything) for aiding driving determination by autonomous vehicles based on information regarding positions and states of vehicles transmitted by the vehicles and for enhancing user convenience, NR-U (New Radio Unlicensed) aimed at system operations conforming to various regulation-related requirements in unlicensed bands, NR UE Power Saving, Non-Terrestrial Network (NTN) which is UE-satellite direct communication for providing coverage in an area in which communication with terrestrial networks is unavailable, and positioning.

[0005] Moreover, there has been ongoing standardization in air interface architecture / protocol regarding technologies such as Industrial Internet of Things (IIoT) for supporting new services through interworking and convergence with other industries, IAB (Integrated Access and Backhaul) for providing a node for network service area expansion by supporting a wireless backhaul link and an access link in an integrated manner, mobility enhancement including conditional handover and DAPS (Dual Active Protocol Stack) handover, and two-step random access for simplifying random access procedures (2-step RACH for NR). There also has been ongoing standardization in system architecture / service regarding a 5G baseline architecture (for example, service based architecture or service based interface) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) for receiving services based on UE positions.

[0006] As 5G mobile communication systems are commercialized, connected devices that have been exponentially increasing will be connected to communication networks, and it is accordingly expected that enhanced functions and performances of 5G mobile communication systems and integrated operations of connected devices will be necessary. To this end, new research is scheduled in connection with eXtended Reality (XR) for efficiently supporting AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality) and the like, 5G performance improvement and complexity reduction by utilizing Artificial Intelligence (AI) and Machine Learning (ML), AI service support, metaverse service support, and drone communication.

[0007] Furthermore, such development of 5G mobile communication systems will serve as a basis for developing not only new waveforms for providing coverage in terahertz bands of 6G mobile communication technologies, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), array antennas and large-scale antennas, metamaterial-based lenses and antennas for improving coverage of terahertz band signals, high-dimensional space multiplexing technology using OAM (Orbital Angular Momentum), and RIS (Reconfigurable Intelligent Surface), but also full-duplex technology for increasing frequency efficiency of 6G mobile communication technologies and improving system networks, AI-based communication technology for implementing system optimization by utilizing satellites and AI (Artificial Intelligence) from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technology for implementing services at levels of complexity exceeding the limit of UE operation capability by utilizing ultra-high-performance communication and computing resources.

[0008] The demand of wireless data traffic is rapidly increasing due to the growing popularity among consumers and businesses of smart phones and other mobile data devices, such as tablets, "note pad" computers, net books, eBook readers, and machine type of devices. In order to meet the high growth in mobile data traffic and support new applications and deployments, improvements in radio interface efficiency and coverage are of paramount importance.

[0009] A method performed by a user equipment (UE) includes receiving information about a report, the information indicating antenna groups, determining, based on the information, a reference antenna group and determining, based on the information and the reference antenna group, for each antenna group, a first delay value and a second delay value. The method further includes transmitting the report including a first indicator indicating the reference antenna group, a second indicator indicating, for each antenna group, an interval to which the first delay value belongs, and a third indicator indicating, for each antenna group, whether the second delay value is inside or outside a pre-defined range via a 1-bit indicator.

[0010] For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts:

[0011] FIGURE 1 illustrates an example wireless network according to embodiments of the present disclosure;

[0012] FIGURE 2 illustrates an example gNodeB (gNB) according to embodiments of the present disclosure;

[0013] FIGURE 3 illustrates an example UE according to embodiments of the present disclosure;

[0014] FIGURE 4A and 4B illustrate an example of a wireless transmit and receive paths according to embodiments of the present disclosure;

[0015] FIGURE 5 illustrates an example of a transmitter structure for beamforming according to embodiments of the present disclosure;

[0016] FIGURE 6 illustrates an example of a transmitter structure for physical downlink shared channel (PDSCH) in a subframe according to embodiments of the present disclosure;

[0017] FIGURE 7 illustrates an example of a receiver structure for PDSCH in a subframe according to embodiments of the present disclosure;

[0018] FIGURE 8 illustrates an example of a transmitter structure for physical uplink shared channel (PUSCH) in a subframe according to embodiments of the present disclosure;

[0019] FIGURE 9 illustrates an example of a receiver structure for a PUSCH in a subframe according to embodiments of the present disclosure;

[0020] FIGURE 10 illustrates a diagram of an antenna port layout according to embodiments of the present disclosure;

[0021] FIGURE 11 illustrates examples of a UE moving on a trajectory located in co-located and distributed antenna groups (AGs) according to embodiments of the present disclosure; and

[0022] FIGURE 12 illustrates an example method performed by a UE in a wireless communication system according to embodiments of the present disclosure.

[0023] The present disclosure relates to delay and frequency reporting for coherent joint transmission.

[0024] In one embodiment, a user equipment (UE) is provided. The UE includes a transceiver and a processor coupled with the transceiver. The processor is configured to receive information about a report. The information indicates antenna groups, where . The processor is configured determine, based on the information, a reference antenna group ; determine, based on the information and the reference antenna group , for each antenna group , a first delay value and a second delay value ; and transmit the report including a first indicator indicating the reference antenna group , a second indicator indicating, for each antenna group , an interval to which the first delay value belongs, and a third indicator indicating, for each antenna group , whether the second delay value is inside or outside a pre-defined range via a 1-bit indicator.

[0025] In another embodiment, a base station (BS) is provided. The BS includes a transceiver and a processor coupled with the transceiver. The processor is configured to transmit information about a report. The information indicates antenna groups including a reference antenna group , where . For each antenna group , a first delay value and a second delay value , is based on the information and the reference antenna group . The processor is further configured to receive the report including a first indicator indicating the reference antenna group , a second indicator indicating, for each antenna group , an interval to which the first delay value belongs, and a third indicator indicating, for each antenna group , whether the second delay value is inside or outside a pre-defined range via a 1-bit indicator.

[0026] In yet another embodiment, a method performed by a user equipment (UE). The method includes receiving information about a report, the information indicating antenna groups, where , determining, based on the information, a reference antenna group , and determining, based on the information and the reference antenna group , for each antenna group , a first delay value and a second delay value . The method further includes transmitting the report including a first indicator indicating the reference antenna group , a second indicator indicating, for each antenna group , an interval to which the first delay value belongs, and a third indicator indicating, for each antenna group , whether the second delay value is inside or outside a pre-defined range via a 1-bit indicator.

[0027] Other technical features may be readily apparent to one skilled in the art from the following figures, descriptions, and claims.

[0028] Before undertaking the DETAILED DESCRIPTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The term "couple" and its derivatives refer to any direct or indirect communication between two or more elements, whether or not those elements are in physical contact with one another. The terms "transmit," "receive," and "communicate," as well as derivatives thereof, encompass both direct and indirect communication. The terms "include" and "comprise," as well as derivatives thereof, mean inclusion without limitation. The term "or" is inclusive, meaning and / or. The phrase "associated with," as well as derivatives thereof, means to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, have a relationship to or with, or the like. The term "controller" means any device, system, or part thereof that controls at least one operation. Such a controller may be implemented in hardware or a combination of hardware and software and / or firmware. The functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. The phrase "at least one of," when used with a list of items, means that different combinations of one or more of the listed items may be used, and only one item in the list may be needed. For example, "at least one of: A, B, and C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C.

[0029] Moreover, various functions described below may be implemented or supported by one or more computer programs, each of which is formed from computer readable program code and embodied in a computer readable medium. The terms "application" and "program" refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or a portion thereof adapted for implementation in a suitable computer readable program code. The phrase "computer readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer readable medium" includes any type of medium capable of being accessed by a computer, such as read only memory (ROM), random access memory (RAM), a hard disk drive, a compact disc (CD), a digital video disc (DVD), or any other type of memory. A "non-transitory" computer readable medium excludes wired, wireless, optical, or other communication links that transport transitory electrical or other signals. A non-transitory computer readable medium includes media where data may be permanently stored and media where data may be stored and later overwritten, such as a rewritable optical disc or an erasable memory device.

[0030] Definitions for other certain words and phrases are provided throughout this patent document. Those of ordinary skill in the art should understand that in many if not most instances, such definitions apply to prior as well as future uses of such defined words and phrases.

[0031] Wireless communication has been one of the most successful innovations in modern history. Recently, the number of subscribers to wireless communication services exceeded five billion and continues to grow quickly. The demand of wireless data traffic is rapidly increasing due to the growing popularity among consumers and businesses of smart phones and other mobile data devices, such as tablets, "note pad" computers, net books, eBook readers, and machine type of devices. In order to meet the high growth in mobile data traffic and support new applications and deployments, improvements in radio interface efficiency and coverage are of paramount importance. To meet the demand for wireless data traffic having increased since deployment of 4G communication systems, and to enable various vertical applications, 5G communication systems have been developed and are currently being deployed.

[0032] FIGURES 1-12 discussed below, and the various, non-limiting embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged system or device.

[0033] To meet the demand for wireless data traffic having increased since deployment of 4G communication systems, and to enable various vertical applications, 5G / NR communication systems have been developed and are currently being deployed. The 5G / NR communication system is implemented in higher frequency (mmWave) bands, e.g., 28 GHz or 60GHz bands, so as to accomplish higher data rates or in lower frequency bands, such as 6 GHz, to enable robust coverage and mobility support. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G / NR communication systems.

[0034] In addition, in 5G / NR communication systems, development for system network improvement is under way based on advanced small cells, cloud radio access networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, coordinated multi-points (CoMP), reception-end interference cancelation and the like.

[0035] The discussion of 5G systems and frequency bands associated therewith is for reference as certain embodiments of the present disclosure may be implemented in 5G systems.　 However, the present disclosure is not limited to 5G systems, or the frequency bands associated therewith, and embodiments of the present disclosure may be utilized in connection with any frequency band. For example, aspects of the present disclosure may also be applied to deployment of 5G communication systems, 6G, or even later releases which may use terahertz (THz) bands.

[0036] The following documents and standards descriptions are hereby incorporated by reference into the present disclosure as if fully set forth herein: [REF1] 3GPP TS 36.211 v17.4.0, "E-UTRA, Physical channels and modulation;" [REF2] 3GPP TS 36.212 v18.0.0, "E-UTRA, Multiplexing and Channel coding;" [REF3] 3GPP TS 36.213 v18.0.0, "E-UTRA, Physical Layer Procedures;" [REF4] 3GPP TS 36.321 v17.6.0, "E-UTRA, Medium Access Control (MAC) protocol specification;" [REF5] 3GPP TS 36.331 v17.6.0, "E-UTRA, Radio Resource Control (RRC) Protocol Specification;" [REF6] 3GPP TR 22.891 v1.2.0; [REF7] 3GPP TS 38.212 v18.0.0, "E-UTRA, NR, Multiplexing and Channel coding;" [REF8] 3GPP TS 38.214 v18.0.0, "E-UTRA, NR, Physical layer procedures for data;" and [REF9] 3GPP TS 38.211 v18.0.0, E-UTRA, NR, Physical channels and modulation;"

[0037] FIGURE 1 illustrates an example wireless network 100 according to embodiments of the present disclosure. The embodiment of the wireless network 100 shown in FIGURE 1 is for illustration only. Other embodiments of the wireless network 100 could be used without departing from the scope of the present disclosure.

[0038] As shown in FIGURE 1, the wireless network 100 includes a gNB 101 (e.g., base station, BS), a gNB 102, and a gNB 103. The gNB 101 communicates with the gNB 102 and the gNB 103. The gNB 101 also communicates with at least one network 130, such as the Internet, a proprietary Internet Protocol (IP) network, or other data network.

[0039] The gNB 102 provides wireless broadband access to the network 130 for a first plurality of user equipments (UEs) within a coverage area 120 of the gNB 102. The first plurality of UEs includes a UE 111, which may be located in a small business; a UE 112, which may be located in an enterprise; a UE 113, which may be a WiFi hotspot; a UE 114, which may be located in a first residence; a UE 115, which may be located in a second residence; and a UE 116, which may be a mobile device, such as a cell phone, a wireless laptop, a wireless PDA, or the like. The gNB 103 provides wireless broadband access to the network 130 for a second plurality of UEs within a coverage area 125 of the gNB 103. The second plurality of UEs includes the UE 115 and the UE 116. In some embodiments, one or more of the gNBs 101-103 may communicate with each other and with the UEs 111-116 using 5G / NR, long term evolution (LTE), long term evolution-advanced (LTE-A), WiMAX, WiFi, or other wireless communication techniques.

[0040] Depending on the network type, the term "base station" or "BS" may refer to any component (or collection of components) configured to provide wireless access to a network, such as transmit point (TP), transmit-receive point (TRP), an enhanced base station (eNodeB or eNB), a 5G / NR base station (gNB), a macrocell, a femtocell, a WiFi access point (AP), or other wirelessly enabled devices. Base stations may provide wireless access in accordance with one or more wireless communication protocols, e.g., 5G / NR 3rdgeneration partnership project (3GPP) NR, long term evolution (LTE), LTE advanced (LTE-A), high speed packet access (HSPA), Wi-Fi 802.11a / b / g / n / ac, etc. For the sake of convenience, the terms "BS" and "TRP" are used interchangeably in this patent document to refer to network infrastructure components that provide wireless access to remote terminals. Also, depending on the network type, the term "user equipment" or "UE" may refer to any component such as "mobile station," "subscriber station," "remote terminal," "wireless terminal," "receive point," or "user device." For the sake of convenience, the terms "user equipment" and "UE" are used in this patent document to refer to remote wireless equipment that wirelessly accesses a BS, whether the UE is a mobile device (such as a mobile telephone or smartphone) or is normally considered a stationary device (such as a desktop computer or vending machine).

[0041] The dotted lines show the approximate extents of the coverage areas 120 and 125, which are shown as approximately circular for the purposes of illustration and explanation only. It should be clearly understood that the coverage areas associated with gNBs, such as the coverage areas 120 and 125, may have other shapes, including irregular shapes, depending upon the configuration of the gNBs and variations in the radio environment associated with natural and man-made obstructions.

[0042] As described in more detail below, one or more of the UEs 111-116 include circuitry, programing, or a combination thereof for performing delay and frequency reporting for coherent joint transmission. In certain embodiments, one or more of the BSs 101-103 include circuitry, programing, or a combination thereof to support delay and frequency reporting for coherent joint transmission.

[0043] Although FIGURE 1 illustrates one example of a wireless network, various changes may be made to FIGURE 1. For example, the wireless network 100 could include any number of gNBs and any number of UEs in any suitable arrangement. Also, the gNB 101 could communicate directly with any number of UEs and provide those UEs with wireless broadband access to the network 130. Similarly, each gNB 102-103 could communicate directly with the network 130 and provide UEs 111-116 with direct wireless broadband access to the network 130. Each gNB 102-103 may communicate with UEs in each coverage 120-125. Further, the gNBs 101, 102, and / or 103 could provide access to other or additional external networks, such as external telephone networks or other types of data networks.

[0044] FIGURE 2 illustrates an example gNB 102 according to embodiments of the present disclosure. The embodiment of the gNB 102 illustrated in FIGURE 2 is for illustration only, and the gNBs 101 and 103 of FIGURE 1 could have the same or similar configuration. However, gNBs come in a wide variety of configurations, and FIGURE 2 does not limit the scope of the present disclosure to any particular implementation of a gNB. For example, the gNB may include a transceiver and at least one processor.

[0045] As shown in FIGURE 2, the gNB 102 includes multiple antennas 205a-205n, multiple transceivers 210a-210n, a controller / processor 225, a memory 230, and a backhaul or network interface 235.

[0046] The transceivers 210a-210n receive, from the antennas 205a-205n, incoming radio frequency (RF) signals, such as signals transmitted by UEs in the wireless network 100. The transceivers 210a-210n down-convert the incoming RF signals to generate IF or baseband signals. The IF or baseband signals are processed by receive (RX) processing circuitry in the transceivers 210a-210n and / or controller / processor 225, which generates processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. The controller / processor 225 may further process the baseband signals.

[0047] Transmit (TX) processing circuitry in the transceivers 210a-210n and / or controller / processor 225 receives analog or digital data (such as voice data, web data, e-mail, or interactive video game data) from the controller / processor 225. The TX processing circuitry encodes, multiplexes, and / or digitizes the outgoing baseband data to generate processed baseband or IF signals. The transceivers 210a-210n up-converts the baseband or IF signals to RF signals that are transmitted via the antennas 205a-205n.

[0048] The controller / processor 225 may include one or more processors or other processing devices that control the overall operation of the gNB 102. For example, the controller / processor 225 could control the reception of uplink (UL) channel signals and the transmission of downlink (DL) channel signals by the transceivers 210a-210n in accordance with well-known principles. The controller / processor 225 could support additional functions as well, such as more advanced wireless communication functions. For instance, the controller / processor 225 could support beam forming or directional routing operations in which outgoing / incoming signals from / to multiple antennas 205a-205n are weighted differently to effectively steer the outgoing signals in a desired direction. As another example, the controller / processor 225 could support methods for delay and frequency reporting for coherent joint transmission. Any of a wide variety of other functions could be supported in the gNB 102 by the controller / processor 225.

[0049] The controller / processor 225 is also capable of executing programs and other processes resident in the memory 230, such as processes to support delay and frequency reporting for coherent joint transmission. The controller / processor 225 may move data into or out of the memory 230 as required by an executing process.

[0050] The controller / processor 225 is also coupled to the backhaul or network interface 235. The backhaul or network interface 235 allows the gNB 102 to communicate with other devices or systems over a backhaul connection or over a network. The interface 235 could support communications over any suitable wired or wireless connection(s). For example, when the gNB 102 is implemented as part of a cellular communication system (such as one supporting 5G / NR, LTE, or LTE-A), the interface 235 could allow the gNB 102 to communicate with other gNBs over a wired or wireless backhaul connection. When the gNB 102 is implemented as an access point, the interface 235 could allow the gNB 102 to communicate over a wired or wireless local area network or over a wired or wireless connection to a larger network (such as the Internet). The interface 235 includes any suitable structure supporting communications over a wired or wireless connection, such as an Ethernet or transceiver.

[0051] The memory 230 is coupled to the controller / processor 225. Part of the memory 230 could include a RAM, and another part of the memory 230 could include a Flash memory or other ROM.

[0052] Although FIGURE 2 illustrates one example of gNB 102, various changes may be made to FIGURE 2. For example, the gNB 102 could include any number of each component shown in FIGURE 2. Also, various components in FIGURE 2 could be combined, further subdivided, or omitted and additional components could be added according to particular needs.

[0053] FIGURE 3 illustrates an example UE 116 according to embodiments of the present disclosure. The embodiment of the UE 116 illustrated in FIGURE 3 is for illustration only, and the UEs 111-115 of FIGURE 1 could have the same or similar configuration. However, UEs come in a wide variety of configurations, and FIGURE 3 does not limit the scope of the present disclosure to any particular implementation of a UE. For example, the UE may include a transceiver and at least one processor.

[0054] As shown in FIGURE 3, the UE　116 includes antenna(s) 305, a transceiver(s) 310, and a microphone 320. The UE　116 also includes a speaker 330, a processor 340, an input / output (I / O) interface (IF) 345, an input 350, a display 355, and a memory 360. The memory 360 includes an operating system (OS) 361 and one or more applications 362.

[0055] The transceiver(s) 310 receives from the antenna(s) 305, an incoming RF signal transmitted by a gNB of the wireless network 100. The transceiver(s) 310 down-converts the incoming RF signal to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is processed by RX processing circuitry in the transceiver(s) 310 and / or processor 340, which generates a processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signal. The RX processing circuitry sends the processed baseband signal to the speaker 330 (such as for voice data) or is processed by the processor 340 (such as for web browsing data).

[0056] TX processing circuitry in the transceiver(s) 310 and / or processor 340 receives analog or digital voice data from the microphone 320 or other outgoing baseband data (such as web data, e-mail, or interactive video game data) from the processor 340. The TX processing circuitry encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The transceiver(s) 310 up-converts the baseband or IF signal to an RF signal that is transmitted via the antenna(s) 305.

[0057] The processor 340 may include one or more processors or other processing devices and execute the OS 361 stored in the memory 360 in order to control the overall operation of the UE 116. For example, the processor 340 could control the reception of DL channel signals and the transmission of UL channel signals by the transceiver(s) 310 in accordance with well-known principles. In some embodiments, the processor 340 includes at least one microprocessor or microcontroller.

[0058] The processor 340 is also capable of executing other processes and programs resident in the memory 360. For example, the processor 340 may execute processes for delay and frequency reporting for coherent joint transmission as described in embodiments of the present disclosure. The processor 340 may move data into or out of the memory 360 as required by an executing process. In some embodiments, the processor 340 is configured to execute the applications 362 based on the OS 361 or in response to signals received from gNBs or an operator. The processor 340 is also coupled to the I / O interface 345, which provides the UE 116 with the ability to connect to other devices, such as laptop computers and handheld computers. The I / O interface 345 is the communication path between these accessories and the processor 340.

[0059] The processor 340 is also coupled to the input 350, which includes, for example, a touchscreen, keypad, etc., and the display 355. The operator of the UE 116 may use the input 350 to enter data into the UE 116. The display 355 may be a liquid crystal display, light emitting diode display, or other display capable of rendering text and / or at least limited graphics, such as from web sites.

[0060] The memory 360 is coupled to the processor 340. Part of the memory 360 could include a random-access memory (RAM), and another part of the memory 360 could include a Flash memory or other read-only memory (ROM).

[0061] Although FIGURE 3 illustrates one example of UE 116, various changes may be made to FIGURE 3. For example, various components in FIGURE 3 could be combined, further subdivided, or omitted and additional components could be added according to particular needs. As a particular example, the processor 340 could be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). In another example, the transceiver(s) 310 may include any number of transceivers and signal processing chains and may be connected to any number of antennas. Also, while FIGURE 3 illustrates the UE 116 configured as a mobile telephone or smartphone, UEs could be configured to operate as other types of mobile or stationary devices.

[0062] FIGURE 4A and FIGURE 4B illustrate an example of wireless transmit and receive paths 400 and 450, respectively, according to embodiments of the present disclosure. For example, a transmit path 400 may be described as being implemented in a gNB (such as gNB 102), while a receive path 450 may be described as being implemented in a UE (such as UE 116). However, it will be understood that the receive path 450 may be implemented in a gNB and that the transmit path 400 may be implemented in a UE. In some embodiments, the transmit path 400 is configured for delay and frequency reporting for coherent joint transmission as described in embodiments of the present disclosure.

[0063] As illustrated in FIGURE 4A, the transmit path 400 includes a channel coding and modulation block 405, a serial-to-parallel (S-to-P) block 410, a size N Inverse Fast Fourier Transform (IFFT) block 415, a parallel-to-serial (P-to-S) block 420, an add cyclic prefix block 425, and an up-converter (UC) 430. The receive path 450 includes a down-converter (DC) 455, a remove cyclic prefix block 460, a S-to-P block 465, a size N Fast Fourier Transform (FFT) block 470, a parallel-to-serial (P-to-S) block 475, and a channel decoding and demodulation block 480.

[0064] In the transmit path 400, the channel coding and modulation block 405 receives a set of information bits, applies coding (such as a low-density parity check (LDPC) coding), and modulates the input bits (such as with Quadrature Phase Shift Keying (QPSK) or Quadrature Amplitude Modulation (QAM)) to generate a sequence of frequency-domain modulation symbols. The serial-to-parallel block 410 converts (such as de-multiplexes) the serial modulated symbols to parallel data in order to generate N parallel symbol streams, where N is the IFFT / FFT size used in the gNB and the UE. The size N IFFT block 415 performs an IFFT operation on the N parallel symbol streams to generate time-domain output signals. The parallel-to-serial block 420 converts (such as multiplexes) the parallel time-domain output symbols from the size N IFFT block 415 in order to generate a serial time-domain signal. The add cyclic prefix block 425 inserts a cyclic prefix to the time-domain signal. The up-converter 430 modulates (such as up-converts) the output of the add cyclic prefix block 425 to a RF frequency for transmission via a wireless channel. The signal may also be filtered at a baseband before conversion to the RF frequency.

[0065] As illustrated in FIGURE 4B, the down-converter 455 down-converts the received signal to a baseband frequency, and the remove cyclic prefix block 460 removes the cyclic prefix to generate a serial time-domain baseband signal. The serial-to-parallel block 465 converts the time-domain baseband signal to parallel time-domain signals. The size N FFT block 470 performs an FFT algorithm to generate N parallel frequency-domain signals. The (P-to-S) block 475 converts the parallel frequency-domain signals to a sequence of modulated data symbols. The channel decoding and demodulation block 480 demodulates and decodes the modulated symbols to recover the original input data stream.

[0066] Each of the gNBs 101-103 may implement a transmit path 400 that is analogous to transmitting in the downlink to UEs 111-116 and may implement a receive path 450 that is analogous to receiving in the uplink from UEs 111-116. Similarly, each of UEs 111-116 may implement a transmit path 400 for transmitting in the uplink to gNBs 101-103 and may implement a receive path 450 for receiving in the downlink from gNBs 101-103.

[0067] Each of the components in FIGURES 4A and 4B may be implemented using only hardware or using a combination of hardware and software / firmware. As a particular example, at least some of the components in FIGURES 4A and 4B may be implemented in software, while other components may be implemented by configurable hardware or a mixture of software and configurable hardware. For instance, the FFT block 470 and the IFFT block 415 may be implemented as configurable software algorithms, where the value of size N may be modified according to the implementation.

[0068] Furthermore, although described as using FFT and IFFT, this is by way of illustration only and should not be construed to limit the scope of the present disclosure. Other types of transforms, such as Discrete Fourier Transform (DFT) and Inverse Discrete Fourier Transform (IDFT) functions, may be used. It will be appreciated that the value of the variable N may be any integer number (such as 1, 2, 3, 4, or the like) for DFT and IDFT functions, while the value of the variable N may be any integer number that is a power of two (such as 1, 2, 4, 8, 16, or the like) for FFT and IFFT functions.

[0069] Although FIGURES 4A and 4B illustrate examples of wireless transmit and receive paths 400 and 450, respectively, various changes may be made to FIGURES 4A and 4B. For example, various components in FIGURES 4A and 4B may be combined, further subdivided, or omitted and additional components may be added according to particular needs. Also, FIGURES 4A and 4B are meant to illustrate examples of the types of transmit and receive paths that may be used in a wireless network. Any other suitable architectures may be used to support wireless communications in a wireless network.

[0070] FIGURE 5 illustrates an example of a transmitter structure 500 for beamforming according to embodiments of the present disclosure. In certain embodiments, one or more of gNB 102 or UE 116 includes the transmitter structure 500. For example, one or more of antenna 205 and its associated systems or antenna 305 and its associated systems may be included in transmitter structure 500. This example is for illustration only and other embodiments may be used without departing from the scope of the present disclosure.

[0071] In a hybrid analog-digital beamforming, analog beamforming corresponds to a 'dynamic / varying' virtualization of multiple antenna elements to obtain one antenna port (or antenna panel). Although a number of antenna elements may be larger for a given form factor, a number of CSI-RS ports, that may correspond to the number of digitally precoded ports, may be limited due to hardware constraints (such as the feasibility to install a large number of analog-to-digital converters (ADCs) / digital-to-analog converters (DACs) at mmWave frequencies) as illustrated in FIGURE 5. Then, one CSI-RS port may be mapped onto a large number of antenna elements that may be controlled by a bank of analog phase shifters 501. One CSI-RS port may then correspond to one sub-array which produces a narrow analog beam through analog beamforming 505. This analog beam may be configured to sweep across a wider range of angles 520 by varying the phase shifter bank across symbols or slots / subframes. The number of sub-arrays (equal to the number of RF chains) is the same as the number of CSI-RS ports NCSI-PORT. A digital beamforming unit 510 performs a linear combination across NCSI-PORTanalog beams to further increase a precoding gain. While analog beams are wideband (hence not frequency-selective), digital precoding may be varied across frequency sub-bands or resource blocks. Receiver operation may be conceived analogously.

[0072] Since the transmitter structure 500 of FIGURE 5 utilizes multiple analog beams for transmission and reception (wherein one or a small number of analog beams are selected out of a large number, for instance, after a training duration that is occasionally or periodically performed), the term "multi-beam operation" is used to refer to the overall system aspect. This includes, for the purpose of illustration, indicating the assigned DL or UL TX beam (also termed "beam indication"), measuring at least one reference signal for calculating and performing beam reporting (also termed "beam measurement" and "beam reporting", respectively), and receiving a DL or UL transmission via a selection of a corresponding RX beam.

[0073] The system of FIGURE 5 is also applicable to higher frequency bands such as >52.6GHz (also termed frequency range 4 or FR4). In this case, the system may employ only analog beams. Due to the O2 absorption loss around 60 GHz frequency (~10 dB additional loss per 100 m distance), a larger number and narrower analog beams (hence a larger number of radiators in the array) are essential to compensate for the additional path loss.

[0074] A communication system includes a DownLink (DL) that conveys signals from transmission points such as Base Stations (BSs) or NodeBs to User Equipments (UEs) and an UpLink (UL) that conveys signals from UEs to reception points such as NodeBs. A UE, also commonly referred to as a terminal or a mobile station, may be fixed or mobile and may be a cellular phone, a personal computer device, or an automated device. An eNodeB (eNB) or gNodeB (gNB), which is generally a fixed station, may also be referred to as an access point or other equivalent terminology. For LTE systems, a NodeB is often referred as an eNodeB. For NR systems, a NodeB is often referred as an gNodeB.

[0075] In a communication system, such as NR or LTE, DL signals may include data signals conveying information content, control signals conveying DL Control Information (DCI), and Reference Signals (RS) that are also known as pilot signals. An eNodeB transmits data information through a Physical DL Shared CHannel (PDSCH). An eNB / gNB transmits DCI through a Physical DL Control CHannel (PDCCH). An eNB / gNB transmits one or more of multiple types of RS including a Channel State Information RS (CSI-RS), or a DeModulation RS (DMRS). An eNB / gNB may transmit a CSI-RS for time / frequency tracking (aka common reference signal (CRS) in LTE or TRS in NR), for CSI reporting. DMRS may be transmitted only in the bandwidth (BW) of a respective PDSCH and a UE may use the DMRS to demodulate data or control information in a PDSCH or a PDCCH, respectively. A transmission time interval for DL channels is referred to as a subframe or slot and may have, for example, duration of 1 millisecond or a value depending on the subcarrier-spacing (SCS).

[0076] DL signals also include transmission of a logical channel that carries system control information. A broadcast control channel (BCCH) is mapped to either a transport channel referred to as a Broadcast CHannel (BCH) when it conveys a Master Information Block (MIB) or to a DL Shared CHannel (DL-SCH) when it conveys a System Information Block (SIB) - see also REF3 and REF 5. Most system information is included in different SIBs that are transmitted using DL-SCH. A presence of system information on a DL-SCH in a subframe (or slot) may be indicated by a transmission of a corresponding PDCCH conveying a codeword with a cyclic redundancy check (CRC) scrambled with a special System Information RNTI (SI-RNTI). Alternatively, scheduling information for a SIB transmission may be provided in an earlier SIB and scheduling information for the first SIB (SIB-1) may be provided by the MIB.

[0077] DL resource allocation is performed in a unit of subframe (or slot) and a group of Physical resource blocks (PRBs). A transmission BW includes of frequency resource units referred to as Resource Blocks (RBs). Each RB includes sub-carriers, or Resource Elements (REs), such as 12 REs. A unit of one RB over one subframe (or slot) is referred to as a PRB. A UE may be allocated RBs for a total of REs for the PDSCH transmission BW.

[0078] UL signals may include data signals conveying data information, control signals conveying UL Control Information (UCI), and UL RS. UL RS includes DMRS and Sounding RS (SRS). A UE transmits DMRS only in a BW of a respective PUSCH or PUCCH. An eNB / gNB may use a DMRS to demodulate data signals or UCI signals. A UE transmits SRS to provide an eNB / gNB with an UL CSI. A UE transmits data information or UCI through a respective Physical UL Shared CHannel (PUSCH) or a Physical UL Control CHannel (PUCCH). If a UE needs to transmit data information and UCI in a same UL subframe (or slot), it may multiplex both in a PUSCH. UCI includes Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK) information, indicating correct (ACK) or incorrect (NACK, negative ACK) detection for a data transport block (TB) in a PDSCH or absence of a PDCCH detection (DTX), Scheduling Request (SR) indicating whether a UE has data in its buffer, and Channel State Information (CSI) enabling an eNB / gNB to perform link adaptation for PDSCH transmissions to a UE. HARQ-ACK information is also transmitted by a UE in response to a detection of a PDCCH indicating a release of semi-persistently scheduled PDSCH (see also REF 3).

[0079] An UL subframe (or slot) includes two slots. Each slot includes symbols for transmitting data information, UCI, DMRS, or SRS. A frequency resource unit of an UL system BW is a RB. A UE is allocated RBs for a total of REs for a transmission BW. A last few subframe (or slot) symbols may be used to multiplex SRS transmissions from one or more UEs.

[0080] FIGURE 6 illustrates an example of a transmitter structure 600 for PDSCH in a subframe according to embodiments of the present disclosure. For example, transmitter structure 600 may be implemented in gNB 102 of FIGURE 1. This example is for illustration only and other embodiments may be used without departing from the scope of the present disclosure.

[0081] As illustrated in FIGURE 6, information bits 610 are encoded by encoder 620, such as a turbo encoder, and modulated by modulator 630, for example using Quadrature Phase Shift Keying (QPSK) modulation. A Serial to Parallel (S / P) converter 640 generates M modulation symbols that are subsequently provided to a mapper 650 to be mapped to REs selected by a transmission BW selection unit 655 for an assigned PDSCH transmission BW, unit 660 applies an Inverse Fast Fourier Transform (IFFT), the output is then serialized by a Parallel to Serial (P / S) converter 670 to create a time domain signal, filtering is applied by filter 680, and a signal transmitted 690. Additional functionalities, such as data scrambling, cyclic prefix insertion, time windowing, interleaving, and others are well known in the art and are not shown for brevity.

[0082] FIGURE 7 illustrates an example of a receiver structure 700 for PDSCH in a subframe according to embodiments of the present disclosure. For example, receiver structure 700 may be implemented by any of the UEs 111-116 of FIGURE 1. This example is for illustration only and other embodiments may be used without departing from the scope of the present disclosure.

[0083] With reference to FIGURE 7, a received signal 710 is filtered by filter 720, REs 730 for an assigned reception BW are selected by BW selector 735, unit 740 applies a Fast Fourier Transform (FFT), and an output is serialized by a parallel-to-serial converter 750. Subsequently, a demodulator 760 coherently demodulates data symbols by applying a channel estimate obtained from a DMRS or a CRS (not shown), and a decoder 770, such as a turbo decoder, decodes the demodulated data to provide an estimate of the information data bits 780. Additional functionalities such as time-windowing, cyclic prefix removal, de-scrambling, channel estimation, and de-interleaving are not shown for brevity.

[0084] FIGURE 8 illustrates an example of a transmitter structure 800 for PUSCH in a subframe according to embodiments of the present disclosure. For example, transmitter structure 800 may be implemented in gNB 103 of FIGURE 1. This example is for illustration only and other embodiments may be used without departing from the scope of the present disclosure.

[0085] As illustrated in FIGURE 8, information data bits 810 are encoded by encoder 820, such as a turbo encoder, and modulated by modulator 830. A Discrete Fourier Transform (DFT) unit 840 applies a DFT on the modulated data bits, REs 850 corresponding to an assigned PUSCH transmission BW are selected by transmission BW selection unit 855, unit 860 applies an IFFT and, after a cyclic prefix insertion (not shown), filtering is applied by filter 870 and a signal is transmitted 880.

[0086] FIGURE 9 illustrates an example of a receiver structure 900 for a PUSCH in a subframe according to embodiments of the present disclosure; For example, receiver structure 900 may be implemented by the UE 116 of FIGURE 3. This example is for illustration only and other embodiments may be used without departing from the scope of the present disclosure.

[0087] As illustrated in FIGURE 9, a received signal 910 is filtered by filter 920. Subsequently, after a cyclic prefix is removed (not shown), unit 930 applies a FFT, REs 940 corresponding to an assigned PUSCH reception BW are selected by a reception BW selector 945, unit 950 applies an Inverse DFT (IDFT), a demodulator 960 coherently demodulates data symbols by applying a channel estimate obtained from a DMRS (not shown), a decoder 970, such as a turbo decoder, decodes the demodulated data to provide an estimate of the information data bits 980.

[0088] There are two types of frequency range (FR) defined in 3GPP 5G NR specifications. The sub-6 GHz range is called frequency range 1 (FR1) and millimeter wave range is called frequency range 2 (FR2). An example of the frequency range for FR1 and FR2 is shown herein.

[0089] Table 0

[0090]

[0091] For MIMO in FR1, up to 32 CSI-RS antenna ports in one CSI-RS resource is supported, and in FR2, up to 8 CSI-RS antenna ports in one CSI-RS resource is supported. A (spatial or digital) precoding / beamforming may be used across these large number of antenna ports in order to achieve MIMO gains. Depending on the carrier frequency, and the feasibility of RF / HW-related components, the (spatial) precoding / beamforming may be fully digital or hybrid analog-digital.

[0092] In fully digital beamforming, there may be one-to-one mapping between an antenna port and an antenna element, or a 'static / fixed' virtualization of multiple antenna elements to one antenna port may be used. Each antenna port may be digitally controlled. Hence, a spatial multiplexing across antenna ports is feasible.

[0093] In next generation cellular standards (e.g. 6G), in addition to FR1 and FR2, new carrier frequency bands may be evaluated, e.g., FR4 (>52.6GHz), terahertz (>100GHz) and upper mid-band (10-15GHz). The number of CSI-RS ports that may be supported for these new bands is likely to be different from FR1 and FR2. In particular, for 10-15GHz band, the max number of CSI-RS antenna ports is likely to be more than FR1, due to smaller antenna form factors, and feasibility of fully digital beamforming (as in FR1) at these frequencies. For instance, the number of CSI-RS antenna ports may grow up to 128. Besides, the NW deployment / topology at these frequencies is also expected to be denser / distributed, for example, antenna ports distributed at multiple (may be non-co-located, hence geographically separated) TRPs within a cellular region may be the main scenario of interest, due to which the number of CSI-RS antenna ports for MIMO may be even larger (e.g. up to 256).

[0094] Likewise, for a cellular system operating in low carrier frequency in general, a sub-1GHz frequency range (e.g. less than 1 GHz) as an example, supporting large number of CSI-RS antenna ports (e.g. 32) or many antenna elements at a single location or remote radio head (RRH) or TRP is challenging due to a larger antenna form factor size needed taking into account carrier frequency wavelength than a system operating at a higher frequency such as 2 GHz or 4 GHz. At such low frequencies, the maximum number of CSI-RS antenna ports that may be co-located at a site (or RRH or TRP) may be limited, for example to 8. This limits the spectral efficiency of such systems. In particular, the multi user MIMO (MU-MIMO) spatial multiplexing gains offered due to large number of CSI-RS antenna ports (such as 32) can't be achieved due to the antenna form factor limitation. One plausible way to operate a system with large number of CSI-RS antenna ports at low carrier frequency is to distribute the physical antenna ports to different panels / RRHs / TRPs, which may be non-collocated. The multiple sites or panels / RRHs / TRPs may still be connected to a single (common) base unit forming a single antenna system, hence the signal transmitted / received via multiple distributed RRHs / TRPs may still be processed at a centralized location.

[0095] As described above, for low (FR1), high (FR2 and beyond), or mid (6-15GHz) band, the NW topology / architecture is likely to be more and more distributed in future due to reasons explained above (e.g. use cases, HW requirements, antenna form factors, mobility etc.). In this disclosure, such a distributed system is referred to as a DMIMO or multiple TRP (mTRP) system (multiple antenna port groups, which may be non-co-located). The transmission in such a system may be coherent joint transmission (CJT), i.e., a layer may be transmitted across / using multiple TRPs, or non-coherent joint transmission (NCJT). Due to distributed nature of operation, the groups of antenna ports (or TRPs) need to be calibrated / synchronized by compensating for the non-idealities such as time / frequency / phase offsets non-ideal backhaul across TRPs, due to HW impairments, different delay profiles, and Doppler profile (in high-speed scenarios) associated with different TRPs.

[0096] In a wireless communication system, MIMO is often identified as an essential feature in order to achieve high system throughput requirements. One of the key components of a MIMO transmission scheme is the accurate CSI acquisition at the eNB (or gNB) (or TRP). For MU-MIMO, in particular, the availability of accurate CSI is necessary in order to guarantee high MU performance. For time division duplexing (TDD) systems, the CSI may be acquired using the SRS transmission relying on the channel reciprocity. For frequency division duplexing (FDD) systems, on the other hand, it may be acquired using the CSI-RS transmission from eNB (or gNB), and CSI acquisition and feedback from UE.

[0097] In 5G or NR systems [REF7, REF8], both low- (aka Type I) and high-resolution (aka Type II) CSI reporting mechanisms are supported. In addition, to reduce Type II CSI reporting, a frequency domain (FD) compression based Type II CSI is also supported, which is based on (a) spatial domain (SD) basis , (b) FD basis , and (c) coefficients 　 that linearly combine SD and FD bases. For a (full TDD or partial FDD) reciprocity, CSI-RS ports may be beamformed (using SRS measurements, assuming UL-DL channel reciprocity in angular / delay), and the SD basis corresponds to a port selection basis.

[0098] In Rel.18, the FD-compression-based Type II CSI is further enhanced for the use case of CJT across up to 4 TRPs, under the idealistic assumptions such as perfectly time and frequency synchronized mTRPs, phase-coherent antenna ports and ideal backhaul links. In practice, however, these assumptions are not valid, and calibration / synchronization across TRPs is necessary in order to make CJT feasible.

[0099] Massive MIMO base stations or TRPs use an on-board coupling network and calibration circuits, referred to as the on-board calibration for brevity, to measure the gain and phase differences among transceivers in the same radio frequency (RF) unit in order to maintain the reciprocity between DL and UL channels, in the TDD system in particular. For the on-board calibration, one RF chain corresponding to one antenna port serves as a reference to other RF chains for other antenna ports. Embodiments of the present disclosure recognizes that in the case of the mTRP system, such reference transceiver's signal needs to be shared between distributed RRHs / panels / modules / TRPs, which are physically far apart or non-co-located. Using RF cables to distribute the reference is not preferable as it limits the deployment scenarios. In addition, the use of different local oscillators (LOs) between distributed antenna modules imposes even more challenges in achieving calibration as the phase of LOs could drift. Periodic calibration is needed to compensate for the phase drift as well.

[0100] Issue 1: In one example, the timing offset may be expressed as , where is due to timing difference between (distributed, non-co-located) TRPs or / and different propagation delays from different TRPs, which amounts to increased frequency-selectivity of the composite channel. The min freq. granularity (supported in NR) is 2 RBs (for precoding matrix indicator (PMI)) and 4 RBs (CQI), which correspond to a max delay spread 2.8 and 1.4 micro second for SCS = 15 and 30 kHz, respectively. This delay spread decreases further with increasing freq. granularity (due to timing offset). For large delay spread, the required freq. granularity for CJT (across TRPs) will be smaller than 2RBs.

[0101] Table 9.6.1.3-1: OTA frequency error minimum requirement

[0102]

[0103] Issue 2: In one example, the frequency offset may be expressed as , where is due to non-ideal (and may be different) local oscillators or crystal types at different TRPs, which results in frequency differences between TRPs. As shown above, the min freq. error = 0.05ppm, according to TS 38.104. The phase change due to freq. error may be significant, especially at higher carrier frequencies.

[0104] In general, the combined (time-frequency) T-F offset may be expressed as . For CJT feasibility, needs to be calibrated frequently.

[0105] Issue 3: non-ideal backhaul links between TRPs, especially when the backhaul links are not fiber-optic cables.

[0106] Issue 4: phase-coherency across antenna ports, both intra-TRP (within each TRP) and inter-TRP (across TRPs).

[0107] In various non-limiting embodiments of this disclosure, the mechanism are procedures are provided for Issue 1 and 2, which are more severe than Issue 3 and 4.

[0108] In one example, a TRP or RRH may be functionally equivalent to (hence may be replaced with) or is interchangeable with one of more of the following: an antenna, or an antenna group (multiple antennae), an antenna port, an antenna port group (multiple ports), a CSI-RS resource, multiple CSI-RS resources, a CSI-RS resource set, multiple CSI-RS resource sets, an antenna panel, multiple antenna panels, a Tx-Rx entity, a (analog) beam, a (analog) beam group, a cell, a cell group.

[0109] This disclosure provides over-the-air (OTA) signaling mechanism for calibration among multiple TRPs or RRHs. The mechanism includes 1) DL RS (e.g. CSI-RS) transmission from mTRPs and measurement (by the UE) and 2) Reporting related to the calibration information (e.g. amp / phase of calibration coefficients). Aspects of the disclosure are as follows:

[0110] Two delay value reporting per TRP, and

[0111] Different bits for alphabet sets associated with the two delay values.

[0112] Although the focus of this disclosure is on 3GPP 5G NR communication systems, various embodiments may apply in general to UEs operating with other RATs and / or standards, such as different releases / generations of 3GPP standards (including beyond 5G, 6G, and so on), IEEE standards (such as 802.16 WiMAX and 802.11 Wi-Fi), and so on.

[0113] A description of example embodiments are provided on the following pages.

[0114] The text and figures are provided solely as examples to aid the reader in understanding the disclosure. They are not intended and are not to be construed as limiting the scope of this disclosure in any manner. Although certain embodiments and examples have been provided, it will be apparent to those skilled in the art based on the disclosures herein that changes in the embodiments and examples shown may be made without departing from the scope of this disclosure.

[0115] Aspects, features, and advantages of the present disclosure are readily apparent from the following detailed description, simply by illustrating a number of particular embodiments and implementations, including the best mode contemplated for carrying out the present disclosure. Embodiments of the present disclosure also capable of other and different embodiments, and its several details may be modified in various obvious respects, all without departing from the spirit and scope of the present disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive. Embodiments of the present disclosure are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings.

[0116] In the following, for brevity, both FDD and TDD are regarded as the duplex method for both DL and UL signaling.

[0117] Although exemplary descriptions and embodiments to follow expect orthogonal frequency division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA), this disclosure may be extended to other OFDM-based transmission waveforms or multiple access schemes such as filtered OFDM (F-OFDM).

[0118] This disclosure covers several components which may be used in conjunction or in combination with one another, or may operate as standalone schemes.

[0119] The following components and embodiments are applicable for UL transmission with cyclic prefix OFDM (CP-OFDM) waveform as well as DFT-SOFDM (DFT-spread OFDM) and SC-FDMA (single-carrier FDMA) waveforms. Furthermore, the following components and embodiments are applicable for UL transmission when the scheduling unit in time is either one subframe (which may include one or multiple slots) or one slot.

[0120] In the present disclosure, the frequency resolution (reporting granularity) and span (reporting bandwidth) of CSI or calibration coefficient reporting may be defined in terms of frequency "subbands" and "CSI reporting band" (CRB), respectively.

[0121] A subband for CSI or calibration coefficient reporting is defined as a set of contiguous PRBs which represents the smallest frequency unit for CSI or calibration coefficient reporting. The number of PRBs in a subband may be fixed for a given value of DL system bandwidth, configured either semi-statically via higher-layer / RRC signaling, or dynamically via L1 DL control signaling or MAC control element (MAC CE). The number of PRBs in a subband may be included in CSI or calibration coefficient reporting setting.

[0122] "CSI or calibration coefficient reporting band" is defined as a set / collection of subbands, either contiguous or non-contiguous, wherein CSI or calibration coefficient reporting is performed. For example, CSI or calibration coefficient reporting band may include the subbands within the DL system bandwidth. This may also be termed "full-band". Alternatively, CSI or calibration coefficient reporting band may include only a collection of subbands within the DL system bandwidth. This may also be termed "partial band".

[0123] The term "CSI or calibration coefficient reporting band" is used only as an example for representing a function. Other terms such as "CSI or calibration coefficient reporting subband set" or "CSI or calibration coefficient reporting bandwidth" may also be used.

[0124] In terms of UE configuration, a UE (e.g., the UE 116) may be configured with at least one CSI or calibration coefficient reporting band. This configuration may be semi-static (via higher-layer signaling or RRC) or dynamic (via MAC CE or L1 DL control signaling). When configured with multiple (N) CSI or calibration coefficient reporting bands (e.g. via RRC signaling), a UE may report CSI associated with CSI reporting bands. For instance, >6GHz, large system bandwidth may require multiple CSI or calibration coefficient reporting bands. The value of n may either be configured semi-statically (via higher-layer signaling or RRC) or dynamically (via MAC CE or L1 DL control signaling). Alternatively, the UE may report a recommended value of n via an UL channel.

[0125] Therefore, CSI parameter frequency granularity may be defined per CSI reporting band as follows. A CSI parameter is configured with "single" reporting for the CSI reporting band with Mnsubbands when one CSI parameter for the Mnsubbands within the CSI reporting band. A CSI parameter is configured with "subband" for the CSI reporting band with Mnsubbands when one CSI parameter is reported for each of the Mnsubbands within the CSI reporting band.

[0126] FIGURE 10 illustrates a diagram of an antenna port layout 1000 according to embodiments of the present disclosure. For example, antenna port layout 1000 of an antenna port layout may be implemented by the BS 102 of FIGURE 2. This example is for illustration only and may be used without departing from the scope of the present disclosure.

[0127] With reference to FIGURE 10, and are the number of antenna ports with the same polarization in the first and second dimensions, respectively. For 2D antenna port layouts, >1, >1, and for 1D antenna port layouts >1 and =1 (or =1 and >1). For a single-polarized (or co-polarized) antenna port layout, the total number of antenna ports is . And, for a dual-polarized antenna port layout, the total number of antenna ports is . An illustration is shown in FIGURE 10 where "X" represents two antenna polarizations. In this disclosure, the term "polarization" refers to a group of antenna ports with the same polarization. For example, antenna ports comprise a first antenna polarization, and antenna ports comprise a second antenna polarization, where is a number of CSI-RS antenna ports and is a starting antenna port number (e.g. , then antenna ports are 3000, 3001, 3002, ...). Dual-polarized antenna payouts are expected in this disclosure. The embodiments (and examples) in this disclosure however are general and are applicable to single-polarized antenna layouts as well.

[0128] Let be a number of antenna groups (AGs). With reference to FIGURE 10, when there are multiple antenna groups ( ), each group ( ) including dual-polarized antenna ports with and ports in two dimensions is expected. Note that the antenna port layouts may be the same ( and ) in different antenna groups, or they may be different across antenna groups. For group g, the number of antenna ports is or (for co-polarized or dual-polarized respectively).

[0129] In one example, an antenna group corresponds to an antenna panel. In one example, an antenna group corresponds to a TRP. In one example, an antenna group corresponds to an RRH. In one example, an antenna group corresponds to CSI-RS antenna ports of a non-zero power (NZP) CSI-RS resource. In one example, an antenna group corresponds to a subset of CSI-RS antenna ports of a NZP CSI-RS resource (comprising multiple antenna groups). In one example, an antenna group corresponds to CSI-RS antenna ports of multiple NZP CSI-RS resources (e.g. comprising a CSI-RS resource set).

[0130] In one example, an antenna group corresponds to a reconfigurable intelligent surface (RIS) in which the antenna group may be (re-)configured more dynamically (e.g. via MAC CE or / and DCI). For example, the number of antenna ports associated with the antenna group may be changed dynamically.

[0131] FIGURE 11 illustrates examples of a UE moving on a trajectory 1100 located in co-located and distributed AGs according to embodiments of the present disclosure. For example, trajectory 1100 located in co-located and distributed AGs may be implemented by any of the UEs 111-116 of FIGURE 1. This example is for illustration only and may be used without departing from the scope of the present disclosure.

[0132] In one example scenario, multiple AGs may be co-located or distributed, and may serve static (non-mobile) or moving UEs. With reference to FIGURE 11, an illustration of AGs serving a moving UE is shown. While the UE moves from a location A to another location B, the UE measures the channel, e.g. via NZP CSI-RS resources, (may also measure the interference, e.g. via CSI interference measurement (CSI-IM) resources or CSI-RS resources for interference measurement), uses the measurement to determine / report CSI or calibration-related information taking into account joint transmission from multiple AGs.

[0133] In one example, the antenna architecture of the MIMO system is structured. For example, the antenna structure at each AG is dual-polarized (single or multi-panel as shown in FIGURE 10. The antenna structure at each AG may be the same. Or the antenna structure at an AG may be different from another AG. Likewise, the number of ports at each AG may be the same. Or the number of ports at one AG may be different from another AG.

[0134] In another example, the antenna architecture of the MIMO system is unstructured. For example, the antenna structure at one AG may be different from another AG.

[0135] A structured antenna architecture is expected in the rest of the disclosure. For simplicity, each AG is equivalent to a panel (cf. FIGURE 10), although, an AG may have multiple panels in practice. The disclosure however is not restrictive to a single panel assumption at each AG, and may easily be extended (covers) the case when an AG has multiple antenna panels.

[0136] In one embodiment, an AG constitutes (or corresponds to or is equivalent to) at least one of the following:

[0137] In one example, an AG corresponds to a TRP.

[0138] In one example, an AG corresponds to a CSI-RS resource. A UE is configured with non-zero-power (NZP) CSI-RS resources, and a CSI reporting is configured to be across multiple CSI-RS resources. This is similar to Class B, 1 configuration in Rel. 14 LTE. The NZP CSI-RS resources may belong to a CSI-RS resource set or multiple CSI-RS resource sets (e.g. resource sets each comprising one CSI-RS resource). The details are as explained in this disclosure herein.

[0139] In one example, an AG corresponds to a CSI-RS resource group, where a group comprises one or multiple NZP CSI-RS resources. A UE is configured with non-zero-power (NZP) CSI-RS resources, and a CSI reporting is configured to be across multiple CSI-RS resources from resource groups. This is similar to Class B, configuration in Rel. 14 LTE. The NZP CSI-RS resources may belong to a CSI-RS resource set or multiple CSI-RS resource sets (e.g. resource sets each comprising one CSI-RS resource). The details are as explained in this disclosure herein. In particular, the CSI-RS resources may be partitioned into resource groups. The information about the resource grouping may be provided together with the CSI-RS resource setting / configuration, or with the CSI reporting setting / configuration, or with the CSI-RS resource configuration.

[0140] In one example, an AG corresponds to a subset (or a group) of CSI-RS ports. A UE is configured with at least one NZP CSI-RS resource comprising (or associated with) CSI-RS ports that may be grouped (or partitioned) multiple subsets / groups / parts of antenna ports, each corresponding to (or constituting) an AG. The information about the subsets of ports or grouping of ports may be provided together with the CSI-RS resource setting / configuration, or with the CSI reporting setting / configuration, or with the CSI-RS resource configuration.

[0141] In one example, an AG corresponds to one or more examples described herein depending on a configuration. For example, this configuration may be explicit via a parameter (e.g. an RRC parameter). Or, it may be implicit.

[0142] In one example, when implicit, it could be based on the value of . For example, when CSI-RS resources, an AG corresponds to one or more examples described herein, and when CSI-RS resource, an AG corresponds to one or more examples described herein.

[0143] In another example, the configuration could be based on the configured codebook. For example, an AG corresponds to a CSI-RS resource or resource group when the codebook corresponds to a decoupled codebook (modular or separate codebook for each AG),and an AG corresponds to a subset (or a group) of CSI-RS ports when codebook corresponds to a coupled (joint or coherent) codebook (one joint codebook across AGs).

[0144] In one example, when AG maps (or corresponds to) a CSI-RS resource or resource group, and a UE may select a subset of AGs (resources or resource groups) and report the CSI or calibration-related information for the selected AGs (resources or resource groups), the selected AGs may be reported via an indicator (e.g. via UCI part 1 of a two-part UCI). For example, the indicator may be a CSI-RS resource indicator (CRI) or a PMI (component) or a new indicator (e.g. a bitmap).

[0145] In one example, when AG maps (or corresponds to) a CSI-RS port group, and a UE may select a subset of AGs (port groups) and report the CSI or calibration-related information for the selected AGs (port groups), the selected AGs may be reported via an indicator (e.g. via UCI part 1 of a two-part UCI). For example, the indicator may be a CRI or a PMI (component) or a new indicator (e.g. a bitmap).

[0146] In one example, CSI-RS herein in this disclosure comprises at least one or a combination of the following: CSI-RS for tracking (TRS), CSI-RS for CSI, CSI-RS for beam management (BM), CSI-RS for mobility or NZP CSI-RS resource for IMR (interference measurement) or a new type / usage of CSI-RS, namely, CSI-RS for calibration.

[0147] In one embodiment, a UE is configured with a calibration mechanism, wherein the UE is configured to perform one or more UL RS transmission(s), or / and to perform one or more DL RS reception(s) / measurement(s), and / or to report calibration-related information (e.g., for calibration coefficient for each TRP).

[0148] This configuration may be performed via higher-layer (e.g., RRC) signaling.

[0149] In one example, this configuration corresponds to a CSI resource setting configured via a higher layer IE CSI-ResourceConfig.

[0150] In one example, this configuration corresponds to a CSI resource set configured via a higher layer IE NZP-CSIRSResourceSet.

[0151] In one example, this configuration corresponds to a NZP CSI resource configured via a higher layer IE NZP-CSIRSResource.

[0152] In one example, this configuration corresponds to a CSI report setting configured via a higher layer IE CSI-ReportConfig.

[0153] In one example, the DL RS(s) may be one of or multiple of CSI-RS for CSI reporting, CSI-RS for tracking (TRS), CSI-RS for beam reporting, DL DMRS, or synchronization signal / physical broadcast channel (SSB / PBCH) or a new type / usage of CSI-RS, namely, CSI-RS for calibration. In one example, DL RS may be a dedicated or new DL RS (for calibration purpose).

[0154] In one example, the UL RS(s) may be one of or multiple of SRS with usage=CB, SRS with usage=non-CB, SRS with usage=beamManagement, SRS with usage=AntennaSwitching, or UL DMRS. In one example, UL RS may be a dedicated or new UL RS (for calibration purpose).

[0155] In one example, the DL RS(s) may be aperiodic (AP) only.

[0156] In one example, the DL RS(s) may be AP or semi-persistent (SP).

[0157] In one example, the DL RS(s) may be AP or periodic (P).

[0158] In one example, the DL RS(s) may be SP or P.

[0159] In one example, the DL RS(s) may be AP or SP or P.

[0160] In one example, the UL RS(s) may be aperiodic (AP) only.

[0161] In one example, the UL RS(s) may be AP or semi-persistent (SP).

[0162] In one example, the UL RS(s) may be AP or periodic (P).

[0163] In one example, the UL RS(s) may be SP or P.

[0164] In one example, the UL RS(s) may be AP or SP or P.

[0165] In one example, the reporting may only be AP. In this case, the reporting may be triggered via a DCI (e.g. a CSI request field in UL-DCI).

[0166] In one example, the reporting may either be AP or SP. For AP, the reporting may be triggered via a DCI (e.g. a CSI request field in UL-DCI), and for SP, it may be triggered via MAC CE or DCI.

[0167] In one example, the reporting may only be UE-initiated (or UE-triggered). In this case, the reporting may be triggered via UL MAC CE (e.g. MAC CE for power headroom report (PHR) reporting) or via a pre-notification message sent by the UE, where this message may be sent via SR (scheduling request) or via UCI (a pre-configured PUCCH or a PUSCH).

[0168] The term 'precoder' in this disclosure may be replaced with a spatial information (or transmission configuration indication (TCI) state, orspatialRelationInfo) or source RS or spatial filter, beamformer, beamforming vectors / matrices, precoding vector / matrices, or any other functionally equivalent quantity, that may be used for DL / UL RS reception / transmission.

[0169] In one embodiment, a UE (e.g., the UE 116) is configured with a measurement and a report (e.g. CSI or calibration report) including calibration-related information (CLI) to enable / facilitate calibration / synchronization across TRPs or AGs or CSI-RS resources. In one example, the measurement may be configured via higher layer IE CSI-ResourceConfig indicating sets of NZP CSI-RS resources. In one example, the measurement may be configured via higher layer IENZP-CSIRS-ResourceSetindicating a set of NZP CSI-RS resources. In one example, the measurement may be configured via higher layer IEMeasObj. In one example, the report may be configured via higher layer CSI-ReportConfig withreportTypeset to a new value, e.g. 'calibration' or 'cjt-calibration'.

[0170] Let be the measurement associated with r-th TRP (or CSI-RS resource or DL RS), where and be the composite / aggregated channel at a T-F unit and be the offsets associated with TRPs, where is configured by NW (e.g., MAC-CE, DCI, RRC), or reported by UE (e.g., via a bit-map indicator or a combinatorial indicator included in the CSI report) or .

[0171] As described in this disclosure, one of the TRPs may be a reference, whose offset may be fixed, e.g. to zero. Without loss generality, the reference TRP (resource) corresponds to (the 1stTRP) for which , i.e., .

[0172] In one example, values of , based on the measurement, may be evaluated / used to determine the report.

[0173] In one example, a low-pass or a window-based approach may be used for the report. In one example, the window corresponds to value of that are around the reference. For instance, and / or , where corresponds to the window length or max value of that may be evaluated / used for the report, may be fixed, or configured, or reported by the UE.

[0174] In one example, the unit of cross link interference (CLI) reporting is at least one of the following examples:

[0175] In one example, for time offset, the unit may be based on the CP length, or the symbol duration, or the slot duration. For example, values within a window / interval, [0, x], x=CP length, min measurement interval. In one example, sec or sec. In one example, sec or sec where .

[0176] In one example, for time offset, the unit may be based on a fractional factor (between 0 and 1) of a time division (TD) unit. For example, values within a window / interval, [0, x], x=TD unit length.

[0177] In one example, For frequency error (in ppm), the unit may be based on the window / interval, [0, x] or [-x, x], x=freq. error value specified in 38.104 (from RAN4). For example, values within a window / interval,[0, x] or [-x, x], x=FD unit length. In one example, x = 0.05 ppm (parts per million).

[0178] In one example, for time offset, the unit may be based on the normalized CP length, or the symbol duration, or the slot duration. For example, values within a window / interval, [0, 1], 1 corresponds to CP length, min measurement interval. In one example, the CP length sec or sec. In one example, the CP length sec or sec where .

[0179] In one example, for time offset, the unit may be based on a normalized fractional factor (between 0 and 1) of a TD unit. For example, values within a window / interval, [0, 1], 1 corresponds to TD unit length.

[0180] In one example, for frequency error (in ppm), the unit may be based on the normalized window / interval, [0, 1] or , 1 corresponds to freq. error value, e.g., specified in 38.104 (from RAN4). For example, values within a window / interval, [0, 1] or , x=FD unit length. In one example, ppm (parts per million).

[0181] Note that CP length may be also expressed as CP= , where is subcarrier spacing, e.g., (or etc) kHz. Or CP length may also be expressed as normal CP length or extended CP length, i.e., normal CP length = and extended CP length = . In this disclosure, CP length may be replaced by or or an approximated CP length or an extended CP length .

[0182] In one example, the CLI corresponds to at least one indicator indicating a measurement RS. For instance, the indicator may be CRI or SSB resource indicator (SSBRI) or other DL RS indicator when the measurement RS is NZP CSI-RS or SSB / PBCH block, or another DL RS. The at least one indicator may provide an implicit information about the offsets.

[0183] In one example, the CLI corresponds to the set of values of or pairs or indicator(s) indicating (quantized) values of . At least one of the following examples of alphabet set is used for quantizing .

[0184] In one example, the alphabet set corresponds to a uniform quantizer in linear scale.

[0185] In one example, includes values, uniformly / equally spaced / separated in , where is the number of bits for quantization and is the max value. In one example, the values include 0 or / and .

[0186] In one example, for time, where is the CP length, and is a scaling. In one example, =1.

[0187] In one example, for time, where is the slot duration, and is a scaling. In one example, =1.

[0188] In one example, for frequency, where is the min requirement on the frequency error, e.g. in parts per million (ppm).

[0189] In one example, includes values, uniformly / equally spaced / separated in where is the number of bits for quantization, is the min value, and is the max value. In one example, the values include or / and .

[0190] In one example, includes values, uniformly / equally spaced / separated in .

[0191] In one example, the alphabet set corresponds to a uniform quantizer in logarithmic scale.

[0192] In one example, the alphabet set corresponds to a non-uniform (e.g. exponential) quantizer .

[0193] In one example, includes Rel.15 3-bit amplitude alphabet set (Table 1).

[0194] In one example, includes Rel.16 3-bit or 4-bit amplitude alphabet set (Table 2, Table 3).

[0195] In one example, includes Rel.18 amplitude alphabet set for time-domain channel property (TDCP) report (Table 4).

[0196] Table 1: Mapping of elements of to

[0197]

[0198] Table 2: Mapping of elements of to

[0199]

[0200] Table 3: Mapping of elements of to

[0201]

[0202] Table 4: Mapping of elements to

[0203]

[0204] In one example, for delay reporting, the alphabet set includes at least one value corresponding to a value larger than the CP length.

[0205] In one example, the alphabet set includes values in where and here is the CP length, as described herein.

[0206] In one example, the alphabet set includes values in (normalized by the CP length) where and here 1 corresponds to the CP length, as described herein.

[0207] In one example, the alphabet set includes values in where , and here is the CP length, as described herein.

[0208] In one example, the alphabet set includes values in (normalized by the CP length) where , and here 1 corresponds to the CP length, as described herein.

[0209] In one example, for delay reporting, the alphabet set includes values corresponding to values larger than the CP length.

[0210] In one example, the alphabet set includes values in where , , and here is the CP length, as described herein.

[0211] In one example, the alphabet set includes values in (normalized by the CP length) where , , and here 1 corresponds to the CP length, as described herein.

[0212] In one example, the alphabet set includes values in where , , and here is the CP length, as described herein.

[0213] In one example, the alphabet set includes values in (normalized by the CP length) where , , and here 1 corresponds to the CP length, as described herein.

[0214] In one example, for delay reporting, the alphabet set includes at least one code point indicating that delay value is larger than the CP length or corresponds to a value larger than the CP length.

[0215] In one example, the alphabet set includes values in where is the CP length, as described above. The code point indicates . In one example, corresponds to NULL, Invalid, or a fixed value larger than x, or out-of-range.

[0216] In one example, the alphabet set includes values in (normalized by the CP length) where 1 corresponds to the CP length, as described above. The code point indicates . In one example, corresponds to NULL, Invalid, or a fixed value larger than x or out-of-range.

[0217] In one example, the alphabet set includes values in where , is the CP length, as described above. The code point indicates . In one example, corresponds to NULL, Invalid, or a fixed value larger than x or out-of-range.

[0218] In one example, the alphabet set includes values in (normalized by the CP length) where , 1 corresponds to the CP length, as described above. The code point indicates . In one example, corresponds to NULL, Invalid, or a fixed value larger than x or out-of-range.

[0219] In one example, for delay reporting, the alphabet set includes at least one code point indicating that delay value is larger than the CP length or corresponds to a value larger than the CP length, or / and includes values corresponding to values larger than the CP length.

[0220] In one example, the alphabet set includes values in where is the CP length and , as described above. The code point indicates . In one example, corresponds to NULL, Invalid, or a fixed value larger than x or out-of-range.

[0221] In one example, the alphabet set includes values in (normalized by the CP length) where 1 corresponds to the CP length and , as described above. The code point indicates . In one example, corresponds to NULL, Invalid, or a fixed value larger than x or out-of-range.

[0222] In one example, the alphabet set includes values in where , is the CP length and , as described above. The code point indicates . In one example, corresponds to NULL, Invalid, or a fixed value larger than x or out-of-range.

[0223] In one example, the alphabet set includes values in (normalized by the CP length) where , 1 corresponds to the CP length and , as described above. The code point indicates . In one example, corresponds to NULL, Invalid, or a fixed value larger than x or out-of-range.

[0224] In one example, is fixed (e.g. 1). In one example, is configured (e.g. RRC). In one example, is reported by the UE.

[0225] In one example, , and is fixed (e.g. and is an integer), is configured (e.g. RRC), is reported by the UE.

[0226] In one example, , and is fixed (e.g. and is an integer), is configured (e.g. RRC), is reported by the UE.

[0227] In one example, for frequency error reporting, the alphabet set includes at least one value corresponding to a value larger than the frequency error .

[0228] In one example, the alphabet set includes values in or where and here is the the frequency error, as described above.

[0229] In one example, the alphabet set includes values in or (normalized by the the frequency error) where and here 1 corresponds to the the frequency error, as described above.

[0230] In one example, the alphabet set includes values in where , and here is the the frequency error, as described above.

[0231] In one example, the alphabet set includes values in (normalized by the the frequency error) where , and here 1 corresponds to the the frequency error, as described above.

[0232] In one example, for frequency error reporting, the alphabet set includes values corresponding to values larger than the the frequency error.

[0233] In one example, the alphabet set includes values in where , and here is the CP length, as described above.

[0234] In one example, the alphabet set includes values in (normalized by the Frequency error) where , , and here 1 corresponds to the Frequency error, as described above.

[0235] In one example, the alphabet set includes values in where , , and here is the Frequency error, as described above.

[0236] In one example, the alphabet set includes values in (normalized by the Frequency error) where , , and here 1 corresponds to the Frequency error, as described above.

[0237] In one example, for frequency error reporting, the alphabet set includes at least one code point indicating that delay value is larger than the Frequency error or corresponds to a value larger than the Frequency error.

[0238] In one example, the alphabet set includes values in where is the Frequency error, as described above. The code point indicates . In one example, corresponds to NULL, Invalid, or a fixed value larger than x.

[0239] In one example, the alphabet set includes values in (normalized by the Frequency error) where 1 corresponds to the Frequency error, as described above. The code point indicates . In one example, corresponds to NULL, Invalid, or a fixed value larger than x.

[0240] In one example, the alphabet set includes values in where , is the Frequency error, as described above. The code point indicates . In one example, corresponds to NULL, Invalid, or a fixed value larger than x.

[0241] In one example, the alphabet set includes values in (normalized by the Frequency error) where , 1 corresponds to the Frequency error, as described above. The code point indicates . In one example, corresponds to NULL, Invalid, or a fixed value larger than x.

[0242] In one example, for frequency error reporting, the alphabet set includes at least one code point indicating that delay value is larger than the Frequency error or corresponds to a value larger than the Frequency error, or / and includes values corresponding to values larger than the Frequency error.

[0243] In one example, the alphabet set includes values in where is the Frequency error and , as described above. The code point indicates . In one example, corresponds to NULL, Invalid, or a fixed value larger than x.

[0244] In one example, the alphabet set includes values in (normalized by the Frequency error) where 1 corresponds to the Frequency error and , as described above. The code point indicates . In one example, corresponds to NULL, Invalid, or a fixed value larger than x.

[0245] In one example, the alphabet set includes values in where , is the Frequency error and , as described above. The code point indicates . In one example, corresponds to NULL, Invalid, or a fixed value larger than x.

[0246] In one example, the alphabet set includes values in (normalized by the Frequency error) where , 1 corresponds to the Frequency error and , as described above. The code point indicates . In one example, corresponds to NULL, Invalid, or a fixed value larger than x.

[0247] In one example, is fixed (e.g. 1). In one example, is configured (e.g. RRC). In one example, is reported by the UE.

[0248] In one example, , and is fixed (e.g. and is an integer), is configured (e.g. RRC), is reported by the UE.

[0249] In one example, , and is fixed (e.g. and is an integer), is configured (e.g. RRC), is reported by the UE.

[0250] In one example, the alphabet set includes codepoints, where the codepoints indicate uniformly quantized frequency offset values (or intervals) between-AFOand AFO. In one example, AFOcorresponds to in an example shown in this disclosure.

[0251] In one example, the alphabet set includes codepoints, where the codepoints indicate uniformly quantized frequency offset values (or intervals) between 0 and AFO. In one example, AFOcorresponds to in an example shown in this disclosure.

[0252] In one example, the CLI corresponds to the set of values of phases associated with (or due to) or indicator(s) indicating (quantized) values of . In one example, . At least one of the following examples of the alphabet set is used for quantizing . In one example, the alphabet set corresponds bit alphabet set.

[0253] In one example, . The 2 values corresponds to binary phase-shift keying (BPSK) .

[0254] In one example, . The 4 values corresponds to QPSK .

[0255] In one example, . The 8 values corresponds to 8PSK .

[0256] In one example, . The 16 values corresponds to 16PSK .

[0257] In one example, is configured via higher layer signaling, e.g. from {3,4}.

[0258] In one example, the UE also reports (indices indicating) the values of associated with the reported . In one example, the UE is configured with (indices indicating) the values of .

[0259] In one example, the CLI may also include amplitude in addition to phase, i.e., .

[0260] At least one of the following examples is used / configured regarding the reporting / calculation.

[0261] In one example, the reporting is absolute, i.e., each of values is determined / reported independently from other values.

[0262] In one example, the reporting is differential (relative) with respect to a base or reference. In one example, the based or reference is , the 1stTRP (resource). That is, the offset value corresponding to is reported / determined w.r.t. to the same corresponding to . In one example, the reference may be fixed (e.g. 0), or configured (e.g. via higher layer) or reported by the UE (as part of the CSI report, either via part 1 or part 2 of a two-part UCI). In one example, the normalized value of the reference may also be reported by the UE.

[0263] In one example, the differential / relative offset value is determined as . The UE reports correlation for , and for .

[0264] In one example, the differential / relative offset is determined as . The UE (e.g., the UE 116) reports offset for , and for .

[0265] In one example, or .

[0266] In one example, or .

[0267] In one example, the report is a standalone / separate report (similar to Rel.18 time-domain channel property, TDCP), and doesn't include any other parameters. The report may be reported via a layer 1 (physical) UL channel such as PUCCH or / and PUSCH. In this case, the report may be multiplexed with other UCI parameters such as HARQ-ACK parameters. Alternatively, the report may be reported via a layer 2 (MAC) UL channel such as UL MAC CE. In this case, the report may be multiplexed with other MAC parameters such as PHR parameters.

[0268] In one example, the report is a non-standalone / joint report and may include other parameters such as CSI parameters (e.g. rank indicator (RI), precoding matrix indicator (PMI), channel quality indicator (CQI), CQI report interval (CRI), layer index (LI))) or / and beam-related parameters (e.g. layer 1 reference signal received power (L1-RSRP), layer 1 signal-to-interference-plus-noise ratio (L1-SINR), CRI, SSBRI). In this case, the (calibration) report is a component (or part of) out of multiple components (or parts of) the CSI / beam report.

[0269] In one example, the CLI may be included as a component of (part of an alphabet set), e.g. Rel.18 Type II CJT alphabet set, and the corresponding configuration may be codebookMode = mode 3 (in addition to mode 1 and mode 2 in Rel.18).

[0270] In one example, a metric to obtain / derive / obtain the CLI is based on auto-( / cross-) correlation or / and power spectrum or power spectrum density of the measurement.

[0271] In one example, the measurement and reporting for T-F offset is decoupled / separate, i.e., one of the two separate mechanisms may be configured / used.

[0272] For time offset , the measurement corresponds to multiple (a burst of) time occasions, where two consecutive time occasions may be separated by symbols or slots.

[0273] For frequency offset , the measurement corresponds to multiple (a burst of) frequency occasions, where two consecutive frequency occasions may be separated by subcarriers or PRBs or subbands (SBs).

[0274] In one example, the measurement and reporting for T-F offset is coupled / joint, i.e., one joint mechanism is used / configured for a 2D measurement and reporting for .

[0275] At least one of the following examples is used / configured regarding the frequency domain granularity of the reporting / calculation of offset value(s).

[0276] In one example, the reporting / calculation of offset value(s) is in a wideband (WB) manner, i.e., offset values are reported common for the entire CSI reporting band.

[0277] In one example, the reporting / calculation of offset value(s) is in a subband (SB) manner, i.e., offset values are reported for each SB in the CSI reporting band. In addition, a reference (WB) offset may also be reported such that Sub-band offset level (s) = sub-band offset index (s) - wideband offset index.

[0278] Likewise, at least one of the following examples is used / configured regarding the time domain granularity of the reporting / calculation of offset value(s).

[0279] In one example, the reporting / calculation of offset value(s) is in a wide-time (WT) manner, i.e., offset values are reported common for the entire time window or duration (in which the report is expected to be valid).

[0280] In one example, the reporting / calculation of offset value(s) is in a sub-time (ST) manner, i.e., offset values are reported for each ST in the time duration (in which the report is expected to be valid). In addition, a reference (WT) offset may also be reported such that ST offset level (s) = ST offset index (s) - WT offset index.

[0281] In one example, the report includes one value for each TRP ( values when including the reference or values when excluding the reference). For time / delay offsets ( delay values sorted in increasing order)

[0282] In one example, the one value corresponds to the 1stdelay .

[0283] In one example, the one value corresponds to the last delay .

[0284] In one example, the one value corresponds to the max of , .

[0285] In one example, the one value corresponds to the Delay spread .

[0286] Likewise, for frequency offsets ( values sorted in increasing order)

[0287] In one example, the one value corresponds to the 1stfrequency .

[0288] In one example, the one value corresponds to the last frequency .

[0289] In one example, the one value corresponds to the max of , .

[0290] In one example, the one value corresponds to the Frequency spread .

[0291] In one example, the report includes two values for each TRP. For time / delay offsets ( delay values sorted in increasing order),

[0292] In one example, the two values may correspond to the 1stand the last values and .

[0293] In one example, the two values may correspond to the max and the min of , .

[0294] In one example, the two values may correspond to the two largest values of , .

[0295] Likewise, For frequency offsets ( values sorted in increasing order),

[0296] In one example, the two values may correspond to the 1stand the last values and .

[0297] In one example, the two values may correspond to the max and the min of , .

[0298] In one example, the two values may correspond to the two largest values of , .

[0299] In one example, the report includes two values for each TRP.

[0300] In one example, the report includes two values for TRPs (excluding the reference TRP).

[0301] In one example, the report includes one value for the reference TRP, and two values for remaining TRPs, i.e., the two values for the reference are 0 and .

[0302] In one example, the report further includes a recommendation about coherency (CJT or NCJT) across TRPs. In one example, it may be implicit via one value, or explicit via an indicator (e.g. 1-bit), or via an -bit or -bit bitmap indicator, where when the bitmap is '0' or '1' then it indicates NCJT and when at least two '1's or '0's then it indicates CJT.

[0303] Various embodiments provide for reference TRP information. In one embodiment, a CLI reporting (described in an example of embodiments herein) is according to at least one of the following examples.

[0304] In one example, the CLI reporting includes one CRI (or DL RS indicator or an indicator) to indicate a reference CSI-RS resource out of or CSI-RS resources.

[0305] In one example, the CLI reporting does not include any CRI information.

[0306] - In one example, a reference CSI-RS resource may be configured by the NW, via higher-layer signaling (i.e., RRC).

[0307] - In one example, a reference CSI-RS resource is fixed, e.g., the lowest (or highest) index of CSI-RS resources.

[0308] - In one example, a reference CSI-RS resource is not indicated / reported / specified / used.

[0309] In one example, the CLI reporting includes a -bit bitmap indicator (or -bit bitmap indicator) to indicate one or multiple CSI-RS resources.

[0310] Various embodiments provide quantization scheme for delay. In one embodiment, for (inter-TRP-)delay reporting (of a CLI reporting described in an example of embodiment I), an alphabet set for quantizing delay values is according to at least one of the following examples.

[0311] In one example, the alphabet set includes 0 value or a codepoint mapping to 0 value.

[0312] In one example, the alphabet set does not include 0 value or a codepoint mapping to 0 value.

[0313] In one example, the alphabet set includes values or codepoints for a range of in unit of CP length, where y may be fixed, e.g., y=1, or y<1, or y>1,or may be configured by the NW via higher-layer signaling (i.e., RRC), or may be determined by the UE, and where is a maximum value of the range (e.g., ) and it may be fixed, configured by the NW, or determined by the UE.

[0314] - In one example, is fixed. In another example, may be configured by the NW. In another example, may be determined by the UE and reported as a part of the reporting.

[0315] - In one example, the values (or codepoints) are values in in unit of CP length.

[0316] - In one example, the values (or codepoints) are values in in unit of CP length.

[0317] - In one example, the values (or codepoints) includes 0 value.

[0318] - In one example, the values (or codepoints) includes a reserved value, e.g., NULL, out-of-range, etc.

[0319] In one example, more specifically, the alphabet set includes codepoints where M-1 codepoints correspond to intervals in in unit of CP length (where ) and 1 codepoint corresponds to a reserved value (e.g., out-of-range, invalid state, NULL, etc). In one example, each codepoint i of the M-1 codepoints corresponds to an interval , where is uniformly spaced between 0 and , , for . The reserved value (e.g., out-of-range) may represent .

[0320] In one example, each codepoint i of the M-1 (or M-2) codepoints corresponds to an interval , where is uniformly spaced between 0 and , , for . The reserved value (e.g., out-of-range) may represent .

[0321] In one example, the alphabet set includes values or codepoints for a range of in (absolute) time unit, where y may be fixed, e.g., y = 1 CP length, or y<1 CP length, or y>1 CP length, or may be configured by the NW via higher-layer signaling (i.e., RRC), or may be determined by the UE, and where is a maximum value of the range (e.g., = a value less than 1, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.5, 3, a value larger than 3 CP ), and it may be fixed, configured by the NW, or determined by the UE.

[0322] - In one example, is fixed. In another example, may be configured by the NW. In another example, may be determined by the UE and reported as a part of the reporting.

[0323] - In one example, the values (or codepoints) are values in in (absolute) time unit.

[0324] - In one example, the values (or codepoints) are values in in (absolute) time unit.

[0325] - In one example, the values (or codepoints) includes 0 value.

[0326] - In one example, the values (or codepoints) includes a reserved value, e.g., NULL, out-of-range, etc.

[0327] In one example, more specifically, the alphabet set includes codepoints where M-1 codepoints correspond to intervals in in (absolute) time unit (where ) and 1 codepoint corresponds to a reserved value (e.g., out-of-range, invalid state, NULL, etc). In one example, each codepoint i of the M-1 codepoints corresponds to an interval , where is uniformly spaced between 0 and , , for . The reserved value (e.g., out-of-range) may represent .

[0328] In one example, each codepoint i of the M-1 (or M-2) codepoints corresponds to an interval , where is uniformly spaced between 0 and , , for . The reserved value (e.g., out-of-range) may represent .

[0329] In an embodiment, for delay reporting (of a CLI reporting described in an example of embodiment I), one or multiple delay values for each of (or ) CSI-RS resource or each of (or N-1)CSI-RS resources are reported as a part of CLI reporting.

[0330] Various embodiments provide for the case of # of delays = 1 for reporting. In one embodiment, one delay value for CSI-RS resource r is quantized using at least one of the schemes described in embodiments herein.

[0331] In one example, one delay value for each of (or ) CSI-RS resources is quantized and indicated by a (separate) per-TRP (i.e., per-CSI-RS resource) indicator.

[0332] In one example, one delay value for each of -1(or N-1)CSI-RS resources is quantized and indicated by a (separate) per-TRP (i.e., per-CSI-RS resource) indicator.

[0333] In one example, one delay value for each of (or ) CSI-RS resources is quantized and the delay values are indicated by a joint indicator.

[0334] In one example, one delay value for each of -1 (or N-1) CSI-RS resources is quantized and the -1 delay values are indicated by a joint indicator.

[0335] Various embodiments provide for case of # of delays = 2 for reporting. In one embodiment, each of two delay values (e.g., first delay tap and last delay tap) for CSI-RS resource r is quantized using at least one of the schemes described in embodiment I or embodiment I.1.2.

[0336] In one example, each of two delay values for each of (or ) CSI-RS resources is quantized and indicated via a (separate) per-TRP (i.e., per-CSI-RS resource) indicator.

[0337] In one example, each of two delay values for each of -1 (or N-1) CSI-RS resources is quantized and indicated via a (separate) per-TRP (i.e., per-CSI-RS resource) indicator.

[0338] In one example, each of two delay values for each of (or ) CSI-RS resources is quantized and the delay values are indicated via a joint indicator.

[0339] In one example, each of two delay values for each of -1 (or N-1) CSI-RS resources is quantized and the delay values are indicated via a joint indicator.

[0340] In one example, for the two delay values, and (where ), for CSI-RS resource , alphabet sets and for the two delay values are the same, i.e., and are quantized using a same alphabet set, where the alphabet set is one of the examples described in embodiments herein.

[0341] In one example, for the two delay values, and (where ),for CSI-RS resource , alphabet sets and for the two delay values may be different, i.e., and are quantized using different alphabet sets and , respectively, where each of the alphabet sets is one of the examples described in embodiments herein.

[0342] In one example, the number of bits for alphabet sets and may be the same, but the alphabet sets and may be different.

[0343] In one example, the number of bits for alphabet sets and may be different, where and are the numbers of bits for alphabet sets and , respectively, and .

[0344] In one example, and , where is quantized / indicated using alphabet set with bits and is indicated by an 1-bit indicator, whether (which may correspond to delay spread) is exceeding CP length or not, or exceeding a threshold value or not, or out-of-range or not, or ON or OFF, etc.

[0345] In one example, and , where is quantized / indicated using alphabet set with bits and is indicated / quantized using alphabet set with 1-bit, e.g., having and values.

[0346] In one example, and , where is quantized / indicated using alphabet set with bits and is indicated / quantized using alphabet set with bits.

[0347] In one example, the number of bits for alphabet sets and may be different, where and are the numbers of bits for alphabet sets and , respectively, and .

[0348] In one example, and , where is quantized / indicated using alphabet set with bits and is indicated by an 1-bit indicator, whether (which may correspond to delay spread) is exceeding CP length or not, or exceeding a threshold value or not, or out-of-range or not, or ON or OFF, etc.

[0349] In one example, and , where is quantized / indicated using alphabet set with bits and is indicated / quantized using alphabet set with 1-bit, e.g., having and values.

[0350] In one example, and , where is quantized / indicated using alphabet set with bits and is indicated / quantized using alphabet set with bits.

[0351] In above examples for the two delay values, and may be referring to at least one of the following examples.

[0352] In one example, corresponds to a first delay tap / offset and corresponds to a last delay tap / offset.

[0353] In one example, corresponds to a first delay tap / offset and corresponds to differential / relative delay value to the first delay tap. In this case, a last delay tap / offset may be expressed as .

[0354] In one example, corresponds to a first delay tap / offset and corresponds to delay spread. In this case, a last delay tap / offset may be expressed as .

[0355] In one example, corresponds to a last delay tap / offset and corresponds to delay spread. In this case, a first delay tap / offset may be expressed as .

[0356] In one example, and are represented in the unit of CP length (i.e., normalized by CP length).

[0357] In one example, and are represented in absolute time unit (without normalization).

[0358] In one example, and are represented in the unit of OFDM-symbol / slot time unit (normalized by OFDM symbol / slot duration).

[0359] In one example, a payload of indicating for a first delay value is given by and a payload of indicating for a second delay value is given by .

[0360] In one example, a payload of indicating for a first delay value is given by and a payload of indicating for a second delay value is given by .

[0361] Various embodiments provided for the case of # of delays > 2 (extension) for reporting. In one embodiment, each of >2 delay values for CSI-RS resource r is quantized using at least one of the schemes described in embodiments herein.

[0362] In one example, each of delay values for each of (or )CSI-RS resources is quantized and indicated via a (separate) per-TRP (i.e., per-CSI-RS resource) indicator.

[0363] In one example, each of delay values for each of (or N-1)CSI-RS resources is quantized and indicated via a (separate) per-TRP (i.e., per-CSI-RS resource) indicator.

[0364] In one example, each of delay values for each of (or )CSI-RS resources is quantized and the delay values are indicated via a joint indicator.

[0365] In one example, each of delay values for each of (or N-1)CSI-RS resources is quantized and the delay values are indicated via a joint indicator.

[0366] In one example, for the delay values, (where ), for CSI-RS resource r, alphabet sets for the delay values are the same, i.e., are quantized using a same alphabet set, where the alphabet set is one of the examples described in embodiments herein.

[0367] In one example, for the delay values, (where ),for CSI-RS resource r, alphabet sets for the delay values may be different, i.e., are quantized using different alphabet sets , respectively, where each of the alphabet sets is one of the examples described in embodiments herein.

[0368] In one example, the number of bits for alphabet sets may be the same, but the alphabet sets may be different.

[0369] In one example, the number of bits for alphabet sets may be different, where are the numbers of bits for alphabet sets respectively.

[0370] In one example, a payload of indicating for a i-th delay value is given by for .

[0371] In one example, a payload of indicating for a i-th delay value is given by for .

[0372] In embodiment, the number of bits for alphabet set , as described in this disclosure, may be according to at least one of the following examples.

[0373] In one example, (or , ) is CSI-RS-resource-common, i.e., a same bit is used across all configured CSI-RS resources.

[0374] In one example, (or , ) is CSI-RS-resource-specific, i.e., a different / independent bit is used across for each configured CSI-RS resource r.

[0375] In one example, depends on the number of CSI-RS resources, i.e., (or N). For example, , with a scaling value of c.

[0376] In one example, is fixed or configured by NW, or determined by UE and reported as a part of reporting.

[0377] In one embodiment, a UE may be configured with a range value of and / or a number of quantization states M (or a number of bits for quantization states (where )) for CJT delay reporting (or frequency reporting, or phase offset reporting or other joint reporting). Here, the CJT delay reporting may be a delay reporting scheme designed based on an example described in / under embodiments herein. In one example, and M (or ) may be designed at least one of the following examples.

[0378] In one example, may be configurable by NW via RRC signaling (or MAC-CE or DCI).

[0379] In one example, M (or ) may be configurable by NW via RRC signaling (or MAC-CE or DCI).

[0380] In one example, and M (or ) may be separately indicated / configured with separate parameters.

[0381] In one example, and M (or ) may be jointly indicated / configured with separate parameters.

[0382] In one example, the number of supported values of is . In one example, . In one example, . In one example, . In one example, . In one example, .

[0383] In one example, the number of supported values of M (or ) is . In one example, . In one example, . In one example, . In one example, .

[0384] In one example, the number of supported values of or is . In one example, . In one example, . In one example, . In one example, .

[0385] In one example, one of the configurable values of corresponds to CP length.

[0386] In one example, one of the configurable values of corresponds to a value smaller than CP length. In one example, corresponds to , where c<1 e.g., c=0.5 or 0.3 or 1 / 3.

[0387] In one example, one of the configurable values of corresponds to a value larger than CP length. In one example, corresponds to , where c>1 e.g., c=1.5 or 1.8 or 2.

[0388] In one example, one of the configurable values of M (or ) corresponds to 32 (i.e., B=5bits).

[0389] In one example, one of the configurable values of M (or ) corresponds to a value smaller than 32. In one example, M corresponds to 16 or 8 or 4 or 2.

[0390] In one example, one of the configurable values of M (or ) corresponds to a value larger than 32. In one example, M corresponds to 64 or 128 or 256.

[0391] In one example, one of the configurable values of (or ) corresponds to (CP length, 32).

[0392] In one example, one of the configurable values of corresponds to (CP length, X), where X corresponds to a value smaller than 32.

[0393] In one example, one of the configurable values of corresponds to (CP length, X), where X corresponds to a value larger than 32.

[0394] In one example, one of the configurable values of corresponds to (c CP length, 16), where c<1, e.g., c=0.5 or 0.3 or 1 / 3.

[0395] In one example, one of the configurable values of corresponds to (c CP length,X), where c<1, e.g., c=0.5 or 0.3 or 1 / 3, and X corresponds to a value larger than 16.

[0396] In one example, one of the configurable values of corresponds to (c CP length, X), where c<1, e.g., c=0.5 or 0.3 or 1 / 3, and X corresponds to a value smaller than 16.

[0397] In one example, one of the configurable values of corresponds to (c CP length, 32), where c>1, e.g., c=1.5 or 1.8 or 2.

[0398] In one example, one of the configurable values of corresponds to (c CP length, X), where c>1, e.g., c=1.5 or 1.8 or 2, and X corresponds to a value larger than 32.

[0399] In one example, one of the configurable values of corresponds to (c CP length, X), where c>1, e.g., c=1.5 or 1.8 or 2, and X corresponds to a value smaller than 32.

[0400] In one example, CP length described in this disclosure corresponds to or or or , where is subcarrier spacing (e.g., 15, 30, 60, 120, 240 kHz) and .

[0401] In one example, one of the configurable values of corresponds to a function of a PMI subband size (e.g., ), where the PMI subband size may be calculated based on the number of RBs per PMI subband, e.g., , where is the number of RBs per CQI subband, is the number of subcarriers per RB, is subcarrier spacing, and R is the number of precoding matrix (PMIs) per CQI subband.

[0402] In one example, each example shown in the above with replacing the CP by a function of a PMI subband size may be another example.

[0403] In one example, the maximum (configurable) value of M (or ) may be determined based on the maximum configurable value (up to 38) and (in {1,4}), e.g., is up to 152. For example, M (or ) does not exceed 256 (or 8 bits).

[0404] In one example, one of the configurable values of corresponds to a function of reference signal spacing (RS frequency density) in frequency-domain (e.g., ) or RB size or subcarrier spacing.

[0405] In one example, each example shown in the above with replacing the CP by a function of reference signal spacing in frequency-domain or RB size or subcarrier spacing may be another example. (e.g., )

[0406] In one example, may be determined based on a value of multiples of a step size, where the step size may be determined by a configured band-width-part (BWP) (in associated CSI-RS resource / resource set measurement), and the multiples may be given by (i.e., M-1).

[0407] In one example, a range value of may be implicitly configured by NW via RS configuration for measurement and a number of quantization states M (or a number of bits B for quantization states (where )) is only configured.

[0408] In one example, a UE is not expected to be configured with where the value of exceeds a measurable delay value from associated CSI-RS resource / resource set. The measurement delay value may be determined RS density in frequency (spacing between two resource allocation of the RS (e.g., TRS RE density, such as 1 RE / RB / port, 3 RE / RB / port).

[0409] FIGURE 12 illustrates an example method 1200 performed by a UE in a wireless communication system according to embodiments of the present disclosure. The method 1200 of FIGURE 12 may be performed by any of the UEs 111-116 of FIGURE 1, such as the UE 116 of FIGURE 3, and a corresponding method may be performed by any of the BSs 101-103 of FIGURE 1, such as BS 102 of FIGURE 2. The method 1200 is for illustration only and other embodiments may be used without departing from the scope of the present disclosure.

[0410] The method 1200 begins with the UE receiving information about a report (1210). For example, in 1210, the information indicatesNTRPantenna groups. In various embodiments, each antenna group of the NTRPantenna groups corresponds to a respective CSI-RS resource set or a respective CSI-RS resource.

[0411] The UE then determines a reference antenna group nrefbased on the information (1220). The UE then determines, for each antenna group n nref, a first delay value Dnand a second delay value dnbased on the information and the reference antenna group nref(1230).

[0412] The UE then transmits the report including a first indicator indicating the reference antenna group nref; a second indicator indicating, for each antenna group n nref,an interval to which the first delay value Dnbelongs, and a third indicator indicating, for each antenna group n nref,whether the second delay value dnis inside or outside a pre-defined range via a 1-bit indicator (1240). In various embodiments, the pre-defined range corresponds to [0, 1CP], where the 1CP corresponds to a 1 CP length.

[0413] In various embodiments, the interval is indicated by an indicator of size bits with an alphabet set, where the alphabet set includes codepoints and the codepoints correspond to equally-spaced intervals in and an 'out-of-range' codepoint, where . In some examples, an i-th interval of the equally-spaced intervals in is given by for , where and the 'out-of-range' codepoint corresponds to . In some examples, a value of is configured via a RRC parameter, where is a set including 32, 64, 128, and 256. In some examples, a value of is configured via a RRC parameter, where is a set including 0.5 CP length and 1 CP length. In some examples, a payload of the second indicator is given by bits and a payload of the third indicator is given by bits.

[0414] Any of the above variation embodiments may be utilized independently or in combination with at least one other variation embodiment. The above flowchart(s) illustrate example methods that may be implemented in accordance with the principles of the present disclosure and various changes could be made to the methods illustrated in the flowcharts herein. For example, while shown as a series of steps, various steps in each figure could overlap, occur in parallel, occur in a different order, or occur multiple times. In another example, steps may be omitted or replaced by other steps.

[0415] Although the present disclosure has been described with exemplary embodiments, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims. None of the descriptions in this application should be read as implying that any particular element, step, or function is an essential element that must be included in the claims scope. The scope of patented subject matter is defined by the claims.

Claims

1.A user equipment (UE) comprising:a transceiver; anda processor coupled with the transceiver and configured to:receive information about a report, the information indicatingantenna groups, where,determine, based on the information, a reference antenna group,determine, based on the information and the reference antenna group, for each antenna group, a first delay valueand a second delay value, andtransmit the report including:a first indicator indicating the reference antenna group;a second indicator indicating, for each antenna group, an interval to which the first delay valuebelongs; anda third indicator indicating, for each antenna group, whether the second delay valueis inside or outside a pre-defined range via a 1-bit indicator.2.The UE of claim 1, wherein each antenna group of the antenna groups corresponds to a respective channel state information-reference signal (CSI-RS) resource set or a respective CSI-RS resource.3.The UE of claim 1, wherein the pre-defined range corresponds to [0, 1CP], where the 1CP corresponds to a 1 cyclic prefix (CP) length.4.The UE of claim 1, wherein:the interval is indicated by an indicator of sizebits with an alphabet set, where:the alphabet set includes M =codepoints; andthecodepoints correspond to-1 equally-spaced intervals in [0,] and an 'out-of-range' codepoint, where>0.5.The UE of claim 4, wherein an i-th interval of the -1 equally-spaced intervals in [0, ] is given by for , where and the 'out-of-range' codepoint corresponds to .6.The UE of claim 4, wherein a value of is configured via a radio resource control (RRC) parameter, where is a set including 32, 64, 128, and 256.7.The UE of claim 4, wherein a value of is configured via a radio resource control (RRC) parameter, where is a set including 0.5 CP length and 1 CP length.8.The UE of claim 4, wherein a payload of the second indicator is given by bits and a payload of the third indicator is given by bits.9.A base station (BS) comprising:a transceiver; anda processor coupled with the transceiver and configured to:transmit information about a report, wherein the information indicatesantenna groups including a reference antenna group, where, and wherein, for each antenna group, a first delay valueand a second delay valueis based on the information and the reference antenna group; andreceive the report including:a first indicator indicating the reference antenna group;a second indicator indicating, for each antenna group, an interval to which the first delay valuebelongs; anda third indicator indicating, for each antenna group, whether the second delay valueis inside or outside a pre-defined range via a 1-bit indicator.10.The BS of claim 9, wherein each antenna group of the antenna groups corresponds to a respective channel state information-reference signal (CSI-RS) resource set or a respective CSI-RS resource.11.The BS of claim 9, wherein the pre-defined range corresponds to [0, 1CP], where the 1CP corresponds to a 1 cyclic prefix (CP) length.12.The BS of claim 9, wherein:the interval is indicated by an indicator of sizebits with an alphabet set, where:the alphabet set includes M =codepoints; andthecodepoints correspond to-1 equally-spaced intervals in [0,] and an 'out-of-range' codepoint, where>0.13.A method performed by a user equipment (UE), the method comprising:receiving information about a report, the information indicatingantenna groups, where,determining, based on the information, a reference antenna group,determining, based on the information and the reference antenna group, for each antenna group, a first delay valueand a second delay value, andtransmitting the report including:a first indicator indicating the reference antenna group;a second indicator indicating, for each antenna group, an interval to which the first delay valuebelongs; anda third indicator indicating, for each antenna group, whether the second delay valueis inside or outside a pre-defined range via a 1-bit indicator.14.The method of claim 13, wherein each antenna group of the antenna groups corresponds to a respective channel state information reference signal (CSI-RS) resource set or a respective CSI-RS resource.15.The method of claim 13, wherein the pre-defined range corresponds to [0, 1CP], where the 1CP corresponds to a 1 cyclic prefix (CP) length.

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