WO2024258218A1

WO2024258218A1 - Method and apparatus for csi report for more than 32 ports

Info

Publication number: WO2024258218A1
Application number: PCT/KR2024/008149
Authority: WO
Inventors: Ameha Tsegaye ABEBE; Youngbum Kim; Seongmok LIM; Youngrok JANG; Hyoungju Ji; Kyungjun CHOI
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2023-06-16
Filing date: 2024-06-13
Publication date: 2024-12-19
Anticipated expiration: 2025-12-16

Abstract

The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. According to various embodiments, a method performed by a user equipment (UE) in a wireless communication system, the method comprising receiving, from a base station, first information configuring a channel state information (CSI)-reference signal (RS) resource set for more than 32 CSI-RS ports, the CSI-RS resource set including at least two CSI-RS resources, and receiving, from the base station, a CSI-RS on the at least two CSI-RS resources which are aggregated, wherein the at least two CSI-RS resources have a same starting resource block (RB).

Description

METHOD AND APPARATUS FOR CSI REPORT FOR MORE THAN 32 PORTS

The present disclosure relates to the field of 5G and beyond 5G communication networks and more particularly to channel state information (CSI) feedback in multiple-input multiple-output (MIMO) system.

5^th generation (5G) mobile communication technologies define broad frequency bands such that high transmission rates and new services are possible, and can 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 (THz) 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.

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.

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.

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.

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.

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.

The above information is presented as background information only to assist with an understanding of the disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the disclosure.

The principal object of the disclosure herein is to disclose methods and apparatus for channel state information (CSI) measurement and reporting for a large number of ports in communication networks, wherein the communication network is at least one of the Fifth Generation (5G) standalone network, a 5G non-standalone (NAS) network or Sixth Generation (6G) network.

As specific object of the disclosure herein is to disclose methods and systems to configure a user equipment (UE) with a CSI measurement for a large number of base-station (BS) antenna ports. Methods are disclosed for mapping the antenna ports to a single or multiple CSI reference resources (CSI-RS).

As a yet another specific object of the disclosure herein is to disclose methods and systems to configure a UE with a CSI report corresponding to a large number of antenna ports.

As a yet another specific object of the disclosure herein is to disclose methods and systems to configure a UE with a CSI measurement for a large number of base station (BS) antenna ports. Methods are disclosed for aggregating multiple CSI-RS resource for the formation of a large number of CSI-RS ports.

As a yet another specific object of the disclosure herein is to disclose methods and systems for a gNode B (gNB) to configure a UE CSI report configuration information for UE to report a CSI with a CSI report based on codebook for a large number of CSI-RS ports.

As a yet another specific object of the disclosure herein is to disclose methods and systems for a UE upon receiving CSI report configuration from the gNB to report a CSI with a CSI report based on codebook for a large number of CSI-RS ports.

The present disclosure has been made to address the above-mentioned problems and disadvantages, and to provide at least the advantages described below.

In accordance with one aspect of the present disclosure, a method performed by a base station in a wireless communication system is provided, the method includes transmitting, to a terminal, configuration information about CSI measurement and reporting for a large number of antenna ports.

In accordance with an aspect of the present disclosure, a method performed by a user terminal in a wireless communication system is provided. The method includes receiving, from a base station, configuration information about CSI measurement and reporting for a large number of antenna ports.

Other aspects, advantages, and salient features of the disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses various embodiments of the disclosure.

Embodiments herein are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:

FIG. 1 illustrates an example wireless network according to an embodiment of the disclosure.

FIGs. 2A and 2B illustrate example wireless transmit and receive paths according to an embodiment of the disclosure.

FIGs. 3A and 3B illustrate an example user equipment (UE) and gNode B (gNB), respectively according to an embodiment of the disclosure.

FIG. 4 illustrates exemplary cross-polarized multiple-input multiple-output (MIMO) antenna system according to an embodiment of the disclosure.

FIG. 5 illustrates exemplary layout for channel state information reference signal (CSI-RS) resource mapping in an orthogonal frequency division multiple access (OFDM) time-frequency grid according to an embodiment of the disclosure.

FIG. 6 illustrates CSI measurement and reporting framework in 5G new radio (NR) according to an embodiment of the disclosure.

FIG. 7 illustrates exemplary time-frequency resources mapping for CSI-RS according to an embodiment of the disclosure.

FIG. 8 illustrates resource element (RE)-level resources mapping of CSI-RS resource in resource block (RB) according to an embodiment of the disclosure.

FIG. 9 illustrates an exemplary embodiment for RB bundling based resource mapping according to an embodiment of the disclosure.

FIG. 10 illustrates a case for CSI-RS resources with a large number of ports with dense RE mapping in RB according to an embodiment of the disclosure.

FIG. 11 illustrates exemplary use cases for CSI-RS resources aggregation for the formation of a large number of CSI-RS ports according to an embodiment of the disclosure.

FIG. 12 illustrates exemplary antenna (CSI ports) layout indication according to an embodiment of the disclosure.

FIG. 13 illustrates a yet another exemplary antenna (CSI ports) layout indication with one-dimensional extension according to an embodiment of the disclosure.

FIG. 14 illustrates a yet another exemplary antenna (CSI ports) layout indication with two-dimensional extension according to an embodiment of the disclosure.

FIG. 15 illustrates exemplary case for one-to-many channel and interference measurement resources association according to an embodiment of the disclosure.

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the disclosure is provided for illustration purpose only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents.

It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.

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.

The 5G communication system is considered to be implemented to include higher frequency (mmWave) bands, such as 28 GHz or 60 GHz bands or, in general, above 6 GHz bands, so as to accomplish higher data rates, or in lower frequency bands, such as below 6 GHz, to enable robust coverage and mobility support. Aspects of the present disclosure may be applied to deployment of 5G communication systems, 6G or even later releases which may use THz bands. 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 communication systems.

In addition, in 5G 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 cancellation and the like.

FIG. 1 illustrates an example wireless network 100 according to an embodiment of the disclosure. The embodiment of the wireless network 100 shown in FIG. 1 is for illustration only. Other embodiments of the wireless network 100 can be used without departing from the scope of this disclosure.

The wireless network 100 includes an gNodeB (gNB) 101, an gNB 102, and an gNB 103. The gNB 101 communicates with the gNB 102 and the gNB 103. The gNB 101 also communicates with at least one Internet Protocol (IP) network 130, such as the Internet, a proprietary IP network, or other data network.

Depending on the network type, the term 'gNB' can refer to any component (or collection of components) configured to provide remote terminals with wireless access to a network, such as base transceiver station, a radio base station, transmit point (TP), transmit-receive point (TRP), a ground gateway, an airborne gNB, a satellite system, mobile base station, a macrocell, a femtocell, a WiFi access point (AP) and the like. Also, depending on the network type, other well-known terms may be used instead of "user equipment" or "UE," such as "mobile station," "subscriber station," "remote terminal," "wireless terminal," or "user device." For the sake of convenience, the terms "user equipment" and "UE" are used in this patent document to refer to equipment that wirelessly accesses a gNB. The UE could be a mobile device or a stationary device. For example, UE could be a mobile telephone, smartphone, monitoring device, alarm device, fleet management device, asset tracking device, automobile, desktop computer, entertainment device, infotainment device, vending machine, electricity meter, water meter, gas meter, security device, sensor device, appliance etc.

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 (SB); a UE 112, which may be located in an enterprise (E); a UE 113, which may be located in a WiFi hotspot (HS); a UE 114, which may be located in a first residence (R); a UE 115, which may be located in a second residence (R); and a UE 116, which may be a mobile device (M) like 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, long-term evolution (LTE), LTE-A, WiMAX, or other advanced wireless communication techniques.

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.

As described in more detail below, one or more of BS 101, BS 102 and BS 103 include two-dimensional (2D) antenna arrays as described in embodiments of the present disclosure. In some embodiments, one or more of BS 101, BS 102 and BS 103 support the codebook design and structure for systems having 2D antenna arrays.

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

FIGs. 2A and 2B illustrate example wireless transmit and receive paths according to an embodiment of the disclosure. In the following description, a transmit path 200 may be described as being implemented in an gNB (such as gNB 102), while a receive path 250 may be described as being implemented in a UE (such as UE 116). However, it will be understood that the receive path 250 can be implemented in an gNB and that the transmit path 200 can be implemented in a UE. In some embodiments, the receive path 250 is configured to support the codebook design and structure for systems having 2D antenna arrays as described in embodiments of the present disclosure.

The transmit path 200 includes a channel coding and modulation block 205, a serial-to-parallel (S-to-P) block 210, a size N Inverse Fast Fourier Transform (IFFT) block 215, a parallel-to-serial (P-to-S) block 220, an add cyclic prefix block 225, and an up-converter (UC) 230. The receive path 250 includes a down-converter (DC) 255, a remove cyclic prefix block 260, a serial-to-parallel (S-to-P) block 265, a size N Fast Fourier Transform (FFT) block 270, a parallel-to-serial (P-to-S) block 275, and a channel decoding and demodulation block 280.

In the transmit path 200, the channel coding and modulation block 205 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 210 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 102 and the UE 116. The size N IFFT block 215 performs an IFFT operation on the N parallel symbol streams to generate time-domain output signals. The parallel-to-serial block 220 converts (such as multiplexes) the parallel time-domain output symbols from the size N IFFT block 215 in order to generate a serial time-domain signal. The add cyclic prefix block 225 inserts a cyclic prefix to the time-domain signal. The up-converter 230 modulates (such as up-converts) the output of the add cyclic prefix block 225 to an RF frequency for transmission via a wireless channel. The signal may also be filtered at baseband before conversion to the RF frequency.

A transmitted RF signal from the gNB 102 arrives at the UE 116 after passing through the wireless channel, and reverse operations to those at the gNB 102 are performed at the UE 116. The down-converter 255 down-converts the received signal to a baseband frequency, and the remove cyclic prefix block 260 removes the cyclic prefix to generate a serial time-domain baseband signal. The serial-to-parallel block 265 converts the time-domain baseband signal to parallel time domain signals. The size N FFT block 270 performs an FFT algorithm to generate N parallel frequency-domain signals. The parallel-to-serial block 275 converts the parallel frequency-domain signals to a sequence of modulated data symbols. The channel decoding and demodulation block 280 demodulates and decodes the modulated symbols to recover the original input data stream.

Each of the gNBs 101-103 may implement a transmit path 200 that is analogous to transmitting in the downlink to UEs 111-116 and may implement a receive path 250 that is analogous to receiving in the uplink from UEs 111-116. Similarly, each of UEs 111-116 may implement a transmit path 200 for transmitting in the uplink to gNBs 101-103 and may implement a receive path 250 for receiving in the downlink from gNBs 101-103.

Each of the components in FIGs. 2A and 2B can 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.2A and 2B 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 270 and the IFFT block 215 may be implemented as configurable software algorithms, where the value of size N may be modified according to the implementation.

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 this disclosure. Other types of transforms, such as Discrete Fourier Transform (DFT) and Inverse Discrete Fourier Transform (IDFT) functions, can 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.

Although FIGs. 2A and 2B illustrate examples of wireless transmit and receive paths, various changes may be made to FIGs. 2A and 2B. For example, various components in FIGs. 2A and 2B can be combined, further subdivided, or omitted and additional components can be added according to particular needs. Also, FIGs. 2A and 2B are meant to illustrate examples of the types of transmit and receive paths that can be used in a wireless network. Any other suitable architectures can be used to support wireless communications in a wireless network.

FIG. 3A illustrates an example UE 116 according to an embodiment of the disclosure. The embodiment of the UE 116 illustrated in FIG. 3A is for illustration only, and the UEs 111-115 of FIG. 1 can have the same or similar configuration. However, UEs come in a wide variety of configurations, and FIG. 3A does not limit the scope of this disclosure to any particular implementation of a UE.

The UE　116 includes an antenna 305, a radio frequency (RF) transceiver 310, transmit (TX) processing circuitry 315, a microphone 320, and receive (RX) processing circuitry 325. The UE 116 also includes a speaker 330, a main processor 340, an input/output (I/O) interface (IF) 345, a keypad 350, a display 355, and a memory 360. The memory 360 includes a basic operating system (OS) program 361 and one or more applications 362.

The RF transceiver 310 receives, from the antenna 305, an incoming RF signal transmitted by an gNB of the network 100. The RF transceiver 310 down-converts the incoming RF signal to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is sent to the RX processing circuitry 325, which generates a processed baseband signal by filtering, decoding, and/or digitizing the baseband or IF signal. The RX processing circuitry 325 transmits the processed baseband signal to the speaker 330 (such as for voice data) or to the main processor 340 for further processing (such as for web browsing data).

The TX processing circuitry 315 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 main processor 340. The TX processing circuitry 315 encodes, multiplexes, and/or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The RF transceiver 310 receives the outgoing processed baseband or IF signal from the TX processing circuitry 315 and up-converts the baseband or IF signal to an RF signal that is transmitted via the antenna 305.

The main processor (or controller) 340 can include one or more processors or other processing devices and execute the basic OS program 361 stored in the memory 360 in order to control the overall operation of the UE 116. For example, the main processor 340 can control the reception of forward channel signals and the transmission of reverse channel signals by the RF transceiver 310, the RX processing circuitry 325, and the TX processing circuitry 315 in accordance with well-known principles. In some embodiments, the main processor 340 includes at least one microprocessor or microcontroller.

The main processor 340 is also capable of executing other processes and programs resident in the memory 360, such as operations for channel quality measurement and reporting for systems having 2D antenna arrays as described in embodiments of the present disclosure as described in embodiments of the present disclosure. The main processor 340 can move data into or out of the memory 360 as required by an executing process. In some embodiments, the main processor 340 is configured to execute the applications 362 based on the OS program 361 or in response to signals received from gNBs or an operator. The main 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 main controller 340.

The main processor 340 is also coupled to the keypad 350 and the display unit 355. The operator of the UE 116 can use the keypad 350 to enter data into the UE 116. The display 355 may be a liquid crystal display or other display capable of rendering text and/or at least limited graphics, such as from web sites. The memory 360 is coupled to the main processor 340. Part of the memory 360 can include a random access memory (RAM), and another part of the memory 360 can include a Flash memory or other read-only memory (ROM).

Although FIG. 3A illustrates one example of UE 116, various changes may be made to FIG. 3A. For example, various components in FIG. 3A can be combined, further subdivided, or omitted and additional components can be added according to particular needs. As a particular example, the main processor 340 can be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). Also, while FIG. 3A illustrates the UE 116 configured as a mobile telephone or smartphone, UEs can be configured to operate as other types of mobile or stationary devices.

FIG. 3B illustrates an example gNB 102 according to an embodiment of the disclosure. The embodiment of the gNB 102 shown in FIG. 3B is for illustration only, and other gNBs of FIG. 1 can have the same or similar configuration. However, gNBs come in a wide variety of configurations, and FIG. 3B does not limit the scope of this disclosure to any particular implementation of an gNB. It is noted that gNB 101 and gNB 103 can include the same or similar structure as gNB 102.

As shown in FIG. 3B, the gNB 102 includes multiple antennas 370a-370n, multiple RF transceivers 372a-372n, transmit (TX) processing circuitry 374, and receive (RX) processing circuitry 376. In certain embodiments, one or more of the multiple antennas 370a-370n include 2D antenna arrays. The gNB 102 also includes a controller/processor 378, a memory 380, and a backhaul or network interface 382.

The RF transceivers 372a-372n receive, from the antennas 370a-370n, incoming RF signals, such as signals transmitted by UEs or other gNBs. The RF transceivers 372a-372n down-convert the incoming RF signals to generate IF or baseband signals. The IF or baseband signals are sent to the RX processing circuitry 376, which generates processed baseband signals by filtering, decoding, and/or digitizing the baseband or IF signals. The RX processing circuitry 376 transmits the processed baseband signals to the controller/ processor 378 for further processing.

The TX processing circuitry 374 receives analog or digital data (such as voice data, web data, e-mail, or interactive video game data) from the controller/processor 378. The TX processing circuitry 374 encodes, multiplexes, and/or digitizes the outgoing baseband data to generate processed baseband or IF signals. The RF transceivers 372a-372n receive the outgoing processed baseband or IF signals from the TX processing circuitry 374 and up-converts the baseband or IF signals to RF signals that are transmitted via the antennas 370a-370n.

The controller/processor 378 can include one or more processors or other processing devices that control the overall operation of the gNB 102. For example, the controller/processor 378 can control the reception of forward channel signals and the transmission of reverse channel signals by the RF transceivers 372a-372n, the RX processing circuitry 376, and the TX processing circuitry 374 in accordance with well-known principles. The controller/processor 378 can support additional functions as well, such as more advanced wireless communication functions. For instance, the controller/processor 378 can perform the blind interference sensing (BIS) process, such as performed by a BIS algorithm, and decodes the received signal subtracted by the interfering signals. Any of a wide variety of other functions can be supported in the gNB 102 by the controller/processor 378. In some embodiments, the controller/ processor 378 includes at least one microprocessor or microcontroller.

The controller/processor 378 is also capable of executing programs and other processes resident in the memory 380, such as a basic OS. The controller/processor 378 is also capable of supporting channel quality measurement and reporting for systems having 2D antenna arrays as described in embodiments of the present disclosure. In some embodiments, the controller/processor 378 supports communications between entities, such as web RTC. The controller/processor 378 can move data into or out of the memory 380 as required by an executing process.

The controller/processor 378 is also coupled to the backhaul or network interface 382. The backhaul or network interface 382 allows the gNB 102 to communicate with other devices or systems over a backhaul connection or over a network. The interface 382 can 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, LTE, or LTE-A), the interface 382 can 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 382 can 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 382 includes any suitable structure supporting communications over a wired or wireless connection, such as an Ethernet or RF transceiver.

The memory 380 is coupled to the controller/processor 378. Part of the memory 380 can include a RAM, and another part of the memory 380 can include a Flash memory or other ROM. In certain embodiments, a plurality of instructions, such as a BIS algorithm is stored in memory. The plurality of instructions are configured to cause the controller/processor 378 to perform the BIS process and to decode a received signal after subtracting out at least one interfering signal determined by the BIS algorithm.

As described in more detail below, the transmit and receive paths of the gNB 102 (implemented using the RF transceivers 372a-372n, TX processing circuitry 374, and/or RX processing circuitry 376) support communication with aggregation of frequency division duplexing (FDD) cells and time division duplexing (TDD) cells.

Although FIG. 3B illustrates one example of a gNB 102, various changes may be made to FIG. 3B. For example, the gNB 102 can include any number of each component shown in FIG. 3. As a particular example, an access point can include a number of interfaces 382, and the controller/processor 378 can support routing functions to route data between different network addresses. As another particular example, while shown as including a single instance of TX processing circuitry 374 and a single instance of RX processing circuitry 376, the gNB 102 can include multiple instances of each (such as one per RF transceiver).

Multiple input multiple output (MIMO) system wherein a BS and/or a UE is equipped with multiple antennas has been widely employed in wireless systems for its advantages in terms of spatial multiplexing, diversity gain and array gain. FIG. 4 illustrates an example of MIMO antenna configuration with 24 antenna elements. In the FIG. 4, cross-polarized 401 antenna elements form a 4x1 subarray. 12 subarrays form a 2V3H MIMO antennas configuration consisting 2 and 3 subarrays in vertical and horizontal dimensions, respectively. Although FIG. 4 illustrates one example of MIMO antenna configuration, the disclosed invention can be applied to various such configurations.

In MIMO systems, the channel state information (CSI) is required at the base station (BS) so that a signal from the BS is received at the UE with maximum possible received power and minimum possible interference. The acquisition of CSI at the BS can be via a measurement at the BS from an uplink (UL) reference signal or via a measurement and feedback by the UE from a downlink (DL) reference signal for time-domain duplexing (or time division duplexing) (TDD) and frequency-domain duplexing (or frequency division duplexing) (FDD) systems, respectively. In 5G FDD systems, the channel state information reference signal (CSI-RS) is the primary reference signal that is used by the UE to measure and report CSI.

In some embodiments, a UE may receive a configuration signaling from a BS for a CSI-RS that can be used for channel measurement. An example of such configuration is illustrated in FIG. 5. In the FIG. 5, 12 antenna ports (CSI-RS ports) are mapped to a CSI-RS with 3 code-domain multiplexing (or code division multiplexing) (CDM) groups, wherein each CDM group is mapped to 4 resource elements (REs) in OFDM time-frequency grid. The antenna ports that are mapped to the same CDM group can be orthogonalized in code-domain by employing orthogonal cover codes. The CSI-RS configuration in FIG. 5 can be related to the MIMO antenna configuration in FIG. 4, by mapping a CSI-RS port to one of the polarization of a subarray. In the 5G NR standards, three time-domain CSI-RS resources configurations, namely: periodic, semi-persistent and aperiodic are possible. In the figure, an illustrative example of periodic configuration is given with a period of 4 slots.

Moreover, a UE can be configured to measure a CSI feedback with a CSI report configuration. A CSI report configuration can be periodic, semi-persistent or aperiodic manner. FIG. 6 depicts the CSI report configuration and CSI measurement configurations that is supported in 5G NR system. A CSI report configuration (602) can be linked to a CSI resource configuration (603). The CSI resource configuration (602) may contain one or more CSI resource sets (604) for channel measurement (CMR) or inference measurement (IMR).

In the case of periodic (P) and semi-persistent (SP) CSI report setting, the CSI resource configuration contains a single CSI resource set. In case of aperiodic (AP) CSI report, a UE can be configured with multiple CSI report triggering states (600) which are linked to one or more associated report configuration information (601). A downlink control information (DCI) may include CSI request which indicates one of the configured triggering states. Moreover, the DCI with CSI request may also contain a resource set selection field (605) to select one of the resources sets (604).

Moreover, a CSI report can be configured with one of the CSI reporting quantities. This may include CSI resource indicator (CRI), the rank indicator (RI), precoding matrix indicator (PMI), channel quality indicator (CQI), layer indicator (LI), signal to interference and noise ratio (SINR), reference signal received power (RSRP). In 5G NR, various CSI reporting quantiles are adopted. In particular, a radio resource control (RRC) parameter reportQuantity set to either 'none', 'cri-RI-PMI-CQI ', 'cri-RI-i1', 'cri-RI-i1-CQI', 'cri-RI-CQI', 'cri-RSRP', 'cri-SINR', 'ssb-Index-RSRP', 'ssb-Index-SINR', 'cri-RI-LI-PMI-CQI', 'cri-RSRP- Index', 'ssb-Index-RSRP- Index', 'cri-SINR- Index' or 'ssb-Index-SINR- Index'.

The CSI reporting can be used for transmission beam management (BM), specifically, in higher frequency bands, e.g., in frequency range 2 (FR2). In this case, the gNB may configure the UE to report one of the following quantities including, 'cri-RSRP', 'cri-SINR', 'ssb-Index-RSRP', 'ssb-Index-SINR', 'cri-RSRP- Index', 'ssb-Index-RSRP- Index', 'cri-SINR- Index' or 'ssb-Index-SINR- Index'.

For a yet another purpose, the CSI report can be used to acquire a digital precoding information and other CSI components. In this case, the gNB may configure with a CSI report with one of the following quantities: 'cri-RI-PMI-CQI ', 'cri-RI-PMI-CQI-Li ', 'cri-RI-i1', 'cri-RI-i1-CQI', 'cri-RI-CQI'.

In 5G NR system CSI-RS resources up to 32 ports are supported. The CSI-RS ports are mapped in frequency domain as shown in FIG. 7. In particular, the CSI-RS ports are mapped to the REs of OFDM resource blocks via a higher layer information element (IE) CSI-RS_ResourceMapping. A parameter nrofPorts configures the number of ports. The parameter density configures the resource block (RB)-level density of CSI-RS ports. If this parameter is set to value x, CSI-RS ports appear x times per RB. All the configured CSI-RS ports are mapped together to the RBs the CSI-RS ports are present. The frequency-domain CSI-RS resource mapping is configured by higher-layer parameter IE CSI-FrequencyOccupation. The parameter startingRB and nrOfRBs define the starting RB (701) and the number of RBs (702) the CSI-RS resources occupy. The parameter startingRB indicates the first RB for CSI-RS occupancy which is indicated by taking the common resource block 0 as reference.

In the time domain, the location of CDM groups of a CSI-RS resource is provided by a higher layer parameter firstOFDMSymbolInTimeDomain and firstOFDMSymbolInTimeDomain2. These parameters indicate up to two starting symbols for the CDM groups of a CSI-RS resource. Moreover, the frequency-domain location of CDM groups of a CSI-RS resource within a physical resource block (PRB) is provided by a frequencyDomainAllocation parameter (803). This parameter can provide frequency domain staring resource element (RE) for each CDM group. The locations could be from a single row, i.e., row1, up to four rows, i.e., row4. FIG. 8 provides an example for time and frequency domain allocation of 32 ports CSI-RS resource. Two starting symbol locations are indicated by l₀ and l₁. Moreover, four frequency domain locations K₀, K₁, K₂ and K₃, are indicated. Each CDM group consist of 4 REs which is indicated by the parameter CDM-Type cdm4-FD2-TD2. Thus, each CDM group consists of 4 CSI-RS ports and 8 CDM groups for the 32 CSI-RS ports.

One of the limitations of the 5G NR CSI-RS configuration (up to Release 18) is that the maximum number of ports supported per CSI-RS resource is 32. Correspondingly, the CSI report associated to a single CSI-RS resource is limited to a maximum of 32 ports. In the following, various methods to support CSI measurement for reporting more than 32 ports is provided.

In accordance with various embodiments of the present disclosure, the following references may be consulted.

[1] RP-193133, New WID: Further enhancements on MIMO for NR, Samsung

[2] 3GPP TS 38.213, V15.12.0(2020-12): "NR; Physical layer procedures for control (Release 15)",

[3] 3GPP TS 38.214, V15.11.0 (2020-09): "NR; Physical layer procedures for data (Release 15)",

[4] 3GPP TS 38.213, V16.4.0 (2020-12): "NR; Physical layer procedures for control (Release 16)"

[5] 3GPP TS 38.214, V16.4.0 (2020-12): "NR; Physical layer procedures for data (Release 16)",

[6] 3GPP TS 38.321, V16.3.0 (2020-12): "NR; Medium Access Control (MAC) protocol specification (Release 16)",

[7] 3GPP TS 38.331, V16.3.1 (2021-01): " NR; Radio Resource Control (RRC) protocol specification

[8] 3GPP TS 38.211, V16.4.0 (2020-12): " NR; Physical channels and modulation."

[9] 3GPP TS 38.212, V16.4.0 (2020-12): " NR; Multiplexing and channel coding."

[10] 3GPP TS 38.215, V16.4.0 (2020-12): " NR; Physical layer measurements"

A specific description of example embodiments is described below.

The text and figures are provided solely as examples to aid the reader in understanding the invention. They are not intended and are not to be construed as limiting the scope of this invention 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 invention.

The below flowcharts illustrate example methods that can 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.

In the below various mechanisms for CSI measurement and reporting framework for a large number of CSI-RS ports is provided.

I. CSI-RS resource with more than 32 ports

As part of the current disclosure, Method I, provides various ways of configuring CSI-RS resource with more than 32 ports. The presented disclosure includes ports to resource block (RB) mapping, time and frequency domain allocation information, CDM group formation and others.

I.1. Sparse Port mapping across PRBs (PRB bundling for port mapping)

In one aspect of this disclosure, Method I.1., the CSI-RS ports are mapped across multiple PRBs. This allows, the maximum number of CSI-RS ports in a PRB to be the same as the legacy one. Contiguous or non-contiguous PRBs can be bundled together for ports mapping purpose. In one aspect of this disclosure, a gNB provides configuration information by including higher layer parameters, e.g., PRB-bundleSize, to configure the UE with information pertaining to PRB bundling for CSI-RS ports mapping.

In one exemplary embodiment, for P CSI-RS ports provided by higher parameter nrofPorts to be mapped to PRB bundle of size K PRBs as provided by higher parameter PRB-bundleSize. For even ports mapping per PRB, each PRB constitutes of P/K ports. Then, the UE expects, for PRB indexk=0,1,..,K, ports P/K ports indexed by

are mapped in the k-th PRB.

In a yet another aspect of this disclosure, Method I.1.1, the gNB provides the time-frequency domain resource mapping information for CSI-RS ports of a CSI-RS resource per PRB, i.e., for a single PRB. Then, the same time-frequency domain resource mapping is repeated across all PRBs in a PRB bundle. (901) in FIG. 9, is one exemplary case in which the time-domain allocation parameters, i.e., l₀,l₁, and frequency-domain allocation parameters, k₀,k₁,k₂,k₃ are the same for the K=2 PRBs of a PRB bundle.

In a yet another aspect of this disclosure, Method I.1.2, the gNB provides the time-frequency domain resource mapping information for CSI-RS ports of a CSI-RS resource across PRBs of a PRB bundle, i.e., across multiple PRBs. (902) in FIG. 9, is one exemplary case in which the time-domain allocation parameters, i.e., l₀,l₁, and frequency-domain allocation parameters, k₀,k₁,...,k₇ are configured across K=2 PRBs of a PRB bundle.

I.2. Dense port mapping in PRBs (More than 32 ports per PRB)

In one aspect of this disclosure, Method I.2., all the CSI-RS ports are mapped to a single PRB. Thus, the gNB provides the ports mapping configuration per PRB. As a result, the number of resource elements of a PRB which are allocated to a CSI-RS resource could be increased as compared to the legacy, thus dense mapping in PRBs. In one aspect of this disclosure, a gNB provides configuration information by including higher layer parameters for time and frequency-domain allocation of REs for CSI-RS ports.

In one exemplary embodiment, i.e., Method I.2.1, the gNB configures the UE with additional time and/or frequency-domain allocation parameters for CDM groups mapping to the resource elements of a PRB. FIG. 10, (1001) depicts how 64 CSI-RS ports can be supported by doubling the number of CDM groups as compared to 32 ports CSI-RS. In TABLE 1, examples are provided for Method I.2.1 to support 64 ports. In particular, for rows 20, 21 and 23, additional time domain locations are assumed. As an example in row, 21, in addition to the legacy firstOFDMSymbolInTimeDomain (l₀) and firstOFDMSymbolInTimeDomain2 (l₁), two new time-domain location indicators firstOFDMSymbolInTimeDomain3 (l₂) and firstOFDMSymbolInTimeDomain4 l₃ are introduced in the disclosed invention to increase the number of CDM groups from 8 to 16. On the other hand, Row 22 is associated to a configuration wherein additional frequency domain location is configured by gNB, i.e., k₄,k₅,k₆ and k₇in addition to the legacy k₀,k₁,k₂,k₃. Thus, the disclosed invention introduces additional frquencyDomainAllocation parameters, i.e., row5, row6, row7, row8. Method I.2.1 is friendly to UE’s processing for channel estimation via CSI-RS, as the size of the CDM group is maintained as the legacy one.

In a yet another embodiment, i.e., Method I.2.2, the gNB configures the UE with larger CDM groups while keeping the maximum number of CDM groups per CSI-RS resource to be the same as the legacy. FIG. 10, (1002) depicts how 64 ports CSI-RS resource can be supported by increasing the size of the CDM groups as compared to 32 ports CSI-RS resource. As one aspect of this embodiment, the gNB may configure the UE with new cdm-Type to accommodate more ports per CDM group. One such example is given in row 25 of TABLE 1. Therein, a new cdm-Type, cdm16-FD2-TD8 is introduced for 16 ports per CDM group and total of 4 CDM groups per CSI-RS resource to support 64 ports. Larger CDM groups, while it improves the noise robustness of channel estimation, it also increases UE's computational complexity for dispreading the received CSI-RS signal.

As a yet another embodiment of the present disclosure, a UE indicates its capability on the cdm-Types it supports. As example, the UE may indicate its capability, by explicitly indicating the cdm-Types it supports or not supports. As another alternative, the UE may indicate its capability by reporting the maximum number of ports per CDM group it supports. As a yet another alternative, the UE may indicate the maximum or the list of length of a CDM group in the time-domain, it supports. As an example, the UE may indicate the

values

4 and 8, if it supports cdm16-FD4-TD4 and 8 cdm16-FD2-TD8, respectively. The time-domain length may impact the number of OFDM symbols the UE has to buffer, hence, the complexity of the UE.

FIG. 11 depicts an exemplary case of the disclosed invention for cdm-Type configured to cdm16-FD2-TD8. As shown in the figure, each CDM group lapse 8 OFDM symbols and two subcarriers. As there are 4 frequency domain locations for the CDM groups, the gNB indicates the frequencyDomainAllocation via a bit string for row4.

II. CSI-RS Resources Aggregation for a Large Number of Ports

In some cases, it is beneficial if CSI-RS resources are aggregated to form a larger number of ports. Such CSI-RS resources aggregation allows keeping simpler CSI-RS configuration potentially reusing the legacy CSI-RS resource configuration (reduced overhead for higher layer signaling) while achieving a flexible extension to a larger number of ports. Additionally, the UE may report CSI with multiple hypotheses on the number of CSI-RS ports, e.g., CSI report for 32 and 64 ports. Such reporting could be useful for network energy saving, i.e., the network can choose to serve the UE with 32 antenna ports and turn of 32 antenna ports, when some conditions are fulfilled.

As one aspect of this disclosure, Method II, the gNB configures multiple CSI-RS resources in a set and additionally configures CSI-RS resources aggregation information to form a large number of CSI-RS ports.

In one aspect of Method II, the gNB indicates the number of aggregated CSI-RS resources through a higher layer parameter which indicates the number of CSI-RS resources aggregated together. One exemplary higher layer parameter is csi-rs-AggregationSize which can be an integer value greater than or equal to 1. If a UE is configured with a CSI-RS resource set with Ks resources, and if the higher layer parameter for indication of the aggregation size indicates N resources per aggregation, then the UE assumes

groups of aggregated resources, wherein group m=0,1,…,M-1 consists of the (m×N)+1…(m+1)×N resources.

Moreover, it is beneficial if the time-domain location of aggregated CSI-RS resources is close to each other. Ideally, the resources are transmitted in the same time-domain symbols as shown by FIG. 12 This has benefits of multiple folds. If the aggregated CSI-RS resources span few symbols in the time domain, the burden on the UE for buffering (storing the estimated samples in memory) is lower. Moreover, the time-domain gap between different CDM groups hence ports is reduced allowing for more accurate CSI measurement.

In order to achieve the aforementioned advantages, various modifications on the legacy CSI-RS resources configurations are needed. In the 5G NR CSI-RS resource set configuration, the starting RB for the CSI-RS resources in a resource set has to be the same. This limits the possibilities for the aggregated CSI-RS resources to be received in the same symbols. For example, to aggregating more than one CSI-RS resources with 32 ports and cdm-Type set to cdm4-FD2-TD2 in the same symbols is not possible. This is because, 8 subcarriers are already occupied by a single resource and aggregating more than one resource in the same symbol would require at least 32 subcarriers. As one aspect of the disclosed invention, to solve the aforementioned limitation, the gNB may configure CSI-RS resources in a set with lower density than 1 density, e.g., dot5 (0.5), dot25 (0.25), etc. and different startingRB. In particular, the gNB may configure the UE by aggregating N CSI-RS resources with density lower or equal to 1/N. Then, the startingRB of the CSI-RS resources in aggregated group can be incremented by 1 or other value start from the first CSI-RS resource. FIG. 12 provides illustration of the aforementioned method where in two 32-ports CSI-RS resources with density=dot5 are aggregated to make 64 ports aggregate group. Then if the startingRB of CSI-RS resource#1 is set to the value X (1201), then the startingRB of the second CSI-RS resource is set to X+1. This method can be applied to various number of CSI-RS ports including 64, 96, 128, etc. without limitation by adjusting the density and starting RB of CSI-RS resources in an aggregate group.

As a yet another aspect of the disclosed invention, up to 2 CSI-RS resources can be aggregated to be received in the same OFDM symbols by configuring them with different parameter for even and odd PRBs, i.e., dot5 ENUMERATED {evenPRBs, oddPRBs} in a CSI-RS_resourceMapping.

III. Reporting Configurations

III.1. CSI Reporting with Type I Single Panel Codebook

The 5G NR CSI reporting with report quantity set to 'cri-RI-PMI-CQI' or 'cri-RI-PMI-CQI-Li' and the codebookType set to 'typeI-singlePanel', 'typeI-MultiPanel' or 'type2' supports up to 32 ports. In the following, the disclosed invention provides additional methods to extend the support for more than 32 ports.

In order to extend the number of ports supported for CSI report with the aforementioned configurations, the port layout configuration for more than 32 ports with the number of ports in each dimensions, i.e., N₁ and N₂, is required.

As one aspect of the disclosed invention, in Method III.1.1, gNB configures the UE with a single antenna layout configuration for N₁ and N₂ to support more than 32 ports. This single antenna layout configuration can be applied for both cases wherein the ports are from a single CSI-RS resource or multiple aggregated CSI-RS resources. TABLE 2 provides possible values for N₁ and N₂ configuration values.

As a yet another aspect of the disclosed invention, in Method III.1.2, gNB configures the UE with a single antenna layout configuration for N₁ and N₂ wherein 2N1N2≤32 with additional parameter to indicate the extension dimension of the aggregated CSI-RS ports.

As one embodiment of Method III.1.2, a gNB configures the UE with a single bit extension dimension indicator. Based on the value of this indicator {0, 1}, the UE may assume that the antenna ports are extended either in the N₁ and N₂ dimensions. For example, if the extension dimension indicates the extension in the N₁ dimension (1301), then the aggregated ports layout will be NN₁×N₂. On the other hand, if the extension indicator indicates extension in the N₂dimension (1302), then the aggregated ports will be N₁×NN₂.

As another aspect of the disclosed invention, a two-dimensional extension indicator can be considerd. This indicator can indicate the number of resources aggregated in each dimension. As an exemplary embodiment, two indicators can be considered n1- Aggregation and n2-Aggregation, each with bit-width

where N is the number of CSI-RS resources aggregated. FIG. 14 depicts exemplary cases where in N=4 and n1- Aggregation=2 and n2-Aggregation=2 for (1400) and n1- Aggregation=4 and n1- Aggregation=2 for (1401).

In some cases, it may be enough for the gNB to indicate the aggregation in one dimension and the UE computes/calculates the aggregation in the other dimension. For example, if N is the number of CSI-RS resources aggregated and gNB indicates aggregation in either N1 or N2 dimension, e.g., n1- Aggregation, UE may compute the aggregation in the either dimension from N and indicated value, e.g., n2- Aggregation=N - n1- Aggregation.

III.2. Other Configurations

In the legacy, 5G NR, the gNB configures the UE with codebook subset restriction (CBSR) which indicates the spatial domain vectors that can be reported vis-a-vis restricted from being reported. In particular, a bitmap parameter n1-n2 forms a bit sequence

where a₀ is the LSB and

is the MSB and where a bit value of zero indicates that PMI reporting is not allowed to correspond to any precoder associated with the bit. The number of bits is given by

.

One limitation of the legacy CBSR configuration when it is extended to the higher number of ports is that, the overhead for CBSR indication. As an example, to indicate a CBSR for 32 ports configuration when n1-n2 is set to (8,2) and (4,4), 256 bits are required. Extension of such approach to 128bits implies the number of bits required for CBSR configuration increases by 4 folds to 1024 bits. As one aspect of the disclosed invention, Method III.2.1, the gNB may configure CBSR with lower granularity, e.g., N₁×N₂-length and applies to group of O₁×O₂ vectors.

A yet another aspect of this disclosure, in Method III.2.2, gNB configures the CBSR with different granularity in the two dimensions. As an example, the gNB configures the UE with higher granularity in the N₁ dimension and lower granularity in the N₂ dimension with a bitmap of length of N₁O₁×N₂. Then, a single bit in the bitmap for CBSR corresponds to O₂ vectors in the N₂ dimension. Similarly, the gNB configures the UE with lower granularity (vector group based) in the N₁ dimension and higher granularity (vector based) in the N₂ dimension with a bitmap of length of N₁×N₂O₂. Then, a single bit in the bitmap for CBSR corresponds to O₁ vectors in the N₂ dimension. Such configuration has advantage when there is imbalance in the sharpness of gNB’s beam (digital and analog) in the two dimensions due to more number of ports in one dimension, e.g., the gNB’s beam appear to be much sharper (narrower) in one dimension than the other. In such cases, the configuration of CBSR and its interpretation can be associated with aggregation parameter.

The above embodiments can be readily generalized to the cases wherein a network applies a scaling or downsizing factors X₁ and X₂ to the legacy CBSR configurations for the N₁ and N₂ dimensions, respectively. As one embodiment of this disclosure, the gNB may configure the UE with

bits CBSR, where a₀ is the LSB and

is the MSB and where a bit value of zero indicates that PMI reporting is not allowed to correspond to any precoder associated with the bit. Except when the number of layers

and the number of antenna ports is 16, 24, or 32, bit

is associated with all precoders based on one of the

quantities

,

When the number of layers

and the number of antenna ports is 16, 24, or 32:

- bits

,

and

are each associated with all precoders based on the

quantity

,

.

- if one or more of the associated bits is zero, then PMI reporting is not allowed to correspond to any precoder based on one of the

quantities

.

In one aspect of this disclosure, the gNB may configure the UE with the CBSR scaling/downsizing factors X₁ and X₂ via higher layer parameter where in the factors X₁ and X₂ take values from {1, O1} and {1, O2}, respectively. In this case the CBSR bitmap have one of the lengths from

as illustrated in Method III.2.1 and Method III.2.2.

In a yet another aspect of this disclosure, the gNB may configure the UE with the CBSR scaling/downsizing factors X₁ and X₂ to take values from {1, 2, 4, 8, 16, 32} wherein

and

.

In a yet another aspect of this embodiment, the gNB configures the UE with the CBSR scaling/downsizing factors X₁ and X₂ to take values from {1, 2, 4, 8, 16, 32} wherein

and

while maintaining the maximum number of bit for CBSR (corresponding to P=32 ports) is maintained to be 256 bits. In particular, the CBSR scaling/downsizing factors X₁ and X₂ for P_CSI≥32 takes possible values while obeying

. This provides flexibility to the gNB in the configuration of CBSR for the required granularity in either of the dimensions while maintaining the configuration overhead. In accordance to this embodiment, TABLE 3 provides possible configurable values for X₁ and X₂.

Another aspect in the CSI measurement is interference measurement. The legacy 5G NR CSI framework provides measurement and reporting framework for interference. For example, resources designated as CSI-IM can be used for interference measurement. If interference measurement is performed on CSI-IM, each CSI-RS resource for channel measurement is resource-wise associated with a CSI-IM resource by the ordering of the CSI-RS resource and CSI-IM resource in the corresponding resource sets. The number of CSI-RS resources for channel measurement equals to the number of CSI-IM resources.

The above configuration and restriction of 5G NR has limitation to be applied for CSI-RS aggregation for formation of large number of ports. As an example, multiple CSI-IM resources are not need to be associated to the aggregated CSI-RS resources for channel measurement.

As one aspect of the current disclosure, in Method III.2.3, the gNB may configure a single CSI-IM resource for a group of aggregated CSI-RS resources. When multiple groups of aggregated CSI-RS resources are present in a resource set, and when the number of aggregated CSI-RS resources is N, then n-th CSI-IM resource is associated to the n-th group of aggregated CSI-RS resources, i.e., CSI-RS resources indexed as (n-1)N+1,(n-1)N+2…,nN. Moreover, the UE may assume the same spatial filter with respect to QCL type-D for receiving the N aggregated CSI-RS resources and the associated CSI-IM resource.

What is described above is only preferred embodiments of the disclosure, and it is not intended to limit the disclosure. Any modifications, equivalents, improvements, etc. made within the spirit and principle of the disclosure should be included in the scope of the disclosure.

While the disclosure has been shown and described with reference to various embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims and their equivalents.

Claims

A user equipment (UE) in a wireless communication system, the UE comprising:

a transceiver; and

a controller coupled to the transceiver, and configured to:

receive, from a base station, first information configuring a channel state information (CSI)-reference signal (RS) resource set for more than 32 CSI-RS ports, the CSI-RS resource set including at least two CSI-RS resources, and

receive, from the base station, a CSI-RS on the at least two CSI-RS resources which are aggregated,

wherein the at least two CSI-RS resources have a same starting resource block (RB).
The UE of claim 1, wherein a first CSI-RS resource of the at least two CSI-RS resources is mapped to an even physical resource block (PRB) and a second CSI-RS resource of the at least two CSI-RS resources is mapped to an odd PRB for a density of 0.5 resource element (RE) per RB per port.
The UE of claim 1, wherein the at least two CSI-RS resources have a same quasi co-located (QCL) value.
The UE of claim 1, wherein the controller is further configured to:

receive, from the base station, second information configuring a codebook subset restriction (CBSR) with spatial domain (SD) basis vectors for a first dimension and a second dimension.
A base station in a wireless communication system, the base station comprising:

a transceiver; and

a controller coupled to the transceiver, and configured to:

transmit, to a user equipment (UE), first information configuring a channel state information (CSI)-reference signal (RS) resource set for more than 32 CSI-RS ports, the CSI-RS resource set including at least two CSI-RS resources, and

transmit, to the UE, a CSI-RS on the at least two CSI-RS resources which are aggregated,

wherein the at least two CSI-RS resources have a same starting resource block (RB).
The base station of claim 5, wherein a first CSI-RS resource of the at least two CSI-RS resources is mapped to an even physical resource block (PRB) and a second CSI-RS resource of the at least two CSI-RS resources is mapped to an odd PRB for a density of 0.5 resource element (RE) per RB per port.
The base station of claim 5, wherein the at least two CSI-RS resources have a same quasi co-located (QCL) value.
The base station of claim 5, wherein the controller is further configured to:

transmit, to the UE, second information configuring a codebook subset restriction (CBSR) with spatial domain (SD) basis vectors for a first dimension and a second dimension.
A method performed by a user equipment (UE) in a wireless communication system, the method comprising:

receiving, from a base station, first information configuring a channel state information (CSI)-reference signal (RS) resource set for more than 32 CSI-RS ports, the CSI-RS resource set including at least two CSI-RS resources; and

receiving, from the base station, a CSI-RS on the at least two CSI-RS resources which are aggregated,

wherein the at least two CSI-RS resources have a same starting resource block (RB).
The method of claim 9, wherein a first CSI-RS resource of the at least two CSI-RS resources is mapped to an even physical resource block (PRB) and a second CSI-RS resource of the at least two CSI-RS resources is mapped to an odd PRB for a density of 0.5 resource element (RE) per RB per port.
The method of claim 9, wherein the at least two CSI-RS resources have a same quasi co-located (QCL) value.
The method of claim 9, further comprising:

receiving, from the base station, second information configuring a codebook subset restriction (CBSR) with spatial domain (SD) basis vectors for a first dimension and a second dimension.
A method performed by a base station in a wireless communication system, the method comprising:

transmitting, to a user equipment (UE), first information configuring a channel state information (CSI)-reference signal (RS) resource set for more than 32 CSI-RS ports, the CSI-RS resource set including at least two CSI-RS resources; and

transmitting, to the UE, a CSI-RS on the at least two CSI-RS resources which are aggregated,

wherein the at least two CSI-RS resources have a same starting resource block (RB).
The method of claim 13, wherein a first CSI-RS resource of the at least two CSI-RS resources is mapped to an even physical resource block (PRB) and a second CSI-RS resource of the at least two CSI-RS resources is mapped to an odd PRB for a density of 0.5 resource element (RE) per RB per port.
The method of claim 13, wherein the at least two CSI-RS resources have a same quasi co-located (QCL) value.