Methods and apparatus for implementing multi-resolution CSI reporting in advanced wireless communication systems

Abstract

The present disclosure relates to a communication method and system for integrating a fifth-generation (5G) communication system for supporting higher data rates beyond a fourth-generation (4G) system with technologies for the Internet of Things (IoT). The present disclosure can be applied to intelligent services based on 5G communication technologies and IoT-related technologies, such as smart home, smart building, smart city, smart car, connected car, healthcare, digital education, smart retail, security, and insurance services. A method for a user equipment (UE) for channel state information (CSI) feedback in a wireless communication system. The method includes: receiving, from a base station (BS), CSI feedback configuration information for precoding matrix indicator (PMI) feedback, the CSI feedback configuration information indicating a linear combination precoding matrix corresponding to a linear combination (LC) of a plurality of L beams and a plurality of coefficients; determining a first PMI (i1) and a second PMI (i2); and transmitting, via an uplink channel, the CSI feedback including the first PMI (i1) and the second PMI (i2) to the BS.

Description

[0001] This application is a divisional application of the invention patent application with the application date of November 22, 2017, the application number of 2017800720112, and the title of "Method and Apparatus for Implementing Multi-Resolution CSI Reporting in Advanced Wireless Communication Systems". Technical Field

[0002] This application generally relates to CSI reporting operations in advanced communication systems. More specifically, the present disclosure relates to CSI reporting based on a linear combination precoding matrix indicator (PMI) codebook in a wireless communication system. Background Art

[0003] To meet the demand for wireless data services that has increased since the deployment of 4G communication systems, efforts have been made to develop improved 5G or pre-5G communication systems. Therefore, 5G or pre-5G communication systems are also referred to as "Beyond 4G Networks" or "Post LTE Systems". 5G communication systems are considered to be implemented in higher frequency (mmWave) bands (e.g., 60 GHz band) in order to achieve higher data rates. To reduce the propagation loss of radio waves and increase the transmission distance, beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antenna technologies have been discussed in 5G communication systems. Additionally, in 5G communication systems, the development for system network improvement is being carried out based on advanced small cells, cloud radio access network (RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, coordinated multi-point (CoMP), receiver-side interference cancellation, etc. In 5G systems, hybrid FSK and QAM modulation (FQAM) and sliding window superimposed coding (SWSC) as advanced coding modulation (ACM) and filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as advanced access technologies have been developed.

[0004] The Internet is a human - centered connection network where humans generate and consume information. Now it is evolving into the Internet of Things (IoT), in which distributed entities such as things exchange and process information without human intervention. The Internet of Everything (IoE) has emerged, which is a combination of IoT technologies and big data processing technologies connected to cloud servers. The implementation of IoT requires technical elements such as "sensing technology", "wired / wireless communication and network infrastructure", "service interface technology", and "security technology". Recently, sensor networks, machine - to - machine (M2M) communication, machine - type communication (MTC), etc. have been studied. Such an IoT environment can provide intelligent Internet technology services that create new value for human life by collecting and analyzing data generated between connected things. IoT can be applied to various fields including smart home, smart building, smart city, smart car or connected car, smart grid, healthcare, smart appliances, and advanced medical services through the integration and combination of existing information technology (IT) and various industrial applications.

[0005] In line with this, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, machine - type communication (MTC), and machine - to - machine (M2M) communication can be implemented through beamforming, MIMO, and array antennas. Cloud radio access network (RAN), as an application of the above - mentioned big data processing technology, can also be considered an example of the integration between 5G technology and IoT technology.

[0006] The initial commercialization of fifth - generation (5G) mobile communication is expected around 2020, and it has recently been gathering increasing momentum with all global technical activities regarding various candidate technologies from industry and academia. The candidate driving forces for 5G mobile communication include large - scale antenna technology from traditional cellular bands up to high frequencies to provide beamforming gain and support increased capacity, new waveforms (e.g., new radio access technology (RAT)) for flexibly adapting to various services / applications with different requirements, new multiple - access schemes for supporting massive connections, etc. The International Telecommunication Union (ITU) has classified the usage scenarios of international mobile telecommunications (IMT) for 2020 and beyond into 3 main groups, such as enhanced mobile broadband, massive machine - type communication (MTC), and ultra - reliable and low - latency communication. Additionally, the ITC has specified target requirements such as a peak data rate of 20 gigabits per second (Gb / s), a user - experience data rate of 100 megabits per second (Mb / s), a 3 - fold improvement in spectral efficiency, support for mobility up to 500 kilometers per hour (km / h), a 1 - millisecond (ms) latency, a connection density of 10^6 devices / km 2 and a 100 - fold improvement in network energy efficiency, as well as 10 Mb / s / m 2The regional communication capacity. Although it is not necessary to meet all requirements simultaneously, the design of the 5G network can provide flexibility to support various applications that meet a part of the above requirements based on use cases. Summary of the Invention

[0007] Technical Problem

[0008] The present disclosure relates to a quasi-fifth generation (5G) or 5G communication system that is to provide higher data rates for supporting a super fourth generation (4G) communication system such as Long Term Evolution (LTE). Embodiments of the present disclosure provide advanced CSI reporting based on a linear combination codebook for a MIMO wireless communication system.

[0009] Technical Solution

[0010] In one embodiment, a user equipment (UE) for channel state information (CSI) feedback in a wireless communication system is provided. The UE includes: a transceiver configured to receive CSI feedback configuration information for precoding matrix indicator (PMI) feedback from a base station (BS), the CSI feedback configuration information indicating a linear combination (LC) precoding matrix corresponding to a linear combination of a plurality of L beams and a plurality of coefficients, wherein: each of the plurality of coefficients includes at least an amplitude coefficient and a phase coefficient, and the PMI includes a first PMI (i1) and a second PMI (i2) respectively indicating a wideband (WB) component and a subband (SB) component of the LC precoding matrix, wherein: the first PMI (i1) includes a first indicator set and a second indicator set, the first indicator set and the second indicator set respectively indicating a common WB component of all layers in a plurality of layers and an independent WB component of each layer in the plurality of layers, the second PMI (i2) includes an indicator set indicating an independent SB component of each layer in the plurality of layers, and the plurality of layers are determined based on a value υ associated with a rank indicator (RI); and at least one processor configured to determine the first PMI (i1) and the second PMI (i2), wherein the transceiver is further configured to transmit the CSI feedback including the first PMI (i1) and the second PMI (i2) to the BS via an uplink channel.

[0011] In another embodiment, a method for a user equipment (UE) for channel state information (CSI) feedback in a wireless communication system is provided. The method includes: receiving CSI feedback configuration information for precoding matrix indicator (PMI) feedback from a base station (BS), the CSI feedback configuration information indicating a linear combination precoding matrix corresponding to a linear combination (LC) of a plurality of L beams and a plurality of coefficients, wherein: each of the plurality of coefficients includes at least an amplitude coefficient and a phase coefficient, and the PMI includes a first PMI (i1) and a second PMI (i2) respectively indicating a wideband (WB) component and a subband (SB) component of the LC precoding matrix, wherein: the first PMI (i1) includes a first indicator set and a second indicator set, the first indicator set and the second indicator set respectively indicating a common WB component of all layers in a plurality of layers and an independent WB component of each layer in the plurality of layers, the second PMI (i2) includes an indicator set indicating an independent SB component of each layer in the plurality of layers, and the plurality of layers are determined based on a value υ associated with a rank indicator (RI); determining the first PMI (i1) and the second PMI (i2); and transmitting the CSI feedback including the first PMI (i1) and the second PMI (i2) to the BS via an uplink channel.

[0012] In yet another embodiment, a base station (BS) for channel state information (CSI) feedback in a wireless communication system is provided. The BS includes: a transceiver configured to send CSI feedback configuration information for precoding matrix indicator (PMI) feedback to a user equipment (UE), the CSI feedback configuration information indicating a linear combination (LC) precoding matrix corresponding to a linear combination of a plurality of L beams and a plurality of coefficients, wherein: each of the plurality of coefficients includes at least one of an amplitude coefficient and a phase coefficient, and the PMI includes a first PMI (i1) and a second PMI (i2) respectively indicating a wideband (WB) component and a subband (SB) component of the LC precoding matrix, wherein: the first PMI (i1) includes a first indicator set and a second indicator set, the first indicator set and the second indicator set respectively indicating a common WB component of all layers in a plurality of layers and an independent WB component of each layer in the plurality of layers, the second PMI (i2) includes an indicator set indicating an independent SB component of each layer in the plurality of layers, and the plurality of layers are determined based on a value υ associated with a rank indicator (RI); and at least one processor configured to reconstruct the LC precoding matrix indicated by the first PMI (i1) and the second PMI (i2), wherein the transceiver is further configured to receive the CSI feedback including the first PMI (i1) and the second PMI (i2) from the UE via an uplink channel.

[0013] From the following figures, description, and claims, other technical features may be readily apparent to those skilled in the art.

[0014] Before presenting the following detailed description, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The term "coupled" 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 each other. The terms "send," "receive," and "transfer" and their derivatives encompass both direct and indirect communication. The terms "include" and "comprise" and their derivatives mean including but not limited to. The term "or" is inclusive, meaning and / or. The phrase "associated with" and its derivatives are intended to include, be included within, interconnected with, contain, be contained within, connected to or coupled with, communicate with, cooperate with, interleave, juxtapose, be adjacent to, bound to or bound by, have, have the property of, be related to, and 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 the form of 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 in conjunction 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 required. 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, B, and C.

[0015] In addition, the various functions described below may be implemented or supported by one or more computer programs, each computer program being formed of 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, instruction sets, procedures, functions, objects, classes, instances, related data, or portions thereof that are adapted to be implemented in 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 that can be accessed by a computer, such as read-only memory (ROM), random access memory (RAM), hard disk drive, compact disc (CD), digital video disc (DVD), or any other type of memory. A "non-transitory" computer-readable medium does not include wired, wireless, optical, or other communication links that transmit transitory electrical or other signals. Non-transitory computer-readable media include media that permanently store data and media that store and later rewrite data, such as rewritable compact discs or erasable memory devices.

[0016] Throughout this patent document, definitions of certain words and phrases are provided. Those of ordinary skill in the art should understand that, in many if not most instances, such definitions apply to the prior and future use of the words and phrases so defined.

[0017] Beneficial effects

[0018] According to at least one of the embodiments of the present disclosure, a method and apparatus for advanced CSI reporting based on a linear combination codebook for a MIMO wireless communication system are provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] To more fully understand 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:

[0020] Figure 1 An example wireless network according to an embodiment of the present disclosure is shown;

[0021] Figure 2 An example eNB according to an embodiment of the present disclosure is shown;

[0022] Figure 3 An example UE according to an embodiment of the present disclosure is shown;

[0023] Figure 4A An example high-level diagram of an orthogonal frequency division multiple access transmission path according to an embodiment of the present disclosure is shown;

[0024] Figure 4B An example high-level diagram of an orthogonal frequency division multiple access reception path according to an embodiment of the present disclosure is shown;

[0025] Figure 5 An example network slice according to an embodiment of the present disclosure is shown;

[0026] Figure 6 An example number of digital chains according to an embodiment of the present disclosure is shown;

[0027] Figure 7 An example of multiplexing two slices according to an embodiment of the present disclosure is shown;

[0028] Figure 8 An example CSI reporting framework according to an embodiment of the present disclosure is shown;

[0029] Figure 9 An example dual-resolution CSI reporting framework according to an embodiment of the present disclosure is shown;

[0030] Figure 10 Another example dual-resolution CSI reporting framework according to an embodiment of the present disclosure is shown;

[0031] Figure 11 shows an example three - resolution CSI reporting framework according to an embodiment of the present disclosure;

[0032] Figure 12 shows an example multi - antenna panel according to an embodiment of the present disclosure;

[0033] Figure 13 shows an example basis set for dimensionality reduction according to an embodiment of the present disclosure;

[0034] Figure 14 shows an example parameterized beam group according to an embodiment of the present disclosure; and

[0035] Figure 15 shows an example flowchart of a method for multi - resolution CSI reporting according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0036] In the following discussion Figures 1 to 15 and the various embodiments for describing the principles of the present disclosure in this patent document are only illustrative and should not be construed in any way as limiting the scope of the present disclosure. Those skilled in the art should understand that the principles of the present disclosure can be implemented in any suitably arranged system or device.

[0037] The following documents are hereby incorporated by reference into the present disclosure as if fully set forth herein: 3GPP TS 36.211 v14.2.0, “E-UTRA, Physical channels and modulation (REF 1)”; 3GPP TS 36.212 v14.2.0, “E-UTRA, Multiplexing and Channel coding; (REF 2)”; 3GPP TS 36.213 v14.2.0, “E-UTRA, Physical Layer Procedures (REF 3)”; 3GPP TS 36.321 v14.2.0, “E-UTRA, Medium Access Control (MAC) protocol specification (REF 4)”; 3GPP TS 36.331 v14.2.0, “Radio Resource Control (RRC) Protocol Specification (REF 5)”; and 3GPP TR 22.891 v1.2.0, “Technical Specification Group Services and System Aspects; Feasibility Study on New Services and Markets Technology; Enablers; Stage 1; (Release 14)”.

[0038] To meet the demand for wireless data traffic that has increased since the deployment of 4G communication systems, efforts have been made to develop improved 5G or pre-5G communication systems. Therefore, 5G or pre-5G communication systems are also referred to as “Beyond 4G Networks” or “Post LTE Systems”.

[0039] The 5G communication system is considered to be implemented in a higher frequency (mmWave) band (e.g., 60 GHz band) in order to achieve higher data rates. To reduce the propagation loss of radio waves and increase the transmission coverage, beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, massive antenna technology, etc. have been discussed in the 5G communication system.

[0040] In addition, in a 5G communication system, development for system network improvement has been carried out based on advanced small cells, cloud radio access network (RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul communication, mobile networks, cooperative communication, coordinated multi-point (CoMP) transmission and reception, interference mitigation and cancellation, etc.

[0041] In a 5G system, hybrid frequency shift keying and quadrature amplitude modulation (FQAM) and sliding window superposition coding (SWSC) as adaptive modulation and coding (AMC) techniques, and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as advanced access techniques have been developed.

[0042] The following Figures 1 to 4B describes various embodiments that implement and utilize orthogonal frequency division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA) communication techniques in a wireless communication system. Figures 1 to 3 The description is not intended to imply a physical or architectural limitation on the ways that can be used to implement different embodiments. Different embodiments of the present disclosure can be implemented in any suitably arranged communication system.

[0043] Figure 1 Shows an example wireless network according to an embodiment of the present disclosure. Figure 1 The embodiment of the wireless network shown is for illustration only. Other embodiments of the wireless network 100 can be used without departing from the scope of the present disclosure.

[0044] As Figure 1 shown, the wireless network includes eNB 101, eNB 102, and eNB 103. eNB 101 communicates with eNB 102 and eNB 103. eNB 101 also communicates with at least one network 130 (such as the Internet, a proprietary Internet protocol (IP) network, or other data networks).

[0045] eNB 102 provides wireless broadband access to network 130 for a first plurality of user equipments (UEs) within the coverage area 120 of eNB 102. The first plurality of UEs includes: UE 111, which may be located in a sub-band (SB); UE 112, which may be located in an enterprise (E); UE 113, which may be located in a WiFi hotspot (HS); UE 114, which may be located in a first residence (R); UE 115, which may be located in a second residence (R); and UE 116, which may be a mobile device (M), such as a mobile phone, a wireless laptop, a wireless PDA, etc. eNB 103 provides wireless broadband access to network 130 for a second plurality of UEs within the coverage area 125 of eNB 103. The second plurality of UEs includes UE 115 and UE 116. In some embodiments, one or more of eNBs 101 - 103 may use 5G, LTE, LTE-A, WiMAX, WiFi, or other wireless communication technologies to communicate with each other and with UEs 111 - 116.

[0046] 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 a transmission point (TP), a transmission and reception point (TRP), an enhanced base station (eNodeB or eNB), a 5G base station (gNB), a macrocell, a femtocell, a WiFi access point (AP), or other wireless enabled devices. The base station may provide wireless access in accordance with one or more wireless communication protocols (e.g., 5G 3GPP new radio interface / access (NR), long term evolution (LTE), LTE-Advanced (LTE-A), high speed packet access (HSPA), Wi-Fi 802.11a / b / g / n / ac, etc.). For convenience, the terms "BS" and "TRP" may be used interchangeably in this patent document to refer to the network infrastructure components that provide wireless access to remote terminals. Additionally, depending on the network type, the term "user equipment" or "UE" may refer to any component such as a "mobile station", "user station", "remote terminal", "wireless terminal", "reception point", or "user equipment". For convenience, the terms "user equipment" and "UE" are used in this patent document to refer to remote wireless devices that wirelessly access a BS, regardless of whether the UE is a mobile device (such as a mobile phone or a smart phone) or a device that is generally considered fixed (such as a desktop computer or a vending machine).

[0047] The dashed lines illustrate the approximate extent of coverage areas 120 and 125, which are shown as approximately circular areas for illustration and explanation purposes only. It should be clearly understood that depending on the configuration of the eNB and the variations in the radio environment associated with natural and man-made obstacles, the coverage areas associated with the eNB (such as coverage areas 120 and 125) can have other shapes, including irregular shapes.

[0048] As described in more detail below, one or more of UEs 111 - 116 include circuitry, programming, or a combination thereof for performing efficient CSI reporting on the PUCCH in an advanced wireless communication system. In certain embodiments, one or more of eNBs 101 - 103 include circuitry, programming, or a combination thereof for receiving efficient CSI reports on the PUCCH in an advanced wireless communication system.

[0049] Although Figure 1 an example of a wireless network is shown, various changes can be made Figure 1 For example, the wireless network can include any number of eNBs and any number of UEs in any suitable arrangement. Additionally, eNB 101 can communicate directly with any number of UEs and provide wireless broadband access to those UEs to network 130. Similarly, each of eNBs 102 - 103 can communicate directly with network 130 and provide direct wireless broadband access to the UEs to network 130. Further, eNBs 101, 102, and / or 103 can provide access to other or additional external networks (such as an external telephone network or other types of data networks).

[0050] Figure 2 An example eNB 102 according to an embodiment of the present disclosure is shown. Figure 2 The embodiment of eNB 102 shown is for illustration only, and Figure 1 eNBs 101 and 103 can have the same or similar configurations. However, eNBs have various configurations, and Figure 2 the scope of the present disclosure is not limited to any particular implementation of the eNB.

[0051] As Figure 2 shown, eNB 102 includes a plurality of antennas 205a - 205n, a plurality of RF transceivers 210a - 210n, transmit (TX) processing circuitry 215, and receive (RX) processing circuitry 220. eNB 102 also includes a controller / processor 225, a memory 230, and a backhaul or network interface 235.

[0052] The RF transceivers 210a - 210n receive input RF signals from the antennas 205a - 205n, such as signals transmitted by UEs in the network 100. The RF transceivers 210a - 210n down - convert the input RF signals to generate IF or baseband signals. The IF or baseband signals are sent to the RX processing circuit 220, which generates a processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signal. The RX processing circuit 220 sends the processed baseband signal to the controller / processor 225 for further processing.

[0053] In some embodiments, the RF transceivers 210a - 201n are capable of sending CSI feedback configuration information for precoding matrix indicator (PMI) feedback to a user equipment (UE), where the CSI feedback configuration information indicates a precoding matrix corresponding to a linear combination (LC) of multiple L beams and multiple coefficients.

[0054] The TX processing circuit 215 receives analog or digital data (such as voice data, web data, email, or interactive video game data) from the controller / processor 225. The TX processing circuit 215 encodes, multiplexes, and / or digitizes the output baseband data to generate a processed baseband or IF signal. The RF transceivers 210a - 210n receive the output processed baseband or IF signal from the TX processing circuit 215 and up - convert the baseband or IF signal to an RF signal transmitted via the antennas 205a - 205n.

[0055] The controller / processor 225 may include one or more processors or other processing devices that control the overall operation of the eNB 102. For example, the controller / processor 225 can control the reception of forward - channel signals and the transmission of reverse - channel signals through the RF transceivers 210a - 210n, the RX processing circuit 220, and the TX processing circuit 215 according to well - known principles. The controller / processor 225 can also support additional functions, such as more advanced wireless communication functions. For example, the controller / processor 225 can support beamforming or directional routing operations, where the output signals from multiple antennas 205a - 205n are weighted differently to effectively direct the output signals in a desired direction. Any of a variety of other functions can be supported in the eNB 102 by the controller / processor 225.

[0056] The controller / processor 225 is also capable of executing programs and other processes residing in the memory 230, such as the OS. The controller / processor 225 can move data into or out of the memory 230 as needed for the execution of processes.

[0057] The controller / processor 225 is also coupled to a backhaul or network interface 235. The backhaul or network interface 235 allows the eNB 102 to communicate with other devices or systems via a backhaul connection or via the network. The interface 235 can support communication via any suitable wired or wireless connection. For example, when the eNB 102 is implemented as part of a cellular communication system (such as a cellular communication system supporting 5G, LTE, or LTE-A), the interface 235 can allow the eNB 102 to communicate with other eNBs via a wired or wireless backhaul connection. When the eNB 102 is implemented as an access point, the interface 235 can allow the eNB 102 to communicate with a larger network (such as the Internet) via a wired or wireless local area network or via a wired or wireless connection. The interface 235 includes any suitable structure that supports communication via a wired or wireless connection, such as an Ethernet or RF transceiver.

[0058] The memory 230 is coupled to the controller / processor 225. A portion of the memory 230 can include RAM, and another portion of the memory 230 can include flash memory or other ROM.

[0059] Although Figure 2 an example of the eNB 102 is shown, various changes can be made Figure 2 thereto. For example, the eNB 102 can include Figure 2 any number of each component shown in Figure 2 . As a specific example, an access point can include a number of interfaces 235, and the controller / processor 225 can support routing functions to route data between different network addresses. As another specific example, although shown as including a single instance of the TX processing circuit 215 and a single instance of the RX processing circuit 220, the eNB 102 can include multiple instances of each (such as one for each RF transceiver). Additionally,

[0060] Figure 3 An example UE 116 according to an embodiment of the present disclosure is shown. Figure 3 The embodiment of the UE 116 shown in Figure 1 is for illustration only, and the UEs 111 - 115 Figure 3 can have the same or similar configurations. However, UEs have various configurations, and

[0061] As Figure 3As shown in the figure, the UE 116 includes an antenna 305, a radio frequency (RF) transceiver 310, a TX processing circuit 315, a microphone 320, and a receive (RX) processing circuit 325. The UE 116 also includes a speaker 330, a processor 340, an input / output (I / O) interface (IF) 345, a touch screen 350, a display 355, and a memory 360. The memory 360 includes an operating system (OS) 361 and one or more applications 362.

[0062] The RF transceiver 310 receives an input RF signal transmitted by the eNB of the network 100 from the antenna 305. The RF transceiver 310 down-converts the input RF signal to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is sent to the RX processing circuit 325, which generates a processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signal. The RX processing circuit 325 sends the processed baseband signal to the speaker 330 (such as for voice data) or to the processor 340 for further processing (such as for web browsing data).

[0063] In some embodiments, the RF transceiver 310 is capable of receiving CSI feedback configuration information for precoding matrix indicator (PMI) feedback from a base station (BS), the CSI feedback configuration information indicating a linear combination precoding matrix corresponding to a linear combination (LC) of multiple L beams and multiple coefficients.

[0064] In some embodiments, the RF transceiver 310 is capable of sending CSI feedback including a first PMI (i1) and a second PMI (i2) to the BS via an uplink channel.

[0065] The TX processing circuit 315 receives analog or digital voice data from the microphone 320 or other output baseband data from the processor 340 (such as web data, email, or interactive video game data). The TX processing circuit 315 encodes, multiplexes, and / or digitizes the output baseband data to generate a processed baseband or IF signal. The RF transceiver 310 receives the output processed baseband or IF signal from the TX processing circuit 315 and up-converts the baseband or IF signal to an RF signal transmitted via the antenna 305.

[0066] The processor 340 may include one or more processors or other processing devices and execute the OS 361 stored in the memory 360 to control the overall operation of the UE 116. For example, the processor 340 can control the reception of forward channel signals and the transmission of reverse channel signals through the RF transceiver 310, the RX processing circuit 325, and the TX processing circuit 315 according to well-known principles. In some embodiments, the processor 340 includes at least one microprocessor or microcontroller.

[0067] The processor 340 is also capable of executing other processes and programs residing in the memory 360, such as processes for CSI reporting on the PUCCH. The processor 340 can move data into or out of the memory 360 as needed for executing the processes. In some embodiments, the processor 340 is configured to execute the application 362 based on the OS 361 or in response to signals received from the eNB or the 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.

[0068] In some embodiments, the processor 340 is also capable of determining a first PMI (i1) and a second PMI (i2).

[0069] The processor 340 is also coupled to the touch screen 350 and the display 355. The operator of the UE 116 can use the touch screen 350 to enter data into the UE 116. The display 355 can be a liquid crystal display, a light emitting diode display, or other display capable of rendering text and / or at least limited graphics such as from a web site.

[0070] The memory 360 is coupled to the processor 340. A portion of the memory 360 can include random access memory (RAM), while another portion of the memory 360 can include flash memory or other read-only memory (ROM).

[0071] Although Figure 3 an example of the UE 116 is shown, various changes can be made Figure 3 thereto. For example, Figure 3 the various components in can be combined, further subdivided, or omitted, and additional components can be added according to specific requirements. As a specific example, the 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). Additionally, although Figure 3 the UE 116 is shown configured as a mobile phone or a smart phone, the UE can be configured to operate as other types of mobile or fixed devices.

[0072] Figure 4A is a high-level diagram of the transmit path circuit. For example, the transmit path circuit can be used for orthogonal frequency division multiple access (OFDMA) communication. Figure 4B is a high-level diagram of the receive path circuit. For example, the receive path circuit can be used for orthogonal frequency division multiple access (OFDMA) communication. In Figure 4A and Figure 4BIn the case of downlink communication, the transmit path circuitry may be implemented in a base station (eNB) 102 or a relay station, and the receive path circuitry may be implemented in a user equipment (e.g., Figure 1 user equipment 116). In other examples, for uplink communication, the receive path circuitry 450 may be implemented in a base station (e.g., Figure 1 eNB 102) or a relay station, and the transmit path circuitry may be implemented in a user equipment (e.g., Figure 1 user equipment 116).

[0073] The transmit path circuitry includes a channel coding and modulation block 405, a serial-to-parallel (S-to-P) block 410, an inverse fast Fourier transform (IFFT) block 415 of size N, a parallel-to-serial (P-to-S) block 420, a cyclic prefix addition block 425, and an upconverter (UC) 430. The receive path circuitry 450 includes a downconverter (DC) 455, a cyclic prefix removal block 460, a serial-to-parallel (S-to-P) block 465, a fast Fourier transform (FFT) block 470 of size N, a parallel-to-serial (P-to-S) block 475, and a channel decoding and demodulation block 480.

[0074] Figure 4A At least some of the components in 400 and Figure 4B 450 may be implemented in the form of software, while other components may be implemented by configurable hardware or a combination of software and configurable hardware. In particular, it should be noted that the FFT blocks and IFFT blocks described in this disclosure document may be implemented as configurable software algorithms, where the value of size N may be modified according to the implementation.

[0075] Furthermore, although this disclosure is directed to embodiments implementing fast Fourier transform and inverse fast Fourier transform, this is for illustration only and should not be construed as limiting the scope of this disclosure. It should be understood that in alternative embodiments of this disclosure, the fast Fourier transform function and the inverse fast Fourier transform function may be readily replaced by discrete Fourier transform (DFT) functions and inverse discrete Fourier transform (IDFT) functions, respectively. It should be understood that for DFT and IDFT functions, the value of the N variable may be any integer (i.e., 1, 4, 3, 4, etc.), while for FFT and IFFT functions, the value of the N variable may be any integer that is a power of 2 (i.e., 1, 2, 4, 8, 16, etc.).

[0076] In the transmit path circuit 400, the channel coding and modulation block 405 receives a set of information bits, applies coding (e.g., LDPC coding) and modulates the input bits (e.g., quadrature phase shift keying (QPSK) or quadrature amplitude modulation (QAM)) to produce a sequence of frequency-domain modulated symbols. The serial-to-parallel block 410 converts (i.e., demultiplexes) the serial modulated symbols into parallel data to produce N parallel symbol streams, where N is the IFFT / FFT size used in the BS 102 and the UE 116. The size N IFFT block 415 then performs an IFFT operation on the N parallel symbol streams to produce a time-domain output signal. The parallel-to-serial block 420 converts (i.e., multiplexes) the parallel time-domain output symbols from the size N IFFT block 415 to produce a serial time-domain signal. The cyclic prefix addition block 425 then inserts a cyclic prefix into the time-domain signal. Finally, the upconverter 430 modulates (i.e., upconverts) the output of the cyclic prefix addition block 425 to an RF frequency for transmission via the wireless channel. The signal may also be filtered at baseband before being converted to the RF frequency.

[0077] The transmitted RF signal arrives at the UE 116 after passing through the wireless channel and performs operations opposite to those at the eNB 102. The downconverter 455 downconverts the received signal to a baseband frequency, and the cyclic prefix removal block 460 removes the cyclic prefix to produce a serial time-domain baseband signal. The serial-to-parallel block 465 converts the time-domain baseband signal to a parallel time-domain signal. The size N FFT block 470 then performs the FFT algorithm to produce N parallel frequency-domain signals. The parallel-to-serial block 475 converts the parallel frequency-domain signals to a sequence of modulated data symbols. The channel decoding and demodulation block 480 demodulates and then decodes the modulated symbols to recover the original input data stream.

[0078] Each of the eNBs 101-103 can implement a transmit path similar to that for transmitting to the user devices 111-116 in the downlink and can implement a receive path similar to that for receiving from the user devices 111-116 in the uplink. Similarly, each of the user devices 111-116 can implement a transmit path corresponding to the architecture for transmitting to the eNBs 101-103 in the uplink and can implement a receive path corresponding to the architecture for receiving from the eNBs 101-103 in the downlink.

[0079] Various embodiments of the present disclosure provide high performance, scalability with respect to the number and geometry of transmit antennas, and a flexible CSI feedback (e.g., reporting) framework and structure for LTE enhancements when supporting FD-MIMO with a large two-dimensional antenna array. To achieve high performance, more accurate CSI in terms of the MIMO channel is needed at the eNB, especially for the FDD scenario. In this case, embodiments of the present disclosure recognize that it may be necessary to replace the previous LTE specification precoding framework (PMI-based feedback). In the present disclosure, the nature of FD-MIMO is considered for the present disclosure. For example, a large 2D antenna array that is closely spaced and mainly oriented towards high beamforming gain rather than spatial multiplexing and has a relatively small angular spread for each UE is used. Thus, compression or dimension reduction of channel feedback according to a set of fixed basis functions and vectors can be achieved. In another example, UE-specific higher layer signaling can be used to obtain updated channel feedback parameters (e.g., channel angular spread) at low mobility. Additionally, CSI reporting (feedback) can also be performed cumulatively.

[0080] Another embodiment of the present disclosure includes a CSI reporting method and process with reduced PMI feedback. This PMI reporting at a lower rate is related to long-term DL channel statistics and represents a selection of a set of precoding vectors recommended by the UE to the eNB. The present disclosure also includes a DL transmission scheme, where the eNB transmits data to the UE through multiple beamforming vectors while utilizing an open-loop diversity scheme. Thus, the use of long-term precoding ensures that open-loop transmit diversity is applied only across a limited number of ports (rather than all ports available for FD-MIMO, e.g., 64), which avoids having to support overly high dimensions for open-loop transmit diversity, reduces the CSI feedback overhead, and improves the robustness when the CSI measurement quality is a problem.

[0081] Use cases for 5G communication systems have been identified and described. Those use cases can be roughly classified into three different groups. In one example, enhanced mobile broadband (eMBB) is identified as having high bit / second requirements, less stringent latency and reliability requirements. In another example, ultra-reliable and low latency (URLL) is identified with less stringent bit / second requirements. In yet another example, massive machine type communication (mMTC) is identified as having a number of devices that can reach as many as 100,000 to 1 million per km 2 but the reliability / throughput / latency requirements may be less stringent. This scenario also involves power efficiency requirements as battery consumption should be minimized as much as possible.

[0082] In LTE technology, the time interval X may include one or more of a DL transmission portion, a guard, a UL transmission portion, and combinations thereof, regardless of whether they are indicated dynamically and / or semi-statically. Additionally, in one example, the DL transmission portion of the time interval X includes downlink control information and / or downlink data transmission and / or reference signals. In another example, the UL transmission portion of the time interval X includes uplink control information and / or uplink data transmission and / or reference signals. Further, the use of DL and UL does not cover other deployment scenarios, such as sidelink, backhaul, relay. In some embodiments of the present disclosure, "subframe" is another name for "time interval X", or vice versa. Enabling 5G networks to support these various services is referred to as network slicing.

[0083] In some embodiments, "subframe" and "time slot" may be used interchangeably. In some embodiments, "subframe" refers to a transmission time interval (TTI), which may include an aggregation of "time slots" for data transmission / reception by a UE.

[0084] Figure 5 A network slice 500 according to an embodiment of the present disclosure is shown. Figure 5 The embodiment of the network slice 500 shown is for illustration only. Figure 5 One or more of the components shown may be implemented with dedicated circuitry configured to perform the indicated functions, or one or more of these components may be implemented by one or more processors executing instructions to perform the indicated functions. Other embodiments are used without departing from the scope of the present disclosure.

[0085] As Figure 5 As shown, the network slice 500 includes the operator's network 510, multiple RANs 520, multiple eNBs 530a, 530b, multiple small cell base stations 535a, 535b, URLL slice 540a, smartwatch 545a, car 545b, truck 545c, smart glasses 545d, power 555a, temperature 555b, mMTC slice 550a, eMBB slice 560a, smartphone (e.g., mobile phone) 565a, laptop 565b, and tablet 565c (e.g., tablet PC).

[0086] The network 510 of the operator includes a number of radio access networks 520 - RAN associated with network devices (e.g., eNBs 530a and 530b, small cell base stations (femto / pico eNBs or Wi-Fi access points) 535a and 535b, etc.). The network 510 of the operator can support various services relying on the slicing concept. In one example, the network supports four slices 540a, 550a, 550b, and 560a. The URLL slice 540a serves UEs (e.g., car 545b, truck 545c, smartwatch 545a, smart glasses 545d, etc.) that require URLL services. Two mMTC slices 550a and 550b serve UEs (e.g., 555b) such as power meters and temperature controls that require mMTC services, and one eMBB slice 560a that requires eMBB serves UEs such as mobile phone 565a, laptop 565b, and tablet 565c.

[0087] In summary, network slicing is a method for handling various different quality of service (QoS) in the network level. To effectively support these various QoSs, slice-specific PHY optimization may also be necessary. Devices 545a / b / c / d, 555a / b, 565a / b / c are examples of different types of user equipment (UE). Figure 5 The different types of user equipment (UE) shown do not necessarily have an association with a specific type of slice. For example, mobile phone 565a, laptop 565b, and tablet 565c are associated with the eMBB slice 560a, but this is only for illustration, and these devices can be associated with any type of slice.

[0088] In some embodiments, a device is configured with more than one slice. In one embodiment, a UE (e.g., 565a / b / c) is associated with two slices, the URLL slice 540a and the eMBB slice 560a. This may be useful for supporting online game applications, in which graphical information is sent through the eMBB slice 560a, and user interaction-related information is exchanged through the URLL slice 540a.

[0089] In the current LTE standard, there is no slice-level PHY, and most PHY functions are utilized in a slice-agnostic manner. UEs are typically configured with a single set of PHY parameters (including transmission time interval (TTI) length, OFDM symbol length, subcarrier spacing, etc.), which may prevent the network from (1) quickly adapting to dynamically changing QoS; and (2) supporting various QoSs simultaneously.

[0090] In some embodiments, a corresponding PHY design for handling different QoS with the network slicing concept is disclosed. It should be noted that the term "slice" is introduced only for convenience to refer to a logical entity associated with common features such as a parameter set, upper layers (including medium access control / radio resource control (MAC / RRC)), and shared UL / DL time - frequency resources. Alternative names for "slice" include virtual cell, super cell, cell, etc.

[0091] Figure 6 An example number of digital chains 600 according to an embodiment of the present disclosure is shown. Figure 6 The embodiment of the number of digital chains 600 shown in [figure] is for illustration only. Figure 6 One or more of the components shown in [figure] may be implemented in the form of dedicated circuitry configured to perform the indicated functions, or one or more of these components may be implemented by one or more processors executing instructions to perform the indicated functions. Other embodiments may be used without departing from the scope of the present disclosure.

[0092] The LTE specification supports up to 32 CSI - RS antenna ports, which enables the eNB to be equipped with a large number of antenna elements (such as 64 or 128). In this case, multiple antenna elements are mapped to one CSI - RS port. For next - generation cellular systems such as 5G, the maximum number of CSI - RS ports may remain the same or increase.

[0093] For the mmWave band, although the number of antenna elements can be large for a given form factor, the number of CSI - RS ports - which may correspond to the number of digital precoding ports - tends to be limited due to hardware constraints such as Figure 6 shown in [figure] (such as the feasibility of installing a large number of ADC / DACs at mmWave frequencies). In this case, one CSI - RS port is mapped to a large number of antenna elements, which can be controlled by a set of analog phase shifters. Then one CSI - RS port can correspond to a sub - array that generates a narrow analog beam through analog beamforming. This analog beam can be configured to scan over a wider angular range by changing the set of phase shifters between symbols or sub - frames. The number of sub - arrays (equal to the number of RF chains) is the same as the number of CSI - RS ports N CSI-PORT The digital beamforming unit performs a linear combination on N CSI-PORT analog beams to further increase the precoding gain. Although the analog beam is broadband (and thus not frequency - selective), the digital precoding changes between frequency sub - bands or resource blocks.

[0094] To achieve digital precoding, an effective design of CSI-RS is a key factor. For this reason, three types of CSI reporting mechanisms corresponding to three types of CSI-RS measurement behaviors are supported in the LTE specification: 1) "Type A" CSI reporting corresponding to non-precoded CSI-RS, 2) "Type B" reporting with K = 1 CSI-RS resource corresponding to UE-specific beamforming CSI-RS, and 3) "Type B" reporting with K>1 CSI-RS resources corresponding to cell-specific beamforming CSI-RS.

[0095] For non-precoded (NP) CSI-RS, a cell-specific one-to-one mapping between CSI-RS ports and TXRUs is utilized. Here, different CSI-RS ports have the same wide beamwidth and direction, and thus typically have cell-wide coverage. For beamforming CSI-RS, (cell-specific or UE-specific) beamforming operations are applied on non-zero power (NZP) CSI-RS resources (which consist of multiple ports). Here, (at least at a given time / frequency) CSI-RS ports have a narrow beamwidth, and thus do not have cell-wide coverage, and (at least from the eNB perspective) at least some CSI-RS port resource combinations have different beam directions.

[0096] In scenarios where the DL long-term channel statistics can be measured by UL signals at the serving eNodeB, UE-specific BF CSI-RS can be easily used. This is typically feasible when the UL-DL duplex distance is small enough. However, when this condition does not hold, the eNodeB requires some UE feedback to obtain an estimate of the DL long-term channel statistics (or either representation of the DL long-term channel statistics). To facilitate this process, the first BF CSI-RS is transmitted according to a period T1 (ms) and the second NP CSI-RS is transmitted according to a period T2 (ms), where T1 ≤ T2. This method is called hybrid CSI-RS. The implementation of hybrid CSI-RS depends largely on the CSI process and the definition of NZP CSI-RS resources.

[0097] In the LTE specification for eFD-MIMO, MIMO has been identified as a necessary feature to meet high system throughput requirements and will continue to be so in NR. One of the key components of the MIMO transmission scheme is accurate CSI acquisition at the eNB (or TRP). Especially for MU-MIMO, accurate CSI must exist to ensure high MU performance. For TDD systems, SRS transmission relying on channel reciprocity can be used to acquire CSI. On the other hand, for FDD systems, CSI-RS transmission from the eNB and CSI acquisition and feedback from the UE can be used to acquire it. In traditional (up to the LTE specification) FDD systems, the CSI feedback framework is "implicit" in the form of CQI / PMI / RI (and CRI in the LTE specification) derived from a codebook assuming SU transmission from the eNB. Due to the inherent SU assumption in CSI derivation, this implicit CSI feedback is not suitable for MU transmission.

[0098] Since future (e.g., NR) systems are likely to be more MU-centric, this SU-MU CSI mismatch may be a bottleneck in achieving high MU performance gains. Another problem with implicit feedback is the scalability for a large number of antenna ports at the eNB. For a large number of antenna ports, the codebook design for implicit feedback is very complex (e.g., in the LTE specification, the total number of type-A codebooks = 44), and it is not guaranteed that the designed codebook will bring reasonable performance benefits in actual deployment scenarios (e.g., at most a small part of the gain can be shown). After recognizing the foregoing problems, RAN1 has agreed to provide specification support for advanced CSI reporting in the LTE specification for eFD-MIMO, which can at least be used as a good starting point for designing advanced CSI schemes in NR MIMO.

[0099] Figure 7 An example of multiplexing two slices 700 according to an embodiment of the present disclosure is shown. Figure 7 The embodiment of multiplexing two slices 700 shown is for illustration only. Figure 7 One or more of the components shown may be implemented in the form of dedicated circuits configured to perform the indicated functions, or one or more of these components may be implemented by one or more processors executing instructions to perform the indicated functions. Other embodiments may be used without departing from the scope of the present disclosure.

[0100] To effectively utilize PHY resources and multiplex various (with different resource allocation schemes, parameter sets, and scheduling policies) slices in the DL-SCH, a flexible and independent frame or subframe design is utilized. In Figure 7 Two exemplary instances of multiplexing two slices within a common subframe or frame are depicted. In Figure 7In this case, a slice may consist of one or two transmission instances, where one transmission instance is composed of a control (CTRL) component (720a, 760a, 660b, 720b, and 760c) and a data component (730a, 770a, 770b, 730b, and 770c). In Figure 7 In this case, two slices (e.g., 710) are multiplexed in the frequency domain, and slices are multiplexed in the time domain (e.g., 750).

[0101] Figure 8 FIG. 800 shows an exemplary CSI reporting framework according to an embodiment of the present disclosure. Figure 8 The embodiment of the CSI reporting framework 800 shown in FIG. is for illustration only. Figure 8 One or more of the components shown in FIG. may be implemented in the form of dedicated circuits configured to perform the indicated functions, or one or more of these components may be implemented by one or more processors executing instructions to perform the indicated functions. Other embodiments may be used without departing from the scope of the present disclosure.

[0102] Hereinafter, for simplicity, both FDD and TDD are considered duplex methods for both DL signaling and UL signaling. Although the following exemplary descriptions and embodiments assume orthogonal frequency division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA), the present disclosure may be extended to other OFDM-based transmission waveforms or multiple access schemes, such as filtered OFDM (F-OFDM).

[0103] In some embodiments 0, a multi-resolution CSI reporting framework is supported in 5G or NR or next-generation communication systems, an example of which is shown as Figure 8 shown. In this framework, the UE receives CSI report configuration regarding CSI resolution or CSI type, for example, via higher layer (e.g., RRC) or MAC layer (e.g., MAC CE) signaling. Some examples of CSI resolution or type include the following: low resolution or implicit reporting of PMI / CQI / RI using a codebook; high resolution or explicit reporting of one channel or / and interference; semi-dynamic or beam cycling reporting of beam groups for precoder cycling; and partial port reporting of CSI corresponding to a subset of antenna ports.

[0104] The UE can be configured with multiple CSI types or resolutions. For example, the UE can be configured with high-resolution (or explicit) and partial-port CSI reporting. According to this configuration, the UE reports explicit CSI for partial antenna ports. Based on the configured CSI resolution or type, the UE report includes at least one or a combination of the following CSI components: Beam Index (BI) or Beam Group Index (BGI); RI; PMI / CQI; channel; eigenvector; covariance matrix; and interference. The UE uses a configured or fixed multi-resolution codebook to report CSI.

[0105] This framework provides more flexible CSI acquisition at the gNB by supporting different use cases, such as users with different CSI reporting capabilities (e.g., CSI resolution (implicit, explicit), number of ports (full-port, partial-port), etc.) and users with low to high mobility (e.g., 0 - 500 kmph). In one example, a set of UEs (S1) can be capable of reporting only implicit or low-resolution CSI and another set of UEs (S2) can be capable of reporting low-resolution (e.g., codebook-based implicit CSI) and high-resolution (e.g., explicit channel reporting). An example of S1 is an LTE UE and an example of S2 is a 5G or NR eMBB UE. The gNB serving both types of UEs (S1 and S2) can use the proposed multi-resolution CSI reporting framework and configure the CSI reporting resolution for each UE according to its CSI reporting capabilities. In another example, a set of UEs S1 can be low-mobility UEs and another set of UEs S2 can be high-mobility UEs. The gNB can then configure low-resolution CSI reporting for the UEs in set S1 and semi-dynamic or beam cycling for the UEs in set S2.

[0106] Figure 9 An example dual-resolution CSI reporting framework 900 according to an embodiment of the present disclosure is shown. Figure 9 The embodiment of the dual-resolution CSI reporting framework 900 shown in is for illustration only. Figure 9 One or more of the components shown in can be implemented in the form of dedicated circuitry configured to perform the indicated functions, or one or more of these components can be implemented by one or more processors executing the indicated functions by executing instructions. Other embodiments are used without departing from the scope of the present disclosure.

[0107] In some sub-embodiments 0, in Figure 9A dual-resolution or dual-type CSI reporting framework is shown, where CSI has two components. The first CSI component (i.e., CSI 1) is common to both resolutions and indicates the selection of a beam group (including L beams). CSI 1 may also include a rank indicator (i.e., RI) associated with the selected beam group. The second CSI component (i.e., CSI 2) is specific to the configured CSI reporting resolution.

[0108] In one example of type I low-resolution CSI reporting, CSI 2 is derived based on an implicit CSI reporting framework (e.g., LTE specifications) and includes CSI components such as PMI / CQI. This CSI type can be configured for users who are not capable of reporting high-resolution (explicit) CSI or for users scheduled for SU transmission. Additionally, this CSI reporting type can be the default CSI reporting type for all NR UEs.

[0109] In another example of type II high-resolution CSI reporting, CSI 2 is derived to explicitly report a quantized DL channel to facilitate more accurate CSI to the eNB. This CSI type can be configured for users who are capable of reporting high-resolution CSI or / and who can be scheduled for MU transmission.

[0110] Figure 10 Another example dual-resolution CSI reporting framework 1000 according to an embodiment of the present disclosure is shown. Figure 10 The embodiment of the dual-resolution CSI reporting framework 1000 shown in is for illustration only. Figure 10 One or more of the components shown in may be implemented in the form of a dedicated circuit configured to perform the indicated functions, or one or more of these components may be implemented by one or more processors executing the indicated functions. Other embodiments are used without departing from the scope of the present disclosure.

[0111] In Figure 10 A dual-type CSI reporting is shown, where (e.g., type II) corresponds to high-resolution or explicit CSI reporting for some antenna ports. Then two CSIs (CSI1 and CSI2) are reported for some antenna ports.

[0112] Figure 11 An example triple-resolution CSI reporting framework 1100 according to an embodiment of the present disclosure is shown. Figure 11 The embodiment of the triple-resolution CSI reporting framework 1100 shown in is for illustration only. Figure 11One or more of the components shown may be implemented in the form of dedicated circuitry configured to perform the indicated functions, or one or more of these components may be implemented by one or more processors executing instructions to perform the indicated functions. Other embodiments are used without departing from the scope of the present disclosure.

[0113] In some sub - embodiment 1, Figure 11 A three - resolution or three - type CSI feedback framework is shown, where CSI has two components. The first CSI component (i.e., CSI 1) is common to all CSI types and indicates the selection of a beam group (including L beams) from a main beam group. CSI 1 may also include a rank indicator (i.e., RI) associated with the selected beam group in some CSI report types. The second CSI component (i.e., CSI 2) is specific to the configured CSI report resolution.

[0114] In one example of type I CSI reporting, low - resolution CSI feedback as illustrated in sub - embodiment 0 is configured. In another example of type II CSI reporting, high - resolution CSI feedback as illustrated in sub - embodiment 0 is configured. In yet another example of type III CSI reporting, semi - dynamic beamforming is configured. In such an example, CSI 2 is derived to report CQI, assuming semi - dynamic beamforming or precoder cycling using the L beams reported in CSI 1. Note that the PMI is not reported in CSI 2. This type can be configured for high - mobility users.

[0115] In some sub - embodiment 2, the codebook for the proposed multi - resolution or multi - type CSI reporting framework is a two - stage codebook: W = W1W2, where the first - stage W1 codebook is common to all or some of these types or resolutions (e.g., similar to the LTE specification class A W1 codebook for beam groups) and the second - stage W2 codebook depends on the configured resolution or type.

[0116] Figure 12 An example multi - antenna panel 1200 according to an embodiment of the present disclosure is shown. Figure 12 The embodiments of the multiple antenna panels 1200 shown are for illustration only. Figure 12 One or more of the components shown may be implemented in the form of dedicated circuitry configured to perform the indicated functions, or one or more of these components may be implemented by one or more processors executing instructions to perform the indicated functions. Other embodiments are used without departing from the scope of the present disclosure.

[0117] In the following, it is assumed that N1 and N2 are the numbers of antenna ports with the same polarization in the first dimension and the second dimension, respectively. For a 2D antenna port layout, we have N1 > 1 and N2 > 1, while for a 1D antenna port layout, N1 > 1 and N2 = 1. Therefore, for a dual-polarized antenna port layout, the total number of antenna ports is 2N1N2.

[0118] In addition, embodiments of the present disclosure are applicable to a setup where we have multiple antenna panels, where each panel is a dual-polarized antenna port with two-dimensional N1 and N2 ports. A diagram showing M antenna panels is shown in Figure 12 . Note that the antenna port layout can be the same or different in different antenna panels.

[0119] In some embodiments 1, the UE is configured with a W1 codebook, which includes the following components: a base set and a beam group selection, each of which can be configured via high-layer signaling (e.g., RRC).

[0120] In an example of the first W1 codebook component, a base set is configured, where depending on whether the UE is configured with CSI reporting with or without dimensionality reduction, the UE is configured with a base set in one of the following examples.

[0121] In one example, a full-dimensional base set is configured. In such an example, the base set is given by , where is an N1N2 × N1N2 identity matrix. In one example, the UE can be configured with a full-dimensional base for type II (explicit) CSI reporting. In another example, if the number of ports is at most X (e.g., X = 8), the UE can be configured with a full-dimensional base.

[0122] In another example, a port selection base set is configured. In such an example, the base set is given by , is a port selection matrix, where L > 1 (e.g., L ∈ {2, 3, 4}) is configurable, and X >= 2L. In one alternative, the number of ports is X = P = 2N1N2 ∈ {4, 8, 12, 16, 24, 32}. In another alternative, X ∈ {2, 4, 8}.

[0123] In yet another example, a reduced-dimensional base set is configured. In such an example, the base set is a 2 × 2 block diagonal matrix whose diagonal block sizes are N1N2 × L1L2. The two diagonal blocks can be the same or different. Assuming the same diagonal blocks, the base set has the following structure: where W is N1N2×L1L2, L1∈{1, 2,.., N1 - 1}, and for a 2D port layout L2∈{1, 2,..., N2 - 1}, while for a 1D port layout L2 = 1. In one example, the UE may be configured with a reduced basis set for both type I (implicit) CSI reporting and type II (explicit) CSI reporting. In another example, if the number of ports is greater than X (e.g., X = 8), the UE may be configured with a reduced basis set. In Figure 13 An example of a reduced basis set is shown.

[0124] Figure 13 An example basis set 1300 for dimensionality reduction according to an embodiment of the present disclosure is shown. Figure 13 The embodiment of the reduced basis set 1300 shown in Figure 13 is for illustration only. One or more of the components shown in

[0125] can be implemented in the form of dedicated circuitry configured to perform the indicated functions, or one or more of these components can be implemented by one or more processors executing instructions to perform the indicated functions. Other embodiments are used without departing from the scope of the present disclosure.

[0125] The oversampled DFT codebook is used as a basis set including O1N1×O2N2 DFT beams, where O1 and O2 are the oversampling factors in the first and second dimensions, respectively. The basis set includes L1 and L2 evenly spaced beams in two dimensions. So, the number of beams in the basis set is L1L2. The basis set is further parameterized by a beam spacing parameter (P1, P2), which represents the spacing between two adjacent beams in two dimensions. For L d and p d (where d = 1, 2), several example values respectively belong to {1, 2,..., N d} and {1, 2,..., O d}. In Figure 13 A diagram of two types of basis sets is shown, where each small square represents a 2D DFT beam. When (p1, p2) = (1, 1), the basis set corresponds to L1L2 closely spaced beams, while when (p1, p2) = (O1, O2), it corresponds to L1L2 orthogonal beams. The UE is configured with one of the basis set types by configuring (L1, L2) and (p1, p2).

[0126] In an example of the second W1 codebook component, beam group selection is configured. In such an example, L beams out of L1L2 are selected from the reported base groups. Some examples of the L values belong to {1, 2, ..., L1L2}. Two alternatives for beam selection are as follows. The UE is configured with one of these alternatives. In an example of parameterization, the selection of the L beams is fixed and parameterized by the codebook parameter Config. In Figure 14 several examples are shown. In another example without constraints, the selection of the L beams is unconstrained and any L beams out of L1L2 can be reported. The base after beam selection is given by W I where I = {(i l , j l ): l = 0, 1, ..., L - 1} is the index set of the L selected beams, and i l ∈ {0, 1, ..., L1 - 1} and j l ∈ {0, 1, ..., L2 - 1}.

[0127] Figure 14 FIG. 1400 shows an example parameterized beam group according to an embodiment of the present disclosure. Figure 14 The embodiment of the parameterized beam group 1400 shown in FIG. is only for illustration. Figure 14 One or more of the components shown in FIG. may be implemented in the form of dedicated circuitry configured to perform the indicated functions, or one or more of these components may be implemented by one or more processors executing instructions to perform the indicated functions. Other embodiments are used without departing from the scope of the present disclosure.

[0128] In some sub - embodiments 3, the UE is configured with one of the following two types of bases, where W I is defined in the foregoing embodiment 1. In an example of base 0, it is configured in the case where W I is orthogonal (i.e., has orthogonal columns). In another example of base 1: it is configured in the case where W I is non - orthogonal (i.e., has non - orthogonal columns). Note that if W I has orthogonal columns, then base 0 and base 1 are the same because B H B = I.

[0129] In some sub - embodiments 4, the UE is configured with at least one of the following alternatives for type I and type IICSI ( Figure 9 and Figure 10)'s W1 basis. In one example of Alternative 0, both Basis 0 and Basis 1 can be configured for both Type I CSI and Type II CSI. In one example of Alternative 1, only Basis 0 can be configured for Type I CSI and both Basis 0 and Basis 1 can be configured for Type II CSI. In one example of Alternative 2, only Basis 1 can be configured for Type I CSI and both Basis 0 and Basis 1 can be configured for Type II CSI. In one example of Alternative 3, only Basis 0 can be configured for Type II CSI and both Basis 0 and Basis 1 can be configured for Type I CSI. In one example of Alternative 4, only Basis 1 can be configured for Type II CSI and both Basis 0 and Basis 1 can be configured for Type I CSI. In one example of Alternative 5, only Basis 0 can be configured for Type I CSI and only Basis 0 can be configured for Type II CSI. In one example of Alternative 6, only Basis 0 can be configured for Type I CSI and only Basis 1 can be configured for Type II CSI. In one example of Alternative 7, only Basis 1 can be configured for Type I CSI and only Basis 0 can be configured for Type II CSI. In one example of Alternative 8, only Basis 1 can be configured for Type I CSI and only Basis 1 can be configured for Type II CSI.

[0130] In some embodiments 2, the UE is configured with a W1 codebook having multiple antenna panels with M ≥ 1 panels (as Figure 12 shown), which has a block diagonal structure with 2M blocks, where the first 2 consecutive blocks are associated with the two polarizations of the first antenna panel, the next 2 consecutive blocks are associated with the two polarizations of the second antenna panel, and so on.

[0131] In one example with M = 2 antenna panels, the W1 basis is according to one of the following alternatives. Hereinafter, the subscript I may be discarded for brevity.

[0132] Only for Basis 0, some examples can be configured as follows. In one example of Basis 0-0, B0 is the basis of Type Basis 0 common to both panels. This basis can be configured if the port layouts of the two panels are the same. In another example of Basis 0-1, B0 and B1 are the two bases of Type Basis 0 of panel 0 and panel 1 respectively. This basis can be configured if the port layouts of the two panels are different.

[0133] Only for Basis 1, some examples can be configured as follows: In one example of Basis 1-0, B0 is the basis of Type Basis 1 common to both panels. This basis can be configured if the port layouts of the two panels are the same. In another example of Basis 1-1, B0 and B1 are two bases of type base 1 of panel 0 and 1 respectively. This base can be configured if the port layouts of the two panels are different.

[0134] For both base 0 and base 1, there can be some alternatives. In one example of base 01: B0 is the base of type base 0 of panel 0, and B1 is the base of type base 1 of panel 1. In another example of base 10: B0 is the base of type base 0 of panel 0, and B1 is the base of type base 1 of panel 1. It is easy to extend this example to more than 2 antenna panels (e.g., 4 panels).

[0135] In some embodiments 3, the UE is configured with a single panel and a W2 codebook for type I and II CSI (as shown in Figure 9 and Figure 10 ) according to at least one of the following alternatives. In one example of type I CSI (implicit), the type I precoder represents beam selection or combination and has the following expression: where for selection, c = [e i e i φ n T where e i is a selection vector of length L, whose i-th entry is 1 and the rest are all zero, where i = 0, 1,..., L - 1. An example of such selection is the LTE release 13 and 14 class A codebooks, while for combination, c = [1 c1 … c 2L-1 T where c i is quantized into a coefficient codebook. Two examples of it are the QPSK or 8-PSK codebook for phase and the N-bit uniform for amplitude. An example of such a codebook is the LTE release 14 advanced CSI codebook.

[0136] In another example of type II CSI (explicit), the type II precoder represents beam combination to report the channel / feature vector / covariance matrix as follows: Channel: for receiving antenna r Covariance matrix: Feature vector: b l is a column of B I ; and the coefficients of the channel and feature vector reports and {c i，j} of the covariance matrix report are quantized using the W2 codebook.

[0137] ​​In some embodiments 4, the UE is configured with a W2 codebook for multiple panels and type I and II CSI ( Figure 9 and Figure 10 ) according to at least one of the following alternatives: In one example, the precoder has the structure kron(c, d), where c is for intra-panel CSI and d is for inter-panel CSI (basis 0-0 and basis 1-0), where kron(c, d) represents the Kronecker product of c and d. In another example, the precoder has the structure [c0 c1] T , where c0 and c1 are W2 for two panels (for all types of bases).

[0138] In some embodiments 5, the UE is configured with a UL codebook that is the same as the DL codebook for type I CSI at 2, 4, and 8 antenna ports at the UE in embodiment 3. Different from the DL codebook parameterized by parameters such as the number of ports (N1, N2) in two dimensions, the oversampling factors (O1, O2) in two dimensions, one of a non-orthogonal basis set or an orthogonal basis set, and the number of beams (L = 1, 2, or 4) selected from the basis set, for the proposed UL codebook, (N1, N2), (O1, O2) (e.g., (8, 8)), and the basis set type (e.g., non-orthogonal) are fixed. However, the number of beams (L value) is configured for the UE by UL transmission-related configuration in UL or DL DCI.

[0139] In some embodiments 6, the UE is configured with a DL codebook for type II CSI (embodiment 3) such that the W2 codebook performs separate quantization of the amplitude and phase of each beam combination coefficient {c l} or {c i，j}, where the phase quantization is reported as SB and the amplitude quantization is reported as only wideband (WB) (alternative 6-0) or only SB (alternative 6-1) or both WB and SB (alternative 6-2), where WB reporting is used to report the WB component of the amplitude (which is common to all SBs) and SB reporting is used to report each SB component of the amplitude. In these embodiments, one of the alternatives can be fixed in the specification. Alternatively, one of the alternatives (alternatives 6-0 to 6-22) is configured for the UE via higher layer (e.g., RRC) or more dynamic (based on MAC CE or DCI) signaling. For the latter alternative, either all three (alternatives 6-0 to 6-2) alternatives are supported, or two of them are supported, which correspond to alternatives 6-0 and 6-1 or alternatives 6-0 and 6-2 or alternatives 6-1 and 6-2.

[0140] In some embodiments, the amplitude quantization type is according to one of the following four alternatives. In one example, amplitude type 0 corresponds to the case where the amplitudes reported for each of the L beams are the same for two antenna polarizations and the same for multiple layers (e.g., for two layers). The coefficient amplitudes for the two layers can be expressed as In another example, amplitude type 1 corresponds to the case where the amplitudes reported for each of the L beams are the same for two antenna polarizations and different for multiple layers (e.g., for two layers). The coefficient amplitudes for the two layers can be expressed as In yet another example, amplitude type 2 corresponds to the case where the amplitudes reported for each of the L beams are different for two antenna polarizations and the same for multiple layers (e.g., for two layers). The coefficient amplitudes for the two layers can be expressed as In yet another example, amplitude type 3 corresponds to the case where the amplitudes reported for each of the L beams are different for two antenna polarizations and different for multiple layers (e.g., for two layers). The coefficient amplitudes for the two layers can be expressed as

[0141] One of the foregoing examples will be discussed and fixed in this disclosure. Alternatively, one of the foregoing examples is configured to the UE via higher layers (e.g., RRC) or more dynamic (based on MAC CE or DCI) signaling. Alternatively, if the amplitude is reported as WB, one of the foregoing examples (e.g., amplitude types 0-3) is fixed or configured, if the amplitude is reported as SB, another of the foregoing examples (e.g., amplitude types 0-3) is fixed or configured, and if the amplitude is reported as both WB and SB, another of the foregoing examples (e.g., amplitude types 0-3) is fixed or configured.

[0142] In some embodiments, the amplitude quantization codebook for WB reporting or SB reporting (the above alternatives 6-0 and 6-1) is according to one of the following: And Where N A is the number of bits quantizing each amplitude. For example, if N A = 2, then entry And if N A = 3, then Let N A，WB and N A，SB be the number of bits reporting the quantized WB and SB amplitudes, respectively.

[0143] In some embodiments, the amplitude quantization codebook for both WB reporting and SB reporting (e.g., the above alternative 6-2) is as follows. Let aWB and a SB represent the quantized WB and SB amplitudes of the coefficients, respectively.

[0144] For WB reporting, use one of the N A，WB bit codebooks C A，0 and C A，1 to report the WB amplitude of each coefficient (a WB ).

[0145] For SB reporting, use one of the corresponding WB amplitude a WB and the following N A，SB bit codebooks to report the SB amplitude of each coefficient (a SB ). In one example, where the reconstructed amplitude using both the WB amplitude component and the SB amplitude component is given by a WB (1 + a SB ). In another example, where the reconstructed amplitude using both the WB amplitude component and the SB amplitude component is given by a WB (1 + a SB ). In yet another example, C A，SB，2 is an N A bit codebook that is a subset D(a A，1 ) of the full N WB bit codebook C A，SB , where N A is fixed and the subset D(a WB ) is determined based on the reported WB component a WB .

[0146] For example, if N A = 3, then and the N A，SB bit subset codebook D(a WB ) used for SB amplitude reporting is determined as follows. In step 0, find the index of the codeword in the full codebook C A，1 that is closest in Euclidean distance to the reported WB amplitude a WB . Let J be the corresponding codeword index. In step 1, the subset codebook D(a WB ) is determined as follows: If then the indices of the selected codewords of C WB that include D(a A，1 ) are Φ = 1 to Otherwise if then the indices of the selected codewords of C WB that include D(a A，1 ) are to or includes D(a WB ) of C A，1 The index of the selected codeword is to That is, the N A，SB bit subset codebook D(a WB ) is given by C A，1 (Φ), where Φ is the set of indices of the selected codewords in C A，1 .

[0147] In some embodiments, the number of bits for both WB amplitude quantization and SB amplitude quantization is according to at least one of the following alternatives: N A，WB = 2 and N A，SB = 1; N A，WB = 2 and N A，SB = 2; N A，WB = 3 and N A，SB = 1; N A，WB = 3 and N A，SB = 2; N A，WB = 4 and N A，SB = 1; and N A，WB = 4 and N A，SB = 2. The present disclosure supports any of the foregoing alternatives, and one of the foregoing alternatives is configured via higher layer RRC or more dynamic MAC CE or DCI signaling.

[0148] In some embodiments, when both WB amplitude and SB amplitude are reported (alternative 6-2 above), then it is according to at least one of the following alternatives. In one example, for each coefficient, one WB amplitude and one SB amplitude are reported. In another example, for each beam (from L W1 beams), the amplitudes of the two coefficients associated with the two polarizations are reported using a common WB amplitude and two different SB amplitudes. In yet another example, for each beam (from L W1 beams), the amplitudes of the two coefficients associated with the two layers are reported using a common WB amplitude and two different SB amplitudes. For more than 2 layers, the common WB amplitude and SB amplitude of each layer are reported. In yet another example, for each beam (from L W1 beams), the amplitudes of the four coefficients associated with the two layers and the two polarizations are reported using a common WB amplitude and four different SB amplitudes. For more than 2 layers, the common WB amplitude and SB amplitude of each layer and each polarization are reported. The present disclosure supports each of the foregoing examples and one of the foregoing examples is configured via higher layer RRC or more dynamic MAC CE or DCI signaling.

[0149] In some embodiments 7, the UE is configured with a DL codebook for type II CSI (embodiment 3), where the W1 beam is freely or unconstrainedly selected according to one of the following alternatives. In an example of alternative 7-0, similar to the LTE specification advanced CSI codebook, the beam (0, 0) is always selected, and the remaining L-1 beams are freely selected from the remaining L1L2-1 beams. In another example of alternative 7-1, any L beams among L1L2 can be selected. For higher-rank type II CSI reports, the nested nature in the W1 beam group is maintained, that is, the W1 beam group is the same for all layers.

[0150] In some embodiments 8, the UE is configured with a DL codebook for type II CSI (embodiment 3), where the W2 codebook for type II CSI is based on beam combination and reports at least one of the following two CSI subtypes. In an example of type II-A, the W2 codebook is used to quantify the precoder, which can be an estimate of the channel eigenvector or any general beamforming vector. In this example, the quantization of the precoder based on linear combination is given by where c = [c0 c1 … c L-1 c L c L+1 … c 2L-1 T , and c i is the complex coefficient for the i-th beam in basis B I and reports the CSI of rank r. The r main precoders are independently reported using the linear combination of L beams. For r layers, r separate PMIs or a single PMI are reported. In another example of type II-B, the W2 codebook is used to quantify a matrix (2N1N2×2N1N2 matrix) as type II CSI, where the quantization based on linear combination is given by where C is a 2L×2L Hermitian matrix. The matrix is thus Hermitian and non-negative definite. An example is the estimate of the channel covariance matrix E(H H H).

[0151] ​For CSI type II-A, the number of coefficients is K = 2L, while for CSI type II-B, the number of coefficients is K = 2L(2L + 1) / 2 = L(2L + 1) because C is a Hermitian matrix. The W2 codebook is used to quantize the following K coefficients. In one embodiment of the strongest beam / coefficient selection, the strongest beam / coefficient corresponding to the coefficient with the largest amplitude is selected and reported, and the remaining K - 1 coefficients are normalized by dividing them by the strongest coefficient and the normalized K - 1 coefficients are reported. Two alternatives for the strongest beam / coefficient selection are as follows. In one alternative (alternative 8-0), the beam (0, 0) of the basis set is the strongest beam. Note that in the case of type II-B CSI, this corresponds to the diagonal coefficient corresponding to the beam (0, 0). In one example (alternative 8-0-0), the beam (0, 0) at a fixed antenna polarization (e.g., +45) is the strongest beam. In this case, no indication of the strongest beam is required. In yet another example (alternative 8-0-1), the beam (0, 0) at either of the two antenna polarizations can be the strongest beam. In this case, 1 bit indication is required to indicate the polarization of the strongest beam. In another alternative (alternative 8-1), any one of the L beams can be the strongest beam. Note that in the case of type II-B CSI, this corresponds to the diagonal coefficients corresponding to the 2L beams. In one example (alternative 8-1-0), the strongest beam is selected from a fixed antenna polarization (e.g., +45). In this case, bit indication is required to indicate the strongest beam. In another example (alternative 8-1-1), the strongest beam is selected from either of the two polarizations. In this case, bit indication is required to indicate the strongest beam.

[0152] The selection of the strongest beam / coefficient can be reported in WB mode (e.g., a common report for all SBs) or in SB mode (e.g., an independent report for each SB). If it is WB, it can be reported jointly with at least one WB CSI report or separately as a separate WB report using PMI1. Alternatively, it can be reported as the WB component of PMI2.

[0153] In one embodiment of quantization, after normalization, the strongest coefficient becomes 1 and thus does not need to be reported. The remaining K - 1 normalized coefficients are quantized using scalar quantization of amplitude and phase respectively. In one example of amplitude quantization, the codebook for amplitude quantization is a B A bit scalar codebook between [0, 1], where B A= 2, 3, or 4. The amplitude quantization is WB or SB or both WB and SB (alternatives 6-0 to 6-2 in embodiment 6). There are two alternatives for amplitude quantization across two polarizations. In another example of alternative 8-2-0, the amplitudes of the two coefficients (associated with two polarizations) for each of the L beams are the same (amplitude types 0 and 1 in embodiment 6). In yet another example of alternative 8-2-1, the amplitudes of the two coefficients (associated with two polarizations) for each of the L beams are different and are independently quantized (amplitude types 2 and 3 in embodiment 6).

[0154] In one embodiment of phase quantization, the codebook for phase quantization is B P bits codebook, where B P = 2, 3, or 4. The phase quantization is reported in SB manner.

[0155] For high layer type II-A CSI reporting, the W2 codebook is as follows. In one example, the strongest beam / coefficient selection for all layers is according to one of the following two alternatives. In one instance of alternative 8-3-0, the strongest beam is the same for all layers. In another example of alternative 8-3-1, the strongest beam can be different for all layers (independently selected). In another example, the amplitude quantization for all layers is according to one of the following two alternatives. In one instance of alternative 8-4-0, the quantized amplitudes are the same for all layers (amplitude types 0 and 2 in embodiment 6). In another example of alternative 8-4-1, the quantized amplitudes are different (independently quantized) for all layers (amplitude types 1 and 3 in embodiment 6). The phase quantization is independent for all layers.

[0156] In some embodiments, the UE is configured to report a two - stage W = W1W2 codebook for type II CSI reports, where the PMI for reporting the LC precoding matrix includes at least two PMIs, namely a first PMI (i1) and a second PMI (i2) that respectively indicate the wide - band (WB) component and the sub - band (SB) component of the LC precoding matrix. Additionally, the first PMI (i1) includes a first set of indicators and a second set of indicators that respectively indicate the common WB component of all layers among multiple layers and the independent WB component of each layer among multiple layers, the second PMI (i2) includes a set of indicators that indicate the independent SB component of each layer among multiple layers, and the number of layers is determined based on a value υ associated with the rank indicator (RI). In one example, the first PMI (i1) includes a first set of indicators that indicate multiple L beams including the common WB component of all layers among multiple layers, and a second set of indicators that indicate the independent WB component of each layer among multiple υ layers, where the independent WB component of each layer includes at least the strongest coefficient among multiple coefficients and the WB amplitude coefficients of the remaining coefficients (all coefficients except the strongest coefficient). In another example, the second PMI (i2) includes a set of indicators that indicate the independent SB component of each layer among multiple υ layers, where the independent SB component of each layer includes at least the SB phase and SB amplitude coefficients of the remaining coefficients (all coefficients except the strongest coefficient).

[0157] In some embodiments 9, the UE is configured with a two - stage W = W1W2 codebook for type II CSI reports for a single panel, where the W1 codebook is used to select an orthogonal basis set including (L1, L2) uniformly - spaced DFT beams, and is used to freely select L ∈ {2, 3, 4, 6, 8} beams from the L1L2 DFT beams in the basis set, where L is configurable (e.g., by RRC) or the UE reports a preferred value of L. This selection is WB. Two examples of the basis set size are (L1, L2) = (4, 2) and (N1, N2), and one of them is fixed or configured. For layer l, the basis including L W1 beams is given by where is a 2D DFT beam, and i, 0, 1... L - 1} are the indices of the L beams after they are sorted such that the beam is the strongest beam for layer l. Note that for rank > 1, the strongest beam index can be different for different layers, so each layer indicates the index of the strongest beam and this indication is WB.

[0158] In some embodiments 9, the UE is configured with a two-stage W = W1W2 codebook for type II CSI reporting for a single panel, where the W2 codebook is used to independently combine L beams with a common W1 beam group for each layer, i.e., the selected L beams are the same for all layers. According to at least one of the alternatives in embodiment 6, the amplitude and phase of the combination coefficients are reported separately in the case where the phase and amplitude are reported for each SB, WB, or both WB and SB. The amplitude scaling matrix A r，l is an L×L diagonal matrix with diagonal elements having amplitudes corresponding to the L coefficients for polarization r and layer l in [0, 1]. The phase of the coefficients for polarization r and layer l is given by c r，l =[c r，l，o ,..., c r，l，L-1 T where

[0159] For rank 1 and rank 2, the precoder is given by and where = 0, 1, l = 0, 1, k1 = O1n1+q1, n1 = 0, 1,..., N1-1, q1 = 0, 1,..., O1-1 and k2 = O2n2+q2, n2 = 0, 1,..., N2-1, q2 = 0, 1,..., O2-1.

[0160] In some embodiments of the joint reporting of L beams, assuming a full orthogonal basis set of size (L1, L2) = (N1, N2), the number of bits for reporting the basis set is B 1，1 = log2(O1O2), the number of bits for reporting the strongest beam is B 1，2 = log2(L1L2) when the strongest beam is selected to be common to all R layers or B 1，2 = log2(RL1L2) when the strongest beam is selected for each layer, and the number of bits for reporting the remaining L-1 beams is So, the total number of bits for reporting the first PMI (PMI1) is or

[0161] In some embodiments, alternatively, the number of bits for reporting the basis set is B 1，1 = log2(O1O2), the number of bits for reporting L beams from the selected basis set is and the number of bits for reporting the strongest beam is when the strongest beam is selected to be common to all R layers or B 1，3 ​= log2(RL). Thus, the total number of bits for reporting the first PMI (PMI1) is or

[0162] In some embodiments with independent reporting of L beams, alternatively, the number of bits for reporting the base set is B 1，1 = log2(O1O2), the number of bits for reporting L beams from the selected base set is B 1，2 = L log2(L1L2), and the number of bits for reporting the strongest beam is or B in the case where the strongest beam is selected to be common to all R layers 1，3 = log2(RL). Thus, the total number of bits for reporting the first PMI (PMI1) is or

[0163] In some embodiments 9-0, the UE is configured with a type II (high-resolution) CSI report for 1-layer and 2-layer codebooks. For 4 antenna ports (e.g., {15, 16, 17, 18}), 8 antenna ports (e.g., {15, 16,..., 22}), 12 antenna ports (e.g., {15, 16,..., 26}), 16 antenna ports (e.g., {15, 16,..., 30}), 24 antenna ports (e.g., {15, 16,..., 38}), and 32 antenna ports (e.g., {15, 16,...46}), when the UE is configured with the higher layer parameter TypeIICodebookEnabled; the values of N1 and N2 are configured with the higher layer parameters CodebookConfig-N1 and CodebookConfig-N2, respectively. The supported configurations of (N1, N2) and the corresponding values of (O1, O2) for a given number of CSI-RS ports are given in Table 1. The number of CSI-RS ports P CSI-RS is 2N1N2; the value of L is configured with the higher layer parameter CodebookConfig-L, where L ∈ {2, 3, 4}. When P CSI-RS = 4, L > 2 is not supported; N PSK 's value is configured with the higher layer parameter CodebookConfig-Phase, where N PSK ∈ {4, 8}; and the UE is configured to set the higher layer parameter CodebookConfig-Amp to WB-Amplitude or WBPlusSB-Amplitude.

[0164] [Table 1] Supported configurations of (N1, N2) and (O1, O2)

[0165]

[0166] When υ ≤ 2, where υ is the relevant RI value, each PMI value corresponds to codebook indices i1 and i2, where

[0167]

[0168]

[0169] The L vectors (or DFT beams) of the linear combination are identified by quantities q, n1, and n2, where

[0170] and In one example, if N2 = 1, then q2 = 0 and for i = 0, 1,..., L - 1 and neither q2 nor n2 is reported. In another example, when (N1, N2) = (2, 1), n1 = [0, 1] and n2 = [0, 0], and n1 is not reported. In yet another example, when (N1, N2) = (4, 1) and L = 4, n1 = [0, 1, 2, 3] and n2 = [0, 0, 0, 0], and n1 is not reported. In yet another embodiment, when (N1, N2) = (2, 2) and L = 4, n1 = [0, 0, 1, 1] and n2 = [0, 1, 0, 1], and n1 is not reported. The strongest beam (or coefficient) on layer l, l = 1,..., υ is identified by where is the vector (or beam) index and identifies the polarization. For l = 1,..., υ, and

[0171] the beam (or coefficient) amplitude indicator and for l = 1,..., υ are The mapping from to the beam (or coefficient) amplitude is given in Table 2, and the mapping from to the beam amplitude is given in Table 3.

[0172] [Table 2] Mapping from to

[0173]

[0174] [Table 3] Mapping from to

[0175]

[0176] The beam (or coefficient) amplitude is represented by l = 1, ..., υ of to represent.

[0177] The beam (or coefficient) phase indicator is c for l = 1, ..., υ l = [c 0，l，0 , c 1，l，0 , ..., c 0，l，L-1 , c 1，l，L-1 .

[0178] When CodebookConfig-Amp is set to WB-Amplitude, for r = 0, 1, l = 1, ..., υ and i = 0, 1, ..., L-1 and not reported for l = 1, ..., υ indicator and (l = 1, ..., υ). Not reported for l = 1, ..., υ and (l = 1, ..., υ) of the remaining 2L-1 elements are reported. As determined by the reported elements of corresponding to the coefficient c l (l = 1, ..., υ) of the elements are reported, where c r，l，i ∈ {0, 1, ..., N PSK -1}.

[0179] When CodebookConfig-Amp is set to WBPlusSB-Amplitude, r = 0, 1, l = 1, ..., υ, and i = 0, 1, ..., L-1. The indicator and (l = 1, ..., υ). Not reported for l = 1, ..., υ and (l = 1, ..., υ) of the remaining 2L-1 elements are reported. Let M l (l = 1, ..., υ) be the number of elements that satisfy of . By the corresponding elements determined and the min(M l , K (SB) )-1 strongest beams (or coefficients) corresponding to the reported elements ofl The elements of (l = 1,..., υ) are reported, where and c r，l，i ∈ {0, 1,..., N PSK − 1}. When two or more elements of are the same, then the element with the lower index (starting from the left - hand size of ) has a higher priority for and c and c l (l = 1,..., υ) reporting. The values of K are given in Table 4. (SB) (l = 1,..., υ) The remaining 2L - min(M l , K (SB) ) elements are not reported. The remaining 2L - min(M l (l = 1,..., υ) elements of c l , K (SB) ) are reported, where c r，l，i ∈ {0, 1, 2, 3}.

[0180] [Table 4] Full - resolution sub - band coefficients when WBPlusSB - Amplitude is configured

[0181] L <![CDATA[K (SB) > 2 4 3 4 4 6

[0182] The codebook entry for υ = 1 is and the codebook entry for υ = 2 is where

[0183] and quantity and are given by for i = 0, 1,..., L - 1. Quantity u m and υ l，m are given by:

[0184]

[0185]

[0186]

[0187] In some embodiments 9-1, the UE is configured with layer 1 and layer 2 codebooks for the following type II (high-resolution) CSI reports. In one example, for 4 antenna ports (e.g., {3000, 3001, 3002, 3003}), 8 antenna ports (e.g., {3000, 3001, ..., 3007}), 12 antenna ports (e.g., {3000, 3001, ..., 3011}), 16 antenna ports (e.g., {3000, 3001, ..., 3015}), 24 antenna ports (e.g., {13000, 3001, ..., 3023}) and 32 antenna ports (e.g., {3000, 3001, ..., 3031}), when the UE is configured to set the higher layer parameter CodebookType to TypeII and the higher layer parameter CodebookParameters to Type2_Parameters, Type2_Parameters contains the parameters {CodebookConfig-N1, CodebookConfig-N2, NumberOfBeams, PhaseAlphabetSize, SubbandAmplitude}: the values of N1 and N2 are configured with the higher layer parameters CodebookConfig-N1 and CodebookConfig-N2 respectively. The supported configurations of (N1, N2) and the corresponding values of (O1, O2) for a given number of CSI-RS ports are given in Table 1. The number P of CSI-RS ports CSI-RS is 2N1N2; the value of L is configured with the higher layer parameter NumberOfBeams, where when P CSI-RS = 4, L = 2 and when P CSI-RS > 4, L ∈ {2, 3, 4}; N PSK 's value is configured with the higher layer parameter PhaseAlphabetSize, where N PSK ∈ {4, 8}; and the UE is configured to set the higher layer parameter SubbandAmplitude to OFF or ON.

[0188] When υ ≤ 2, where υ is the relevant RI value, each PMI value corresponds to codebook indices i1 and i2, where and

[0189] The combined L vectors are identified by indices i 1，1 、i 1，2 and i 1，3 where

[0190] and In one example, if N2 = 1, then for i = 0, 1, ..., L-1, i 1，2 = 0 and and i 1，2 and n2 are not reported. In another example, when (N1, N2) = (2, 1), n1 = [0, 1] and n2 = [0, 0], and i 1，3 is not reported. In yet another example, when (N1, N2) = (4, 1) and L = 4, n1 = [0, 1, 2, 3] and n2 = [0, 0, 0, 0], and i 1，3 is not reported. In yet another example, when (N1, N2) = (2, 2) and L = 4, n1 = [0, 0, 1, 1] and n2 = [0, 1, 0, 1], and i 1，3 is not reported.

[0191] Two alternatives for reporting [n1n2] are as follows. In one example of alternative 9-1-0 (independent reporting), for i = 0, 1, ..., L-1 using per-vector (beam) bits to report independently. In another example of alternative 9-1-1 (joint reporting), i = 0, 1, ..., L-1 are reported jointly according to the combined index where is the (sorted) orthogonal beam index (where the corresponding oversampled DFT beam index and and is the extended binomial coefficient.

[0192] The strongest coefficient on layer l, l = 1, ..., υ is identified by The amplitude coefficient indicator i 1，5，l and i 2，2，l are of l = 1, ..., υ Table 5 gives the mapping from to the amplitude coefficient and Table 6 gives the mapping from to the amplitude coefficient The amplitude coefficient is represented by for l = 1, ..., υ.

[0193] [Table 5] Elements of i 1，5，l : to mapping

[0194]

[0195] [Table 6] Elements of i 2，2，l : to Mapping

[0196]

[0197] The phase coefficient indicator is i for l = 1,..., υ 2，1，l = c l = [c l，0 , c l，1 ,..., c l，2L-1 . The amplitude and phase coefficient indicators are reported as follows. In one example, the indicator and (l = 1,..., υ). Not reported for l = 1,..., υ and In another example, The remaining 2L - 1 elements of (l = 1,..., υ) are reported, where Let M l (l = 1,..., υ) be the number of elements that satisfy of . In yet another example, and c l (l = 1,..., υ) The remaining 2L - 1 elements are reported as follows. In one instance, when SubbandAmplitude = OFF, for l = 1,..., υ and i = 0, 1,..., 2L - 1 Not reported for l = 1,..., υ And for l = 1,..., υ, as determined by the reported elements of The M -1 elements corresponding to the coefficients that satisfy l are reported, where c l，i ∈ {0, 1,..., N PSK -1}, and the remaining 2L - M l elements of c l are not reported and are set to c l，i = 0. In another instance, when SubbandAmplitude = ON, for l = 1,..., υ, as determined by the corresponding elements of The l , K (2) )) - 1 strongest coefficients corresponding to the and c l elements are reported, where and c l，i ∈ {0, 1,..., N PSK -1}. The value of K (2) is given in Table 7. The remaining 2L - min(M l , K (2) )) elements are not reported and are set to c l The remaining 2L - min(M l , K (2) ) elements are reported, where c l，i ∈ {0, 1, 2, 3}. In another instance, when the two reported elements and are the same (i.e., ), then the element min(x, y) is given preference to be included in and c l (l = 1,..., υ) report the set of min(M l , K (2) ) - 1 strongest coefficients. In another alternative, max(x, y) is given preference to be included in and c l (l = 1,..., υ) report the set of min(M l , K (2) ) - 1 strongest coefficients.

[0198] [Table 7] Full - resolution sub - band coefficients when SubbandAmplitude = ON

[0199] L <![CDATA[K (2) > 2 4 3 4 4 6

[0200] The codebooks for 1 - 2 layers are given in Table 8, where the quantities and are given by for i = 0, 1,..., L - 1, and the quantities u m and υ l，m are given by:

[0201]

[0202]

[0203]

[0204] [Table 8] Codebooks for 1 - and 2 - layer CSI reporting using antenna ports [3000 to 2999 + P CSI-RS

[0205]

[0206] ​

[0207] In some embodiments 9-2, the UE is configured with layer-1 and layer-2 codebooks for the following type II (high-resolution) CSI reports. For 4 antenna ports (e.g., {3000, 3001, 3002, 3003}), 8 antenna ports (e.g., {3000, 3001, …, 3007}), 12 antenna ports (e.g., {3000, 3001, …, 3011}), 16 antenna ports (e.g., {3000, 3001, …, 3015}), 24 antenna ports (e.g., {13000, 3001,...,3023}) and 32 antenna ports (e.g., {3000, 3001,...,3031}), when the UE is configured to set the higher layer parameter CodebookType to Type2_Parameters, where Type2_Parameters contains the parameters {CodebookConfig-N1, CodebookConfig-N2, NumberOfBeams, PhaseAlphabetSize, SubbandAmplitude}: the values of N1 and N2 are configured with the higher layer parameters CodebookConfig-N1 and CodebookConfig-N2 respectively. The supported configurations of (N1, N2) and the corresponding values of (O1, O2) for a given number of CSI-RS ports are given in Table 1. The number P of CSI-RS ports CSI-RS is 2N1N2; the value of L is configured with the higher layer parameter NumberOfBeams, where L ∈ {2, 3, 4}. When P CSI-RS = 4, L > 2 is not supported; N PSK 's value is configured with the higher layer parameter PhaseAlphabetSize, where N PSK ∈ {4, 8}; and the UE is configured to set the higher layer parameter SubbandAmplitude to OFF or ON.

[0208] When υ ≤ 2, where υ is the relevant RI value, each PMI value corresponds to codebook indices i1 and i2, where and

[0209] The L vectors through codebook combination are identified by indices i 1，1 and i 1，2 where and In one example, if N2 = 1, then q2 = 0 and for i = 0, 1,..., L-1 And neither q2 nor n2 is reported. In another example, when (N1, N2) = (2, 1), n1 = [0, 1] and n2 = [0, 0], and i 1，2 is not reported. In yet another example, when (N1, N2) = (4, 1) and L = 4, n1 = [0, 1, 2, 3] and n2 = [0, 0, 0, 0], and i 1，2 is not reported. In yet another example, when (N1, N2) = (2, 2) and L = 4, n1 = [0, 0, 1, 1] and n2 = [0, 1, 0, 1], and i 1，2 is not reported. In yet another example, two alternatives for reporting [q1 q2] are as follows.

[0210] In one example of alternative 9 - 2 - 0 (independent reporting), q1 and q2 are reported independently using only bits and bits when N2 = 1. In another example of alternative 9 - 2 - 1 (joint reporting), q1 and q2 are reported jointly according to one of two methods: (1) For given q1 and q2, report i 1，1 = O2q1 + q2 ∈ {0, 1,..., O1O2 - 1} and thus requires bits (if N2 > 1) or only 2 bits (if N2 = 1). For a given i 1，1 , and q2 = i 1，1 mod O1; (2) For given q1 and q2, report i 1，1 = O1q2 + q1 ∈ {0, 1,..., O1O2 = 1} and thus requires bits (if N2 > 1) or only 2 bits (if N2 = 1). For a given i 1，1 , and q1 = i 1，1 mod O2.

[0211] The strongest coefficients on layer l, l = 1,..., υ are identified by i 1，3，l ∈ {0, 1,..., 2L - 1}. The amplitude coefficient indicators i 1，4，l and i 2，2，l for l = 1,..., υ are given in Table 5 for the mapping from to the amplitude coefficient and given in Table 6 for the mapping from to the amplitude coefficient . The amplitude coefficients are represented by for l = 1,..., υ.

[0212] The phase coefficient indicator is i for l = 1,..., υ 2，1，l = c l = [c l，0 , c l，1 ,..., c l，2L-1 . The amplitude and phase coefficient indicators are reported as follows. In one example, the indicators and are not reported for l = 1,..., υ and In another example, the remaining 2L - 1 elements of i 1，4，1 (l = 1,..., υ) are reported, where let M l (l = 1,..., u) be the number of elements of i that satisfy 1，4，1 . In another example, i 2，1，l and i 2，2，l (l = 1,... υ) of the remaining 2L - 1 elements are reported as follows. In one instance, when SubbandAmplitude = OFF, for l = 1,..., υ and i = 0, 1,..., 2L - 1 i is not reported for l = 1,..., υ 2，2，l , and for l = 1,..., υ, i 1，4，1 as determined by the reported elements corresponding to the coefficients that satisfy of i 2，1，l of the M l - 1 elements are reported, where c l，i ∈ {0, 1,..., N PSK - 1}, and the remaining 2L - M 2，1，l elements of i l are not reported and are set to c l，i = 0. In another instance, when SubbandAmplitude = ON, for l = 1,..., υ, i 1，4，l as determined by the corresponding elements of i l corresponding to the min(M (2) , K 2，2，l and i 2，1，l of the elements of the - 1 strongest coefficients are reported, where and c l，i ∈ {0, 1,..., N PSK - 1}. The value of K (2) is given in Table 7. The remaining 2L - min(M 2，2，l , K l , K (2) ) elements of i i 2，1，l The remaining 2L - min(M l , K (2) )) elements are reported, where c l，i ∈ {0, 1, 2, 3}. In yet another instance where SubbandAmplitude = ON, when the two elements 1，4，1 of the reported i and are the same (lying ), then the element min(x, y) is preferentially considered to be included in the set of min(M 2，2，l and i 2，1，l (l = 1,..., υ) reported l , K (2) ) - 1 strongest coefficients. In another alternative, max(x, y) is preferentially considered to be included in the set of min(M 2，2，l and i 2，1，l (l = 1,..., υ) reported l , K (2) ) - 1 strongest coefficients.

[0213] The codebooks for layers 1 - 2 are given in Table 9, where the quantities and are given by for i = 0, 1,..., L - 1, and the quantities u m and u l，m are given by:

[0214]

[0215]

[0216]

[0217] [Table 9] Codebooks for CSI reporting for layers 1 and 2 using antenna ports [3000 to 2999 + P CSI-RS

[0218]

[0219]

[0220] In some embodiments 10, the UE is configured with a two-stage W = W1W2 codebook of rank 1 and rank 2 as follows. In one example, the number of supported ports is at most 32 ports, i.e., X = P ∈ {4, 8, 12, 16, 24, 32}. In another example, the W1 codebook is a port selection codebook (e.g., Embodiment 1). In yet another example, the rank R two-stage precoding matrix structure is as follows: W = W1W2, and each column of W is normalized to where L ∈ {2, 3, 4} or L ∈ {1, 2, 3, 4} is configurable, and X ≥ 2L; and for rank 2 (R = 2) where is the coefficient i and the wideband (WB) coefficient amplitude scaling factor on polarization r and layer l, is the coefficient i and the subband (SB) coefficient amplitude coefficient scaling factor on polarization r and layer l, and c r，l，i is the coefficient i and the combined coefficient (phase) on polarization r and layer l.

[0221] In yet another example, the codebook for phase reporting can be configured (via RRC) between QPSK (2 bits) and 8PSK (3 bits). In yet another example, the amplitude scaling mode can be configured (via RRC) between WB + SB (with unequal bit allocation) and only WB.

[0222] Each layer reports the strongest coefficient from 2L coefficients in a WB manner, where each layer requires bits. The remaining (2L - 1) coefficients are normalized by the strongest coefficient and each layer reports the amplitude and phase of the normalized 2L - 1 coefficients.

[0223] The reporting of amplitude scaling is as follows: Each amplitude scaling is independently selected for each beam, polarization, and layer; the UE is configured to report the wideband amplitude with or without subband amplitude; the wideband amplitude codebook is which requires 3 bits for each WB amplitude; the subband amplitude codebook is which requires 1 bit for each SB amplitude; and the PMI payload (amplitude and phase) can vary depending on whether the WB amplitude is zero.

[0224] The reporting of the phase of the combined coefficient is as follows: Each phase is independently reported for each SB, and each phase is selected for each beam, polarization, and layer; and the phase codebook is (2 bits) or (3 bits).

[0225] In a certain embodiment 10-0, the port selection matrix is based on a fixed port selection pattern. For example, where is a length X / 2 port selection column vector with all entries being zero except for the i-th entry which is 1, and d ∈ {1, 2, 3, 4} is configurable (via RRC), and d ≤ L and d < X. The overhead of port selection reporting using the W1 codebook is which is reported in the WB manner and is common to all layers and two polarizations.

[0226] In a certain embodiment 10-1, the port selection matrix is based on free port selection from any one of X / 2 ports. The overhead of port selection reporting using the W1 codebook is bits, which is reported in the WB manner and is common to all layers and two polarizations.

[0227] In a certain embodiment 10-2, the UE is configured with layer 1 and layer 2 codebooks for the following type II (high-resolution) CSI reporting. For 4 antenna ports (e.g., {15, 16, 17, 18}), 8 antenna ports (e.g., {15, 16,..., 22}), 12 antenna ports (e.g., {15, 16,..., 26}), 16 antenna ports (e.g., {15, 16,..., 30}), 24 antenna ports (e.g., {15, 16,..., 38}), and 32 antenna ports (e.g., {15, 16,...46}), when the UE is configured with the higher layer parameter TypeIIBFCSI-RSCodebookEnabled: the number of CSI-RS ports is given by P CSI-RS ∈ {4, 8, 12, 16, 24, 32}; the value of d is configured with the higher layer parameter CodebookConfig-d, where d ∈ {1, 2, 3, 4}; the value of L is configured with the higher layer parameter CodebookConfig-L, where L ∈ {2, 3, 4}. When P CSI-RS = 4, L > 2 is not supported; N PSK 's value is configured with the higher layer parameter CodebookConfig-Phase, where N PSK ∈ {4, 8}; and the UE is configured to set the higher layer parameter CodebookConfig-Amp to WB-Amplitude or WBPlusSB-Amplitude.

[0228] When υ ≤ 2, where υ is the relevant RI value, each PMI value corresponds to codebook indices i1 and i2, where

[0229]

[0230]

[0231] Antenna port throughput i 1，1 is selected, where the strongest beam (or coefficient) on layer l, l = 1,..., υ is identified by where is the beam (or coefficient) index and identifies the polarization. Report for l = 1,..., υ and beam (or coefficient) amplitude indicator and are for l = 1,..., υ

[0232]

[0233]

[0234]

[0235]

[0236] The mapping from to the beam (or coefficient) amplitude is given in Table 2 and the mapping from to the beam amplitude is given in Table 3. The beam (or coefficient) amplitude is represented by for l = 1,..., υ.

[0237] The beam (or coefficient) phase indicator is c for l = 1,..., υ l = [c 0，l，0 , c 1，l，0 ,..., c 0，l，L-1 , C 1，l，L-i . When CodebookConfig-Amp is set to WB-Amplitude, for r = 0, 1, l = 1,..., υ and i = 0, 1,..., L-1 and c r，l，i ∈ {0, 1,..., N PSK -1}. The indicator is not reported for l = 1,..., υ and... The indicator and and c l (l = 1,..., υ) of the remaining 2L-1 elements are reported. When CodebookConfig-Amp is set to WBPlusSB-Amplitude, r = 0, 1, …, υ and i = 0, 1, …, L - 1. The indicator and (l = 1, …, υ). Not reported for l = 1, …, υ and the remaining 2L - 1 elements of (l = 1, …, υ) are reported. As determined by the corresponding elements of with K (SB) - 1 strongest beams (or coefficients) corresponding to and c l (l = 1, …, υ) are reported, where and c r，l，i ∈ {0, 1, …, N PSK - 1}. When two elements of are the same, then the element with the smaller index (starting from the left - hand size of ) has a higher priority for reporting. The value of K (SB) is given in Table 4. (l = 1, …, υ) the remaining 2L - K (SB) elements are not reported. The remaining 2L - K l elements of c (SB) (l = 1, …, υ) are reported, where c r，l，i ∈ {0, 1, 2, 3}.

[0238] The codebook entry for υ = 1 is and the codebook entry for υ = 2 is where l = 1, 2, and quantity is given by and υ m is the column vector of P CSI-RS / 2 elements that contains the value 1 in the element (m mod P CSI-RS / 2) and zeros elsewhere, i.e., v m = [o 1×m 1 o 1x(Lm-1) T where 0 1×0 = [] (empty) and 0 1×m is the zero vector of length m.

[0239] ​In one embodiment 10-3, the UE is configured with layer 1 and layer 2 codebooks for the following type II (high-resolution) CSI reports. For 4 antenna ports (e.g., {3000, 3001, 3002, 3003}), 8 antenna ports (e.g., {3000, 3001,..., 3007}), 12 antenna ports (e.g., {3000, 3001,..., 3011}), 16 antenna ports (e.g., {3000, 3001,..., 3015}), 24 antenna ports (e.g., {13000, 3001,..., 3023}), and 32 antenna ports (e.g., {3000, 3001,..., 3031}), when the UE is configured to set the higher layer parameter CodebookType to Type2_Parameters, where Type2_Parameters contains the parameters {CodebookConfig-N1, CodebookConfig-N2, NumberOfBeams, PhaseAlphabetSize, SubbandAmplitude, PortSelectionSamplingSize}: the number of CSI-RS ports is given by P CSI-RS ∈ {4, 8, 12, 16, 24, 32}: the value of L is configured with the higher layer parameter NumberOfBeams, where when P CSI-RS > 4, L ∈ {2, 3, 4} and when P CSI-RS = 4, L = 2; the value of d is configured with the higher layer parameter PortSelectionSamplingSize, where d ∈ {1, 2, 3, 4}, and d ≤ L, or N PSK 's value is configured with the higher layer parameter PhaseAlphabetSize, where N PSK ∈ {4, 8}; and the UE is configured to set the higher layer parameter SubbandAmplitude to OFF or ON.

[0240] When υ ≤ 2, where υ is the relevant RI value, each PMI value corresponds to codebook indices i1 and i2, where and L antenna ports per polarization are selected by amount i 1，1 where the strongest coefficient on layer l, l = 1,..., υ is identified by . The coefficient amplitude indicators i 1，5，l and i 2，2，l are for l = 1,..., υ and are given in Table 5 is given from Mapping to coefficient amplitudes is given in Table 6 and the mapping from to coefficient amplitudes is also given. The coefficient amplitudes are represented by for l = 1, ..., υ. The coefficient phase indicators are i for l = 1, ..., υ 2，1，l = c l = [c l，0 , c l，1 , ..., c l，2L-1 .

[0241] The coefficient amplitudes and phase indicators are reported as follows. In one example, the indicators and (l = 1, ..., υ) are reported. and are not reported for l = 1, ..., υ. In another example, the remaining 2L - 1 elements of let M l (l = 1, ..., υ) be the number of elements of that satisfy . In another example, and the remaining 2L - 1 elements of c l (l = 1, ..., υ) are reported as follows. In one instance, when SubbandAmplitude = OFF, for l = 1, ..., υ and i = 0, 1, ..., 2L - 1 is not reported for l = 1, ..., υ and for l = 1, ..., υ, the M - 1 elements of c corresponding to the coefficients that satisfy l as determined by the reported coefficients of l are reported, where c l，i ∈ {0, 1, ..., N PSK - 1}, and the remaining 2L - M l elements of c l are not reported and are set to c l，i = 0. In another instance, when SubbandAmplitude = ON, for l = 1, ..., υ, the corresponding to the min(M l , K (2) ) - 1 strongest coefficients as determined by the corresponding elements of and c lThe elements of are reported, where and c l，i ∈ {0, 1,... N PSK - 1}. The values of K (2) are given in Table 7. The remaining 2L - min(M l , K (2) ) elements are not reported and are set to c l The remaining 2L - min(M l , K (2) ) elements are reported, where c l，i ∈ {0, 1, 2, 3}. In yet another instance, when SubbandAmplitude = ON, when the two reported elements and are the same (i.e., ), then the element min(x, y) is preferentially considered to be included in and c l (l = 1,..., υ) reports the set of min(M l , K (2） ) - 1 strongest coefficients. In another alternative, max(x, y) is preferentially considered to be included in and c l (l = 1,..., υ) reports the set of min(M l , K (2) ) - 1 strongest coefficients.

[0242] The codebooks for 1 - 2 layers are given in Table 10, where the quantity is given by

[0243]

[0244] and υ m is the column vector of P CSI-RS / 2 elements that contains the value 1 in the element (m mod P CSI-RS / 2) and zeros elsewhere.

[0245] [Table 10] Codebooks for CSI reporting for layers 1 and 2 using antenna ports [3000 to 2999 + P CSI-RS

[0246]

[0247]

[0248] In some embodiments 10-4, the UE is configured with layer-1 and layer-2 codebooks for the following type-II (high-resolution) CSI reports. For 4 antenna ports (e.g., {3000, 3001, 3002, 3003}), 8 antenna ports (e.g., {3000, 3001, ..., 3007}), 12 antenna ports (e.g., {3000, 3001, ..., 3011}), 16 antenna ports (e.g., {3000, 3001, ..., 3015}), 24 antenna ports (e.g., {13000, 3001, ..., 3023}), and 32 antenna ports (e.g., {3000, 3001, ..., 3031}), when the UE is configured to set the higher layer parameter CodebookType to Type2_Parameters, where Type2_Parameters contains the parameters {CodebookConfig-N1, CodebookConfig-N2, NumberOfBeams, PhaseAlphabetSize, SubbandAmplitude, PortSelectionSamplingSize}: the number of CSI-RS ports is given by P CSI-RS ∈ {4, 8, 12, 16, 24, 32}: the value of L is configured with the higher layer parameter NumberOfBeams, where when P CSI-RS = 4, L = 2 and when P CSI-RS > 4, L ∈ {2, 3, 4}; the value of d is configured with the higher layer parameter PortSelectionSamplingSize, where d ∈ {1, 2, 3, 4}, and d ≤ L, or N PSK 's value is configured with the higher layer parameter PhaseAlphabetSize, where N PSK ∈ {4, 8}; and the UE is configured to set the higher layer parameter SubbandAmplitude to OFF or ON.

[0249] When υ ≤ 2, υ is the relevant RI value, and each PMI value corresponds to codebook indices i1 and i2, where and

[0250] L antenna ports per polarization are selected by index i 1，1 , where the strongest coefficient on layer l, l = 1, ..., υ is identified by i 1，3，l ∈ {0, 1, ..., 2L - 1}. The amplitude coefficient indicator i 1，4，l and i2，2，l for l = 1, ..., υ is given in Table 5 from to the amplitude coefficient and is given in Table 6 from to the amplitude coefficient .

[0251] The amplitude coefficient is represented by for l = 1, ..., υ . The phase coefficient indicator is i for l = 1, ..., υ 2，1，l = c l = [c l，0 , c l，1 , …, c l，2L-1 .

[0252] The amplitude and phase coefficient indicators are reported as follows. In one example, the indicators and are not reported for l = 1, ..., υ and . In another example, the remaining 2L - 1 elements of i 1，4，1 (l = 1,.., υ) are reported, where let M l (l = 1, ..., υ) be the number of elements of i that satisfy 1，4，1 . In yet another example, i 2，1，l and i 2，2，l (l = 1, ..., υ) the remaining 2L - 1 elements are reported as follows: In one instance, when SubbandAmplitude = OFF, for l = 1, ..., υ and i = 0, 1, ..., 2L - 1 i is not reported for l = 1, ..., υ 2，2，l , and for l = 1, ..., υ, as determined by the reported elements of i 1，4，1 the M - 1 elements corresponding to the coefficients that satisfy 2，1，l are reported, where c l ∈ {0, 1, ..., N l，i - 1}, and the remaining 2L - M PSK elements of i 2，1，l are not reported and are set to c l = 0. In another instance, when SubbandAmplitude = ON, for l = 1, ..., υ, as determined by the corresponding elements of i l，i the min(M 1，4，l , K l ​(2) ) - The i corresponding to the -1 strongest coefficients 2，2，l and i 2，1，l of the elements are reported, where and c l，i ∈ {0, 1,..., N PSK -1}. The values of K are given in Table 7. The remaining 2L - min(M (2) , K 2，2，l ) elements of i are not reported and are set to l i (2) . The remaining 2L - min(M , K 2，1，l ) elements of i are reported, where c l ∈ {0, 1, 2, 3}. In another instance, when SubbandAmplitude = ON, when the two elements of the reported i (2 are the same (i.e., l，i ), then the element min(x, y) is preferentially considered to be included in the set of min(M 1，4，1 , K ) - 1 strongest coefficients reported by i and i (l = 1,..., υ). In another alternative, max(x, y) is preferentially considered to be included in the set of min(M 2，2，l , K 2，1，l ) - 1 strongest coefficients reported by i l , K (2) ) and i 2，2，l (l = 1,..., υ). 2，1，l The codebooks for 1 - 2 layers are given in Table 11, where the quantity l is given by (2) , and υ

[0253] is a column vector of P / 2 elements that contains the value 1 in the element (m mod P

[0254]

[0255] / 2) and zeros elsewhere (where the first element is the element 0). m is the element (m mod P CSI-RS / 2) that contains the value 1 and zeros elsewhere. The codebooks for CSI reporting using antenna ports [3000 to 2999 + P CSI-RS for 1 layer and 2 layers are given in Table 11.

[0256] [Table 11] Codebooks for CSI reporting for 1 layer and 2 layers using antenna ports [3000 to 2999 + P CSI-RS

[0257]

[0258] ​Figure 15 FIG. 1500 shows an example flowchart of a method for multi - resolution CSI reporting according to an embodiment of the present disclosure that can be performed by a UE. Figure 15 The embodiment of the method 1500 shown in FIG. 1500 is for illustration only. Figure 15 One or more of the components shown in FIG. 1500 can be implemented with dedicated circuitry configured to perform the indicated functions, or one or more of these components can be implemented by one or more processors executing instructions to perform the indicated functions. Other embodiments are used without departing from the scope of the present disclosure.

[0259] As Figure 15 shown in FIG. 1500, the method 1500 starts at 1505. In step 1505, the UE receives CSI feedback configuration information for precoding matrix indicator (PMI) feedback from a base station (BS), the CSI feedback configuration information indicating a linear combination (LC) precoding matrix corresponding to a linear combination of a plurality of L beams and a plurality of coefficients. In step 1505, each of the plurality of coefficients includes at least an amplitude coefficient and a phase coefficient, and the PMI includes a first PMI (i1) and a second PMI (i2) respectively indicating a wide - band (WB) component and a sub - band (SB) component of the LC precoding matrix. Additionally, in step 1505, the first PMI (i1) includes a first indicator set and a second indicator set respectively indicating a common WB component for all layers among the plurality of layers and an independent WB component for each layer among the plurality of layers, the second PMI (i2) includes an indicator set indicating an independent SB component for each layer among the plurality of layers, and the plurality of layers is determined based on a value υ associated with a rank indicator (RI).

[0260] Next, in step 1510, the UE determines the first PMI (i1) and the second PMI (i2).

[0261] In step 1510, the first PMI (i1) includes a first indicator set S1 = [i 1，1 i 1，2 indicating a plurality of L beams including a common WB component for all layers among the plurality of layers. In some embodiments, the first PMI (i1) includes a second indicator set to indicate an independent WB component for each layer among the plurality of υ = 1 or υ = 2 layers, where υ = 1 is the first layer and υ = 2 is the first and second layers. In these embodiments, i 1，3，1 and i 1，3，2 respectively indicate the strongest coefficients among the plurality of coefficients for each of the first and second layers, and i 1，4，1 and i 1，4，2 respectively indicate the plurality of WB amplitude coefficients for each of the first and second layers.

[0262] In some embodiments, in step 1510, the second PMI (i2) includes a set of indicators to indicate the independent SB components of each of the multiple υ = 1 or υ = 2 layers, where υ = 1 is the first layer and υ = 2 is the first and second layers, and where i 2，1，1 and i 2，1，2 respectively indicate the multiple SB phase coefficients of each of the first and second layers.

[0263] In some embodiments, in step 1510, the second PMI (i2) includes a set of indicators to indicate the independent SB components of each of the multiple υ = 1 or υ = 2 layers, where υ = 1 is the first layer and υ = 2 is the first and second layers, and where i 2，2，1 and i 2，2，2 respectively indicate the multiple SB amplitude coefficients of each of the first and second layers.

[0264] In these embodiments, the amplitude coefficients are determined as given in the table:

[0265]

[0266] In these embodiments, the LC codebooks for both υ = 1 and υ = 2 are given by the following table:

[0267]

[0268]

[0269] and where υ = 1 is the first layer and υ = 2 is the first and second layers.

[0270] Finally, in step 1515, the UE sends CSI feedback including the first PMI (i1) and the second PMI (i2) to the BS via an uplink channel.

[0271] In some embodiments, in step 1505, the CSI feedback configuration information includes the values of multiple L DFT beams, the value of the phase alphabet size N PSK the value of and (N1, N2), and where L is determined such that L ∈ {2, 3, 4}, N PSK is determined as N PSK ∈ {4, 8}, and (N1, N2) and (O1, O2) are determined as:

[0272]

[0273] In some embodiments, in step 1505, the CSI feedback configuration information includes the value of L ∈ {2, 3, 4}, N PSKA value ∈ {4, 8}, the number of CSI-RS ports P at the BS CSI-RS Values ∈ {4, 8, 12, 16, 24, 32} and a value d ∈ {1, 2, 3, 4}, where The first PMI (i1) includes an indication of a plurality of P CSI-RS / 2 select L antenna port selection first indicator set, where this selection is common to all layers in a plurality of layers; and the LC codebooks for both υ = 1 and υ = 2 are given by the following table:

[0274]

[0275]

[0276] And where υ = 1 is the first layer and υ = 2 is the first and second layers.

[0277] Although the present disclosure has been described with example embodiments, various changes and modifications can be suggested to those skilled in the art. The present disclosure is intended to cover such changes and modifications as fall within the scope of the appended claims.

[0278] 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 within the scope of the claims. The scope of the patent subject matter is defined only by the claims. Moreover, unless the exact words "means for" are followed by a participle, the claims are not intended to invoke 35 U.S.C. § 112(f).

Claims

1. A user equipment (UE) in a wireless communication system, the UE comprising: A transceiver; A processor, the processor being connected to the transceiver and configured to: Receive, from a base station, configuration information associated with a type II port selection codebook, where the configuration information includes the number of beams L, a sampling size parameter for port selection, a phase alphabet size N PSK , and information indicating whether wideband (WB) amplitude feedback or WB and subband (SB) amplitude feedback will be performed; Identify a precoding matrix indicator (PMI) of a precoding matrix, the precoding matrix corresponding to a linear combination of L beams and a plurality of coefficients associated with each of L channel state information reference signal (CSI-RS) ports, wherein: The plurality of coefficients includes at least an amplitude coefficient and a phase coefficient, The PMI includes a first PMI (i1) indicating a wideband (WB) component of the precoding matrix and a second PMI (i2) indicating a sub-band (SB) component of the precoding matrix, The first PMI (i1) includes a first indicator and a second indicator, the first indicator indicating the L CSI-RS ports common to all layers in one or more layers based on the sampling size parameter, the second indicator indicating an independent WB component of each layer in the one or more layers, and The second PMI (i2) includes a set of indicators indicating an independent SB component of each layer in the one or more layers; and Transmit the CSI feedback including the first PMI (i1) and the second PMI (i2) on an uplink channel to the base station.

2. The UE according to claim 1, wherein, The value of the first indicator (i 1,1 ) in the first PMI (i1) is included in the set , where P CSI-RS is the number of CSI-RS ports and d is the sampling size parameter.

3. The UE according to claim 2, wherein, The value of the sampling size parameter d is included in {1, 2, 3, 4}, and d is equal to or less than 4. The UE according to claim 1, wherein The second indicator in the first PMI (i1) includes which indicates an independent WB component for each of the one or more υ = 1 or υ = 2 layers, where: υ = 1 corresponds to the first layer and υ = 2 corresponds to the first and second layers, i 1，3，1 and i 1，3，2 respectively indicate the strongest coefficients among the plurality of coefficients of each of the first layer and the second layer, and i 1，4，i and i 1，4，2 respectively indicate a plurality of WB amplitude coefficients for each of the first layer and the second layer.

5. The UE according to claim 1, wherein, The second PMI (i2) includes: Indicator set which indicates the independent SB components of each of the one or more υ = 1 or υ = 2 layers; and Indicator set which, in the case where the information indicates that the WB and SB amplitude feedback will be performed, indicates the independent SB components of each of the one or more υ = 1 or υ = 2 layers, where: υ = 1 corresponds to the first layer, υ = 2 corresponds to the first and second layers, i 2，1，1 and i 2，1，2 respectively indicate a plurality of SB phase coefficients of each of the first layer and the second layer, and i 2，2，1 and i 2，2，2 respectively indicate a plurality of SB amplitude coefficients of each of the first layer and the second layer.

6. A method performed by a user equipment (UE) in a wireless communication system, the method comprising: Receive, from a base station, configuration information of channel state information (CSI) feedback associated with a type II port selection codebook, where the configuration information includes a number of beams L, a sampling size parameter for port selection, a phase alphabet size N PSK , and information indicating whether wideband (WB) amplitude feedback or WB and subband (SB) amplitude feedback will be performed; Identify a precoding matrix indicator (PMI) of a precoding matrix, the precoding matrix corresponding to a linear combination of L beams and a plurality of coefficients associated with each of L channel state information reference signal (CSI-RS) ports, wherein: The plurality of coefficients includes at least an amplitude coefficient and a phase coefficient, The PMI includes a first PMI (i1) indicating a wideband (WB) component of the precoding matrix and a second PMI (i2) indicating a sub-band (SB) component of the precoding matrix, The first PMI (i1) includes a first indicator and a second indicator, the first indicator indicating the L CSI-RS ports common to all layers in one or more layers based on the sampling size parameter, the second indicator indicating an independent WB component of each layer in the one or more layers, and The second PMI (i2) includes a set of indicators indicating an independent SB component of each layer in the one or more layers; and Transmit the CSI feedback including the first PMI (i1) and the second PMI (i2) on an uplink channel to the base station.

7. The method according to claim 6, wherein The value of the first indicator (i 1，1 ) in the first PMI (i1) is included in the set , where P CSI-RS is the number of CSI-RS ports and d is the sampling size parameter.

8. The method according to claim 7, wherein The value of the sampling size parameter d is included in {1, 2, 3, 4}, and d is equal to or less than 9. The method according to claim 6, wherein The second indicator in the first PMI (i1) includes which indicates an independent WB component for each of the one or more ν = 1 or ν = 2 layers, where: ν = 1 corresponds to the first layer and ν = 2 corresponds to the first and second layers, i 1，3，1 and i 1，3，2 respectively indicate the strongest coefficients among the plurality of coefficients of each of the first layer and the second layer, and i 1，4，1 and i 1，4，2 respectively indicate a plurality of WB amplitude coefficients for each of the first layer and the second layer.

10. The method according to claim 6, wherein, The second PMI (i2) includes: Indicator set which indicates the independent SB components of each of said one or more υ = 1 or υ = 2 layers; and Indicator set which, in the case where the said information indicates that the WB and SB amplitude feedback will be carried out, indicates the independent SB components of each of the said one or more υ = 1 or υ = 2 layers, where: υ = 1 corresponds to the first layer, υ = 2 corresponds to the first and second layers, i 2，1，1 and i 2，1，2 respectively indicate a plurality of SB phase coefficients of each of the first layer and the second layer, and i 2，2，1 and i 2，2，2 respectively indicate a plurality of SB amplitude coefficients for each of the first layer and the second layer.

11. A base station in a wireless communication system, the base station comprising: A transceiver; A processor, the processor being connected to the transceiver and configured to: Send configuration information of channel state information CSI feedback associated with a type II port selection codebook to a user equipment UE, where the configuration information includes the number of beams L, a sampling size parameter for port selection, a phase alphabet size N PSK and information indicating whether wideband WB amplitude feedback or WB and subband SB amplitude feedback will be performed; Receive the CSI feedback from the UE on an uplink channel, the CSI feedback including a precoding matrix indicator PMI of a precoding matrix, the precoding matrix corresponding to a linear combination of L beams and a plurality of coefficients associated with each of L channel state information reference signal CSI-RS ports, wherein: The plurality of coefficients includes at least an amplitude coefficient and a phase coefficient, The PMI includes a first PMI (i1) indicating a wideband WB component of the precoding matrix and a second PMI (i2) indicating a subband SB component of the precoding matrix, The first PMI (i1) includes a first indicator and a second indicator, the first indicator indicating the L CSI-RS ports common to all layers in one or more layers based on the sampling size parameter, the second indicator indicating an independent WB component of each layer in the one or more layers, and The second PMI (i2) includes a set of indicators indicating independent SB components of each layer in the one or more layers.

12. The base station according to claim 11, wherein, The value of the first indicator (i 1，1 ) in the first PMI (i1) is included in the set , where P CSI-RS is the number of CSI-RS ports and d is the sampling size parameter.

13. The base station according to claim 12, wherein, The value of the sampling size parameter d is included in {1, 2, 3, 4}, and d is equal to or less than 14. The base station according to claim 11, wherein, The second indicator in the first PMI (i1) includes which indicates an independent WB component for each of the one or more υ = 1 or υ = 2 layers, where: υ = 1 corresponds to the first layer and υ = 2 corresponds to the first and second layers, i 1，3，1 and i 1，3，2 respectively indicate the strongest coefficients among the plurality of coefficients of each of the first layer and the second layer, and i 1，4，1 and i 1，4，2 respectively indicate a plurality of WB amplitude coefficients of each of the first layer and the second layer.

15. The base station according to claim 11, wherein, The second PMI (i2) includes: Indicator set which indicates the independent SB components of each of the one or more υ = 1 or υ = 2 layers; and Indicator set which, in the case where the said information indicates that the WB and SB amplitude feedback will be carried out, indicates the independent SB component of each of the said one or more υ = 1 or υ = 2 layers, where: υ = 1 corresponds to the first layer, υ = 2 corresponds to the first and second layers, i 2，1，1 and i 2，1，2 respectively indicate a plurality of SB phase coefficients for each of the first layer and the second layer, and i 2，2，1 and i 2，2，2 respectively indicate a plurality of SB amplitude coefficients of each of the first layer and the second layer.

16. A method performed by a base station in a wireless communication system, the method including: Send configuration information of channel state information CSI feedback associated with a type II port selection codebook to a user equipment UE, where the configuration information includes information on the number of channel state information reference signal CSI-RS ports, the number of beams L, a sampling size parameter for port selection, and a phase alphabet size N PSK and information indicating whether wideband WB amplitude feedback or WB and subband SB amplitude feedback will be performed; Receive the CSI feedback from the UE on an uplink channel, the CSI feedback including a precoding matrix indicator PMI of a precoding matrix, the precoding matrix corresponding to a linear combination of L beams and a plurality of coefficients associated with each of L CSI-RS ports, wherein: The plurality of coefficients includes at least an amplitude coefficient and a phase coefficient, The PMI includes a first PMI (i1) indicating a wideband WB component of the precoding matrix and a second PMI (i2) indicating a subband SB component of the precoding matrix, The first PMI (i1) includes a first indicator and a second indicator, the first indicator indicating the L CSI-RS ports common to all layers in one or more layers based on the sampling size parameter, the second indicator indicating an independent WB component of each layer in the one or more layers, and The second PMI (i2) includes a set of indicators indicating independent SB components of each layer in the one or more layers.

17. The method according to claim 16, wherein The value of the first indicator (i 1，1 ) in the first PMI (i1) is included in the set , where P CSI-RS is the number of CSI-RS ports and d is the sampling size parameter.

18. The method according to claim 17, wherein, The value of the sampling size parameter d is included in {1, 2, 3, 4}, and d is equal to or less than 19. The method according to claim 16, wherein The second indicator in the first PMI (i1) includes which indicates an independent WB component for each of the one or more υ = 1 or υ = 2 layers, where: υ = 1 corresponds to the first layer and υ = 2 corresponds to the first and second layers, i 1，3，1 and i 1，3，2 respectively indicate the strongest coefficients among the plurality of coefficients of each of the first layer and the second layer, and i 1，4，1 and i 1，4，2 respectively indicate a plurality of WB amplitude coefficients for each of the first layer and the second layer.

20. The method according to claim 16, wherein The second PMI (i2) includes: Indicator set which indicates the independent SB components of each of the one or more υ = 1 or υ = 2 layers; and Indicator set which, in the case where the said information indicates that the WB and SB amplitude feedback will be carried out, indicates the independent SB components of each of the said one or more υ = 1 or υ = 2 layers, where: υ = 1 corresponds to the first layer, υ = 2 corresponds to the first and second layers, i 2，1，1 and i 2，1，2 respectively indicate a plurality of SB phase coefficients for each of the first layer and the second layer, and i 2，2，1 and i 2，2，2 respectively indicate a plurality of SB amplitude coefficients of each of the first layer and the second layer.

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