CN117099324A - Method and apparatus for high resolution CSI codebook - Google Patents

Abstract

Apparatus and methods for high resolution CSI codebooks are provided. The method comprises the following steps: receiving configuration information about a Channel State Information (CSI) report, the configuration information including a parameter d Σ1, where d is the number of principal components; determining a left principal component vector; determining a right principal component vector; determining a main singular value; and transmitting a CSI report including a Precoding Matrix Indicator (PMI) indicating a left principal component vector, a right principal component vector, and a dominant singular value, wherein at least one of the left principal component vector, the right principal component vector, and the dominant singular value is selected from the adaptive codebook.

Description

Method and apparatus for high resolution CSI codebook

Technical Field

The present disclosure relates generally to wireless communication systems, and more particularly, to methods and apparatus for high resolution CSI codebooks.

Background

The 5G mobile communication technology defines a wide frequency band, enables high transmission rates and new services, and can be implemented not only in a "below 6 GHz" frequency band such as 3.5GHz, but also in a "above 6 GHz" frequency band called millimeter waves including 28GHz and 39 GHz. In addition, in order to achieve a transmission rate 50 times faster than that of the 5G mobile communication technology and an ultra-low latency of one tenth of that of the 5G mobile communication technology, it has been considered to implement the 6G mobile communication technology (referred to as a super 5G system) in a terahertz band (e.g., 95GHz to 3THz band).

In the early stages of the development of 5G Mobile communication technology, in order to support services and meet performance requirements related to enhanced Mobile BroadBand (eMBB), ultra-reliable low latency communication (Ultra Reliable Low Latency Communications, URLLC), and large-scale Machine-type communication (emtc), there has been standardization regarding: beamforming and massive MIMO for reducing radio wave path loss and increasing radio wave transmission distance in millimeter waves; a support parameter set (e.g., operating multiple subcarrier spacings) for dynamic operation that effectively utilizes millimeter wave resources and slot formats; an initial access technology for supporting multi-beam transmission and broadband; definition and operation of BWP (BandWidth Part); new channel coding methods such as LDPC (Low Density Parity Check ) codes for large data transmission and polarization codes for highly reliable transmission of control information; l2 pretreatment; and a network slice for providing a private network dedicated to a particular service.

Currently, in view of services that the 5G mobile communication technology will support, discussions are being made about improvement and performance enhancement of the initial 5G mobile communication technology, and there has been physical layer standardization with respect to technologies such as: V2X (Vehicle-to-everything) for assisting driving determination of the autonomous Vehicle based on information about the position and state of the Vehicle transmitted by the Vehicle, and for enhancing user convenience; NR-U (New Radio Unlicensed ), for system operation in an unlicensed band that meets various regulatory-related requirements; NR UE saves energy; a Non-terrestrial network (Non-Terrestrial Network, NTN) that is a UE-satellite direct communication for providing coverage in areas where communication with the terrestrial network is unavailable; and positioning.

Furthermore, there has been ongoing standardization in terms of air interface architecture/protocols with respect to technologies such as: industrial internet of things (Industrial Internet of Things, IIoT) for supporting new services through interworking and fusion with other industries; an IAB (Integrated Access and Backhaul ) for providing a node for network service area extension by supporting a wireless backhaul link and an access link in an integrated manner; mobility enhancements, including conditional handoffs and DAPS (Dual Active Protocol Stack ) handoffs; and two-step random access for simplifying the random access procedure (2-step RACH for NR). There has also been ongoing standardization in terms of system architecture/services related to 5G baseline architecture (e.g., service-based architecture or service-based interface) for combining network function virtualization (Network Functions Virtualization, NFV) and Software Defined Networking (SDN) technologies, and mobile edge computing (Mobile Edge Computing, MEC) for receiving services based on UE location.

As 5G mobile communication systems are commercialized, connection apparatuses having exponentially increased will be connected to communication networks, and accordingly, it is expected that enhanced functions and performances of the 5G mobile communication systems and integrated operations of the connection apparatuses will be necessary. For this purpose, new studies related to the following are planned: augmented Reality (XR) for effectively supporting AR (Augmented Reality ), VR (Virtual Reality), MR (Mixed Reality), and the like; 5G performance improvement and complexity reduction through the use of artificial intelligence (Artificial Intelligence, AI) and Machine Learning (ML); AI service support; meta-universe service support; and unmanned aerial vehicle communication.

Further, such development of the 5G mobile communication system will be the basis not only for developing new waveforms for providing coverage of the terahertz band of the 6G mobile communication technology, multi-antenna transmission technologies such as Full dimension MIMO (FD-MIMO), array antennas and massive antennas, metamaterial-based lenses and antennas for improving coverage of the terahertz band signals, high Dimensional spatial multiplexing technology using OAM (Orbital Angular Momentum ) and RIS (Reconfigurable Intelligent Surface, reconfigurable intelligent surface), but also for developing Full duplex technology for improving frequency efficiency of the 6G mobile communication technology and improving a system network, AI-based communication technology for implementing system optimization by utilizing satellites and AI (artificial intelligence) and internalizing end-to-end AI support functions from a design stage, and next generation distributed computing technology for implementing a degree of complexity of services exceeding the UE operation capability limit by utilizing ultra-high performance communication and computing resources.

Disclosure of Invention

Technical problem

For cellular systems operating in the frequency range below 1GHz (e.g., less than 1 GHz), supporting a large number of CSI-RS antenna ports (e.g., 32) at a single location or remote radio head (remote radio head, RRH) is challenging because at these frequencies a larger antenna form factor size is required compared to systems operating at higher frequencies, such as 2GHz or 4 GHz. At such low frequencies, the maximum number of CSI-RS antenna ports that can be co-located at a single site (or RRH) may be limited to, for example, 8. This limits the spectral efficiency of such systems. In particular, the MU-MIMO spatial multiplexing gain provided by a large number of CSI-RS antenna ports (such as 32) cannot be achieved. One way to operate a 1GHz below system with a large number of CSI-RS antenna ports is based on distributing the antenna ports at multiple locations (or panels/RRHs). Multiple sites or panels/RRHs can still be connected to a single (common) base unit, so that signals transmitted/received via multiple distributed RRHs can still be processed at a centralized location.

Solution to the problem

Embodiments of the present disclosure provide methods and apparatus for high resolution codebooks in wireless communication systems.

In one embodiment, a UE in a wireless communication system is provided. The UE includes a transceiver configured to receive configuration information regarding Channel State Information (CSI) reporting, the configuration information including a parameter d Σ1, where d is a number of principal components. The UE also includes a processor operably coupled to the transceiver. The processor is configured to: determining a left principal component vector; determining a right principal component vector; and determining dominant singular values, wherein the transceiver is further configured to transmit a CSI report comprising a Precoding Matrix Indicator (PMI) indicating a left dominant component vector, a right dominant component vector, and dominant singular values, wherein at least one of the left dominant component vector, the right dominant component vector, and the dominant singular values is selected from an adaptive codebook.

In another embodiment, a BS in a wireless communication system is provided. The BS includes a processor configured to generate configuration information regarding CSI reports, the configuration information including a parameter d Σ1, where d is the number of principal components. The BS also includes a transceiver operably coupled to the processor. The transceiver is configured to: transmitting configuration information; and receiving a CSI report including a PMI indicating a left principal component vector, a right principal component vector, and a dominant singular value, wherein at least one of the left principal component vector, the right principal component vector, and the dominant singular value is based on the adaptive codebook.

In yet another embodiment, a method for operating a UE is provided. The method comprises the following steps: receiving configuration information about the CSI report, wherein the configuration information comprises a parameter d & gt1, and d is the number of main components; determining a left principal component vector; determining a right principal component vector; determining a main singular value; and transmitting a CSI report including a PMI indicating a left principal component vector, a right principal component vector, and a dominant singular value, wherein at least one of the left principal component vector, the right principal component vector, and the dominant singular value is selected from the adaptive codebook.

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

Before proceeding with the following detailed description, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The term "couple" and its derivatives refer to any direct or indirect communication between two or more elements, whether or not those elements are in physical contact with one another. The terms "transmit," "receive," and "communicate," and derivatives thereof, encompass both direct and indirect communication. The terms "include" and "comprise," as well as derivatives thereof, are intended to be inclusive and not limiting. The term "or" is inclusive, meaning and/or. The phrase "associated with … …" and its derivatives are intended to include, be included within … …, interconnect with … …, contain, be included within … …, connect to … … or connect to … …, couple to … … or couple to … …, be communicable with … …, cooperate with … …, interleave, juxtapose, be proximate to … …, bind to … … or bind to … …, have attributes of … …, have relationships with … …, and the like. The term "controller" means any device, system, or portion thereof that controls at least one operation. Such a controller may be implemented in hardware or a combination of hardware and software and/or firmware. The functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. The phrase "at least one of … …," when used with a list of items, means that different combinations of one or more of the listed items can be used, and that only one item in the list may be required. For example, "at least one of A, B and C" includes any combination of the following: A. b, C, A and B, A and C, B and C, and a and B and C.

Furthermore, the various functions described below may be implemented or supported by one or more computer programs, each of which is formed from computer readable program code and embodied in a computer readable medium. The terms "application" and "program" refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or portions thereof adapted for implementation in a suitable computer readable program code. The phrase "computer readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer readable medium" includes any type of medium capable of being accessed by a computer, such as Read Only Memory (ROM), random access memory (random access memory, RAM), a hard disk drive, a Compact Disc (CD), a digital video disc (digital video disc, DVD), or any other type of memory. "non-transitory" computer-readable media do not include wired, wireless, optical, or other communication links that transmit transitory electrical or other signals. Non-transitory computer readable media include media that can permanently store data and media that can store data and be later rewritten (such as rewritable optical disks or erasable memory devices).

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

Advantageous effects of the invention

According to embodiments of the present disclosure, the UE may perform CSI reporting based on the high resolution codebook.

According to embodiments of the present disclosure, the efficiency of CSI reporting may be improved by reducing the overhead of CSI reporting in distributed MIMO.

Drawings

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

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

FIG. 2 illustrates an example gNB in accordance with an embodiment of the present disclosure

Fig. 3 illustrates an example UE in accordance with an embodiment of the present disclosure;

fig. 4A illustrates a high-level diagram of an orthogonal frequency division multiple access transmit path according to an embodiment of the present disclosure;

fig. 4B illustrates a high-level diagram of an orthogonal frequency division multiple access receive path according to an embodiment of the present disclosure;

fig. 5 shows a transmitter block diagram for PDSCH in a subframe according to an embodiment of the disclosure;

Fig. 6 shows a receiver block diagram for PDSCH in a subframe according to an embodiment of the disclosure;

fig. 7 shows a transmitter block diagram for PUSCH in a subframe according to an embodiment of the disclosure;

fig. 8 shows a receiver block diagram for PUSCH in a subframe according to an embodiment of the disclosure;

fig. 9 illustrates an example antenna block or array forming a beam according to an embodiment of this disclosure;

FIG. 10 illustrates an example D-MIMO system according to embodiments of the present disclosure;

FIG. 11 illustrates an example D-MIMO system according to embodiments of the present disclosure;

fig. 12 illustrates an example of PCA-based explicit CSI compression in accordance with embodiments of the present disclosure;

fig. 13 shows a flowchart of a method for operating a UE in accordance with an embodiment of the present disclosure; and

fig. 14 shows a flowchart of a method for operating a BS according to an embodiment of the present disclosure.

Detailed Description

Figures 1 through 14, discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will appreciate that the principles of the present disclosure may be implemented in any suitably arranged system or device.

The following documents and standard descriptions are incorporated by reference into this disclosure as if fully set forth herein: 3GPP TS 36.211v17.0.0, "E-UTRA, physical channel and modulation" (referred to herein as "REF 1"); 3GPP TS 36.212v17.0.0, "E-UTRA, multiplexing and channel coding" (referred to herein as "REF 2"); 3GPP TS 36.213v17.0.0, "E-UTRA, physical layer procedure" (referred to herein as "REF 3"); 3GPP TS 36.321v16.6.0, "E-UTRA, media Access Control (MAC) protocol Specification" (referred to herein as "REF 4"); 3GPP TS 36.331v16.7.0, "E-UTRA, radio Resource Control (RRC) protocol Specification" (referred to herein as "REF 5"); 3GPP TS 38.211v17.0.0, "NR, physical channel and modulation" (referred to herein as "REF 6"); 3GPP TS 38.212v17.0.0, "E-UTRA, NR, multiplexing, and channel coding" (referred to herein as "REF 7"); 3GPP TS 38.213v17.0.0, "NR, physical layer process for control" (referred to herein as "REF 8"); 3GPP TS 38.214v 17.0.0; "NR, physical layer procedure for data" (referred to herein as "REF 9"); 3GPP TS 38.215v17.0.0, "NR, physical layer measurement" (referred to herein as "REF 10"); 3GPP TS 38.321v16.7.0, "NR, media Access Control (MAC) protocol specification" (referred to herein as "REF 11"); and 3GPP TS 38.331v16.7.0, "NR, radio Resource Control (RRC) protocol specification" (referred to herein as "REF 12").

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

Hereinafter, for brevity, both FDD and TDD are considered as duplex methods for both DL signaling and UL signaling.

Although the following exemplary description and embodiments assume orthogonal frequency division multiplexing (orthogonal frequency division multiplexing, OFDM) or orthogonal frequency division multiple access (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).

In order to meet the increasing demand for wireless data traffic since the deployment of 4G communication systems, and in order to implement various vertical applications, 5G/NR communication systems have been developed and are currently being deployed. A 5G/NR communication system is considered to be implemented in a higher frequency (millimeter wave) band (e.g., 28GHz or 60GHz band) in order to achieve a higher data rate, or in a lower frequency band (e.g., 6 GHz) in order to achieve robust coverage and mobility support. Beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, massive antenna techniques are discussed in 5G/NR communication systems in order to reduce propagation loss of radio waves and increase transmission distances.

Further, in the 5G/NR communication system, development for system network improvement is being conducted based on advanced small cells, cloud radio access networks (radio access networks, RAN), ultra dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, coordinated multipoint (coordinated multi-points, coMP), reception-side interference cancellation, and the like.

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

Fig. 1-4B below describe various embodiments implemented in a wireless communication system utilizing Orthogonal Frequency Division Multiplexing (OFDM) or Orthogonal Frequency Division Multiple Access (OFDMA) communication techniques. The descriptions of fig. 1-3 are not meant to imply physical or architectural limitations with respect to the manner in which different embodiments may be implemented. The various embodiments of the present disclosure may be implemented in any suitably arranged communication system. The present disclosure covers several components that may be used in combination or combination with one another or that may operate as a stand-alone solution.

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

As shown in fig. 1, the wireless network includes a gNB 101, a gNB 102, and a gNB 103. The gNB 101 communicates with the gNB 102 and the gNB 103. The gNB 101 is also in communication with at least one network 130, such as the Internet, a proprietary Internet protocol (Internet Protocol, IP) network, or other data network.

The gNB 102 provides wireless broadband access to the network 130 for a first plurality of User Equipment (UE) within the coverage area 120 of the gNB 102. The first plurality of UEs includes: UE 111, which may be located in a small business; UE 112, which may be located in enterprise (E); UE 113, which may be located in a WiFi Hotspot (HS); UE 114, which may be located in a first home (R); a UE 115, which may be located in a second home (R); and UE 116, which may be a mobile device (M), such as a cellular telephone, wireless laptop, wireless PDA, or the like. The gNB 103 provides wireless broadband access to the network 130 for a second plurality of UEs within the coverage area 125 of the gNB 103. The second plurality of UEs includes UE 115 and UE 116. In some embodiments, one or more of the gNBs 101-103 may communicate with each other and with the UEs 111-116 using 5G, LTE, LTE-A, wiMAX, wiFi or other wireless communication techniques.

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 Transmit Point (TP), a transmit-receive 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 device. The base station may provide wireless access according to one or more wireless communication protocols, e.g., 5g 3gpp new radio interface/access (NR), long term evolution (long term evolution, LTE), LTE-advanced (LTE-a), high speed packet access (high speed packet access, HSPA), wi-Fi 802.11a/b/g/n/ac, etc. For convenience, the terms "BS" and "TRP" are used interchangeably in this patent document to refer to the network infrastructure components that provide wireless access to remote terminals. Furthermore, the term "user equipment" or "UE" may refer to any component, such as a "mobile station", "subscriber station", "remote terminal", "wireless terminal", "reception point" or "user equipment", depending on the type of network. For convenience, the terms "user equipment" and "UE" are used in this patent document to refer to a remote wireless device that wirelessly accesses the BS, whether the UE is a mobile device (such as a mobile phone or smart phone) or is generally considered a stationary device (such as a desktop computer or vending machine).

The dashed lines illustrate the general extent of coverage areas 120 and 125, which are shown as being generally circular for purposes of illustration and explanation only. It should be clearly understood that the coverage areas associated with the gnbs, such as coverage areas 120 and 125, may have other shapes, including irregular shapes, depending on the configuration of the gnbs and the variations in the radio environment associated with the natural and man-made obstructions.

As described in more detail below, one or more of UEs 111-116 include circuitry, programming, or a combination thereof for: receiving configuration information about channel state information (channel state information, CSI) reports, the configuration information comprising a parameter d+_1, where d is the number of primary components; determining a left principal component vector; determining a right principal component vector; determining a main singular value; and transmitting a CSI report comprising a precoding matrix indicator (precoding matrix indicator, PMI) indicating a left principal component vector, a right principal component vector and a principal singular value, wherein at least one of the left principal component vector, the right principal component vector and the principal singular value is selected from the adaptive codebook. One or more of the gnbs 101-103 include circuitry, programming, or a combination thereof for: generating configuration information about a Channel State Information (CSI) report, the configuration information including a parameter d Σ1, where d is the number of principal components; transmitting configuration information; and receiving a CSI report including a Precoding Matrix Indicator (PMI) indicating a left principal component vector, a right principal component vector, and a dominant singular value, wherein at least one of the left principal component vector, the right principal component vector, and the dominant singular value is based on an adaptive codebook.

Although fig. 1 shows one example of a wireless network, various changes may be made to fig. 1. For example, the wireless network may include any number of gnbs and any number of UEs in any suitable arrangement. Further, the gNB 101 may communicate directly with any number of UEs and provide these UEs with wireless broadband access to the network 130. Similarly, each gNB 102-103 may communicate directly with the network 130 and provide the UE with direct wireless broadband access to the network 130. Furthermore, the gnbs 101, 102, and/or 103 may provide access to other or additional external networks (such as external telephone networks or other types of data networks).

Fig. 2 illustrates an example gNB 102, according to an embodiment of the disclosure. The embodiment of the gNB 102 shown in fig. 2 is for illustration only, and the gnbs 101 and 103 of fig. 1 may have the same or similar configuration. However, there are a variety of configurations of the gnbs, and fig. 2 is not intended to limit the scope of the present disclosure to any particular implementation of a gNB.

As shown in fig. 2, the gNB 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. The gNB 102 also includes a controller/processor 225, memory 230, and a backhaul or network interface 235.

RF transceivers 210a-210n receive incoming RF signals, such as signals transmitted by UEs in network 100, from antennas 205a-205 n. The RF transceivers 210a-210n down-convert incoming RF signals to generate IF or baseband signals. The IF or baseband signal is sent to RX processing circuit 220, and RX processing circuit 220 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 signals to a controller/processor 225 for further processing.

TX processing circuitry 215 receives analog or digital data (such as voice data, web data, email, or interactive video game data) from controller/processor 225. TX processing circuitry 215 encodes, multiplexes, and/or digitizes the outgoing baseband data to generate a processed baseband or IF signal. RF transceivers 210a-210n receive outgoing processed baseband or IF signals from TX processing circuitry 215 and upconvert the baseband or IF signals to RF signals transmitted via antennas 205a-205 n.

The controller/processor 225 may include one or more processors or other processing devices that control the overall operation of the gNB 102. For example, controller/processor 225 may control the reception of DL channel signals and the transmission of UL channel signals via RF transceivers 210a-210n, RX processing circuitry 220, and TX processing circuitry 215, in accordance with well-known principles. The controller/processor 225 may also support additional functions, such as higher-level wireless communication functions.

For example, the controller/processor 225 may support a beamforming operation or a directional routing operation in which outgoing signals from the plurality of antennas 205a-205n are weighted differently to effectively steer the outgoing signals in a desired direction. The controller/processor 225 may support any of a wide variety of other functions in the gNB 102.

The controller/processor 225 is also capable of executing programs and other processes residing in memory 230, such as an OS. The controller/processor 225 may move data into and out of the memory 230 as needed to execute a process.

The controller/processor 225 is also coupled to a backhaul or network interface 235. Backhaul or network interface 235 allows the gNB 102 to communicate with other devices or systems through a backhaul connection or through a network. The interface 235 may support communication over any suitable wired or wireless connection(s). For example, when the gNB 102 is implemented as part of a cellular communication system (such as a cellular communication system supporting 5G, LTE or LTE-a), the interface 235 may allow the gNB 102 to communicate with other gnbs over a wired or wireless backhaul connection. When the gNB 102 is implemented as an access point, the interface 235 may allow the gNB 102 to communicate over a wired or wireless local area network or over a wired or wireless connection to a larger network, such as the internet. Interface 235 includes any suitable structure that supports communication over a wired or wireless connection, such as an ethernet or RF transceiver.

Memory 230 is coupled to controller/processor 225. A portion of memory 230 may include RAM and another portion of memory 230 may include flash memory or other ROM.

Although fig. 2 shows one example of the gNB 102, various changes may be made to fig. 2. For example, the gNB 102 may include any number of each of the components shown in FIG. 2. As a particular example, an access point may include multiple interfaces 235 and the controller/processor 225 may support routing functions to route data between different network addresses. As another particular example, while shown as including a single instance of TX processing circuitry 215 and a single instance of RX processing circuitry 220, the gNB 102 may include multiple instances of each (such as one instance per RF transceiver). Furthermore, the various components in fig. 2 may be combined, further subdivided, or omitted, and additional components may be added according to particular needs.

Fig. 3 illustrates an example UE 116 according to an embodiment of this disclosure. The embodiment of UE 116 shown in fig. 3 is for illustration only and UEs 111-115 of fig. 1 may have the same or similar configuration. However, there are a variety of configurations for the UE, and fig. 3 does not limit the scope of the present disclosure to any particular implementation of the UE.

As shown in fig. 3, UE 116 includes an antenna 305, a Radio Frequency (RF) transceiver 310, TX processing circuitry 315, a microphone 320, and Receive (RX) processing circuitry 325.UE 116 also includes speaker 330, processor 340, input/output (I/O) interface 345, touch screen 350, display 355, and memory 360. The memory 360 includes an Operating System (OS) 361 and one or more applications 362.

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

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

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

Processor 340 is also capable of executing other processes and programs resident in memory 360, such as processes for: receiving configuration information about Channel State Information (CSI) reports, the configuration information comprising a parameter d Σ1, where d is the number of principal components; determining a left principal component vector; determining a right principal component vector; determining a main singular value; and transmitting a CSI report including a Precoding Matrix Indicator (PMI) indicating a left principal component vector, a right principal component vector, and a dominant singular value, wherein at least one of the left principal component vector, the right principal component vector, and the dominant singular value is selected from the adaptive codebook. Processor 340 is also coupled to I/O interface 345, I/O interface 345 providing UE 116 with the ability to connect to other devices, such as laptop computers and handheld computers. I/O interface 345 is the communication path between these accessories and processor 340.

Processor 340 is also coupled to touch screen 350 and display 355. An operator of UE 116 may input data to UE 116 using touch screen 350. Display 355 may be a liquid crystal display, a light emitting diode display, or other display capable of presenting text and/or at least limited graphics, such as limited graphics from a website.

A memory 360 is coupled to the processor 340. A portion of memory 360 may include Random Access Memory (RAM) and another portion of memory 360 may include flash memory or other Read Only Memory (ROM).

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

Fig. 4A is a high-level diagram of a transmit path circuit. For example, the transmit path circuitry may be used for Orthogonal Frequency Division Multiple Access (OFDMA) communications. Fig. 4B is a high-level diagram of a receive path circuit. For example, the receive path circuitry may be used for Orthogonal Frequency Division Multiple Access (OFDMA) communications. In fig. 4A and 4B, for downlink communications, the transmit path circuitry may be implemented in the base station (gNB) 102 or relay station, while the receive path circuitry may be implemented in a user equipment (e.g., user equipment 116 of fig. 1). In other examples, for uplink communications, the receive path circuitry 450 may be implemented in a base station (e.g., the gNB 102 of fig. 1) or a relay station, while the transmit path circuitry may be implemented in a user equipment (e.g., the user equipment 116 of fig. 1).

The transmit path circuitry includes a channel coding and modulation block 405, a serial-to-P (S-to-P) block 410, an inverse fast fourier transform (Inverse Fast Fourier Transform, IFFT) block 415 of size N, a parallel-to-serial (P-to-S) block 420, an add cyclic prefix block 425, and an up-converter (UC) 430. The receive path circuitry 450 includes a down-converter (DC) 455, a remove cyclic prefix block 460, a serial-to-parallel (S-to-P) block 465, a fast fourier transform (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.

At least some of the components in fig. 4a400 and 4b 450 may be implemented in software, while other components may be implemented by configurable hardware or a mixture 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, wherein the value of size N may be modified depending on the implementation.

Furthermore, while the present disclosure is directed to embodiments implementing a fast fourier transform and an inverse fast fourier transform, this is merely illustrative and may not be construed as limiting the scope of the present disclosure. It will be appreciated that in alternative embodiments of the present disclosure, the inverse fast fourier transform function and the inverse fast fourier transform function may be readily replaced by a discrete fourier transform (discrete Fourier transform, DFT) function and an inverse discrete fourier transform (inverse discrete Fourier transform, IDFT) function, respectively. It is 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.).

In transmit path circuitry 400, a channel coding and modulation block 405 receives a set of information bits, applies a coding (e.g., LDPC coding) and modulates (e.g., quadrature phase shift keying (quadrature phase shift keying, QPSK) or quadrature amplitude modulation (quadrature amplitude modulation, QAM)) input bits to produce a sequence of frequency domain modulation symbols. Serial-to-parallel block 410 converts (i.e., demultiplexes) the serial modulation symbols into parallel data to produce N parallel symbol streams, where N is the IFFT/FFT size used in BS102 and UE 116. The IFFT block 415 of size N then performs an IFFT operation on the N parallel symbol streams to produce a time domain output signal. Parallel-to-serial conversion block 420 converts (i.e., multiplexes) the parallel time-domain output symbols from IFFT block 415 of size N to produce a serial time-domain signal. The cyclic prefix block 425 is added and then the cyclic prefix is inserted into the time domain signal. Finally, up-converter 430 modulates (i.e., up-converts) the output of the add cyclic prefix block 425 to an RF frequency for transmission via a wireless channel. The signal may also be filtered at baseband before being converted to RF frequency.

The transmitted RF signals arrive at the UE 116 after traversing the wireless channel and perform the inverse of the operation at the gNB 102. The down converter 455 down converts the received signal to baseband frequency and the remove cyclic prefix block 460 removes the cyclic prefix to produce a serial time domain baseband signal. Serial to parallel block 465 converts the time domain baseband signal into a parallel time domain signal. The FFT block 470 of size N then performs an FFT algorithm to produce N parallel frequency domain signals. Parallel to serial conversion block 475 converts the parallel frequency domain signals into a sequence of modulated data symbols. The channel decoding and demodulation block 480 demodulates and then decodes the modulation symbols to recover the original input data stream.

Each of the gnbs 101-103 may implement a transmit path similar to that transmitted in the downlink to the user devices 111-116, and may implement a receive path similar to that received in the uplink from the user devices 111-116. Similarly, each of user devices 111-116 may implement a transmit path corresponding to an architecture for transmitting in the uplink to gNBs 101-103, and may implement a receive path corresponding to an architecture for receiving in the downlink from gNBs 101-103.

Use cases of 5G communication systems have been identified and described. These use cases can be roughly classified into three different groups. In one example, an enhanced mobile broadband (eMBB) is determined to meet high bit/second requirements with less stringent latency and reliability requirements. In another example, ultra-reliable and low latency (URLL) is determined with less stringent bit/second requirements. In yet another example, large-scale machine type communication (mctc) is determined as a number of devices per square kilometer, which may be as many as 10 to 100 tens of thousands, but reliability/throughput/latency requirements may be less stringent. This scenario may also involve power requirements, as battery consumption may be minimized as much as possible.

The communication system includes a Downlink (DL) that conveys signals from a transmission point, such as a Base Station (BS) or a NodeB, to a User Equipment (UE), and an Uplink (UL) that conveys signals from the UE to a reception point, such as a NodeB. The UE, also commonly referred to as a terminal or mobile station, may be fixed or mobile and may be a cellular telephone, a personal computer device or an automated device. An eNodeB, which is typically a fixed station, may also be referred to as an access point or other equivalent terminology. For LTE systems, the NodeB is commonly referred to as an eNodeB.

In a communication system such as an LTE system, DL signals may include data signals conveying information content, control signals conveying DL control information (DL control information, DCI), and reference signals (reference signals, RS), also referred to as pilot signals. The eNodeB transmits data information over a physical DL shared channel (physical DL shared channel, PDSCH). The eNodeB transmits DCI over a physical DL control channel (physical DL control channel, PDCCH) or Enhanced PDCCH (EPDCCH).

The eNodeB transmits acknowledgement information in a physical hybrid ARQ indicator channel (physical hybrid ARQ indicator channel, PHICH) in response to a data Transport Block (TB) transmission from the UE. The eNodeB transmits one or more of several types of RSs, including UE-Common RSs (CRS), channel state information RSs (channel state information RS, CSI-RS), or demodulation RSs (DMRS). The CRS is transmitted over the DL system Bandwidth (BW) and may be used by UEs to obtain channel estimates to demodulate data or control information or perform measurements. To reduce CRS overhead, the eNodeB may transmit CSI-RS in the time and/or frequency domain with less density than CRS. The DMRS may be transmitted only in BW of the corresponding PDSCH or EPDCCH, and the UE may use the DMRS to demodulate data or control information in the PDSCH or EPDCCH, respectively. The transmission time interval of the DL channel is called a subframe and may have a duration of, for example, 1 millisecond.

The DL signal also includes the transmission of logical channels carrying system control information. The BCCH is mapped to a transport channel called a broadcast channel (broadcast channel, BCH) when DL signals convey a master information block (master information block, MIB) or to a DL shared channel (DL shared channel, DL-SCH) when DL signals convey a system information block (System Information Block, SIB). Most of the system information is included in different SIBs transmitted using the DL-SCH. The presence of system information on the DL-SCH in a subframe may be indicated by a transmission of a corresponding PDCCH conveying a codeword with a cyclic redundancy check (cyclic redundancy check, CRC) scrambled with a system information RNTI (SI-RNTI). Alternatively, the scheduling information for SIB transmission may be provided in an earlier SIB, and the scheduling information for the first SIB (SIB-1) may be provided by the MIB.

DL resource allocation is performed in units of subframes and a set of physical resource blocks (physical resource block, PRBs). The transmission BW includes frequency resource units called Resource Blocks (RBs). Each RB includes N _EPDCCH A subcarrier or Resource Element (RE), such as 12 REs. A unit of one RB on one subframe is called a PRB. UEs may be allocated a total of BW for PDSCH transmission N of RE _s ＝(n _s0 +y·N _EPDCCH ) mod D RBs. />

The UL signals may include data signals conveying data information, control signals conveying UL control information (UL control information, UCI), and UL RSs. UL RS includes DMRS and Sounding RS (SRS). The UE transmits the DMRS only in BW of the corresponding PUSCH or PUCCH. The eNodeB may use the DMRS to demodulate the data signal or UCI signal. The UE transmits SRS to provide UL CSI to the eNodeB. The UE transmits data information or UCI through a corresponding physical UL shared channel (physical UL shared channel, PUSCH) or physical UL control channel (Physical UL control channel, PUCCH). If the UE needs to transmit data information and UCI in the same UL subframe, the UE may multiplex both in PUSCH. UCI includes hybrid automatic repeat request acknowledgement (Hybrid Automatic Repeat request acknowledgement, HARQ-ACK) information indicating correct (ACK) or incorrect (NACK) detection of data TBs in PDSCH or absence of PDCCH Detection (DTX), scheduling request (scheduling request, SR) indicating whether the UE has data in a buffer of the UE, rank Indicator (RI) and channel state information (channel state information, CSI) enabling the eNodeB to perform link adaptation for PDSCH transmission to the UE. HARQ-ACK information is also sent by the UE in response to detecting PDCCH/EPDCCH indicating release of the semi-persistent scheduled PDSCH.

The UL subframe includes two slots. Each time slot includes a data message, UCI, DMRS, or SRS for transmittingAnd a symbol. The frequency resource element of the UL system BW is an RB. The UE is allocated a total +.>N of RE _RB And RB. For PUCCH, N _RB =1. The last subframe symbol may be used to multiplex SRS transmissions from one or more UEs. The number of subframe symbols available for data/UCI/DMRS transmission is +.>Wherein if the last subframe symbol is used for transmitting SRS, N _SRS =1, otherwise, N _SRS ＝0。

Fig. 5 shows a transmitter block diagram 500 for PDSCH in a subframe according to an embodiment of the disclosure. The embodiment of the transmitter block diagram 500 shown in fig. 5 is for illustration only. One or more of the components shown in fig. 5 may be implemented in dedicated circuitry configured to perform the functions, or one or more of the components may be implemented by one or more processors that execute instructions to perform the functions. Fig. 5 does not limit the scope of the present disclosure to any particular implementation of transmitter block diagram 500.

As shown in fig. 5, information bits 510 are encoded by an encoder 520, such as a turbo encoder, and modulated by a modulator 530, for example using Quadrature Phase Shift Keying (QPSK) modulation. A serial-to-parallel (S/P) converter 540 generates M modulation symbols which are then provided to a mapper 550 to be mapped to REs selected by a transmission BW selection unit 555, a unit 560 applies an Inverse Fast Fourier Transform (IFFT) for the assigned PDSCH transmission BW, and a parallel-to-serial (P/S) converter 570 serializes the output to generate a time domain signal, a filter 580 applies filtering, and a transmission 590 signal. Additional functions such as data scrambling, cyclic prefix insertion, time windowing, interleaving, etc. are well known in the art and are not shown for the sake of brevity.

Fig. 6 shows a receiver block diagram 600 for PDSCH in a subframe according to an embodiment of the disclosure. The embodiment of diagram 600 shown in fig. 6 is for illustration only. One or more of the components shown in fig. 6 may be implemented in dedicated circuitry configured to perform the functions, or one or more of the components may be implemented by one or more processors that execute instructions to perform the functions. Fig. 6 is not intended to limit the scope of the present disclosure to any particular embodiment of diagram 600.

As shown in fig. 6, the received signal 610 is filtered by a filter 620, the RE 630 is selected for the assigned received BW by a BW selector 635, a Fast Fourier Transform (FFT) is applied by unit 640, and the output is serialized by a parallel to serial converter 650. Subsequently, demodulator 660 coherently demodulates the data symbols by applying channel estimates obtained from the DMRS or CRS (not shown), and decoder 670 (such as a turbo decoder) decodes the demodulated data to provide estimates of information data bits 680. For simplicity, additional functions such as time window, cyclic prefix removal, descrambling, channel estimation and deinterleaving are not shown.

Fig. 7 shows a transmitter block diagram 700 for PUSCH in a subframe, according to an embodiment of the disclosure. The embodiment of block diagram 700 shown in fig. 7 is for illustration only. One or more of the components shown in fig. 7 may be implemented in dedicated circuitry configured to perform the functions, or one or more of the components may be implemented by one or more processors that execute instructions to perform the functions. Fig. 7 is not intended to limit the scope of the present disclosure to any particular embodiment of block diagram 700.

As shown in fig. 7, information data bits 710 are encoded by an encoder 720 (such as a turbo encoder) and modulated by a modulator 730. A Discrete Fourier Transform (DFT) unit 740 applies DFT to the modulated data bits, a transmission BW selection unit 755 selects REs 750 corresponding to the assigned PUSCH transmission BW, a unit 760 applies IFFT, and after cyclic prefix insertion (not shown), a filter 770 applies filtering and transmits 780 a signal.

Fig. 8 shows a receiver block diagram 800 for PUSCH in a subframe according to an embodiment of the disclosure. The embodiment of block diagram 800 shown in fig. 8 is for illustration only. One or more of the components shown in fig. 8 may be implemented in dedicated circuitry configured to perform the functions, or one or more of the components may be implemented by one or more processors that execute instructions to perform the functions. Fig. 8 is not intended to limit the scope of the present disclosure to any particular embodiment of block diagram 800.

As shown in fig. 8, a filter 820 filters the received signal 810. Subsequently, after cyclic prefix removal (not shown), element 830 applies an FFT, a receive BW selector 845 selects REs 840 corresponding to the assigned PUSCH receive BW, element 850 applies an Inverse DFT (IDFT), demodulator 860 coherently demodulates the data symbols by applying channel estimates obtained from the DMRS (not shown), and decoder 870 (such as a turbo decoder) decodes the demodulated data to provide estimates of information data bits 880.

Fig. 9 illustrates an example antenna block or array 900 according to an embodiment of this disclosure. The embodiment of the antenna block or array 900 shown in fig. 9 is for illustration only. Fig. 9 is not intended to limit the scope of the present disclosure to any particular implementation of antenna block or array 900.

The rel.14lte and rel.15nr specifications support up to 32 CSI-RS antenna ports, which enables enbs to be equipped with a large number of antenna elements (such as 64 or 128). In this case, multiple antenna elements are mapped onto one CSI-RS port. For the millimeter wave band, while the number of antenna elements may be greater for a given form factor, the number of CSI-RS ports (which may correspond to the number of digital pre-coding ports) tends to be limited due to hardware constraints, such as the feasibility of installing a large number of ADCs/DACs at millimeter wave frequencies, as shown in fig. 9. In this case, one CSI-RS port is mapped onto a large number of antenna elements that can be controlled by a set of analog phase shifters 901. Then, one CSI-RS port may correspond to generation by analog beamforming 905A sub-array of narrow analog beams. The analog beam may be configured to sweep a wider angular range (920) by changing the phase shifter sets between symbols or subframes. The number of subarrays (equal to the number of RF chains) and the number of CSI-RS ports N _CSI-PORT The same applies. Digital beamforming unit 910 is at N _CSI-PORT Linear combining is performed between the analog beams to further increase the precoding gain. Although the analog beams are wideband (and thus not frequency selective), the digital precoding may vary between frequency sub-bands or resource blocks. Receiver operation is similarly contemplated.

Since the above-described system utilizes multiple analog beams for transmission and reception (where, for example, one or a small number of analog beams are selected from a large number of analog beams after a training duration (performed from time to time)), the term "multi-beam operation" is used to refer to the overall system aspect. For purposes of illustration, this includes indicating an assigned DL or UL Transmit (TX) beam (also referred to as a "beam indication"), measuring at least one reference signal for calculating and performing beam reporting (also referred to as "beam measurement" and "beam reporting", respectively), and receiving DL or UL transmissions via selection of a corresponding Receive (RX) beam.

The above system is also applicable to higher frequency bands, such as the >52.6GHz band (also known as FR 4). In this case, the system can only employ analog beams. Due to the O2 absorption loss around 60GHz frequency (about 10dB of additional loss at 100m distance), more and sharper analog beams (and thus a greater number of radiators in the array) will be required to compensate for the additional path loss.

On the other hand, in lower frequency bands, such as FR1 or in particular below 1GHz, the number of antenna elements cannot be increased in a given form factor due to the larger wavelength. As an example, for the case of a wavelength size (λ) of the center frequency 600MHz, which is 50cm, 4m is required for a Uniform Linear Array (ULA) antenna panel of 16 antenna elements in the case of a distance of half wavelength between two adjacent antenna elements. Considering that a plurality of antenna elements are mapped to one digital port in practical cases, the size required for an antenna panel supporting a large number of antenna ports (e.g., 32 CSI-RS ports) at the gNB becomes very large in such a low frequency band, and this results in difficulty in deploying a 2-D antenna array in the size of a conventional form factor. This may result in a limited number of physical antenna elements and CSI-RS ports that may then be supported at a single site and limit the spectral efficiency of such systems.

Fig. 10 illustrates an example system of distributed MIMO (D-MIMO) 1000 according to an embodiment of this disclosure. The embodiment of the example system for D-MIMO 1000 shown in fig. 10 is for illustration only. Fig. 10 is not intended to limit the scope of the present disclosure to any particular implementation of the example system of D-MIMO 1000.

As shown in fig. 10, one approach to solving the above-described problem is to form a plurality of antenna panels (e.g., antenna modules, RRHs) with a small number of antenna ports, instead of integrating all antenna ports in a single panel (or single site), and distributing the plurality of panels in a plurality of locations/sites (or RRHs), as shown in fig. 18.

Fig. 11 illustrates an example system of D-MIMO 1100 according to an embodiment of this disclosure. The embodiment of the example system for D-MIMO 1100 shown in fig. 11 is for illustration only. Fig. 11 is not intended to limit the scope of the present disclosure to any particular implementation of the example system of D-MIMO 1100.

As shown in fig. 11, a plurality of antenna panels at a plurality of locations may still be connected to a single base unit, and thus signals transmitted/received via a plurality of distributed panels may be processed in a centralized manner by a single base unit. In another embodiment, it is possible that multiple distributed antenna panels are connected to communicate with each other and jointly support more than one base unit of a single antenna system.

One problem that may occur in distributed MIMO is that the CSI reporting overhead becomes huge. One approach to solving the large CSI overhead problem is to introduce an effective CSI codebook suitable for distributed MIMO, e.g., using panel/RRH domain compression. By exploiting the channel correlation between the panels/RRHs in the CSI codebook design, the amount of CSI feedback can be significantly reduced. However, in general, the existence of channel correlation between the panels/RRHs is not guaranteed, and thus it may be necessary to include all CSI for all RRHs/panels without compressed CSI reporting. In this case, if a type II based multi-panel/multi-RRH codebook is designed and Spatial Domain (SD) and Frequency Domain (FD) bases are independently selected for each RRH/panel, the number of channel series corresponding to the SD/FD vector pairs to be reported to NW will increase linearly with the number of RRHs/panels, and thus become very large. Therefore, it is expected that a plurality of CSI reporting times (blocks) becomes unavoidable.

The present disclosure proposes various CSI reporting methods to support such a problem in distributed MIMO.

All the following components and embodiments are applicable to UL transmissions with CP-OFDM (cyclic prefix OFDM ) waveforms, DFT-SOFDM (DFT-spread OFDM) and SC-FDMA (single-carrier FDMA) waveforms. Furthermore, when the scheduling unit in time is one subframe (which may consist of one or more slots) or one slot, all the following components and embodiments are applicable to UL transmissions.

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

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

The "CSI or calibration coefficient reporting band" is defined as a contiguous or non-contiguous set/collection of subbands in which CSI or calibration coefficient reporting is performed. For example, the CSI or calibration coefficient reporting band may include all sub-bands within the DL system bandwidth. This may also be referred to as "full band". Alternatively, the CSI or calibration coefficient reporting band may include only a set of subbands within the DL system bandwidth. This may also be referred to as "partial band".

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

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

Thus, the CSI parameter frequency granularity of each CSI reporting band may be defined as follows. When one CSI parameter is used for all M in the CSI reporting band _n Sub-band, utilized for having M _n The CSI parameters are configured for "single" reporting of CSI reporting bands of the subbands. When reporting M in band for CSI _n When reporting one CSI parameter per one of the subbands, the method is used for having M _n The CSI parameters are configured for "subbands" of the CSI reporting band of the subbands.

Fig. 12 shows an example of a graphical representation of PCA-based explicit CSI compression 1200 in accordance with embodiments of the present disclosure. The illustrated example embodiment of PCA-based explicit CSI compression 1200 shown in fig. 12 is for illustration only. Fig. 12 is not intended to limit the scope of the present disclosure to any particular implementation of the illustrated example of PCA-based explicit CSI compression 1200.

In one embodiment I, the UE is configured to report "explicit CSI" of the channel, dominant eigenvector or covariance matrix for each subband (subband, SB) based on compression techniques such as principal component analysis (principal component analysis, PCA) to exploit correlation in the spatial (across antennas) and frequency (across SB) domains jointly.

Fig. 12 shows a diagram of explicit CSI compression based on PCA. Let N be the number of explicit CSI components that need to be reported in each SB. Although N is used as the number of antenna (or CSI-RS) ports in fig. 12, the number N may be used in various ways, for example:

Channel: n=2n ₁ N ₂ ×N _r ×k

Feature vector (Eigenvector): n=2n ₁ N ₂ ×r

Covariance matrix: n=2n ₁ N ₂ ×2N ₁ N ₂ ，

Wherein 2N ₁ N ₂ Is the number of antenna ports at NW (i.e., N ₁ 、N ₂ The number of antenna ports in the first and second dimensions, respectively), N _r Is the number of antennas at the UE, r is the number of primary eigenvectors, and k is the number of subcarriers in the SB for which DL channels are explicitly reported.

In another example, the channel of each layer p (p-th principal eigenvector) may be compressed based on PCA.

Let K be the number of SBs for explicit CSI reporting. For each SB, the UE uses DL measurement RS (e.g., CSI-RS) to estimate/measure/derive unquantized or simulated explicit CSI, and then constructs an NxK explicit CSI matrix as follows

Wherein c _l，s Corresponds to the first explicit CSI component for SB. Execution H _N，K To represent singular value decomposition of (2)

Wherein the method comprises the steps of

·U＝[u ₀ u ₁ … u _D-1 ]Is a left eigenvector matrix (eigenvectors including length N);

·V＝[v ₀ v ₁ … v _D-1 ]is a right eigenvector matrix (eigenvectors including length K);

·∑＝diag([σ ₀ σ ₁ … σ _D-1 ]) Is according to sigma ₀ ≥σ ₁ ≥…≥σ _D-1 Diagonal matrix of ordered singular values, and

·D＝min(K，N)。

then, and "main" singular value σ ₀ ，...σ _d-1 The corresponding D principal components (where 1.ltoreq.d.ltoreq.D) and the corresponding left and right eigenvector matrices are constructed as

U _d ＝[u ₀ u ₁ … u _d-1 ]

V _d ＝[v ₀ v ₁ … v _d-1 ]

∑ _d ＝diag([σ ₀ σ ₁ … σ _d-1 ]。

The reduced-dimension or compressed explicit CSI matrix is then given by

To report compressed H _N，K The UE uses one of the following alternatives:

alternative 0: the UE will explicit CSI matrix H _N，K Conversion to R _d ＝H _N，K V _d Quantizing R using codebook _d And V _d The quantized matrix is then reported to the NW, which reconstructs the explicit CSI matrix as

Alternative 1: UE quantization U using codebook _d 、V _d Sum sigma _d They are then reported to the NW, which reconstructs the explicit CSI matrix as

In the remainder of this disclosure, it is assumed that alternative 1 is used for explicit CSI reporting. However, embodiments of the present disclosure are generic and apply to alternative 0.

The real and imaginary parts of the complex are considered as two real numbers, respectively, the total number of reported (real) explicit CSI components being 2d (k+n) +r, where r=0 for alternative 0 and r=d for alternative 1. Thus, the total compression achieved before quantization is

In one approach, the d value is configured to the UE, e.g., via higher layer RRC signaling (or L1/L2 signaling through PDCCH/MAC-CE). In another approach, the UE reports the preferred d value in CSI reports. In another approach, it is fixed, for example fixed at 1.

In one embodiment II, the UE is configured with a transmitter for U _d 、V _d And/or sigma _d For individual quantization of

U _d ＝[u ₀ u ₁ … u _d-1 ]Is a column of (2);

V _d ＝[v ₀ v ₁ … v _d-1 ]is a column of (2); and

∑ _d ＝diag([σ ₀ σ ₁ … σ _d-1 ]diagonal elements of (a) are included.

In one example, for U _d 、V _d Sum sigma _d May be identical for both or all of the codebooks.

In one example, for U _d 、V _d Sum sigma _d The amplitude (or power) codebooks of two or all of (a) may be the same (or have a possible scaling).

For U _d And V _d The amplitude codebooks of (a) may be identical or identical with a scaling factor.

For U _d Sum sigma _d The amplitude codebooks of (a) may be identical or identical with a scaling factor.

For V _d Sum sigma _d The amplitude codebooks of (a) may be identical or identical with a scaling factor.

For U _d 、V _d Sum sigma _d The amplitude codebooks of (a) may be identical or identical with a scaling factor.

In one example, for U _d And V _d May be identical.

In one embodiment II.1, U _d Each element u in the column _n，m The codebook may be selected from a codebook comprising phase and amplitude components, where N e {0,1,..N-1 } and m e {0,1,..d-1 }.

In one example ii.1.1, the codebook for phase values may be 4-PSK, 8-PSK, 16-PSK, an..the., or X-PSK, where the X-PSK requires log ₂ X bits, where X may be fixed or configured.

In one example ii.1.2, the codebook for amplitude values may be a set of Y equidistant points in [0,1 ]. For example, y=16 (4-bit amplitude codebook).

In one example ii.1.3, the codebook for amplitude values may be a set of Y non-equidistant points in [0,1 ]. For example, y=16 (4-bit amplitude codebook), wherein:

4-bit amplitude codebook

In one example II.1.4, U _d Each element u in column m of (2) _n，m (i.e. U) _d The nth row and the mth column) may be selected from different codebooks.

In one example II.1.4.1, column u _m The amplitude values of the elements in (a) may be selected from the following codebook:

·|u _0，m i is selected from the base codebook, which may be, for example, equidistant/non-equidistant log as shown in example ii.1.2/ii.1.3 ₂ A Y-bit amplitude codebook; and

amplitude of the j-th line entry (i.e., |u) _j，m I) is selected from scaled versions of the base codebook, e.g.,wherein (1)>Is the basic codebook, and ∈ -> />

In one example, a _j Can be determined asNote that each feature vector is a unit norm vector, so it should satisfy +.>Therefore, the amplitude of the j-th row should be less than or equal toBy narrowing the codebook by a for the j-th line amplitude _j The resolution of the codebook may be adaptively increased over a given number of codebook bases. This is an example of an adaptive codebook, where the codebook set for the j entry can be adaptively modified based on all or some of the previously selected j-1 values, and the base codebook is used for the first entry.

In one example, the reverse order of the above example may be used, i.e., selecting |u from the base codebook _N-1，m I, and forThere is->In the case of (1)>In selecting the j-th line entry |u _j，m Amplitude of i. In another example, another predetermined order of row entries for using the base codebook and scaled versions of the base codebook may be used. In another example, the predetermined order may be configured or fixed.

Note that since the above example considers the case of a predetermined order, no report is required to indicate the order. In one example, the order is reported as part of CSI reporting.

In another example, for the j-th line entry, |u _j，m I is selected from a limited set of base codebooks, e.g., this can reduce the representation codebook +.>Because it is limited to the number of bits of the set { c } _i |c _i ≤a _j In }. This is an example of an adaptive codebook, where the codebook set for the j entry can be adaptively modified based on all or some of the previously selected j-1 values, and the base codebook is used for the first entry.

In one example II.1.4.2, each element u _n，m (U _d N-th row and m-th column) of (c) the amplitude value may depend on its value at U _d The mth column vector u of (2) _m Is selected from different codebooks.

For example, column u _m The elements in (a) can be controlled according to amplitude (vibrationWeb) order (i.eOrdering, wherein subscript i ^＊ Is with column u _m The row index corresponding to the ith maximum amplitude among the elements in (a), and the amplitude of each element may be selected from the following codebook:

the maximum amplitude (i.e.,) Is selected from a base codebook, which may be, for example, equidistant/non-equidistant log as shown in example II.1.2/II.1.3 ₂ A Y-bit amplitude codebook; and

the jth maximum amplitude (i.e.,) Is selected from scaled versions of the base codebook, for example,wherein (1)>Is the basic codebook, and ∈ ->

In one example, a _j Can be determined asNote that each feature vector is a unit norm vector, and thus +.>Therefore, the j-th maximum amplitude should be less than or equal to +.>And (j-1) th maximum amplitude +>As well as the same. By narrowing the codebook by a for the jth maximum amplitude _j The resolution of the codebook may be adaptively increased over a given number of codebook bases. This is an example of an adaptive codebook (based on unit norm properties), where the codebook set for j entries can be adaptively modified based on all or some of the previously selected j-1 values, and the base codebook is used for the first entry.

Note that an indication of the ordered index is required. In one example, utilization log is reported ₂ N-! Bits (N permutations) to indicate an indication of each ordered index.

In another example, the jth maximum amplitude (i.e.,) Is selected from a limited set of basic codebooks, e.g.)> This can reduce the representation codebook +.>Because it is limited to the number of bits of the set { c } _i |c _i ≤a _j In }. This is an example based on an adaptive codebook, where the codebook set for j entries can be adaptively modified based on all or some of the previously selected j-1 values, and the base codebook is used for the first entry.

In another example, a portion of the ordered indices apply only to example ii.1.4.2, while the other remaining indices apply to example ii.1.4.1. For example, report vs. v ε [1, N]Corresponding indexes of maximum amplitude (thus requiringBit to indicate), and for these indices,codebook->And atCodebook in case of (2)>For maximum amplitude and next v-1 maximum amplitudes, and the amplitude corresponding to the remaining row index j is fromIn the case of->Where a is the sum of squares of the amplitudes of j-1 remaining entries in a predetermined order.

In one example, v may be configured by the NW. In one example, v is fixed to a certain value, e.g., v=1. In another example, v may be determined by the UE using a predetermined rule. For example, once a _j Becoming less than 0.1, the remaining index does not count into the set of v maximum amplitudes.

In one embodiment II.2, U _d Each element u in the column of (2) _n,m The codebook may be selected from a codebook comprising a phase component and a power component (square of amplitude), where N e {0,1,..N-1 } and m e {0,1,..d-1 }.

In one example II.2.1, the codebook for the phase values may be 4-PSK, 8-PSK, 16-PSK, … …, or X-PSK, where X-PSK requires log ₂ X bits.

In one example ii.2.2, the codebook for power values may be a set of Y equidistant points in [0,1 ]. For example, y=16 (4-bit amplitude codebook).

In one example ii.2.3, the codebook for power values may be a set of Y non-equidistant points in [0,1 ]. For example, y=16 (4-bit amplitude codebook), where each element is a codebook of squares of each element in the 4-bit amplitude codebook shown in example ii.1.3.

In one example II.2.4, U _d Each element u in column m of (2) _n,m (i.e., U) _d The nth and mth columns) power values may be selected from different codebooks.

In one example II.2.4.1, column u _m The power values of the elements of (a) may be selected from a codebook in which each element is the square of each element of the codebook, respectively, as shown in example ii.1.4.1.

In one example II.2.4.2, column u _m The power values of the elements of (a) may be selected from a codebook in which each element is the square of each element of the codebook, respectively, as shown in example ii.1.4.2.

In one embodiment II.3, U _d May be selected from a codebook comprising unit norm vectors.

In one embodiment II.4, U _d The selection may be from a codebook comprising a set of matrices of size N x d, the columns of which are unit norms and are orthogonal.

In one embodiment II.5, V _d Each element v in the column of (2) _k,l The codebook may be selected from a codebook comprising phase and amplitude components, where K e {0, 1..k-1 } and l e {0, 1..d-1 }.

In one example II.5.1, the codebook for the phase values may be 4-PSK, 8-PSK, 16-PSK, … …, or X-PSK, where X-PSK requires log ₂ X bits.

In one example ii.5.2, the codebook for amplitude values may be a set of Y equidistant points in [0,1 ]. For example, y=16 (4-bit amplitude codebook).

In one example ii.5.3, the codebook for amplitude values may be a set of Y non-equidistant points in [0,1 ]. For example, y=16 (4-bit amplitude codebook), where the 4-bit amplitude codebook is as shown in example ii.1.3.

In one example II.5.4, V _d Each element v in column l of (2) _k,l (i.e., V _d The k-th row and the l-th column) may be selected from different codebooks.

In one example II.5.4.1, column v _l The amplitude values of the elements of (c) may be selected from a codebook generated by the same method according to example ii.1.4.1.

In one example II.5.4.2, column v _l The amplitude values of the elements of (c) may be selected from a codebook generated by the same method according to example ii.1.4.2.

In one embodiment II.6, V _d Each element v in the column of (2) _k,l The codebook may be selected from a codebook comprising a phase component and a power component (square of amplitude), where K e {0,1,..K-1 } and l e {0,1,..d-1 }.

In one example II.6.1, the codebook for the phase values may be 4-PSK, 8-PSK, 16-PSK, … …, or X-PSK, where X-PSK requires log ₂ X bits.

In one example ii.6.2, the codebook for power values may be a set of Y equidistant points in [0,1 ]. For example, n=16 (4-bit amplitude codebook).

In one example ii.6.3, the codebook for power values may be a set of Y non-equidistant points in [0,1 ]. For example, n=16 (4-bit amplitude codebook), where each element is a codebook of squares of each element in the 4-bit amplitude codebook shown in example ii.1.3.

In one example II.6.4, V _d Each element v in column l of (2) _k,l (i.e. V _d The k-th row and the l-th column) may be selected from different codebooks.

In one example II.6.4.1, column v _m The power values of the elements of (a) may be selected from a codebook in which each element is the square of each element of the codebook, respectively, as shown in example ii.5.4.1.

In one example II.6.4.2, column v _m The power values of the elements of (a) may be selected from a codebook in which each element is the square of each element of the codebook, respectively, as shown in example ii.5.4.2.

In one embodiment II.7, V _d May be selected from a codebook comprising unit norm vectors.

In one embodiment II.8, V _d The selection may be from a codebook comprising a set of matrices of size N x d, the columns of which are unit norms and are orthogonal.

In example II.9, sigma _d May be selected from a codebook according to one of the following examples.

In one example ii.9.1 Σ _d The codebook of diagonal entries of (a) may be 0, A]Is a set of Z equidistant points. For example, a=10, z=16 (4-bit codebook for singular values). The value a may be fixed, or configured, or reported by the UE (as part of CSI reporting).

In one example ii.9.2, Σ _d The codebook of diagonal entries of (a) may be 0, A]Is a set of Z non-equidistant points. For example, a=10, z=16 (4-bit codebook for singular values), where:

4-bit codebook for singular values

The value a may be fixed, configured, or reported by the UE (as part of CSI reporting).

In one example ii.9.3, Σ _d May be selected from different codebooks in the following manner:

0 th diagonal element (i.e., σ _o ) Is selected from the base codebook. For example, the base codebook may be example ii.9.1 or ii.9.2

J-th diagonal element (i.e., σ _j ) Is selected from scaled versions of the base codebook, for example,wherein (1)>Is the basic codebook, and ∈ ->

In one example, b _j Can be determined as a selected value sigma _j-1 And maximum value ofIs a ratio of (2). That is to say that the first and second,wherein->In one example, if the base codebook is example II.9.1 or II.9.2, then +. >Note that it guarantees a maximum +.>Not exceeding sigma _j-1 Thereby sigma _j Can maintain constraint sigma ₀ ≥σ ₁ …≥σ _d-1 From 0 to sigma _j-1 Is selected from the codebook of (a). By narrowing the codebook by b for the j-th diagonal element _j The resolution of the codebook may be adaptively increased over a given number of codebook bases. This is an example of an adaptive codebook, where the codebook set for the j entry can be adaptively modified based on all or some of the previously selected j-1 values, and the base codebook is used for the first entry.

In one embodiment III, the UE is configured to report explicit CSI for R RRHs (or panels), R.gtoreq.1, based on a compression technique such as PCA compression.

In one embodiment III.1, each channel of each of the plurality of RRH/panels may be represented as(for->) Wherein->Is RRH/Panel->Explicit CSI component for each SB. In one example, a->Wherein->And->RRH->Number of antenna ports in the first dimension and the second dimension. In another example, a->

The UE is configured to estimate/quantize/derive each based on PCA compression/codebook (i.e., via component I)And the compressed and quantized channel can be expressed as:

wherein the method comprises the steps of Is selected from, for example, a codebook that can be designed from component II.

The value d may be for all RRHsThe same applies. Alternatively, the value d may be specific to each RRH, e.g., d ₁ Can be used for RRHl, wherein d ₁ The values may differ between RRHs. In the remainder of this disclosure, the same d values are assumed for simplicity. These embodiments can be extended to different d _l Value case.

In one embodiment III.1.1, the UE is configured to report all RRH/panels at one time

In one example III.1.1.1, exceptIn addition, inter-RRH/inter-panel components may be included. In one example, the RRH/inter-panel component may contain phase and amplitude values, phase and power values, or only phase values. The phase value, amplitude value, and power value may be selected codebooks, such as those designed according to examples ii.1.1, ii.1.2, ii.1.3, ii.2.2, and ii.2.3.

In one example iii.1.1.2, no inter-RRH/inter-panel component is included in the CSI report. In this case the number of the elements to be formed is,is responsible for all CSI, including the portion corresponding to the RRH/inter-panel component. />

In one embodiment iii.1.2, the UE is configured to report all of all RRHs/panels using multiple CSI reporting instants

In one example iii.1.2.1, each CSI reporting time instant contains a partial PCA component of all CSI. For example, two CSI reporting instants may be configured to report all CSI, and the UE is configured to report d at the first CSI reporting instant ₁ PCA component and reporting d at a second CSI reporting time instant ₂ PCA component. That is, the UE:

● At the position ofFirst CSI reporting time (primary CSI reporting stage) reporting

● Reporting at a second CSI reporting instant (refined CSI reporting stage)

It can be extended to the case with more than two CSI reporting instants.

In one example iii.1.2.2, the method is similar to example iii.1.1.1 except thatIn addition, inter-RRH/inter-panel components may be included.

In one example iii.1.2.3, similar to example iii.1.1.2, no inter-RRH/inter-panel components are included in the CSI report.

In embodiment iii.1.3, the UE is configured to report each RRH/panel at each CSI reporting instantIs>In this case, R CSI reporting instants are configured for the UE to report all CSI.

In one example iii.1.3.1, for each RRH/paneld may be configured differently. In this case, the UE may:

reporting at CSI reporting time ttransport

In one example, CSI reporting time t may be a different RRH/panel index For example RRH/Panel->The order of CSI reporting time t may be determined by the channel quality between the channels of the RRH.

In one example iii.1.3.2, the method is similar to example iii.1.1.1 except thatIn addition, inter-RRH/inter-panel components may be included.

In one example iii.1.3.3, similar to example iii.1.1.2, no inter-RRH/inter-panel component is included in the CSI report.

In one embodiment iii.1.4, the UE is configured to report each RRH/panel using multiple CSI reporting instantsIs>In this case, the total number of CSI reporting times reporting all CSI of all RRH/panels may be expressed as +.>Wherein->Is RRH/Panel->CSI reporting time of (a) is determined. In one example, a-> Thus N _CSI ＝2R。

In one illustrationIn example III.1.4.1, each CSI reporting time instance comprises RRH/PanelIs included in the CSI. For example, two CSI reporting instants may be configured to report CSI for each RRH/panel, and the UE is configured to report d at the first CSI reporting instant ₁ PCA component and reporting d at a second CSI reporting time instant ₂ PCA component. That is, the UE: />

At RRH/PanelIs reported at the first CSI reporting time (primary CSI reporting stage)

At RRH/PanelIs reported at the second CSI reporting time (refined CSI reporting stage)

In one example, d for different RRHs/panels ₁ And d ₂ Different configurations may be performed.

In one example, it may be extended to the case with more than two CSI reporting instants for each RRH.

In one example iii.1.4.2, the method is similar to example iii.1.1.1 except thatIn addition, inter-RRH/inter-panel components may be included.

In one example iii.1.4.3, similar to example iii.1.1.2, no inter-RRH/inter-panel component is included in the CSI report.

In one embodiment iii.1.5, the UE is configured to report each group using multiple CSI reporting instantsWherein R RRH/panels are divided into groups +.>In this case, the total number of CSI reporting times reporting all CSI of all RRH/panels may be expressed as +.>Wherein N is _CSI，i Is RRH/Panel set->CSI reporting time of (a) is determined. In one example, N _CSI，i ＝2，/>Thus N _CSI ＝2G。

In one example iii.1.5.1, each CSI reporting time instant contains a groupPartial PCA component of the RRH/CSI of the panel. For example, two CSI reporting instants may be configured as reporting group +.>CSI of RRH/panel in (c), and the UE is configured to report d at a first CSI reporting time instant ₁ PCA component and reporting d at a second CSI reporting time instant ₂ PCA component. That is, the UE:

● In the group ofIs reported at the first CSI reporting time (primary CSI reporting stage)

● In the group ofIs reported at the second CSI reporting time (refined CSI reporting stage)

In one example, d for different RRH/panel groups ₁ And d ₂ Different configurations may be performed.

In one example, it may be extended to the case with more than two CSI reporting instants for each group of RRHs/panels.

In one example iii.1.5.2, the method is similar to example iii.1.1.1 except thatIn addition, inter-RRH/inter-panel components may be included.

In one example iii.1.5.3, similar to example iii.1.1.2, no inter-RRH/inter-panel component is included in the CSI report.

In one embodiment III.2, multiple (R) RRHs/panels are partitioned into groupsAnd each group->The channel of the RRH/panel in (c) can be expressed as +.>(for j=0, 1.,. P-1), wherein +.>Is a group ofExplicit CSI component for each SB at RRH/panel in (b). In one example of this, in one implementation,wherein the method comprises the steps of/>And->Are respectively group->RRH->The number of antenna ports in the first and second dimensions. In another example, a->

The UE is configured to estimate/quantize/derive based on PCA compression/codebook (i.e., via component I)And the compressed and quantized channel can be expressed as:

For j=0, 1..p-1

Wherein the method comprises the steps ofIs selected from, for example, a codebook that can be designed from component II.

In one example, p=1, which considers that all channels of all RRHs/panels will be jointly compressed.

In examples III.2.1, III.2.2, III.2.3, III.2.4 and III.2.5, the use ofReplace->By means ofDirect extensions of examples III.1.1, III.1.2, III.1.3, III.1.4 and III.1.5 are presented.

Any of the above-described variant embodiments may be utilized independently or in combination with at least one other variant embodiment.

Fig. 13 shows a flowchart of a method 1300 for operating a User Equipment (UE), in accordance with an embodiment of the present disclosure, the method 1300 may be performed by a UE, such as UE 116. The embodiment of the method 1300 shown in fig. 13 is for illustration only. Fig. 13 is not intended to limit the scope of the present disclosure to any particular embodiment.

As shown in fig. 13, method 1300 begins at step 1302. In step 1302, the UE (e.g., 111-116 as shown in FIG. 1) receives configuration information regarding the CSI report, the configuration information including a parameter d+.1, where d is the number of primary components.

In step 1304, the UE determines a left principal component vector.

In step 1306, the UE determines the right principal component vector.

In step 1308, the UE determines dominant singular values.

In step 1310, the UE transmits a CSI report including a PMI indicating a left principal component vector, a right principal component vector, and a dominant singular value, wherein at least one of the left principal component vector, the right principal component vector, and the dominant singular value is selected from the adaptive codebook.

In one embodiment, the UE selects a respective amplitude of an element of one of the left principal component vectors from the adaptive codebook based on the unit norm attribute.

In one embodiment, the UE selects an amplitude of a first element from a first base codebook; selecting an amplitude of a j-th element from a scaled version of the first base codebook; and a scaling factor is calculated based on the respective amplitudes of the previous j-1 elements.

In one embodiment, the UE selects an amplitude of a first element from a first base codebook; selecting an amplitude of a j-th element from a limited set of the first base codebook; and determining the elements in the limited set based on the respective amplitudes of the previous j-1 elements.

In one embodiment, the UE selects a respective amplitude of an element of one of the right principal component vectors from the adaptive codebook based on the unit norm attribute.

In one embodiment, the UE selects an amplitude of the first element from the second base codebook; selecting an amplitude of a j-th element from a scaled version of the second base codebook; and a scaling factor is calculated based on the respective amplitudes of the previous j-1 elements.

In one embodiment, the UE selects an amplitude of the first element from the second base codebook; selecting an amplitude of a j-th element from the limited set of second base codebooks; and determining the elements in the limited set based on the respective amplitudes of the previous j-1 elements.

In one embodiment, the UE selects a first dominant singular value from a third base codebook; selecting a j-th dominant singular value from a scaled version of the third base codebook; and calculates a scaling factor based on the j-1 dominant singular values.

Fig. 14 shows a flowchart of another method 1400 according to an embodiment of the disclosure, the method 1400 may be performed by a Base Station (BS), such as BS 102. The embodiment of method 1400 shown in fig. 14 is for illustration only. Fig. 14 is not intended to limit the scope of the present disclosure to any particular embodiment.

As shown in fig. 14, method 1400 begins at step 1402. In step 1402, the BS (e.g., 101-103 as shown in FIG. 1) generates configuration information regarding Channel State Information (CSI) reporting, the configuration information including a parameter d+.1, where d is the number of primary components.

In step 1404, the BS transmits configuration information.

In step 1406, the BS receives a CSI report including a Precoding Matrix Indicator (PMI) indicating a left principal component vector, a right principal component vector, and principal singular values, wherein at least one of the left principal component vector, the right principal component vector, and the principal singular values is based on an adaptive codebook.

In one embodiment, the respective amplitudes of the elements of one of the left principal component vectors are based on a first adaptive codebook according to a first unit norm attribute, and the respective amplitudes of the elements of one of the right principal component vectors are based on a second adaptive codebook according to a second unit norm attribute.

In one embodiment, the amplitude of the first element of one of the left principal component vectors is based on a first base codebook, the amplitude of the j-th element of one of the left principal component vectors is based on a scaled version of the first base codebook, the scaling factor of one of the left principal component vectors is based on the corresponding amplitude of the previous j-1 elements of the left principal component vector, the amplitude of the first element of one of the right principal component vectors is based on a second base codebook, the amplitude of the j-th element of one of the right principal component vectors is based on a scaled version of the second base codebook, and the scaling factor of one of the right principal component vectors is based on the corresponding amplitude of the previous j-1 elements of the right principal component vectors.

In one embodiment, the amplitude of the first element of one of the left principal component vectors is based on a first base codebook, the amplitude of the j-th element of one of the left principal component vectors is based on a limited set of the first base codebook, the elements of the limited set are based on the respective amplitudes of the previous j-1 elements of one of the left principal component vectors, the amplitude of the first element of one of the right principal component vectors is based on a second base codebook, the amplitude of the j-th element of one of the right principal component vectors is based on a limited set of the second base codebook, and the elements of the limited set are based on the respective amplitudes of the previous j-1 elements of one of the right principal component vectors.

The above-described flow diagrams illustrate example methods that may be implemented according to the principles of the present disclosure, and various changes may be made to the methods illustrated in the flow diagrams herein. For example, while shown as a series of steps, individual steps in each figure may overlap, occur in parallel, occur in a different order, or occur multiple times. In another example, these steps may be omitted or replaced with other steps.

Although the present disclosure has been described with exemplary embodiments, various changes and modifications may be suggested to one skilled in the art. The disclosure is intended to embrace such alterations and modifications that fall within the scope of the appended claims. Any description of the present application should not be construed as implying that any particular element, step, or function is a essential element which must be included in the scope of the claims. The scope of patented subject matter is defined by the claims.

Claims (15)

1. A User Equipment (UE), comprising:

a transceiver configured to receive configuration information regarding Channel State Information (CSI) reporting, the configuration information comprising a parameter d Σ1, where d is the number of principal components; and

a processor operably coupled to the transceiver, the processor configured to:

Determining a left principal component vector;

determining a right principal component vector; and

the dominant singular values are determined and,

wherein the transceiver is further configured to transmit the CSI report including a Precoding Matrix Indicator (PMI) indicating the left principal component vector, the right principal component vector, and the principal singular values, wherein at least one of the left principal component vector, the right principal component vector, and the principal singular values is selected from an adaptive codebook.

2. The UE of claim 1, wherein the respective amplitudes of the elements of one of the left principal component vectors are selected from an adaptive codebook based on a unit norm attribute.

3. The UE of claim 2, wherein:

the amplitude of the first element is selected from the first base codebook,

the amplitude of the j-th element is selected from a scaled version of the first base codebook or a limited set of the first base codebook,

calculating a scaling factor based on the respective amplitudes of the previous j-1 elements, and

the elements of the restricted set are determined based on the respective amplitudes of the previous j-1 elements.

4. The UE of claim 1, wherein the respective amplitudes of the elements of one of the right principal component vectors are selected from an adaptive codebook based on a unit norm attribute.

5. The UE of claim 4, wherein:

the amplitude of the first element is selected from the second base codebook,

selecting the amplitude of the j-th element from the scaled version of the second base codebook or the limited set of the second base codebook, and

calculating a scaling factor based on the respective amplitudes of the previous j-1 elements, and

the elements of the restricted set are determined based on the respective amplitudes of the previous j-1 elements.

6. The UE of claim 1, wherein:

a first dominant singular value is selected from a third base codebook,

selecting the j-th dominant singular value from the scaled version of the third base codebook, and

the scaling factor is calculated based on the j-1 dominant singular values.

7. A Base Station (BS), comprising:

a processor configured to generate configuration information regarding Channel State Information (CSI) reporting, the configuration information comprising a parameter d Σ1, where d is the number of principal components; and

a transceiver operably coupled to the processor, the transceiver configured to:

transmitting the configuration information; and

the method includes receiving the CSI report including a Precoding Matrix Indicator (PMI) indicating a left principal component vector, a right principal component vector, and a dominant singular value, wherein at least one of the left principal component vector, the right principal component vector, and the dominant singular value is based on an adaptive codebook.

8. The BS of claim 7, wherein:

selecting a respective amplitude of an element of one of the left principal component vectors from a first adaptive codebook based on a first unit norm attribute, and

a respective amplitude of an element of one of the right principal component vectors is selected from a second adaptive codebook based on a second unit norm attribute.

9. The BS of claim 8, wherein:

the amplitude of the first element of one of the left principal component vectors is based on a first base codebook,

the amplitude of the j-th element of one of the left principal component vectors is based on a scaled version of the first base codebook,

the scaling factor of one of the left principal component vectors is based on the respective amplitudes of the previous j-1 elements of the left principal component vector,

the amplitude of the first element of one of the right principal component vectors is based on a second base codebook,

the amplitude of the j-th element of one of the right principal component vectors is based on a scaled version of the second base codebook, and

the scaling factor of one of the right principal component vectors is based on the respective amplitudes of the previous j-1 elements of the right principal component vector.

10. The BS of claim 8, wherein:

the amplitude of the first element of one of the left principal component vectors is based on a first base codebook,

The amplitude of the j-th element of one of the left principal component vectors is based on the limited set of the first base codebook,

the elements of the restricted set are based on respective amplitudes of previous j-1 elements of one of the left principal component vectors,

the amplitude of the first element of one of the right principal component vectors is based on a second base codebook,

the amplitude of the j-th element of one of the right principal component vectors is based on the limited set of the second base codebook, and

the elements of the restricted set are based on respective amplitudes of previous j-1 elements of one of the right principal component vectors.

11. A method performed by a User Equipment (UE) in a wireless communication system, the method comprising:

receiving configuration information about Channel State Information (CSI) reports, the configuration information comprising a parameter d Σ1, where d is the number of principal components;

determining a left principal component vector;

determining a right principal component vector;

determining a main singular value; and

transmitting the CSI report including a Precoding Matrix Indicator (PMI) indicating the left principal component vector, the right principal component vector, and the dominant singular value, wherein at least one of the left principal component vector, the right principal component vector, and the dominant singular value is selected from an adaptive codebook.

12. The method of claim 11, further comprising:

selecting a respective amplitude of an element of one of the left principal component vectors from a first adaptive codebook based on a first unit norm attribute; and

a respective amplitude of an element of one of the right principal component vectors is selected from a second adaptive codebook based on a second unit norm attribute.

13. The method of claim 12, further comprising:

selecting an amplitude of the first element from the first base codebook or the second base codebook;

selecting an amplitude of a j-th element from a scaled version of one of the first base codebook and the second base codebook; and

the scaling factor is calculated based on the respective amplitudes of the previous j-1 elements.

14. The method of claim 12, further comprising:

selecting an amplitude of the first element from the first base codebook or the second base codebook;

selecting an amplitude of a j-th element from a limited set of one of the first base codebook and the second base codebook; and

the elements of the restricted set are determined based on the respective amplitudes of the previous j-1 elements.

15. The method of claim 11, further comprising:

selecting a first dominant singular value from a third base codebook;

Selecting a j-th dominant singular value from a scaled version of the third base codebook; and

the scaling factor is calculated based on the j-1 dominant singular values.