CN116615870A

CN116615870A - Codebook for distributed MIMO transmission

Info

Publication number: CN116615870A
Application number: CN202180083973.4A
Authority: CN
Inventors: 默德赛弗·拉赫曼; 艾可·努格罗霍·翁戈萨努西
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2020-12-14
Filing date: 2021-12-13
Publication date: 2023-08-18
Also published as: KR20230117109A; WO2022131713A1

Abstract

The present disclosure relates to a communication method and system that fuses a fifth generation (5G) communication system for supporting higher data rates than a fourth generation (4G) system with techniques for internet of things (IoT). The present disclosure may be applied to smart services based on 5G communication technology and IoT-related technology, such as smart home, smart building, smart city, smart car, networked car, healthcare, digital education, smart retail, security and security services. The present disclosure relates to Channel State Information (CSI) reporting based on codebooks for distributed MIMO transmission.

Description

Codebook for distributed MIMO transmission

Technical Field

The present disclosure relates generally to wireless communication systems, and more particularly, to CSI reporting based on codebooks for distributed MIMO transmissions.

Background

In order to meet the increased demand for wireless data services since the deployment of 4G communication systems, efforts have been made to develop improved 5G or quasi 5G communication systems. Therefore, a 5G or quasi 5G communication system is also referred to as a "super 4G network" or a "LTE-after-system". A 5G communication system is considered to be implemented in a higher frequency (mmWave) band (e.g., 60GHz band) in order to achieve a higher data rate. In order to reduce propagation loss of radio waves and increase transmission distance, beamforming, massive Multiple Input Multiple Output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, massive antenna techniques are discussed in 5G communication systems. In addition, in the 5G communication system, development for system network improvement is performed based on advanced small cells, cloud Radio Access Networks (RANs), ultra dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, coordinated multipoint (CoMP), reception-side interference cancellation, and the like. In 5G systems, hybrid FSK and QAM modulation (FQAM) as Advanced Code Modulation (ACM) and Sliding Window Superposition Coding (SWSC) have been developed, as well as Filter Bank Multicarrier (FBMC), non-orthogonal multiple access (NOMA) and Sparse Code Multiple Access (SCMA) as advanced access techniques.

The internet, which is a human-centric connected network in which humans generate and consume information, is now evolving into the internet of things (IoT) in which distributed entities such as things exchange and process information without human intervention. Internet of everything (IoE) has emerged as a combination of IoT technology and big data processing technology through connection with cloud servers. As IoT implementations have required technical elements such as "sensing technology," "wired/wireless communication and network infrastructure," "service interface technology," and "security technology," sensor networks, machine-to-machine (M2M) communications, machine Type Communications (MTC), etc. have recently been investigated. Such IoT environments may provide intelligent internet technology services that create new value for human life by collecting and analyzing data generated among networking. IoT may be applied in a variety of fields including the following through fusion and combination between existing Information Technology (IT) and various industrial applications: smart home, smart building, smart city, smart car or networking car, smart grid, healthcare, smart home appliances, and advanced medical services.

In keeping with this, various attempts have been made to apply 5G communication systems to IoT networks. For example, techniques such as sensor networks, machine Type Communications (MTC), and machine-to-machine (M2M) communications may be implemented through beamforming, MIMO, and array antennas. The application of cloud Radio Access Networks (RANs) as the big data processing technology described above may also be considered as an example of a convergence between 5G technology and IoT technology.

Understanding and properly estimating the channel between a User Equipment (UE) and a Base Station (BS), e.g., a gNode B (gNB), is important for efficient and effective wireless communication. To properly estimate DL channel conditions, the gNB may send reference signals (e.g., CSI-RS) to the UE for DL channel measurements, and the UE may report (e.g., feedback) information about the channel measurements, such as CSI, to the gNB. With such DL channel measurements, the gNB is able to select appropriate communication parameters to efficiently and effectively perform wireless data communication with the UE.

Disclosure of Invention

Technical problem

For efficient and effective wireless communication, it is desirable to design a codebook for a distributed MIMO antenna structure.

Technical proposal

Embodiments of the present disclosure provide methods and apparatus to enable Channel State Information (CSI) reporting based on a codebook for distributed MIMO transmission in a wireless communication system.

In one embodiment, a UE for CSI reporting in a wireless communication system is provided. The UE includes: a transceiver configured to receive information regarding Channel State Information (CSI) reporting, the information comprising a number N _RRH > 1 and RRH r, wherein: n (N) _RRH Number of Remote Radio Heads (RRH), RRH r includes a set of P _CSIRS，r A number of Channel State Information Reference Signal (CSIRS) antenna ports, and r=1,.. _RRH . The UE further includes: a processor operatively connected to the transceiver. The processor is configured to, based on the information: from N _RRH Selecting the strongest RRH from the RRHs; and determining a CSI report comprising an indicator indicating the strongest RRH. The transceiver is further configured to: the CSI report including an indicator indicating the strongest RRH is sent.

In another embodiment, a BS in a wireless communication system is provided. The BS includes: a processor configured to generate information regarding Channel State Information (CSI) reporting, the information including a number N _RRH > 1 and RRHr, wherein: n (N) _RRH Number of Remote Radio Heads (RRH), RRH r includes a set of P _CSIRS，r A number of Channel State Information Reference Signal (CSIRS) antenna ports, and r=1,.. _RRH . The BS further includes: a transceiver operatively connected to the processor. The transceiver is configured to: transmitting the information; and receiving the CSI report, wherein the CSI report includes an indication from N _RRH An indicator of the strongest RRH selected from the RRHs.

In yet another embodiment, a method for operating a UE is provided. The method comprises the following steps: receiving information about Channel State Information (CSI) reports, the information comprising a number N _RRH > 1 and RRH r, wherein: n (N) _RRH Number of Remote Radio Heads (RRH), RRH r includes a set of P _CSIRS，r A number of Channel State Information Reference Signal (CSIRS) antenna ports, and r=1,.. _RRH The method comprises the steps of carrying out a first treatment on the surface of the From N _RRH Selecting the strongest RRH from the RRHs; determining a CSI report comprising an indicator indicating the strongest RRH; to be used forAnd sending the CSI report including an indicator indicating the strongest RRH.

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

Advantageous effects

In accordance with the present disclosure, several codebook design alternatives for D-MIMO antenna structures are provided for efficient and effective wireless communication.

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 numbers indicate like parts:

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

FIG. 2 illustrates an example gNB, according to 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 distributed MIMO (D-MIMO) system according to embodiments of the present disclosure;

fig. 11 illustrates an example antenna port layout according to an embodiment of the disclosure;

fig. 12 illustrates an example of type I Single Panel (SP) and type I Multi Panel (MP) codebook based MIMO transmission in accordance with an embodiment of the present disclosure;

Fig. 13 illustrates an example D-MIMO with a single antenna panel per RRH in accordance with an embodiment of the disclosure;

fig. 14 illustrates an example D-MIMO with multiple antenna panels per RRH in accordance with an embodiment of the disclosure;

fig. 15 illustrates an example D-MIMO in which each RRH may have a single antenna panel or multiple antenna panels in accordance with an embodiment of the disclosure;

fig. 16 shows a flowchart of a method for operating a UE in accordance with an embodiment of the present disclosure; and

fig. 17 shows a flowchart of a method for operating a BS according to an embodiment of the present disclosure.

Detailed Description

Before 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, mean inclusion without limitation. The term "or" is inclusive, meaning and/or. The phrase "associated with … …" and derivatives thereof means inclusion, inclusion within … …, interconnection with … …, inclusion within … …, connection to or with … …, coupling to or with … …, communicable with … …, collaboration with … …, interleaving, juxtaposition, proximity to, binding to or binding with … …, having, attributes of … …, having relation to … …, 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 one of the following combinations: A. b, C, A and B, A and C, B and C, 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 (RAM), a hard disk drive, a Compact Disc (CD), a Digital Video Disc (DVD), or any other type of memory. Non-transitory "computer-readable media" excludes wired, wireless, optical, or other communication links that carry transitory electrical or other signals. Non-transitory computer readable media include media in which data may be permanently stored and media in which data may be stored and later overwritten, such as rewritable optical disks or erasable storage devices.

Definitions for certain other 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 uses, as well as future uses, of such defined words and phrases.

Figures 1 through 17, 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 apparatus.

The following documents and standard descriptions are hereby incorporated by reference into the present disclosure as if fully set forth herein: 3GPP TS 36.211 v16.6.0, "E-UTRA, physical channels and modulation" (herein "REF 1"); 3GPP TS 36.212 v16.6.0, "E-UTRA, multiplexing and Channel coding" (herein "REF 2"); 3GPP TS 36.213 v16.6.0, "E-UTRA, physical Layer Procedures" (herein "REF 3"); 3GPP TS 36.321 v16.6.0, "E-UTRA, medium Access Control (MAC) protocol specification" (herein "REF 4"); 3GPP TS 36.331 v16.6.0, "E-UTRA, radio Resource Control (RRC) protocol specification" (herein "REF 5"); 3GPP TR 22.891 v14.2.0 (herein "REF 6"); 3GPP TS 38.212 v16.6.0, "E-UTRA, NR, multiplexing and channel coding" (herein "REF 7"); and 3GPP TS 38.214 v16.6.0, "E-UTRA, NR, physical layer procedures for data" (herein "REF 8").

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 modification 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 (OFDM) or Orthogonal Frequency Division Multiple Access (OFDMA), the present disclosure may be extended to other OFDM-based transmission waveforms or multiple access schemes, such as filtered OFDM (F-OFDM).

In order to meet the increased demand for wireless data services since the deployment of 4G communication systems and 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 (mmWave) band (e.g., 28GHz band or 60GHz band) in order to achieve a higher data rate, or a 5G/NR communication system is considered to be implemented in a lower frequency band (such as 6 GHz) in order to achieve robust coverage and mobility support. In order to reduce propagation loss of radio waves and increase transmission distance, 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 addition, in the 5G/NR communication system, development for system network improvement is performed based on advanced small cells, cloud Radio Access Networks (RANs), ultra dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, coordinated multipoint (CoMP), reception-side interference cancellation, and the like.

The discussion of the 5G system and the frequency bands associated therewith is for reference purposes 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 applicable to 5G communication systems, 6G, or even deployment of later versions that may use terahertz (THz) frequency bands.

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

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 the 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 (IP) network, or other data network.

The gNB 102 provides wireless broadband access to a network 130 for a first plurality of User Equipment (UEs) within a coverage area 120 of the gNB 102. The first plurality of UEs includes: UE 111, which may be located in a small enterprise; 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 cell phone, wireless laptop, wireless PDA, etc. 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 Transmission Point (TP), a Transmission Reception Point (TRP), an enhanced base station (eNodeB or eNB), a 5G base station (gNB), a macrocell, a femtocell, a WiFi Access Point (AP), or other wirelessly enabled device. The base station may provide wireless access in accordance with one or more wireless communication protocols (e.g., 5g 3gpp new wireless interface/access (NR), long Term Evolution (LTE), LTE-advanced (LTE-a), high Speed Packet Access (HSPA), wi-Fi 802.11a/b/g/n/ac, etc.). For convenience, the terms "BS" and "TRP" are used interchangeably in this patent document to refer to the network infrastructure component that provides wireless access to a remote terminal. Also, depending on the network type, the term "user equipment" or "UE" may refer to any component such as a "mobile station," "subscriber station," "remote terminal," "wireless terminal," "receiving point," or "user device," etc. 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 to be a stationary device (such as a desktop computer or vending machine).

The dashed lines illustrate the approximate extent of coverage areas 120 and 125 that are shown as approximately circular for illustration and explanation purposes 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 variations associated with natural and man-made obstructions in the wireless environment.

As described in more detail below, one or more of UEs 111-116 include circuitry, programming, or a combination thereof for: receiving information about Channel State Information (CSI) reports, the information comprising a number N _RRH > 1 and RRH r, wherein: n (N) _RRH Number of Remote Radio Heads (RRH), RRH r includes a set of P _CSIRS，r A number of Channel State Information Reference Signal (CSIRS) antenna ports, and r=1,.. _RRH The method comprises the steps of carrying out a first treatment on the surface of the From N _RRH Selecting the strongest RRH from the RRHs; determining a CSI report comprising an indicator indicating the strongest RRH; and transmitting the CSI report including an indicator indicating the strongest RRH. One or more of the gnbs 101-103 include circuitry, programming, or a combination thereof for: generating information about Channel State Information (CSI) reports, the information comprising a number N _RRH > 1 and RRH r, wherein: n (N) _RRH Number of Remote Radio Heads (RRH), RRH r includes a set of P _CSIRS，r A number of Channel State Information Reference Signal (CSIRS) antenna ports, and r=1,.. _RRH The method comprises the steps of carrying out a first treatment on the surface of the Transmitting the information; and receiving the CSI report, wherein the CSI report includes an indication from N _RRH An indicator of the strongest RRH selected from the RRHs.

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. Also, 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, gNB 101, gNB 102, and/or gNB 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 gNB 101 and the gNB 103 of fig. 1 may have the same or similar configuration. However, the gNB has a variety of configurations, and fig. 2 does not limit the scope of the disclosure to any particular implementation of the 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 signals or baseband signals. The IF signal or baseband signal is sent to RX processing circuit 220, which generates a processed baseband signal by filtering, decoding, and/or digitizing the baseband signal 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 data 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 signal or IF signal. RF transceivers 210a-210n receive outgoing processed baseband signals or IF signals from TX processing circuitry 215 and upconvert the baseband signals 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 UL channel signals and the transmission of DL channel signals by 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 or 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. Any of a wide variety of other functions may be supported in the gNB 102 through the controller/processor 225.

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 enables 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. 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 enable 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 enable 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. Portions 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 component shown in FIG. 2. As a particular example, an access point can include many interfaces 235 and the controller/processor 225 can support routing functions to route data between different network addresses. As another particular example, while shown as including a single instance of TX processing circuitry 215 and a single instance of RX processing circuitry 220, the gNB 102 may include multiple instances of each (such as one for each RF transceiver). Likewise, 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 can have the same or similar configuration. However, the UE has a variety of configurations, 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 (IF) 345, touch screen 350, display 355, and memory 360. 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 an incoming RF signal to generate an Intermediate Frequency (IF) signal or a baseband signal. The IF signal or baseband signal is sent to RX processing circuit 325, which generates a processed baseband signal by filtering, decoding, and/or digitizing the baseband signal or IF signal. RX processing circuit 325 sends the processed baseband signal to speaker 330 (such as for voice data) or to 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 signal or IF signal. RF transceiver 310 receives an outgoing processed baseband signal or IF signal from TX processing circuitry 315 and up-converts the baseband signal or IF signal to an RF signal that is 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 the reception of DL channel signals and the transmission of UL channel signals by 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 residing in memory 360, such as processes for: receiving information about Channel State Information (CSI) reports, the information comprising a number N _RRH > 1 and RRH r, wherein: n (N) _RRH Number of Remote Radio Heads (RRH), RRH includes a set of P _CSIRS，r A number of Channel State Information Reference Signal (CSIRS) antenna ports, and r=1,.. _RRH The method comprises the steps of carrying out a first treatment on the surface of the From N _RRH Selecting the strongest RRH from the RRHs; determining a CSI report comprising an indicator indicating the strongest RRH; and transmitting the CSI report including an indicator indicating the strongest RRH. Processor 340 may move data into and out of memory 360 as needed to execute a process. In some embodiments, the processor 340 is configured to execute the application 362 based on the OS 361 or in response to a signal received from the gNB or operator. Processor 340 is also coupled to I/O interface 345, which provides 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 use touch screen 350 to type data into UE 116. Display 355 may be a liquid crystal display, a light emitting diode display, or other display capable of rendering text, such as from a website, and/or at least limited graphics.

Memory 360 is coupled to processor 340. Portions 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 (CPUs) and one or more Graphics Processing Units (GPUs). Also, 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 device (e.g., user device 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 device (e.g., the user device 116 of fig. 1).

The transmit path circuitry includes a channel coding and modulation block 405, a serial-to-parallel (S-to-P) block 410, an Inverse Fast Fourier Transform (IFFT) block 415 of size N, a parallel-to-serial (P-to-S) block 420, 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 size N Fast Fourier Transform (FFT) block 470, a parallel-to-serial (P-to-S) block 475, and a channel decoding and demodulation block 480.

At least some of the components of fig. 4a400 and 4b 450 may be implemented in software, while other components may be implemented in configurable hardware or a mixture of software and configurable hardware. In particular, 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 relates to embodiments implementing a fast fourier transform and an inverse fast fourier transform, this is by way of illustration only and should not be construed to limit the scope of the present disclosure. It will be appreciated that in alternative embodiments of the present disclosure, the fast fourier transform function and the inverse fast fourier transform function may be easily replaced with a Discrete Fourier Transform (DFT) function and an 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) to the input bits, and modulates (e.g., quadrature Phase Shift Keying (QPSK) or Quadrature Amplitude Modulation (QAM)) 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 BS 102 and UE 116. The size N IFFT block 415 then performs an IFFT operation on the N parallel symbol streams to produce a time domain output signal. Parallel-to-serial block 420 converts (i.e., multiplexes) the parallel time-domain output symbols from size N IFFT block 415 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 conversion to RF frequency.

The transmitted RF signals arrive at the UE 116 after passing through the wireless channel and perform operations that are inverse to those 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 to a parallel time-domain signal. The size N FFT block 470 then performs an FFT algorithm to produce N parallel frequency domain signals. Parallel-to-serial block 475 converts the parallel frequency-domain signal into a sequence of modulated data symbols. The channel decoding and demodulation block 480 demodulates the modulation symbols and then decodes to recover the original input data stream.

Each of the gnbs 101-103 may implement a transmit path similar to transmitting to the user devices 111-116 in the downlink and may implement a receive path similar to receiving from the user devices 111-116 in the uplink. 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.

A communication system includes a Downlink (DL) that conveys signals from a transmission point, such as a Base Station (BS) or NodeB, to a User Equipment (UE) and an Uplink (UL) that conveys signals from the UE to a reception point, such as 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 automation 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 often referred to as an eNodeB.

In a communication system such as an LTE system, a DL signal may include a data signal conveying information content, a control signal conveying DL Control Information (DCI), and a Reference Signal (RS), also referred to as a pilot signal. The eNodeB transmits data information through a Physical DL Shared Channel (PDSCH). The eNodeB transmits DCI over a Physical DL Control Channel (PDCCH) or Enhanced PDCCH (EPDCCH).

The eNodeB transmits acknowledgement information in a 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 multiple types of RSs, including UE-Common RSs (CRSs), channel state information RSs (CSI-RSs), or demodulation RSs (DMRSs). 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 to perform measurements. To reduce CRS overhead, the eNodeB may transmit CSI-RS in the time and/or frequency domain at a smaller 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 (BCH) when DL signals convey a Master Information Block (MIB) or to a DL shared channel (DL-SCH) when DL signals convey a 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 (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 of the first SIB (SIB-1) may be provided by the MIB.

DL resource allocation is performed in units of subframes and Physical Resource Block (PRB) groups. The transmission BW includes frequency resource units called Resource Blocks (RBs). Each RB includesIndividual subcarriers or Resource Elements (REs), such as 12 REs. A unit of one RB on one subframe is called a PRB. Total +.>RE, M can be allocated to UE _PDSCH And RB.

The UL signals may include data signals conveying data information, control signals conveying 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 (PUSCH) or 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 (HARQ-ACK) information indicating the Absence of Correct (ACK) or incorrect (NACK) detection or PDCCH Detection (DTX) for a data TB in a PDSCH, scheduling Request (SR) indicating whether the UE has data in a buffer of the UE, rank Indicator (RI) and Channel State Information (CSI) enabling the eNodeB to perform link adaptation for PDSCH transmission to the UE. HARQ-ACK information is also transmitted by the UE in response to detecting PDCCH/EPDCCH indicating release of the semi-persistently scheduled PDSCH.

One UL subframe (or slot) includes two slots. Each time slot includes a data message, UCI, DMRS, or SRS for transmittingAnd a symbol. The frequency resource unit of UL system BW is RB. For a total of +.>The UE is allocated N by 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 isWherein N is the last subframe symbol if used to transmit SRS _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 components shown in fig. 5 may be implemented with specialized circuitry configured to perform the indicated functions, or one or more components may be implemented by one or more processors executing instructions to perform the indicated 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 for mapping to REs selected by a transmission BW selection unit 555 for an assigned PDSCH transmission BW, an Inverse Fast Fourier Transform (IFFT) is applied by unit 560, the output is then serialized by a parallel-to-serial (P/S) converter 570 to create a time domain signal, the filtering is applied by filter 580, and the signal is sent 590. Additional functions such as data scrambling, cyclic prefix insertion, time windowing, interleaving, and other functions are well known in the art and are not shown for simplicity.

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 components shown in fig. 6 may be implemented with specialized circuitry configured to perform the indicated functions, or one or more components may be implemented by one or more processors executing instructions to perform the indicated functions. Fig. 6 does not limit the scope of the present disclosure to any particular implementation of diagram 600.

As shown in fig. 6, the received signal 610 is filtered by a filter 620, REs 630 for assigned received BW are selected by a BW selector 635, a unit 640 applies a Fast Fourier Transform (FFT), 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. Additional functions such as time windowing, cyclic prefix removal, descrambling, channel estimation and de-interleaving are not shown for simplicity.

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 components shown in fig. 5 may be implemented with specialized circuitry configured to perform the indicated functions, or one or more components may be implemented by one or more processors executing instructions to perform the indicated functions. Fig. 7 does not limit the scope of the present disclosure to any particular implementation 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 a DFT to the modulated data bits, REs 750 corresponding to the assigned PUSCH transmission BW are selected by a transmission BW selection unit 755, an IFFT is applied by unit 760, and after cyclic prefix insertion (not shown), filtering is applied by filter 770 and the signal is sent 780.

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 components shown in fig. 8 may be implemented with specialized circuitry configured to perform the indicated functions, or one or more components may be implemented by one or more processors executing instructions to perform the indicated functions. Fig. 8 does not limit the scope of the present disclosure to any particular implementation of block diagram 800.

As shown in fig. 8, the received signal 810 is filtered by a filter 820. Subsequently, after removing the cyclic prefix (not shown), element 830 applies an FFT, REs 840 corresponding to the assigned PUSCH reception BW are selected by reception BW selector 845, 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.

In the next generation cellular system, various use cases exceeding the capability of the LTE system are envisaged. Known as 5G or fifth generation cellular systems, systems capable of operating below 6GHz and above 6GHz (e.g., in the mmWave regime) are one of the requirements. In 3GPP TR 22.891, 74 5G use cases have been identified and described; these use cases can be roughly classified into three different groups. The first group is called "enhanced mobile broadband (eMBB)" for high data rate services where latency and reliability requirements are less stringent. The second group is referred to as "ultra-reliable and low latency (URLL)" for applications where the data rate requirements are less stringent but the latency is less tolerant. The third group is called "large-scale MTC (mctc)", which is directed to a large number of low-power device connections (such as 1 million per square kilometer) that are less critical in terms of reliability, data rate, and latency.

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 does not limit the scope of the present disclosure to any particular implementation of antenna block or array 900.

For the mmWave band, although 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 mmWave 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. One CSI-RS port may then correspond to one sub-array that produces a narrow analog beam by analog beamforming 905. This analog beam may be configured to scan 920 across a wider range of angles by changing the set of phase shifters across 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 spans N _CSI-PORT The analog beams perform linear combining to further increase the precoding gain. Although the analog beams are wideband (and thus not frequency selective), the digital precoding may vary across frequency subbands or resource blocks.

To achieve digital precoding, efficient design of CSI-RS is a determinant. For this reason, three types of CSI reporting mechanisms corresponding to three types of CSI-RS measurement behaviors are supported, for example, a "class a" CSI report corresponding to a non-precoded CSI-RS, a "class B" report with k=1 CSI-RS resources corresponding to a UE-specific beamformed CSI-RS, and a "class B" report with K >1 CSI-RS resources corresponding to a cell-specific beamformed CSI-RS.

For non-precoded (NP) CSI-RS, a cell-specific one-to-one mapping between CSI-RS ports and TXRUs is utilized. Different CSI-RS ports have the same wide beamwidth and direction and therefore typically have cell wide coverage. For beamformed CSI-RS, beamforming operations, whether cell-specific or UE-specific, are applied on non-zero power (NZP) CSI-RS resources (e.g., comprising multiple ports). At least at a given time/frequency, the CSI-RS ports have a narrow beamwidth and therefore do not have cell-wide coverage services, and at least from the perspective of the gNB. At least some CSI-RS port-resource combinations have different beam directions.

In the scenario where DL long-term channel statistics can be measured by UL signals at the serving eNodeB, UE-specific BF CSI-RS can be easily used. This is generally possible when the UL-DL duplex distance is sufficiently small. However, when this condition is not true, some UE feedback is necessary for the eNodeB to obtain an estimate of DL long-term channel statistics (or any representation thereof). To facilitate such a process, a first BF CSI-RS is transmitted in periods T1 (ms) and a second NP CSI-RS is transmitted in periods T2 (ms), where T1 is less than or equal to T2. This method is called hybrid CSI-RS. The implementation of hybrid CSI-RS depends mainly on the definition of CSI processes and NZP CSI-RS resources.

In wireless communication systems, MIMO is often identified as a necessary feature in order to achieve high system throughput requirements. One of the key components of a MIMO transmission scheme is accurate CSI acquisition at the eNB (or gNB) (or TRP). In particular, for MU-MIMO, the availability of accurate CSI is necessary in order to guarantee high MU performance. For TDD systems, SRS transmission relying on channel reciprocity may be used to acquire CSI. On the other hand, for FDD systems, CSI-RS transmission from the eNB (or gNB) and CSI acquisition and feedback from the UE may be used to acquire it. In a conventional FDD system, the CSI feedback framework is "implicit" in the form of CQI/PMI/RI (also CRI and LI) derived from the codebook, assuming SU transmissions from the eNB (or gNB). This implicit CSI feedback is insufficient for MU transmissions due to the inherent SU assumption in deriving CSI. Such SU-MU CSI mismatch will be a bottleneck to achieving high MU performance gain, since future (e.g., NR) systems are likely to be more MU-centric. Another problem with implicit feedback is the scalability of a larger number of antenna ports at the eNB (or gNB). For a large number of antenna ports, the codebook design for implicit feedback is quite complex (e.g., 44 class a codebooks in total in the 3GPP LTE specifications), and there is no guarantee that the designed codebook will bring reasonable performance benefits in the actual deployment scenario (e.g., a small percentage gain can be shown at most). Recognizing the foregoing problems, the 3GPP specifications also support advanced CSI reporting in LTE.

In 5G or NR systems [ REF7, REF8]In the above mentioned "implicit" CSI reporting paradigm from LTE is also supported and referred to as type I CSI reporting. In addition, high resolution CSI reporting (referred to as type II CSI reporting) is also supported to provide more accurate CSI information to the gNB for use cases such as high order MU-MIMO. However, the overhead of type II CSI reporting may be problematic in practical UE implementations. One way to reduce the type II CSI overhead is based on Frequency Domain (FD) compression. In release 16NR, DFT-based FD compression of type II CSI has been supported (referred to as release 16 enhanced type II codebook in REF 8). Some key components of this feature include (a) a Spatial Domain (SD) substrate W ₁ (b) FD substrate W _f And (c) linearly combining coefficients of the SD substrate and the FD substrateIn a non-reciprocal FDD system, the complete CSI (including all components) needs to be reported by the UE. However, when there is reciprocity or partial reciprocity between UL and DL, some of the CSI components may be obtained based on an UL channel estimated using SRS transmission from the UE. In version 16NR, DFT-based FD compression is extended to this partial reciprocity case (called version 16 enhanced type II port selection codebook in REF 8), where W ₁ Based on D in (2)The SD substrate of FT is replaced with SD CSI-RS port selection, i.e., a>L out of the CSI-RS ports are selected (the selection is common for both antenna polarizations or halves of the CSI-RS ports). In this case, the CSI-RS ports are beamformed in the SD (assuming UL-DL channel reciprocity in the angular domain), and beamforming information may be obtained at the gNB based on the UL channel estimated using SRS measurements.

Fig. 10 illustrates an example distributed MIMO (D-MIMO) system 1000 in accordance with an embodiment of the disclosure. The embodiment of distributed MIMO (D-MIMO) system 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 a distributed MIMO (D-MIMO) system 1000.

NR supports up to 32 CSI-RS antenna ports. 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 one site or Remote Radio Head (RRH) is challenging due to the larger antenna form factor at these frequencies when 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 may be co-located at a site (or RRH) may be limited, for example, to 8. This limits the spectral efficiency of such systems. In particular, MU-MIMO spatial multiplexing gains 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 sites (or RRHs). Multiple sites or RRHs can still be connected to a single (common) baseband unit, so signals transmitted/received via multiple distributed RRHs can still be processed at a centralized location. For example, 32 CSI-RS ports may be distributed across 4 RRHs, each with 8 antenna ports. Such a MIMO system may be referred to as a distributed MIMO (D-MIMO) system as shown in fig. 10.

All of 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 transmission.

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

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

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

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

In terms of UE configuration, the UE may be configured with at least one CSI reporting band. This configuration may be semi-static (via higher layer signaling or RRC) or dynamic (via MAC CE or L1 DL control signaling). When configured with multiple (N) CSI reporting bands (e.g., via RRC signaling), the UE may report CSI associated with n+.n CSI reporting bands. For example, >6GHz large system bandwidth may require multiple CSI 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, it is possible to followThe CSI reporting band defines CSI parameter frequency granularity. 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. 11 illustrates an example antenna port layout 1100 according to an embodiment of this disclosure. The embodiment of the antenna port layout 1100 shown in fig. 11 is for illustration only. Fig. 11 does not limit the scope of the present disclosure to any particular implementation of the antenna port layout 1100.

As shown in fig. 11, N ₁ And N ₂ The number of antenna ports having the same polarization in the first and second dimensions, respectively. For 2D antenna port layout, N ₁ ＞1，N ₂ > 1, and for a 1D antenna port layout, N ₁ > 1 and N ₂ =1. Thus, for a dual polarized antenna port layout, when each antenna is mapped to one antenna port, the total number of antenna ports is 2N ₁ N ₂ . A diagram in which an "X" represents two antenna polarizations is shown in fig. 11. In this disclosure, the term "polarization" refers to a set of antenna ports. For example, antenna portsIncluding a first antenna polarization and an antenna portIncluding a second antenna polarization, where P _CSIRS Is the number of CSI-RS antenna ports and X is the starting antenna port number (e.g., x=3000, then antenna ports are 3000, 3001, 3002..).

Let N _g Is the number of antenna panels at the gNB. When there are a plurality of antenna panels (N _g > 1), we assume that each panel has N in two dimensions ₁ And N ₂ Dual polarized antenna of each portA line port. This is shown in fig. 11. Note that the antenna port layout may or may not be identical in different antenna panels.

As described in section 5.2.2.2.1 of [ REF8], a type I single panel codebook has the following rank 1 (layer 1) precoder structure:

wherein P is _CSI-RS ＝2N ₁ N ₂ Is the number of CSI-RS antenna ports, phi _n ＝e ^jπn/2 Is an in-phase value spanning two antenna polarizations, and

is a two-dimensional DFT vector. The support value for n is {0,1,2,3}, which corresponds to QPSK in-phase {1, j, -1, -j }. (N) ₁ ，N ₂ ，O ₁ ，O ₂ ) The support value of the table ₁ Given.

Table 1: (N) ₁ ，N ₂ ) And (O) ₁ ，O ₂ ) Support configuration of (c)

As described in section 5.2.2.2.2 of [ REF8], a type I multi-panel codebook has the following rank 1 (1 layer) precoder structure for codebook mode=1:

wherein the method comprises the steps of

Wherein the method comprises the steps of

The following rank 1 (1 layer) precoder structure for codebook mode=2:

/>

wherein the method comprises the steps of

Wherein the method comprises the steps of

Wherein P is _CSI-RS ＝2N _g N ₁ N ₂ Is the number of CSI-RS antenna ports. For codebook mode=1, n, p ₁ 、p ₂ 、p ₃ The support value of each of (1, 2, 3) is {0,1,2,3}, which corresponds to QPSK in-phase {1, j, -1, -j }. For codebook mode=2, n ₀ Is {0,1,2,3}, which indicates that QPSK is in-phase {1, j, -1, -j }, p ₁ 、p ₂ The support value of each of (1, 2, 3) is {0,1,2,3}, which indicates in-phaseAnd n is ₁ 、n ₂ The support value of (1) is {0,1}, which indicates in-phaseThat is to say that the first and second,

a _p ＝e ^jπ/4 e ^jπp/2

b _n ＝e ^-jπ/4 e ^jπn/2 。

(N _g ，N ₁ ，N ₂ ，O ₁ ，O ₂ ) The support values for (2) are given in table 2.

Table 2: (N) _g ，N ₁ ，N ₂ ) And (O) ₁ ，O ₂ ) Support configuration of (c)

An illustration of MIMO transmission based on release 15 type I Single Panel (SP) and type I multi-panel (MP) codebooks is shown in fig. 12. Those skilled in the art will appreciate that fig. 12 illustrates an example type I Single Panel (SP) and type I multi-panel (MP) codebook based MIMO transmission 1200 in accordance with an embodiment of the present disclosure. The embodiment of a MIMO transmission 1200 based on a type I single-panel (SP) and type I multi-panel (MP) codebook shown in fig. 12 is for illustration only. Fig. 12 does not limit the scope of the present disclosure to any particular implementation of MIMO transmission 1200 based on type I Single Panel (SP) and type I multi-panel (MP) codebooks.

In the present disclosure, several codebook design alternatives for D-MIMO antenna structures are presented.

In one example, the antenna architecture of a D-MIMO system is structured. For example, the antenna structure at each RRH is dual polarized (single panel or multi panel as shown in fig. 11). The antenna structure at each RRH may be the same. Alternatively, the antenna structure at one RRH may be different from the antenna structure at another RRH. Likewise, the number of ports at each RRH may be the same. Alternatively, the number of ports of one RRH may be different from the number of ports of another RRH.

In another example, the antenna architecture of a D-MIMO system is unstructured. For example, the antenna structure at one RRH may be different from the antenna structure at another RRH.

In this disclosure, we assume a structured antenna architecture.

In one embodiment I.1, the UE is configured (e.g., via higher layer signaling) with a D-MIMO codebook, where the value of the number of RRHs is defined by N _RRH And (5) parameterizing.

In one example I.1.1, N _RRH The value of (2) is fixed. For example, N _RRH =2 or 3 or 4 or 8.

In one example I.1.2, N _RRH Is configured, for example, via RRC signaling as part of a codebook configuration or CSI reporting configuration, or is indicated via MAC CE or DCI, or a combination of two or more of RRC, MAC CE and DCI. N (N) _RRH Is configured from a set of support values. In one example, the set of support values is {2,4} or {2,3,4} or {2,4,8} or {2,4,6,8}.

In one example, separate RRC parameters are used to configure N _RRH Is a value of (2).

In one example, joint RRC parameters are used to configure N _RRH And the value of at least one additional parameter. For example, parameter N in version 15 type I multi-panel codebook _g Can be used as N _g And N _RRH And a combination parameter of the two.

In one example I.1.3, N _RRH The value of (whether fixed or configured) undergoes a constraint (or condition). In one example of a constraint, the total number of ports across all RRHs belongs to the value set {4,8, 12, 16, 24, 32} or {4,8, 12, 16, 24, 32, 48, 64} or {8, 16, 24, 32, 48, 64}.

In one embodiment I.2, the total number of ports across all RRHs (denoted N _CSI-RS ) Is determined according to at least one of the following examples.

In one embodiment I.2.1, N _CSI-RS ＝N _RRH ×N _CSI-RS，r 2N _RRH N ₁ N ₂ Wherein the antenna structure is assumed to be the same at each RRH, i.e. for all r＝1，...，N _RRH N is described as _CSI-RS，r ＝2N ₁ N ₂ . In one example of this, in one implementation,wherein (N) _1，r ，N _2，r ) Is a parameter of the r-th RRH, assuming that the antenna structure can span and the RRHs are different, i.e., N _CSI-RS，r ＝2N _1，r N _2，r 。

Table 1, which may be based on, for example, a release 15 type I single-panel (or multi-panel) codebook, is configured via RRC parameters (N ₁ ，N ₂ ). Likewise, the parameters (N) for each r can be configured via RRC, e.g., based on table 1 of the release 15 type I single-panel (or multi-panel) codebook _1，r ，N _2，r ). In one example, (N) _RRH ，N ₁ ，N ₂ ) By mapping them to (N) _g ，N ₁ ，N ₂ ) Similar to release 15 type I multi-panel codebook table 2 (via RRC) configuration. In one example, when N _CSI-RS，r When=2, the value (N ₁ ，N ₂ ) Or (N) _1，r ，N _2，r )＝(1，1)。

In one example I.2.1A, N _CSI-RS ＝N _RRH ×N _CSI-RS，r Where the antenna structure is assumed to be the same at each RRH, i.e., N for all r=1 _RRH N is described as _CSI-RS，r =p. In one example of this, in one implementation,wherein N is _CSI-RS，r Is a parameter of the r-th RRH, assuming that the antenna structure can be different across RRHs. Parameters P may be configured, for example, from {2,4,8, 12, 16, 24, 32} or {4,8, 12, 16, 24, 32} via RRC. Likewise, the parameter N of each r may be configured via RRC, e.g., from {2,4,8, 12, 16, 24, 32} or {4,8, 12, 16, 24, 32} _CSI-RS，r 。

In one example, N _RRH And N _CSI-RS，r The value is such that N _CSI-RS ＝N _RRH ×N _CSI-RS，r Belonging to the field {4,8,12 16, 24, 32} or {4,8, 12, 16, 24, 32, 48, 64} or {8, 12, 16, 24, 32, 48} or {8, 12, 16, 24, 48, 64}.

In one example, when N _RRH When=2, N _CSI-RS，r Belonging to {2,4,8, 12, 16} or {2,4,8, 12, 16, 24, 32} or {4,8, 12, 16, 24, 32}.

In one example, when N _RRH When=4, N _CSI-RS，r Belonging to {2,4,8} or {2,4,8, 12, 16} or {4,8, 12, 16}.

In one example, when N _RRH When=8, N _CSI-RS，r Belonging to {2,4} or {2,4,8} or {4,8}.

In one example of this, in one implementation, r=1 and the number of the groups, N _RRH N of (2) _CSI-RS，r The different values of the number of values and the total number of CSI-RS ports are in accordance with at least one example in table 3.

TABLE 3 Table 3

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In one example, a UE is configured with N distributed across all RRHs _CSI-RS One CSI-RS resource of each CSI-RS port. In one example, a UE is configured with N _RRH Multiple CSI-RS resources with N _CSI-RS，r The r-th CSI-RS resource of the CSI-RS port is associated with the r-th RRH.

In one example I.2.2, N _CSI-RS ＝N _RRH N ₁ N ₂ Where the antenna structure is assumed to be the same at each RRH, i.e., N for all r=1 _RRH N is described as _CSI-RS，r ＝N ₁ N ₂ . In one example of this, in one implementation,wherein (N) _1，r ，N _2，r ) Is a parameter of the r-th RRH, provided that the antenna structure can be different across RRHs, i.e., N _CSI-RS，r ＝N _1，r N _2，r 。

In one example I.2.3, N _CSI-RS ＝aN _RRH N ₁ N ₂ Where a=1 (e.g., co-polarized antenna) or 2 (e.g., dual polarized antenna) and assuming that the antenna structure is the same at each RRH, i.e., for all r=1, n. _RRH N is described as _CSI-RS，r ＝N ₁ N ₂ . In one example of this, in one implementation,wherein a is _r =1 or 2 and (N _1，r ，N _2，r ) Is a parameter of the r-th RRH, provided that the antenna structure can be different across RRHs, i.e., N _CSI-RS，r ＝a _r N _1，r N _2，r 。a _r The value across RRHs of (c) may be the same. Alternatively, it may be different and thus vary across RRHs. / >

In one embodiment I.3, the CSI-RS port numbering for D-MIMO is in accordance with at least one of the following examples.

In one embodiment i.3.1, the CSI-RS ports are numbered in the following order: CSI-RS port for RRH1, CSI-RS port for RRH2, and so on.

In one example i.3.2, CSI-RS ports are numbered in the following order: CSI-RS ports with first polarization for RRH1, CSI-RS ports with second polarization for RRH1, CSI-RS ports with first polarization for RRH2, CSI-RS ports with second polarization for RRH2, and so on.

In one example i.3.3, CSI-RS ports are numbered in the following order: CSI-RS ports with first polarization for RRH1, CSI-RS ports with first polarization for RRH2, CSI-RS ports with second polarization for RRH1, CSI-RS ports with second polarization for RRH 2.

In one example, the first polarization refers to one first half (first set) of antenna ports having a first antenna polarization (e.g., +45), and the second polarization refers to one second half (second set) of antenna ports having a second antenna polarization (e.g., -45).

In one embodiment ii.1, the UE is configured (e.g., via higher layer signaling) with a D-MIMO codebook having a two-level precoder structure (for each layer) e.g., similar to (or based on) a release 15NR type II codebook, or a three-level precoder structure (for each layer) e.g., similar to (or based on) a release 16NR type II codebook. For two stages, the precoder for a layer may be denoted as w=w ₁ W ₂ Wherein the component W ₁ For reporting/indicating a basis matrix comprising L basis vectors, and a component W ₂ For reporting/indicating one of the common L basis vector selection (for each layer) for both polarizations and the in-phase value of both polarizations. Note that when l=1, it is not necessary to pass through W ₂ Any beam selection is made. For three phases, N for layer ₃ The individual precoders can be represented asWherein the component W ₁ Spatial Domain (SD) basis matrix for reporting/indicating a component W comprising SD basis vectors _f Frequency Domain (FD) basis matrix for reporting/indicating a vector comprising FD basis and component +.>For reporting/indicating with SD and FD substratesThe vector corresponds to the coefficient.

Fig. 13 illustrates an example D-MIMO 1300 in which each RRH has a single antenna panel, according to an embodiment of the disclosure. The embodiment of D-MIMO 1300 with a single antenna panel per RRH shown in fig. 13 is for illustration only. Fig. 13 does not limit the scope of the present disclosure to any particular implementation of D-MIMO 1300 with a single antenna panel per RRH.

As shown in fig. 13, in one embodiment ii.2, each RRH has a single antenna panel. Component W ₁ There is a block diagonal structure comprising X diagonal blocks, with 1 (co-polarized) diagonal block or 2 (dual polarized) diagonal blocks associated with each RRH.

In one example ii.2.1, x=n _RRH A co-polarized (mono-polarized) antenna structure is assumed at each RRH. In one example, when N _RRH When=2, component W ₁ Given by the formula:

wherein B is ₁ Is the base matrix of the first RRH, and B ₂ Is the base matrix of the second RRH. In one example of this, in one implementation,l including the r-th RRH _r Individual columns or beams (or basis vectors). In one example, L for all r values _r L (value of L common to RRHs), for example, l=1. In one example, L _r Can be different across RRHs (RRH-specific L values), e.g., L _r Can take values (fixed or configured) from {1,4 }.

In one example ii.2.2, x=2n _RRH A dual polarized (cross polarized) antenna structure is assumed at each RRH.

In one example, when N _RRH When=2, component W ₁ Given by the formula:

wherein B is ₁ Is the base matrix of the first RRH and is common (identical) to the two polarizations corresponding to the first diagonal block and the second diagonal block, and B ₂ Is the base matrix of the second RRH and is common (identical) to the two polarizations corresponding to the third and fourth diagonal blocks. In general, the (2 r-1) th diagonal block and the (2 r) th diagonal block correspond to the two antenna polarizations of the r-th RRH. In one example of this, in one implementation, L including the r-th RRH _r Individual columns or beams (or basis vectors). In one example, L for all r values (L values common to RRHs) _r L, e.g., l=1. In one example, L _r May be different across RRHs (RRH-specific L values), e.g., L _r Can take values (fixed or configured) from {1,4 }.

In one example, when N _RRH =2, component W ₁ Given by the formula:

wherein B is ₁ Is the base matrix of the first RRH and is common (identical) to the two polarizations corresponding to the first and third diagonal blocks, and B ₂ Is the base matrix of the second RRH and is common (identical) to the two polarizations corresponding to the second diagonal block and the fourth diagonal block. In general, the r diagonal block and (r+N) _RRH ) The diagonal blocks correspond to the two antenna polarizations of the r-th RRH. In one example of this, in one implementation,l including the r-th RRH _r Individual columns or beams (or basis vectors). In one example, L for all r values _r L (value of L common to RRHs), for example, l=1. In one example, L _r May be different across RRHs (RRH-specific L values), e.g., L _r Values (fixed or configured) may be taken from {1,4 }.

In one example, when N _RRH When=2, component W ₁ Given by the formula:

wherein B is _1，1 And B _1，2 Is a base matrix of first and second antenna polarizations of the first RRH corresponding to the first and second diagonal blocks, and B _2，1 And B _2，2 Is a base matrix of first and second antenna polarizations of the second RRH corresponding to the third and fourth diagonal blocks. In general, the (2 r-1) th diagonal block and the (2 r) th diagonal block correspond to the two antenna polarizations of the r-th RRH. In one example of this, in one implementation,p-th polarized L including r-th RRH _r，p Individual columns or beams (or basis vectors). In one example, L for all r and p values _r，p L (value of L common to RRHs and common to polarizations), for example, l=1. In one example, L for all p values _r，p ＝L _r (RRH specific and polarization common L value). In one example, L for all r values _r，p ＝L _p (RRH common and polarization specific L value). In one example, L _r，p Can be different across RRHs (RRH-specific and polarization-specific L values).

In one example, when N _RRH When=2, component W ₁ Given by the formula:

wherein B is _1，1 And B _1，2 Is a base matrix of first and second antenna polarizations of the first RRH corresponding to the first and third diagonal blocks, and B _2，1 And B _2，2 Is a base matrix of first and second antenna polarizations of the second RRH corresponding to the second and fourth diagonal blocks. In general, the R diagonal block and (R+N) _RRH ) The diagonal blocks correspond to the two antenna polarizations of the r-th RRH. In one example of this, in one implementation,p-th polarized L including r-th RRH _r，p Individual columns or beams (or basis vectors). In one example, L for all r and p values _r，p L (value of L common to RRHs and common to polarizations), for example, l=1. In one example, L for all p values _r，p ＝L _r (RRH specific and polarization common L value). In one example, L for all r values _r，p ＝L _p (RRH-specific and polarization-specific L values). In one example, L _r，p Can be different across RRHs (RRH-specific and polarization-specific L values).

In one example ii.2.3,wherein a for co-polarized (mono-polarized) antenna structure at the r-th RRH _r =1, whereas for dual polarized (cross polarized) antenna structure at the r-th RRH a _r ＝2。

In one example, when N _RRH When=2, component W ₁ Given by the formula:

wherein B is ₁ Is the base matrix of the first RRH, and B ₂ Is the base matrix of the second RRH and is common (identical) to the two polarizations corresponding to the second and third diagonal blocks.

In one ofIn the example, when N _RRH When=2, component W ₁ Given by the formula:

wherein B is ₁ Is the base matrix of the first RRH, and B _2，1 And B _2，2 Is a base matrix of first and second antenna polarizations of the second RRH corresponding to the second and third diagonal blocks.

Fig. 14 illustrates an example D-MIMO 1400 in which each RRH has multiple antenna panels, according to an embodiment of the disclosure. The embodiment of D-MIMO 1400 with multiple antenna panels per RRH shown in fig. 14 is for illustration only. Fig. 14 does not limit the scope of the present disclosure to any particular implementation of D-MIMO 1400 with multiple antenna panels per RRH.

As shown in fig. 14, in one embodiment ii.3, each RRH has multiple antenna panels. Component W ₁ Having a block diagonal structure comprising X diagonal blocks, where N _g，r Individual (co-polarized) diagonal blocks or 2N _g，r Diagonal block and a method for manufacturing the same _g，r The r-th RRH of the panels is associated with and N for all values of r _g，r > 1. Note that N for two RRHs in fig. 14 _g，r ＝2。

In this case (of multiple panels at RRH), it is possible to pass through the interface between W ₁ Diagonal blocks corresponding to a plurality of panels are added to extend the example in embodiment ii.2 in a straightforward manner.

Fig. 15 illustrates an example D-MIMO 1500 in which each RRH may have a single antenna panel or multiple antenna panels, according to embodiments of the disclosure. The embodiment of D-MIMO 1500 in which each RRH shown in fig. 15 may have a single antenna panel or multiple antenna panels is for illustration only. Fig. 15 does not limit the scope of the present disclosure to any particular implementation of D-MIMO 1500 where each RRH may have a single antenna panel or multiple antenna panels.

As shown in fig. 15, in oneIn embodiment ii.4, each RRH may have a single antenna panel or multiple antenna panels. Component W ₁ Having a block diagonal structure comprising X diagonal blocks, where N _g，r Individual (co-polarized) diagonal blocks or 2N _g，r Diagonal block and a method for manufacturing the same _g，r The r-th RRH of the panels is associated and N when the r-th RRH has a single panel _g，r =1, and N when the nth RRH has multiple panels _g，r ＞1。

In the case of multiple panels at RRH, this can be done by ₁ Diagonal blocks corresponding to a plurality of panels are added to extend the example in embodiment ii.2 in a straightforward manner.

In one embodiment II.5, the component W is included ₁ Has columns selected from a set of oversampled 2D DFT vectors. When the antenna port layout is the same across the RRHs, for a given antenna port layout in two dimensions (N ₁ ，N ₂ ) And an oversampling factor (O) ₁ ，O ₂ ) DFT vector v _l，m Can be expressed as follows.

Where l e {0,1,., o. ₁ N ₁ -1 and m.epsilon.0, 1, O ₂ N ₂ -1}。

When antenna port layouts can be different across RRHs, for a given antenna port layout (N _1，r ，N _2，r ) And an oversampling factor (O) _1，r ，O _2，r ) DFT vectorCan be expressed as follows.

Wherein l _r ∈{0，1，...，O _1，r N _1，r -1 and m _r ∈{0，1，...，O _2，r N _2，r -1}。

In one example, the oversampling factor is common to the RRHs, and thus remains the same across the RRHs. For example, O _1，r ＝O ₁ ＝O _2，r ＝O ₂ =4. In one example, the oversampling factor is RRH specific and thus independent for each RRH. For example, O _1，r ＝O _2，r X and x is selected from {2,4,8} (fixed or configured).

In one example, the oversampling factor is fixed, e.g., O for a low resolution (type I) codebook ₁ ＝O ₂ =4, whereas for high resolution (type II) codebooks O ₁ ＝O ₂ =1. In one example, the oversampling factor is configured, for example, via RRC, wherein the configured value is common to all RRHs, or independent for each RRH (i.e., one value is configured for each RRH).

In one embodiment ii.6, each RRH may have a single antenna panel or multiple antenna panels (see fig. 15). Component W ₁ Having a block diagonal structure comprising x=2 diagonal blocks, where N _g，r Diagonal blocks or N _g，r =1 (dual polarization) diagonal blocks and include N _g，r The r-th RRH of the panels is associated and N when the r-th RRH has a single panel _g，r =1, and N when the nth RRH has multiple panels _g，r ＞1。

In one embodiment III.1, the codebook includes the codebook for N _RRH Additional components due to > 1 RRH.

In one example III.1.1The additional components include inter-RRH phase. In one example, the inter-RRH phase value corresponds to N _RRH -1 phase value (e.g. assuming that one RRH is a reference and has a fixed phase value = 1). In another example, the inter-RRH phase value corresponds to N _RRH Phase values. inter-RRH phase values can be quantized/reported as scalars using a scalar codebook (e.g., QPSK (2 bits per phase) or 8PSK (3 bits per phase)), or quantized/reported as vectors using a vector codebook (e.g., DFT codebook). Furthermore, for dual polarized antennas at the RRH, the inter-RRH phase may be the same for both polarizations of the RRH. Alternatively, it may be independent for both polarizations of the RRH. At least one of the following examples is for inter-RRH phase reporting.

In one example iii.1.1.1, inter-RRH phase is reported in Wideband (WB) mode, i.e., one value is reported for all SBs in the configured CSI reporting band. Because of the WB report, it can be included in the W of the codebook ₁ In the component. Alternatively, it may be included in the new component, i.e., W of the codebook ₃ Is a kind of medium.

In one example iii.1.1.2, inter-RRH phase is reported in sub-band (SB) fashion, i.e., one value is reported for each SB in the configured CSI reporting band. Since SB report, it can be included in W of codebook ₂ In the component. Alternatively, it may be included in the new component, i.e., W of the codebook ₃ Is a kind of medium.

In one example iii.1.1.3, inter-RRH phase is reported in WB plus SB fashion, i.e., one WB phase value is reported for all SBs in the configured CSI reporting band and one SB value is reported for each SB in the configured CSI reporting band. Since WB plus SB reports, WB portions may be included in W of the codebook ₁ In the component and SB portion can be included in W of codebook ₂ In the component. Alternatively, both the WB portion and SB portion may be included in the new component, i.e., W of the codebook ₃ Is a kind of medium.

In one example iii.1.2, the additional components include inter-RRH phases and inter-RRH amplitudes, wherein details regarding inter-RRH phases are as illustrated in example iit.1.1. Note that inter-RRH amplitude is required because the UE is not equidistant from the RRHs. At the position ofIn one example, the inter-RRH amplitude value corresponds to N _RRH -1 amplitude value (for example, assume one RRH is a reference and has a fixed amplitude value=1). In another example, the inter-RRH amplitude value corresponds to N _RRH The amplitude values. inter-RRH amplitude values can be quantized/reported as scalars using a scalar codebook (e.g., 2 bits per amplitude or 3 bits per amplitude) or quantized/reported as vectors using a vector codebook. Also, for dual polarized antennas at the RRH, the inter-RRH amplitude may be the same for both polarizations of the RRH. Alternatively, it may be independent for both polarizations of the RRH. At least one of the following examples is for inter-RRH amplitude and phase reporting.

In one example iii.1.2.1, inter-RRH amplitude is reported in Wideband (WB) mode, i.e., one value is reported for all SBs in the configured CSI reporting band. Because of the WB report, it can be included in the W of the codebook ₁ In the component. Alternatively, it may be included in the new component, i.e., W of the codebook ₃ Is a kind of medium. At least one of the following examples is for inter-RRH phase.

In one example iii.1.2.1.1, inter-RRH phase is reported according to example iii.1.1.1.

In one example iii.1.2.1.2, inter-RRH phases are reported according to example iii.1.1.2.

In one example iii.1.2.1.3, inter-RRH phase is reported according to example iii.1.1.3.

In one example iii.1.2.2, inter-RRH amplitude is reported in sub-band (SB) fashion, i.e., one value is reported for each SB in the configured CSI reporting band. Since SB report, it can be included in W of codebook ₂ In the component. Alternatively, it may be included in the new component, i.e., W of the codebook ₃ Is a kind of medium. At least one of the following examples is for inter-RRH phase.

In one example iii.1.2.2.1, inter-RRH phase is reported according to example iii.1.1.1.

In one example iii.1.2.2.2, inter-RRH phases are reported according to example iii.1.1.2.

In one example iii.1.2.2.3, inter-RRH phase is reported according to example iii.1.1.3.

In one example iii.1.2.3, inter-RRH amplitude is reported in WB plus SB fashion, i.e., one WB amplitude value is reported for all SBs in the configured CSI reporting band and one SB value is reported for each SB in the configured CST reporting band. Since WB plus SB reports, WB portions may be included in W of the codebook ₁ In the component and SB portion can be included in W of codebook ₂ In the component. Alternatively, both the WB portion and SB portion may be included in a new component such as W of the codebook ₃ Is a kind of medium. At least one of the following examples is for inter-RRH phase.

In one example iii.1.2.3.1, inter-RRH phase is reported according to example iii.1.1.1.

In one example iii.1.2.3.2, inter-RRH phases are reported according to example iii.1.1.2.

In one example iii.1.2.3.3, inter-RRH phase is reported according to example iii.1.1.3.

In one example iii.1.3, the additional component includes inter-RRH amplitude, wherein details regarding inter-RRH amplitude are as illustrated in example iii.1.2.

In one example iii.1.4, the additional component includes inter-RRH power, where details about inter-RRH power are illustrated as in example iii.1.2 by replacing the amplitude with power. In one example, the square of the inter-RRH amplitude is equal to the inter-RRH power.

In one example iii.1.5, the additional components include inter-RRH phase and inter-RRH power, wherein details regarding inter-RRH phase are as illustrated in example iii.1.1 and details regarding inter-RRH power are as illustrated in example iii.1.2 by replacing amplitude with power. In one example, the square of the inter-RRH amplitude is equal to the inter-RRH power.

In one example iii.1.6, the additional component includes an indicator indicating the strongest RRH (for reference). Because of the distributed architecture, the strongest RRH may be reported to indicate a reference RRH for which inter-RRH components (such as amplitude or/and phase) are reported. The inter-RRH amplitude and phase associated with the strongest RRH may be set to a fixed value, such as 1. At least one of the following examples is for the strongest RRH report.

AtIn one example iii.1.6.1, the strongest RRH (indicator) is reported in WB mode, i.e. one value (indicator) is reported for all SBs. Because of the WB report, it can be included in the W of the codebook ₁ In the component. Alternatively, it may be included in the new component, i.e., W of the codebook ₃ Is a kind of medium.

In one example iii.1.6.2, the strongest RRH (indicator) is reported in SB fashion, i.e., one value (indicator) is reported for each SB. Since SB report, it can be included in W of codebook ₂ In the component. Alternatively, it may be included in the new component, i.e., W of the codebook ₃ Is a kind of medium.

In one example, the strongest RRH is reported in a layer common manner, i.e., when the number of layers >1 (or rank > 1), one strongest RRH is reported for all layers in common.

In one example, the strongest RRHs are reported in a layer-specific manner, i.e., when the number of layers >1 (or rank > 1), one strongest RRH is reported for each layer of the number of layers.

The amplitude/phase associated with the strongest RRH may be fixed, e.g., fixed to 1. In alternative designs, the strongest RRH may be configured (e.g., via RRC signaling, or via MAC CE or DCI, or a combined indication of two or more of RRC, MAC CE, and DCI), or may be fixed (e.g., RRH 1 is always strongest).

In one embodiment III.1.4, RRH selection is performed, where from N _RRH A subset of the Z RRHs is selected among the RRHs and CSI is reported for the selected Z RRHs. In one example, RRH selection is configured via RRC signaling, or indicated via MAC CE or DCI or a combination of two or more of RRC, MAC CE and DCI. In another example, RRH selection is performed by the UE, e.g., the UE reports an indicator of this selection or reports inter-RRH amplitude (or power) =0 indicating that RRH is not selected.

In one example, RRH selection is performed in a layer-common manner, i.e., when the number of layers >1 (or rank > 1), RRH selection is performed commonly for all layers.

In one example, RRH selection is performed in a layer-specific manner, i.e., when the number of layers >1 (or rank > 1), RRH selection is performed for each layer of the number of layers.

In one example iii.1.4.1, the UE is configured with a type I codebook for D-MIMO (e.g., by setting the RRC parameter codeboottype=typei-D-MIMO), where the codebook includes components (on/off) for RRH selection.

In one example, this component is separate (dedicated to RRH selection). For example, use is made of a composition comprising N _RRH A bit sequence of bits, wherein each bit of the bit sequence is associated with an RRH, and a bit value of "1" is used to indicate that the RRH is selected, and a bit value of "0" is used to indicate that the RRH is not selected. For example viaThe combined index of bit signalling indication is used to indicate +.>The RRH selection assumption, i.e., W1 basis vector selection in the release 15NR type I codebook.

In another example, this component is combined (joint) with the amplitude component of the codebook, where the amplitude codebook includes a value of 0 (among other values greater than 0), and a value of "0" is used to indicate/report that the RRH is not selected and a bit value greater than 0 is used to indicate/report that the RRH is selected, and the indicated/reported value indicates the amplitude weighting in the precoder/calculation.

In one example iii.1.4.2, the UE is configured with a type II codebook (or type II port selection) for D-MIMO (e.g., by setting RRC parameter codebook type = TypeII-D-MIMO or TypeII-port selection-D-MIMO), where the codebook includes components (on/off) for RRH selection.

In another example, this component is combined (joint) with the amplitude component of the codebook, where the amplitude codebook includes a value of 0 (among other values greater than 0), and a value of "0" is used to indicate/report that the RRH is not selected, while a bit value greater than 0 is used to indicate/report that the RRH is selected, and the indicated/reported value indicates the amplitude weighting in the precoder/calculation.

In one example iii.1.4.3, the UE is configured to report CSI based on the D-MIMO codebook using two-part UCI, UCI part 1 and UCI part 2, and UCI part 1 is used to indicate/report RRH selection. In one example, the two-part UCI is configured only if the UE is configured to report SB CSI reporting based on the D-MIMO codebook. In one example, the two-part UCI is configured only if the UE is configured with a type II or type II port selection codebook for D-MIMO.

In one example iii.1.4.4, the UE is configured to report CSI based on the D-MIMO codebook using two-part UCI, UCI part 1 and UCI part 2, and UCI part 2 is used to indicate/report RRH selection. In one example, the two-part UCI is configured only if the UE is configured to report SB CSI reporting based on the D-MIMO codebook. In one example, the two-part UCI is configured only if the UE is configured with a type II or type II port selection codebook for D-MIMO.

In one example iii.1.4.5, the UE is configured to report the D-MIMO codebook based CSI using a single-part UCI for indicating/reporting RRH selection. In one example, the single-part UCI is configured only if the UE is configured to report WB CSI reporting based on the D-MIMO codebook. In one example, the single-part UCI is configured only when the UE is configured with a type I codebook for D-MIMO.

In one example, the UE is configured with two-part UCI (part 1 and part 2) for D-MIMO codebook-based CSI reporting.

In one example, UCI portion 1 includes information about RRH selection.

In one example, UCI portion 1 includes information about the strongest RRH.

In one example, UCI portion 1 includes both information about the strongest RRH and information about RRH selection.

In one example, UCI portion 2 includes information about RRH selection.

In one example, UCI part 2 includes information about the strongest RRH.

In one example, UCI portion 2 includes both information about the strongest RRH and information about RRH selection.

In one example, the UE is configured with a single-part UCI for RRH selection reporting.

In one example, this configuration is limited to the case where WB CSI reporting is configured (i.e., for SB CSI reporting, two-part UCI is used to report RRH selection).

In one example, this configuration is limited to the case when a type I codebook for D-MIMO is configured (i.e., for a type II codebook, two-part UCI is used to report RRH selection).

In one example, the UE is configured with a single-part UCI for the strongest RRH report.

In one example, this configuration is limited to the case when WB CSI reporting is configured (i.e., for SB CSI reporting, two-part UCI is used to report RRH selection).

In one example, the UE is configured with a single-part UCI for both RRH selection and strongest RRH report.

In one example, the parameter Z is fixed, e.g., 2. In one example, the parameter Z is configured, for example, via RRC. In one example, the parameter Z is reported by the UE, e.g., via UCI part 1 of a two-part UCI comprising part 1 and part 2. The reported Z value may be based on a minimum Z value _min That is, the UE may report any Z such that Z _min ≤Z≤N _RRH . Alternatively, the reported Z value may be based on a maximum Z value _max That is, the UE may report any Z such that Z.ltoreq.Z _max . Alternatively, the reported Z value may be based on a minimum Z value _min And maximum value Z _max That is, the UE may report any Z such that Z _min ≤Z≤Z _max . Value Z _min Or/and Z _max May be fixed or configured (e.g., RRC) or reported by the UE as part of the UE capability report.

In one example, both Z and an indicator indicating the selected RRH are reported via UCI part 1.

In one example, Z is reported via UCI part 1 and an indicator indicating the selected RRH is reported via UCI part 2.

In the present disclosure, codebook component W ₁ Finger via a first PMI indicator i ₁ A precoder (or precoding matrix) component indicated by the component of (a) is provided. Likewise, codebook component W ₂ Finger via a second PMI indicator i ₂ A precoder (or precoding matrix) component indicated by the component of (a) is provided. Likewise, new codebook component W ₃ Finger via a third PMI indicator i ₃ A precoder (or precoding matrix) component indicated by the component of (a) is provided.

In one embodiment IV.1, the codebook for D-MIMO transmission has one of the following designs.

In one example iv.1.1, the codebook has a decoupled (separate) design for inter-RRH and intra-RRH components. For example, (inter RRH, intra RRH) = (type I ) or (type I, type II) or (type II ), where type I implies that the corresponding codebook component has similarity to the version 15NR type I codebook and, as such, type II implies that the corresponding codebook component has similarity to the version 15 or 16NR type II codebook.

In one example iv.1.2, the codebook has a coupled (joint) design for inter-RRH components and intra-RRH components. For example, (inter-RRH, intra-RRH) has a similar type I or type II design.

In one embodiment IV.2, W ₂ The component has one of the following high-level designs.

In one example IV.2.1, W ₂ The component has a type I structure. In one example, only at W ₁ Where l=1 or L _r =1, i.e. only one beam or basis vector for each layer (or precoder for each layer). In one example, at W ₁ L > 1 or L _r > 1 (e.g., 4), i.e., a plurality of beams or basis vectors are included in W ₁ But the UE selects one beam or basis vector for each layer from the L beams (or a precoder for each layer). In one example, the UE is at W ₁ Is configured with l=1 or L > 1, and the UE selects/reports W accordingly ₁ 。

Design 1:

o single panel: cross-polarization in-phase, inter-RRH phase

Multi-panel: cross-polarized in-phase, inter-panel phase, inter-RRH phase

Design 2:

o single panel: in-phase of combination

Multi-panel: at least two or all of the cross-polarization in-phase, inter-panel phase, inter-RRH phase are combined

In one example IV.2.2, W ₂ The component has a type II structure. In one example, L > 1, and the value of L is configured (e.g., via RRC signaling) from a set of support values. In one example, the set of support values belongs to {2,3,4,6}.

Design 1:

individual amplitude components for polarization or/and panel or/and RRH

Design 2:

combined amplitude of o

In one embodiment iv.3, the D-MIMO codebook includes both phase intervening encoders corresponding to precoders or precoding matrices where all entries are non-zero, and non-phase intervening encoders corresponding to precoders or precoding matrices having at least one zero entry per row or column.

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

Fig. 16 illustrates a flow diagram of a method 1600 for operating a User Equipment (UE), as may be performed by a UE such as UE 116, in accordance with an embodiment of the present disclosure. The embodiment of method 1600 shown in fig. 18 is for illustration only. Fig. 18 is not intended to limit the scope of the present disclosure to any particular implementation.

As shown in fig. 16, method 1600 begins at step 1602. In step 1602, the UE (e.g., 111-116 as shown in fig. 1) receives information regarding Channel State Information (CSI) reporting, the information including a number N _RRH > 1 and RRHr, wherein: n (N) _RRH Number of Remote Radio Heads (RRH), RRH includes a set of P _CSIRS，r A number of Channel State Information Reference Signal (CSIRS) antenna ports, and r=1,.. _RRH 。

In step 1604, the UE is from N _RRH The strongest RRH is selected from the RRHs.

In step 1606, the UE determines a CSI report that includes an indicator indicating the strongest RRH.

In step 1608, the UE sends a CSI report including an indicator indicating the strongest RRH.

In one embodiment, r=1 for each rrh..n _RRH The information includes information about P _CSIRS，r Is a piece of information of (a).

In one embodiment, P _CSIRS，r ＝2N _1，r N _2，r And regarding P _CSIRS，r The information of (2) corresponds to (N) _1，r ，N _2，r ) Is a value of (2).

In one embodiment, the strongest RRH is reported as a Wideband (WB) or Subband (SB), where WB corresponds to a single value common to all subbands in the CSI reporting band, and SB corresponds to multiple values, one value for each subband in the CSI reporting band.

In one embodiment, the strongest RRH is reported as layer common or layer specific, where layer common corresponds to a single value common to all layers, and layer specific corresponds to multiple values, one value for each layer.

In one embodiment, the amplitude associated with the strongest RRH = 1.

In one embodiment, the UE determines the CSI report including an indicator indicating an RRH selection in which N _RRH Z RRHs of the RRHs are selected, wherein the CSI report is for N _RRH The selected Z RRHs of the RRHs are determined, and 1.ltoreq.Z.ltoreq.N _RRH 。

In one embodiment, the indicator indicating RRH selection is length N _RRH Is a bit sequence of (2)Wherein b _r =0 indicates that RRH r is not selected, and b _r =1 indicates that RRH r is selected.

In one embodiment, the indicator indicating RRH selection isA bit combination indicator, wherein,is a ceiling (rising) function.

In one embodiment, the indicator indicating the selection of RRHs indicates the amplitude value (a _r ) Wherein a is _r =0 indicates that RRH r is not selected, and a _r > 0 indicates RRH r is selected.

In one embodiment, the RRH selection is reported as layer common or layer specific, where layer common corresponds to a single value common to all layers, and layer specific corresponds to multiple values, one value for each layer.

In one embodiment, the UE transmits a CSI report via a two-part Uplink Control Information (UCI) including part 1 and part 2, and UCI part 1 includes information about RRH selection.

Fig. 17 shows a flowchart of another method 1700, as may be performed by a Base Station (BS), such as BS 102, in accordance with an embodiment of the disclosure. The embodiment of method 1700 shown in fig. 17 is for illustration only. Fig. 17 is not intended to limit the scope of the present disclosure to any particular implementation.

As shown in fig. 17, method 1700 begins at step 1702. In step 1702, the BS (e.g., 101-103 as shown in fig. 1) generates information about Channel State Information (CSI) reports, including a number N _RRH > 1 and RRHr, wherein: n (N) _RRH Number of Remote Radio Heads (RRH), RRH r includes a set of P _CSIRS，r A number of Channel State Information Reference Signal (CSIRS) antenna ports, and r=1,.. _RRH 。

In step 1704, the BS transmits information.

In step 1706, the BS receives a CSI report, wherein the CSI report includes an indication from N _RRH An indicator of the strongest RRH selected from the RRHs.

The above-described flowcharts illustrate example methods that can be implemented in accordance with the principles of the present disclosure, and various changes can be made to the methods illustrated in the flowcharts herein. For example, while shown as a series of steps, the various steps in each figure may overlap, occur in parallel, occur in a different order, or occur multiple times. In another example, 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 present disclosure is intended to embrace such alterations and modifications that fall within the scope of the appended claims. No description of the present application should be construed as implying that any particular element, step, or function is an essential element which must be included in the scope of the claims. The scope of patented subject matter is defined by the claims.

Claims

1. A User Equipment (UE), the UE comprising:

a transceiver configured to receive information regarding Channel State Information (CSI) reporting, the information comprising a number N _RRH > 1 and RRH r, wherein:

N _RRH number of Remote Radio Heads (RRH),

RRH r includes a group P _CSIRS，r A plurality of Channel State Information Reference Signal (CSIRS) antenna ports, an

r＝1，...，N _RRH The method comprises the steps of carrying out a first treatment on the surface of the And

a processor operably coupled to the transceiver, the processor configured to, based on the information:

from N _RRH Selecting the strongest RRH from the RRHs; and

determining a CSI report comprising an indicator indicating the strongest RRH;

wherein the transceiver is configured to: the CSI report including an indicator indicating the strongest RRH is sent.

2. The UE of claim 1, wherein for each RRH r=1 _RRH The information includes information about P _CSIRS，r And wherein P _CSIRS，r ＝2N _1，r N _2，r And the reference to P _CSIRS,r The information of (2) corresponds to(N _1,r ,N _2,r ) Is a value of (2).

3. The UE of claim 1, wherein the strongest RRH is reported as a wideband (wB) or a Subband (SB), wherein wB corresponds to a single value common to all subbands in a CSI reporting band, and SB corresponds to multiple values, one value for each subband in the CSI reporting band.

4. The UE of claim 1, wherein the strongest RRH is reported as layer-common or layer-specific, wherein the layer-common corresponds to a single value common to all layers and the layer-specific corresponds to multiple values, one value for each layer.

5. The UE of claim 1, wherein an amplitude associated with the strongest RRH = 1.

6. The UE of claim 1, wherein the processor is further configured to: determining the CSI report including an indicator indicating an RRH selection in which the N is _RRH Z RRHs of the RRHs are selected, wherein the CSI report is for the N _RRH The selected Z RRHs of the RRHs are determined, and 1.ltoreq.Z.ltoreq.N _RRH 。

7. The UE of claim 6, wherein the indicator indicating the RRH selection is of length N _RRH Is a bit sequence of (2)Wherein b _r =o indicates RRH r is not selected, and b _r =1 indicates that RRH r is selected.

8. The UE of claim 6, wherein the indicator indicating the RRH selection isBit composition indicator, wherein ∈>Is an upper limit function.

9. The UE of claim 6, wherein the indicator indicating the RRH selection indicates an amplitude value (a _r ) Wherein a is _r =o indicates RRH r is not selected, whereas a _r > O indicates RRH r is selected.

10. The UE of claim 6, wherein the RRH selection is reported as layer common or layer specific, wherein the layer common corresponds to a single value common to all layers and the layer specific corresponds to a plurality of values, one value for each layer.

11. The UE of claim 6, wherein the transceiver is configured to: the CSI report is transmitted via two-part Uplink Control Information (UCI) including part 1 and part 2, and UCI part 1 includes information about the RRH selection.

12. A Base Station (BS), the BS comprising:

a processor configured to generate information regarding Channel State Information (CSI) reporting, the information including a number N _RRH > 1 and RRH r, wherein:

N _RRH number of Remote Radio Heads (RRH),

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

transmitting the information; and

the CSI report is received and the received data is transmitted,

wherein the CSI report includes an indication from N _RRH An indicator of the strongest RRH selected from the RRHs.

13. The BS of claim 12, wherein, for each rrhr=1, N _RRH The information includes information about P _CSIRS，r Information of (c), and

wherein P is _CSIRS，r ＝2N _1，r N _2，r And the reference P _CSIRS，r The information of (2) corresponds to (N) _1，r ，N _2，r ) Is used as a reference to the value of (a),

wherein the strongest RRH is reported as a Wideband (WB) or a Subband (SB), where WB corresponds to a single value common to all subbands in a CSI reporting band, and SB corresponds to multiple values, one value for each subband in the CSI reporting band.

14. A method for operating a User Equipment (UE), the method comprising:

receiving information about Channel State Information (CSI) reports, the information comprising a number N _RRH > 1 and RRH r, wherein:

N _RRH number of Remote Radio Heads (RRH),

r＝1，...，N _RRH ；

From N _RRH Selecting the strongest RRH from the RRHs;

determining a CSI report comprising an indicator indicating the strongest RRH; and

the CSI report including an indicator indicating the strongest RRH is sent.

15. A method for operating a Base Station (BS), the method comprising:

generating information about Channel State Information (CSI) reports, the information comprising a number N _RRH > 1 and RRH r, wherein:

N _RRH remote noneThe number of line heads (RRH),

transmitting the information; and

the CSI report is received and the received data is transmitted,