KR102398220B1 - Codebook design and structure for advanced wireless communication systems - Google Patents

Abstract

A base station (BS) is provided in a wireless communication system. The base station transmits information related to a first configuration for reference signals and a second configuration for precoding matrix reporting, and transmits reference signals according to a first configuration comprising a plurality of antenna ports; Receive feedback information including a plurality of indicators derived from reference signals according to the second configuration from the terminal. The base station includes a controller that transforms the plurality of indicators into one of predefined precoding matrices.

Description

CODEBOOK DESIGN AND STRUCTURE FOR ADVANCED WIRELESS COMMUNICATION SYSTEMS

This disclosure relates generally to a codebook design and structure for a two dimensional transmit antennas array. These two-dimensional arrays are often associated with multiple-input-multiple-output (MIMO) systems called full-dimension multiple-input-multiple-output (FD-MIMO).

Wireless communication is one of the most successful innovations in modern history. In recent years, the number of subscribers of wireless communication services has exceeded 5 billion, and is rapidly increasing. Demand for wireless data traffic is increasing with tablets, “note pad” net books, eBook readers, and machine type devices. BACKGROUND OF THE INVENTION [0002] Smart phones and other mobile data devices are growing rapidly due to the increased popularity among consumers and businesses. In order to satisfy high growth in mobile data traffic and to support new applications and deployments, improvement of radio interface efficiency and coverage is important.

An embodiment of the present disclosure provides a codebook design for an improved wireless communication system.

의 형식을 가지는 미리 정의된 프리코딩 매트릭스들 중 하나로 변환하고, 상기 φ는 공동-페이징(co-phasing) 인자이고, h 및 v는 각각 크기 N₁×1 및 N₂×1의 벡터들인 제어기를 포함하는 송수신기를 포함한다.In a first embodiment, a base station (BS) capable of communicating with a user equipment (UE) is provided. The base station transmits a CSI-RS according to a channel state information-reference signal (CSI-RS) configuration including a plurality of antenna ports, and physical downlink shared channels (PDSCH) ) to transmit downlink signals including a CSI-RS configuration reported on, a precoding matrix configuration for a precoding matrix indicator (PMI), and the first and second oversampling factors O ₁ and O _2, a precoding-matrix configuration including the first and second numbers N ₁ and N ₂ is transmitted, and a plurality of PMIs derived from the UE using a CSI-RS according to the precoding-matrix configuration are uplinked. It includes a transceiver for receiving a link signal, and determines the number of PMIs.

Convert a controller to _one of _the predefined precoding matrices having the form It includes a transceiver that includes.

상기 D1 = O1·N1 및 D2 = O2·N2, 이고 m1 및 m2는 양의 정수이다.In some embodiments, for N ₁ =4 and N ₂ =2, h and v are

Wherein D1 = O1·N1 and D2 = O2·N2, and m1 and m2 are positive integers.

의 형식을 가지는 미리 정의된 프리코딩 매트릭스들 중 하나로 변환하는 과정을 포함하고, 상기 φ는 공동-페이징 인자이고, h 및 v는 각각 크기 N₁×1 및 N₂×1의 벡터들이다.In a second embodiment, a method for a base station is provided. The method includes a process of transmitting a CSI-RS according to a CSI-RS configuration including a plurality of antenna ports, a CSI-RS configuration reported on the PDSCH, and a precoding-matrix configuration for PMI. Transmitting downlink signals. process, and send the precoding-matrix configuration including the first and second oversampling factors O ₁ and O _{2 ,} the first and second numbers N ₁ and N ₂ , and to the precoding-matrix configuration from the UE Accordingly, the process of receiving an uplink signal including a plurality of PMIs derived using the CSI-RS, and the number of PMIs

transforming it into _{one of} predefined precoding matrices having the form

의 형식을 가지는 미리 정의된 프리코딩 매트릭스들 중 하나에 대응하고, 상기 φ는 공동-페이징 인자이고, h 및 v는 각각 크기 N₁×1 및 N₂×1의 벡터들이다.In a third embodiment, a UE capable of communicating with a base station is provided. The UE receives the CSI-RS according to the CSI-RS configuration including a plurality of antenna ports, the CSI-RS configuration reported on the PDSCH, and the downlink signals including the precoding-matrix configuration for the PMI. second and second oversampling factors O ₁ and O ₂ , a transceiver for receiving a precoding-matrix configuration comprising first and second numbers N ₁ and N ₂ , O ₁ and O ₂ ; Demodulates and decodes downlink signals to obtain higher-layer configuration values for N ₁ and N ₂ , and determines a plurality of PMIs derived using CSI-RS according to a precoding-matrix configuration, and a base station a controller for causing the transceiver to transmit an uplink signal including a plurality of PMIs, wherein the plurality of PMIs are

Corresponding to _one of _the predefined precoding matrices having the form

의 형식을 가지는 미리 정의된 프리코딩 매트릭스들 중 하나에 대응하고, 상기 φ는 공동-페이징 인자이고, h 및 v는 각각 크기 N₁×1 및 N₂×1의 벡터들이다.In a fourth embodiment, a method for a UE capable of communicating with a base station is provided. The method includes a process of receiving a CSI-RS according to a CSI-RS configuration including a plurality of antenna ports, a CSI-RS configuration reported on a PDSCH, and a precoding-matrix configuration for PMI Receiving downlink signals including a matrix configuration receiving a precoding-matrix configuration comprising first and second oversampling factors O ₁ and O ₂ , first and second numbers N ₁ and N ₂ , O ₁ and O ₂ , N A process of demodulating and decoding downlink signals to obtain higher-layer configuration values for ₁ and N ₂ , and a process of determining a plurality of PMIs derived using a CSI-RS according to a precoding-matrix configuration, a base station , comprising the step of a transceiver transmitting an uplink signal including a plurality of PMIs, wherein the plurality of PMIs are

Corresponding to _one of _the predefined precoding matrices having the form

In a fifth embodiment, a base station is provided in a wireless communication system. The base station transmits information about a first configuration for reference signals and a second configuration for a precoding matrix report, and transmits reference signals according to a first configuration including a plurality of antenna ports, from the terminal, a second and a transceiver for receiving feedback information including a plurality of indicators derived from reference signals according to a configuration. The base station includes a controller that converts the plurality of indicators into predefined precoding matrices. Each of the predefined precoding matrices includes a first element and a second element. The first element comprises a product of a first value indicative of an azimuth channel and a second value indicative of an elevation channel. The second element comprises a product of a first and a second value that are phase-shifted.

In a sixth embodiment, a method for a base station in a wireless communication system is provided. The method includes transmitting information about a first configuration for reference signals and a second configuration for a precoding matrix report, transmitting reference signals according to a first configuration including a plurality of antenna ports, and a terminal; a process of receiving feedback information including a plurality of indicators derived from reference signals according to a second configuration, and converting the plurality of indicators into predefined precoding matrices. Each of the predefined precoding matrices includes a first element and a second element. The first element comprises a product of a first value indicative of an azimuth channel and a second value indicative of an elevation channel. The second element includes a product of the first and second values that are phase-shifted.

In a seventh embodiment, a terminal is provided in a wireless communication system. The terminal receives information about a first configuration for reference signals and a second configuration for a precoding matrix report, receives reference signals according to a first configuration including a plurality of antenna ports, and according to a second configuration and a transceiver for transmitting feedback information comprising a plurality of indicators derived from reference signals. By the base station, the plurality of indicators are converted into predefined precoding matrices. Each of the predefined precoding matrices includes a first element and a second element. The first element comprises a product of a first value indicative of an azimuth channel and a second value indicative of an elevation channel. The second element includes a product of the first and second values that are phase-shifted.

In an eighth embodiment, a method for a terminal in a wireless communication system is provided. The method comprises the steps of: receiving information about a first configuration for reference signals and a second configuration for a precoding matrix report; receiving reference signals according to a first configuration comprising a plurality of antenna ports; 2 Transmitting feedback information including a plurality of indicators derived from reference signals according to a configuration; By the base station, the plurality of indicators are converted into predefined precoding matrices. Each of the predefined precoding matrices includes a first element and a second element. The first element comprises a product of a first value indicative of an azimuth channel and a second value indicative of an elevation channel. The second element includes a product of the first and second values that are phase-shifted.

Other technical features will become readily apparent to those skilled in the art from the following drawings, descriptions and claims.

Before entering into the specifics for carrying out the following disclosure, it may be advantageous to set forth definitions of certain words and phrases used throughout this disclosure. The term “couple” and its derivatives may refer to any direct or interfering communication between two or more components. The terms “transmit,” “receive,” and “communicate,” as well as derivatives of the above terms, may include both direct and indirect communication. The terms “include ( include)", "comprise" as well as derivatives thereof may mean to include without limitation. The term "or" may have an inclusive meaning and/or. The phrase "associated with " and "associated therewith," as well as derivatives thereof, include, be included within, interconnect with, contain, within be contained within, connect to or with, couple to or with, be communicable with, with cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, of can mean have a property of, have a relationship to or with, etc. The term "controller" refers to hardware, and hardware and software ) and/or firmware (firmware) may mean any device, system, or part thereof that controls at least one operation, which may be implemented in combination. may be centralized or decentralized, regardless of whether the phrase “at least one of” when used with an Other combinations of items on the top may be used, which may mean that only one item in the list may be requested. For example, “at least one of A, B, and C” may include one of A, B, C, A and B, A and C, B and C, and A, B, and C.

In addition, various functions described below may be executed or supported by one or more computer programs. Each of the above functions is formed from computer readable program code and formed in a computer readable medium. The terms “application” and “program” refer to computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or suitable computer programs. It may mean a portion thereof suitable for implementation of a readable program code (code). The phrase “computer readable program code” may include any type of computer code, including source code, object code, and executable code. The phrase “computer-readable medium” means read only memory (ROM), random access memory (RAM), hard disk drive, compact disc (CD), digital video disc (DVD), or memory ( may include any type of media that can be accessed by a computer, such as any other type of memory). A “non-transitory” computer-readable medium may exclude wired, wireless, optical, or other communication links that transmit transitory electronic or other signals. A non-transitory computer readable medium is a medium in which data, such as a rewritable optical disc or an erasable memory device, can be stored and subsequently overwritten, and the data is permanent. It may include media that can be stored as

Definitions of specific words and phrases may be provided throughout this disclosure. A person skilled in the art should understand that, in most cases, these definitions can apply to past as well as future uses with the words and phrases defined.

Communication system performance can be improved.

For a more complete understanding of the present disclosure and its advantages, the following descriptions are made with reference to the accompanying drawings. In the drawings, like reference numbers indicate like elements.
1 illustrates a wireless network according to the present disclosure.
2A and 2B illustrate wireless transmit and receive paths in accordance with the present disclosure.
3A shows an example of user equipment (UE) according to the present disclosure.
3B illustrates an example of an evolved node B (eNB) according to this disclosure.
4A and 4B show two-dimensional antenna arrays comprising 16 dual-polarized antenna elements according to the present disclosure.
5 illustrates another numbering of transmit antenna elements according to the present disclosure.
6 illustrates an entire precoding operation according to the present disclosure.
7A, 7B and 7C show UE operations when an eNB according to the present disclosure uses methods 1 to 3 individually.
8 is a process for a basis vector configuration of a UE according to the present disclosure.
9 illustrates an entire base station (BS) precoding operation for a rank 2 channel according to the present disclosure.
10 shows another full BS precoding operation for a rank 2 channel according to the present disclosure.
11 shows a flowchart for basis vector selection in accordance with the present disclosure.
12 shows an example of a switching criterion for a basis vector selection block according to the present disclosure.
13 shows a flowchart for an operating process of a BS according to the present disclosure.
14 shows a flow diagram for an operating process of a UE according to the present disclosure.

1-14 discussed below and the various embodiments used to explain the principles of the present disclosure are for illustrative purposes only and should not be construed as limiting the scope of the present disclosure in any way. Those skilled in the art will appreciate that the principles of the present disclosure may be implemented in any suitably deployed wireless communication system.

The following documents and standards are incorporated into this disclosure as if fully disclosed herein. (1) 3GPP ( ^3rd generation partnership project) TS 36.211, “E-UTRA, Physical channels and modulation”, Release-12, (2) 3GPP TS 36.212, “E-UTRA, Multiplexing and channel coding”, Release-12 , (3) 3GPP TS 36.213, “E-UTRA, Physical layer procedures”, Release-12.

1 shows an example of a wireless network 100 according to the present disclosure. The embodiment of the wireless network 100 shown in FIG. 1 is merely for convenience of description. Other embodiments of the wireless network 100 may be used without departing from the scope of the present disclosure.

The wireless network 100 includes an evolved Node B (eNB) 101 , an eNB 102 , and an eNB 103 . The eNB 101 communicates with the eNB 102 and the eNB 103 . The eNB 101 also communicates with at least one Internet protocol network 130 such as the Internet, a proprietary IP (proprietary IP) network, or another data network.

Depending on the network type, other well-known terms such as “base station” or “access point (AP)” may be used instead of “eNodeB” or “eNB,” or the like. For convenience, the terms "eNodeB" or "eNB" are used herein to denote a network infrastructure configuration that provides wireless connectivity to a remote terminal. Also, depending on the network type, other well-known terms such as "mobile base station", "subscriber station", "remote terminal", "wireless terminal" and "user equipment" may be used instead of "user equipment" or "UE" can For convenience, the terms “user equipment” and “UE,” refer herein to a remote wireless device that wirelessly connects to an eNB, the UE being either a mobile device (eg, a mobile phone or smart phone) or a fixed device ( For example, a desktop computer or vending machine).

The eNB 102 provides a wireless broadband connection to the network 130 to a first plurality of UEs within a coverage area 120 of the eNB 102 . The first plurality of UEs are UE 111 that can be located in a small business (small business), UE 112 that can be located in a large enterprise (enterprise), UE 113 that can be located in a WiFi hot spot, a first residential area UE 114 may be located, UE 115 may be located in a second residential area, and UE of UE 116 may be a mobile device such as a cell phone, wireless laptop, wireless PDA and the like. The eNB 103 provides a wireless broadband connection to the network 130 to a second plurality of UEs within a coverage area 125 of the eNB 103 . The second plurality of UEs include UE 115 and UE 116 . In some embodiments, one or more eNB 101 to eNB 103 each communicate with each other, or 5G (5th generation), LTE (long term evolution), LTE-A (advanced), WiMAX (worldwide interoperability for microwave access) or It can communicate with UEs 111 - 116 using other advanced wireless communication technologies.

The dotted line simply represents the schematic extent of the coverage areas 120 and 125, which are represented as close to circles for illustration and illustration purposes. It should be clearly understood that coverage areas related to eNBs, such as coverage areas 120 and 125, may have other shapes including irregular shapes that vary depending on the configuration of the eNBs and changes in the wireless environment due to natural and man-made obstructions. do.

As described in more detail below, one or more of BS 101, BS 102 and BS 103 include 2D antenna arrays as described in an embodiment of the present disclosure. In some embodiments, one or more of BS 101, BS 102 and BS 103 support a codebook design and structure for systems with 2D antenna arrays.

Although FIG. 1 shows an example of a wireless network 100, various changes are possible with respect to FIG. 1 . For example, wireless network 100 may include any number of eNBs and any number of UEs in any suitable structure. In addition, the eNB 101 may directly communicate with an arbitrary number of UEs, and may provide a wireless broadband connection to the network 130 to any number of UEs. Each of the eNBs 102 to 103 may communicate directly with the network 130 and provide the UEs with direct wireless broadband access to the network 130 . In addition, the eNBs 101 , 102 and/or 103 may provide connectivity to other or additional external networks, such as external telephone networks or other types of data networks.

2A and 2B show examples of wireless transmit and receive paths in accordance with the present disclosure. In the following description, while receive path 250 is described as being implemented in a UE (eg, UE 116 ), transmit path 200 may be described as being implemented in an eNB (eg, eNB 102 ). However, it will also be understood that the transmit path 200 is implemented in the UE and the receive path 250 is implemented in the eNB. In some embodiments, receive path 250 is configured to support codebook design and structure for systems with 2D antenna arrays, as described in embodiments of the present disclosure.

The transmission path 200 is a channel coding and modulation block 205, a serial to parallel (S-to-P) block 210, an inverse fast Fourier transform of size N (IFFT) ) block 215 , a parallel to serial (P-to-S) block 220 , a cyclic prefix (CP) addition block 225 , and an up-converter (UC) 230 . The receive path 250 includes a down-converter (DC) 255, a CP removal block 260, a serial-to-parallel transform (S-to-P) block 265, and a fast fourier transform (FFT) block 270 of size N. , a parallel-to-serial transformation block 275, and a channel decoding and demodulation block 280.

In transmit path 200, a channel coding and modulation block 205 receives a series of information bits, applies coding (eg, low density parity check (LDPC) coding), and a sequence of frequency domain modulation symbols ( sequence), modulates (eg, quadrature phase shift keying (QPSK) or quadrature amplitude modulation (QAM)) the input bits. Serial-to-parallel conversion block 210 (eg, de-multiplexes) of size N Convert the serially modulated frequency domain symbols to parallel data to make parallel symbol streams of IFFT is computed on parallel symbol streams of size N to produce output signals of Transform (i.e., multiplex) the output symbols CP addition block 225 adds CP to the time domain signal Up-converter block 230 converts the output of CP addition block 225 to an RF frequency for transmission over a wireless channel modulates (such as up-converts).The signal can be filtered at baseband before conversion to an RF frequency.

After the RF signal transmitted from the eNB 102 passes through the radio channel, it arrives at the UE 116, and the reverse process of the process performed in the eNB 102 is executed in the UE 116. The down-converter 255 down-converts the received signal to a baseband frequency, and the CP removal block 260 removes the CP to generate a serial time domain baseband signal. The serial-to-parallel conversion block 265 converts the time-domain baseband signal into parallel time-domain signals. The size N FFT block 270 executes an FFT algorithm to generate parallel frequency domain signals of size N. The parallel-to-serial conversion block 275 converts the parallel frequency domain signals into a sequence of modulated data symbols. Channel decoding and demodulation block 280 decodes and demodulates the modulated symbols to recover the original input data stream.

Each of the eNBs 101 to 103 may implement a transmission path 200 similar to transmission in downlink (DL) to UEs 111 to 116, and similar to reception in uplink (UL) from UEs 111 to 116 A receive path 250 may be implemented. Similarly, each of the UEs 111 to 116 may implement a transmission path 200 similar to transmission in the uplink to the eNBs 101 to 103, and may implement a reception path 250 similar to reception in the downlink from the eNBs 101 to 103.

Each of the configurations in FIGS. 2A and 2B may be implemented using only hardware or a combination of hardware and software/firmware. As a specific example, at least some configurations of FIGS. 2A and 2B may be implemented in software, while some other configurations are implemented by hardware or a combination of software and configurable hardware. For example, the FFT block 270 and the IFFT block 215 may be implemented as configurable software algorithms and the size N may vary depending on the implementation.

Also, this is merely an example, and this should not be construed as limiting the scope of the present disclosure. Other types of transform may be used, eg, discrete fourier transform (DFT) and inverse discrete fourier transform (IDFT) functions. Using the DFT and IDFT functions, the value of N can be any integer value (eg, 1, 2, 3, 4, etc.), and using the FFT or IFFT functions, the value of N is a power of 2 It may have a squared value (eg, 1, 2, 4, 8, 16).

2A and 2B show examples of wireless transmit and receive paths, various changes may be made to FIGS. 2A and 2B . For example, various components of FIGS. 2A and 2B may be combined, subdivided, or omitted, and additional components may be added according to specific needs. 2A and 2B are also intended to illustrate examples of types of transmit and receive paths that may be used in a wireless network. Any other suitable structures for supporting wireless communication in a wireless network may be used.

3A shows an example of UE 116 according to this disclosure. The embodiment of the UE 116 illustrated in FIG. 3A is merely for convenience of description, and UEs 111 to 115 of FIG. 1 may have the same or similar configuration. However, UEs vary widely in configurations, and FIG. 3A does not limit the scope of the present disclosure to any particular implementation of a UE.

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

The RF transceiver 310 receives, from the antenna 305, an RF signal transmitted by the eNB of the network 100 . The RF transceiver 310 may down-convert the received RF signal to generate an RF intermediate frequency (IF) or baseband signal. The intermediate frequency or baseband signal is transmitted to receive (RX) processing circuitry 325, which filters, decodes, and/or digitizes the baseband or intermediate frequency signal to generate a processed baseband signal. The reception processing circuit 325 transmits the processed baseband signal to the speaker 330 (eg, voice data) or the main processor 340 to further process the processed baseband signal (eg, web browsing data).

The transmit (TX) processing circuitry 315 receives analog or digital voice data from the microphone 320, or receives outgoing baseband data (eg, web data, ebail or interactive video game data, etc.) from the main processor 340 . The transmit processing circuitry 315 encodes, multiplexes, and/or digitizes the external baseband data to generate a processed baseband or intermediate frequency signal. The RF transceiver 310 receives the externally processed baseband or intermediate frequency signal from the transmit processing circuit 315, and up-converts the baseband or intermediate frequency signal into an RF signal transmitted through the antenna 305 .

The main processor 340 may include one or more processors or other processing units, and may execute a basic operating system (OS) program 361 stored in the memory 360 to control the overall operation of the UE 116 . For example, main processor 340 may control reception of forward channel signals and transmission of reverse channel signals by RF transceiver 310 , receive processing circuitry 325 , and transmit processing circuitry 315 according to well known techniques. In some embodiments, the main processor 340 includes at least one microprocessor or microcontroller.

The main processor 340 may execute programs stored in other processors and memory 360, such as an operation for measuring channel quality, as described in embodiments of the present disclosure, and may report to systems having two-dimensional antenna arrays . The main processor 340 may store or output data required during the execution process in the memory 360 . In some embodiments, the main processor 340 is configured to execute applications based on the operating system program 361 or to execute applications according to signals received from eNBs or an operator. Also, the main processor 340 may be coupled to an I/O interface 345, which allows the UE 116 to be coupled to other devices such as notebooks and portable computers. I/O interface 345 is the communication path between these accessories and the main controller 340.

The main processor 340 may be coupled to the input device 350 and the display 355 . An operator of UE 116 may use keypad 350 to enter data into UE 116 . The display 355 may include a liquid crystal display (LCD) or other type of display device capable of rendering at least one graphic element such as text and/or a web site. there is.

The memory 360 may be coupled to the main processor 340 . Part of the memory 360 may include random access memory (RAM), and another part of the memory 360 may include read only memory (ROM) or flash memory.

Although FIG. 3A shows an example of UE 116 , various modifications may be made to FIG. 3A . For example, the components shown in FIG. 3A may be combined or separated from each other according to specific needs, and may be added or omitted. For example, the main processor 340 may be divided into a plurality of processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). Also, the UE 116 shown in FIG. 3A may be configured as a portable telephone or a smart phone, and the UE 116 may be configured to operate as a mobile device or other form of stationary device.

3B shows an example of an eNB 102 according to this disclosure. The embodiment of the eNB 102 shown in FIG. 3B is only for convenience of description, and other eNBs of FIG. 1 may have the same or similar configuration. However, eNBs vary widely in configurations, and FIG. 3B does not limit the scope of the present disclosure to any particular implementation of an eNB. The eNB 101 and the eNB 103 may include the same or different structures as the eNB 102 .

As shown in FIG. 3B , the eNB 102 may include a plurality of antennas 370a to 370n, a transmit processing unit 374, and a receive processing unit 376 . In some embodiments, one or more of the plurality of antennas 370a to 370n may include two-dimensional antenna arrays. Further, the eNB 102 may include a controller/processor 378 , a memory 380 , and a backhaul/network interface 382 .

The RF transceivers 372a through 372n may receive a received RF signal from the antennas 370a through 370n, such as signals transmitted by UEs or other eNBs. RF transceivers 372a through 372n may down-convert the received RF signal to generate intermediate frequency or baseband signals. The intermediate frequency or baseband signals are transmitted to receive processing circuitry 376, which filters, decodes, and/or digitizes the baseband or intermediate frequency signals to generate processed baseband signals. The receive processing circuitry 376 sends the processed baseband signals to the controller/processor 378 for further processing of the processed baseband signals.

The transmit processing circuitry 374 receives analog or digital data (eg, voice data, web data, e-mail, or interactive video game data) from the controller/processor 378 . Transmit processing circuitry 374 encodes, multiplexes, and/or digitizes external baseband data to generate processed baseband or intermediate frequency signals. The RF transceivers 372a through 372n receive externally processed baseband or intermediate frequency signals from the transmit processing circuitry 374, and up-convert the baseband or intermediate frequency signals transmitted through antennas 370a-370n into RF signals.

The controller/processor 378 may include one or more processors or other processing devices for controlling the overall operation of the eNB 102 . For example, the controller/processor 378 may control reception of forward channel signals and transmission of reverse channel signals by RF transceivers 372a through 372n, receive processing circuitry 376, and transmit processing circuitry 324, in accordance with well-known principles. The controller/processor 378 may support advanced wireless communication technologies as well as additional functions. For example, the controller/processor 378 may perform the BIS process, as performed by a blind interference sensing (BIS) algorithm, and decode signals subtracted by the interfering signals. can Various other functions may be supported at the eNB 102 by the controller/processor 378 . In some embodiments, the controller/processor 378 includes at least one microprocessor or microcontroller.

Also, the controller/processor 378 may execute programs and other processes stored in the memory 380 like a basic operating system. The controller/processor 378 may support channel quality measurement and report the measurement to systems with two-dimensional antenna arrays, as described in embodiments of the present disclosure. In some embodiments, the controller/processor 378 supports communication between entities, such as a real-time clock (RTC). The controller/processor 378 may store data required by the running process in or output from the memory 380 .

In addition, the controller/processor 378 is coupled with a backhaul or network interface 335 . The backhaul or network interface 382 may allow the eNB 102 to communicate with other devices or systems via a backhaul connection or network. Interface 382 may support communication over any wired or wireless connection. For example, when the eNB 102 may be implemented as part of a cellular communication system (eg, 5G, LTE, or LTE-A, etc.), the interface 382 may be configured to allow the eNB 102 to communicate with another eNB through a wired or wireless backhaul connection. may be permitted to communicate with When the eNB 102 is implemented as an access point, the interface 382 may allow the eNB 102 to communicate via a connection to a wired or wireless local area network or a larger wired or wireless network (eg, the Internet). The interface 382 has any suitable structure supported through a wired or wireless connection, such as Ethernet or RF transceiver.

Memory 380 is faulty with controller/processor 325. A portion of the memory 380 may include random access memory (RAM), and another portion of the memory 380 may include a flash memory or other read only memory (ROM). In certain embodiments, a plurality of instructions, such as a BIS algorithm, are stored in the memory. The plurality of instructions are configured to: after subtracting at least one interfering signal determined by the BIS algorithm, the controller/processor 378 performs a BIS process, and decodes the received signal.

As described in more detail below, the transmit and receive paths of the eNB 102 (implemented using RF transceivers 372a through 372n , transmit processing circuitry 374 , and/or receive processing circuitry 376 ) are subjected to frequency division duplexing. ) and cells (cells) and time division duplexing (time division duplexing) support communication with an aggregation of cells.

Although FIG. 3B shows an example of an eNB 102 , various modifications may be made to FIG. 3B . For example, the eNB 102 may include any number of each element shown in FIG. 3 . As a specific example, the access point may include multiple interfaces 382, and the controller/processor 378 may support routing functions for route data between different network addresses. In another specific example, although shown as including a single instance of transmit processing circuitry 374 and a single instance of receive processing circuitry 376, the eNB 102 may include multiple instances of each (eg, one per RF transceiver). instance of).

4 직사각형 포맷(format)으로 배열된 16개의 이중-편파(dual-polarized) 안테나 요소들로 설계된 이차원 안테나 배열들을 도시한다. 도 4a는 안테나 포트(antenna port, AP) 인덱싱 1을 갖는 4

4 이중-편파 안테나 배열 400을 도시하고, 도 4b는 아테나 포트 인덱싱 2를 갖는 동일한 4

4 이중-편파 안테나 배열 410을 도시한다. 도 4a 및 4b에 나타낸 실시 예는 설명의 편의를 위한 것이다. 본 개시의 범위를 벗어나지 않는 한, 다른 실시 예들이 이용될 수 있다. 4A and 4B are, according to embodiments of the present disclosure, 4

4 shows two-dimensional antenna arrays designed with 16 dual-polarized antenna elements arranged in a rectangular format. Figure 4a is an antenna port (antenna port, AP) 4 with indexing 1

4 shows a dual-polarized antenna arrangement 400, FIG. 4b is the same 4 with Athena port indexing 2

4 A dual-polarization antenna arrangement 410 is shown. The embodiment shown in FIGS. 4A and 4B is for convenience of description. Other embodiments may be used without departing from the scope of the present disclosure.

4 이중 편파 배열은 16

2=32 개의 요소들의 배열로 보여(view)질 수 있다. 수평 차원(horizontal dimension)을 통한 방위각 빔포밍(azimuthal beamforming)에 더하여, (4 행들로 구성된)수직 차원(vertical dimension)은 고도 빔포밍(elevation beamforming)을 이용할 수 있다. Rel. 12 LTE 표준(TS 36.211 섹션 6.3.4.2 와 6.3.4.4 및 TS 36.213 섹션 7.2.4)에서 다중 입력 다중 출력(multi input multi output, MIMO) 프리코딩(precoding)은 1차원 안테나 배열을 위한 프리코딩 이득(gain)을 제공하도록 크게 설계된다. 고정된 빔포밍(즉, 안테나 가상화)이 고도(elevation) 차원을 통해 구현될 수 있지만, 고정된 빔포밍은 채널의 공간 및 주파수 선택 특성에 의해 제공되는 잠재 이득(potential gain)을 뛰어넘을 수 없다. In certain embodiments, each labeled antenna element is logically mapped to a single antenna port. In general, one antenna port may correspond to a plurality of antenna elements combined through virtualization. 4

4 double polarization arrangement is 16

It can be viewed as an array of 2=32 elements. In addition to azimuthal beamforming through a horizontal dimension, a vertical dimension (consisting of 4 rows) may use elevation beamforming. Rel. 12 Multi input multi output (MIMO) precoding in the LTE standard (TS 36.211 sections 6.3.4.2 and 6.3.4.4 and TS 36.213 section 7.2.4) is a precoding gain for a one-dimensional antenna array. It is largely designed to provide a gain. Although fixed beamforming (i.e., antenna virtualization) can be implemented through the elevation dimension, fixed beamforming cannot exceed the potential gain provided by the spatial and frequency selective characteristics of the channel. .

5 illustrates another numbering of transmit antenna elements 500 (or transceiver unit (TXRU)) according to embodiments of the present disclosure. The embodiment shown in FIG. 5 is for convenience of description, and other embodiments may be used without departing from the scope of the present disclosure.

In certain embodiments, the eNB may be equipped with a two-dimensional rectangular antenna array (or TXRUs) comprising M rows and N columns polarized with P=2, wherein each antenna array element comprises: indexed by (m, n, p), as shown in Fig. 5, M and N are 4, m = 0, ... , M-1, n = 0, … , N-1, p = 0, … , P-1. In one example, (1-dimensional, 1D subarray partition), in later embodiments, (M, N) is (N _H , N _V ) or (N ₁ , N ₂ ) can be marked.

In some embodiments, the UE is configured with a CSI-RS resource including Q (Q=MNP) channel state information-reference signal (CSI-RS) ports. The CSI-RS resource is related to MNP resource elements in a pair of physical resource blocks (PRBs) in a subframe.

CSI- RS and CSI feedback configuration

In some embodiments, the UE is configured with a CSI-RS including Q antenna ports (antenna ports A(1) to A(Q)) through a higher layer. UE 116 may further include a CSI reporting configuration through a higher layer in relation to the CSI-RS configuration. The CSI reporting configuration includes an information element (IE) indicating CSI-RS separation information (or component PMI port configuration).

As described in Table 1 below, an example of a method for instructing separation of PMI reports is to explicitly configure M, N, and P, and implicitly configure Q.

Component PMI Port Configuration M… Select from a positive even number, e.g. {1,2,4,,, 16}
N… Select from a positive even number, e.g. {1,2,4,,, 16}
P… either 1 or 2
Q = M N P … Implicitly derived from explicitly constructed M, N, P

In conventional LTE, MIMO precoding is performed with either CRS (see TS 36.211 section 6.3.4.2) or UE-specific reference signal (UE-RS) (see TS 36.211 section 6.3.4.4). can be In each case, each UE operating in spatial multiplexing mode is configured to report CSI, which may include a precoding matrix indicator (PMI) (ie, a precoding codebook index). The PMI report is derived from one of the standardized codebooks below. Two antenna ports: {TS 36.211 Table 6.3.4.2.3-1};}; Four antenna ports: {TS 36.211 Table 6.3.4.2.3-2} or {TS 36.213 Table 7.2.4-0A, B, C, and D}; and 8 antenna ports: {TS 36.213 Table 7.2.4-1, 2, 3, 4, 5, 6, 7, and 8}

N_L의 크기의 프리코딩 매트릭스 W와 관련되어 있고, N_c은 한 행(열 들의 개수와 같음)의 안테나 포트들의 수이고, N_L은 송신 계층들의 수 이다. If the eNB follows the UE's PMI recommendation, the eNB may precode the transmitted signal according to the recommended precoding vector/matrix (for a given subframe and physical resource block (PRB)). Regardless of whether the eNB follows the UE's recommendation, the UE is configured to report the PMI according to the above-mentioned precoding codebook. Here, PMI (which may consist of a single index or a pair of indexes) is of size N _c

It relates to a precoding matrix W of size N _L , where N _c is the number of antenna ports in one row (equal to the number of columns), and N _L is the number of transmission layers.

Rel . 12 LTE 8-send double codebook

Tables 2 and 3 are codebooks for rank-1 and rank-2 (1-layer and 2-layer) CSI reporting for UEs configured with 8 transmit antenna port transmissions. To determine the codeword (CW) for each codebook, two indices, i ₁ and i ₂ , must be selected. In this precoder expression, the following two variables are used.

Table 2 below shows a codebook for 1-layer CSI reporting using 15 to 22 antenna ports.

When the most recently reported RI is 1, m and n are derived as two indices i ₁ and i ₂ according to <Table 2>, which results in a rank-1 precoder as shown in Equation 2 below .

Table 3 below shows a codebook for 2-layer CSI reporting using 15 to 22 antenna ports.

When the most recently reported R1 is 2, according to <Table 3>, m, m' and n are derived as two indices i ₁ and i ₂ , which is a rank-2 precoder as shown in Equation 3 below. causes

은 랭크-2 송신을 용이하게 하는 2개의 다른 유형의 채널 조건들에 대해 사용될 수 있도록 구성된다는 것을 유의해야 한다.

It should be noted that is configured to be usable for two different types of channel conditions that facilitate rank-2 transmission.

i ₂ = {0, 1, … , 7} one subset of the codebook associated with m = m' includes codewords, and the same beams (v _m ) construct a rank-2 precoder as in Equation 4 below. used for

이러한 랭크-2 프리코더들은 다르게 편파된 2개의 안테나들에 의해 생성된 2개의 직교 채널들을 따라, 강한 신호들을 수신할 수 있는 UE들에 대해 사용될 수 있다.In this case, for the two columns, the two columns are orthogonal in the two-layer precoder because of the different signs that ϕ _n applies to.

These rank-2 precoders may be used for UEs capable of receiving strong signals along two orthogonal channels created by two differently polarized antennas.

Rel . 12 LTE Alternative 4-send double codebook

Based on a concept similar to 8-send, an alternative 4-send codebook can be described as follows.

Table 4 below shows a codebook for 1-layer CSI reporting using 0 to 3 or 15 to 18 antenna ports.

Table 5 below shows a codebook for 2-layer CSI reporting using antenna ports 0 to 3 or 15 to 18.

For FD-MIMO using a two-dimensional antenna array (two-dimensional precoding), a high-performance, scalable (with respect to the number and geometry of transmit antennas), and a flexible CSI feedback framework ( framework) and structure. To achieve high performance, more accurate CSI (preferably quantized MIMO channel) in the eNB is needed. This is particularly the case for FDD scenarios where short-term reciprocity is not feasible. In this case, the old LTE (eg REl. 12) precoding framework (PMI-based feedback) may need to be replaced. However, feedback of the quantized channel coefficient may be excessive in terms of feedback requirements.

In this disclosure, the following characteristics of FD-MIMO are considered for the proposed schemes:

1. The use of large two-dimensional antenna arrays placed close together according to a relatively small cluster (mainly aimed at high beamforming gain rather than spatial multiplexing) is spread to each UE: this is the “compression of the quantized channel feedback” Allows for "compression" or "dimensionality reduction". In this case, a set of basis functions/vectors is used, and the quantization essentially expresses the MIMO channel in terms of a linear combination of these basis functions/vectors.

2. Low mobility as a target scenario for FD-MIMO: possibility to update quantization parameters at a low rate (long-term channel statistics such as channel angle spread), for example, Using UE-specific higher-layer signaling, in addition, CSI feedback can be used cumulatively.

3. Although time-varying basis functions/vectors may be used (eg derived from EVD or SVD and fed back from UE to eNB), basis functions derived mainly from channel angle spread properties/ A small channel angle spread ensures the use of a fixed master-set of vectors. For a given channel angle spreading characteristic, a subset of a fixed master-set (known in advance to the UE and eNB) is selected by the eNB and signaled to the UE.

The entire codebook configuration operation according to some embodiments of the present disclosure is as follows (assuming a two-dimensional antenna array:

1. The UE receives _NP antenna ports and CSI-RS (channel state information reference signals) configuration corresponding to the CSI-RS. NP may be decomposed into NP and _{N H} · _{N V} . According to the notation in the embodiments related to FIG. 5 , _NH is 2N and N _V is M. In one example where N _V is 4 and N _H is 8, the cross polarization (x-pol) dimension is calculated for one row rather than one column.

2. With the processed CSI-RS, the UE derives channel state information (channel quality information, CQI), a precoding matrix indicator (PMI), and / or a rank indicator (rank indicator, RI) . remind:

2.1 RI corresponds to the recommended rank (number of transmission layers).

2.2 PMI corresponds to the recommended precoding matrix, and each column saying w consists of a linear combination of basis vectors.

1 벡터이다. 또한, 이후 실시 예들에서 모 집합은 마스터 집합으로 불릴 수도 있다.2.2.1 where A={a _l } is a set of basis vectors constituting L individual basis vectors, selected apart from a mother set containing a large number (>>L) of basis vectors, Each basis vector a _l is N _P

1 is a vector. Also, in the following embodiments, the parent set may be referred to as a master set.

2.2.1.1. Configuration or reporting of the number of basis vectors L: In one method, L is configured as a higher-layer by the eNB. In another method, the UE reports a recommended value of L for the eNB.

2.2.1.2. As with the antenna ports indexed in Figure 4b, a _l can be further decomposed:

1 및 N_V

1의 DFT 벡터들로, 상기 h_l 및 v_l 는 오버샘플링(oversampled)된다.where magnitude N _H representing the azimuth and elevation channel responses for a given pair of azimuth and elevation angles, respectively

1 and N _V

With DFT vectors of 1, the h _l and v _l is oversampled.

2.1.2.1. When other antenna port indexing is used as shown in FIG. 4B, the Kronecker multiplication formula described above needs to be modified. For example, if indexing in FIG. 4A is assumed, the following equations should be used instead.

2.2.1.2.2. For simplicity, the following mathematical descriptions assume the antenna port indexing given in FIG. 4B. A person skilled in the art can derive corresponding (conceptually equivalent) equations from the disclosed expressions.

상기 v∈W_V; 및 H={h_l}_l=1,2,3,4 는 LTE Rel-10 8-송신 코드북(표 2 및 표 3)의 i₁에 대응하는 4개의 빔들에 대응한다. 즉, H={v_2i,v_2i+1,v_2i+2,v_2i+3}이고, 여기서, v_m은 <수학식 10>과 같다.2.2.1.2.3. In one example, L is 4. furthermore

The v∈W _V ; and H={h _l } _l=1,2,3,4 correspond to 4 beams corresponding to i ₁ of the LTE Rel-10 8-transmission codebook (Tables 2 and 3). That is, H = {v _2i ,v _2i+1 ,v _2i+2 ,v _2i+3 }, where v _m is the same as <Equation 10>.

2.2.1.3. a _l can be further decomposed as follows:

1 및 N_V

1의 DFT 벡터들로 상기 h_l 및 v_l 는 오버샘플링 된다; 그리고, φ_l은 <수학식 12>와 같다.where, magnitude N _H representing the azimuth and elevation channel responses for a given pair of azimuth and elevation angles, respectively

1 and N _V

With DFT vectors of 1, the h _l and v _l is oversampled; And, φ _l is the same as <Equation 12>.

Represents the co-phase of the cross-polarization arrangement. In this case, the parent set can be a product set as follows.

과 연관된 인덱스들은 i₁ 및 i₂를 나타내고, <표 2>에 따른 특정한 프리코더들에 맵핑되는 집합들이다. 게다가, v_l과 관련된 인덱스들은 i₃로서 표현되고, 그리고 그들은 길이 N_V의 DFT 벡터들로 오버 샘플링 된 Q_V에 일대일 맵핑 된다. 상기 Q_V는 고도 코드북 크기를 나타내는 양의 정수이고, N_V의 함수로서 결정될 수 있다.In one method, the index tuple (i ₁ , i ₂ , i ₃ ) points to the basis vector a _l and

Indexes associated with i ₁ and i ₂ are sets mapped to specific precoders according to <Table 2>. In addition, the indices associated with v _l are expressed as i ₃ , and they are mapped one-to-one to Q _V oversampled with DFT vectors of length N _V . The Q _V is a positive integer representing the height codebook size, and may be determined as a function of N _V .

상기 v∈W_V; 및 H={h_l}_l=1,2,3,4 는 LTE Rel-10 8-송신 코드북(표 2 및 표 3)의 i₁에 대응하는 4개의 빔들에 대응한다. 즉, H={v_2i,v_2i+1,v_2i+2,v_2i+3}, 여기서, v_m은 이하 <수학식 14>와 같다.2.2.1.4. In one example, L is 4. furthermore

the v∈W _V; and H={h _l } _l=1,2,3,4 correspond to 4 beams corresponding to i ₁ of the LTE Rel-10 8-transmission codebook (Tables 2 and 3). That is, H = {v _2i ,v _2i+1 ,v _2i+2 ,v _2i+3 }, where v _m is the same as in <Equation 14> below.

1의 DFT 벡터는 이하 <수학식 15>와 같다.2.2.1.5. For example, size 4

The DFT vector of 1 is as shown in Equation 15 below.

wherein D=2 ⁿ , where n is a positive integer. DFT vectors oversampled to other sizes can be similarly constructed.

2.2.2. C={c _l } is a set corresponding to an L scaling factor, and each element of the set is a complex number. Some alternatives for c _l quantization are:

2.2.2.1. The real and imaginary components of c _l are quantized separately. N _Re is a quantization bit for a real dimension, and N _Im is a quantization bit for an imaginary dimension. In one method, N _Re is N _Im .

2.2.2.2. The magnitude and phase components of c _l are quantized separately, N _A quantization bits are for magnitude, and N _Ph quantization bits are for phase.

2.2.2.3 Some details of quantization methods can be found in US Patent Application No. No. 9, 2015, filed Jan. 9, 2015. 14/593,711, which is incorporated herein by reference in its entirety.

2.3. When the selected PMI and the selected RI are used for precoding, a modulation and coding scheme that allows the UE to receive a physical downlink shared channel (PDSCH) packet with a constant (eg, 0, 1) packet error probability. CQI corresponds to .

2.4. The UE may select an RI and PMI that allows the best (or highest) CQI for PDSCH transmission with a constant (eg, 0.1) error probability.

3. When triggered for an aperiodic physical uplink shared channel (PUSCH) report, the UE reports PMI/CQI/RI in a single PUSCH.

3.1. In one method, the PMI corresponding to the basis vector set A is wideband (ie, only one set is reported in the aperiodic report), and the PMI corresponding to the coefficient set C is a subband (ie a plurality of sets). sets, eg one per subband in periodic reporting).

3.2. In one method, the PMIs corresponding to h _l and v _l are broadband, and the set of coefficients C and the co-phasing factor φ are subbands.

4. When configured with periodic reporting, in one subframe with period Q, in another subframe with period P and RI, the UE transmits CQI/PMI on a physical uplink control channel (PUCCH) report.

4.1. In one method, the PMI corresponding to the basis vector set A is reported less frequently (ie, reported with a larger period) than the PMI corresponding to the coefficient set C.

4.2. In another method, the PMI corresponding to h ₁ and v ₁ is reported less frequently than the PMI corresponding to the coefficient set C and the co-paging factor φ.

4.3. In the above two methods (a) and (b), the less frequently reported PMI is reported from the same PUCCH resource pool as the same method and/or RI.

4.4. In another method, the PMI corresponding to the basis vector set A and the PMI corresponding to the coefficient set C are reported together with one self-contained PMI report.

4.5. In one method, the PMI corresponding to the basis vector set {a _l } is reported less frequently (ie, reported with a larger period) than the PMI corresponding to the coefficient set {c _l }.

UE Examples of feedback definitions

Example 1: Construction of basis vector A and instruction of L basis vectors

It is desirable to use a small feedback overhead for indicating the L basis vectors. To achieve this goal, one possibility is to decompose the information into pieces, and try to compress the pieces of information individually. For example, this may be done by utilizing the correlation of each piece of information across the frequency domain and basis vectors.

의 집합을 지시하는 제3 필드. 이러한 경우, 대응하는 베이시스 벡터들 A={a_l:l=0,1,...,L-1}는 아래의 식으로 결정된다.In one such method, the UE is configured in at least the following three fields to inform the selected L basis vectors: L vectors representing azimuth domain channel directions (A _H ={h _l :l=0,1, a first field indicating a set of ...,L-1}); a second field indicating a vector (denoted by v) indicating elevation domain channel directions; L co-phasing factors representing phase changes between the two polarization directions

A third field indicating the set of . In this case, the corresponding basis vectors A={a _l :l=0,1,...,L-1} are determined by the following equation.

Each field may be correlated across frequency domain and basis vectors, which may be utilized to reduce feedback overhead.

으로 사용되는 것으로 가정된다. 이러한 방법은 L개의 베이시스 벡터들에 걸친 공동-페이징 인자들의 상관 관계가 높을 때 사용될 수 있다.In one such method, a common co-paging factor is used for all L basis vectors, for feedback information generation, i.e.

is assumed to be used as This method can be used when the correlation of co-paging factors across the L basis vectors is high.

The first and second fields indicate channel directions in the azimuth and elevation domains, and the channel direction information is typically bandwidth independent. Conversely, co-paging factors are frequency selective.

Looking at these channel characteristics, the first and second fields are proposed as wide bands, and the third field is subband. In one example where this compression is applied with common co-paging factors, 4 bits are used to indicate the first field, 2 bits are used for the second field, and 2 bits are used for the third field. Then, in this case, the total number of bits used for basis vector feedback for K subbands is (2K + 6) bits (= 4 bits + 2 bits + 2 bits·K subbands).

이다.For the indication of the first field, the first PMI (i ₁ ) of the Rel-10 8-transmission codebook (Table 2) may be reused, and the first PMI basically indicates four oversampled DFT vectors. In this case, the number of basis vectors selected in the subset L is fixed at 4. With L=4, the first field is an integer i = 0, 1, ... _{. _ _ _ _ _ _ _ _} thing) per

am.

의 DFT 벡터일 수 있고, 상기 D=2ⁿ 이고, n은 양의 정수이다. 이것은 Rel-10 i₁처럼 동일한 특성들의 집합을 공유하는 추가적인 필드이다.Similarly, the vector corresponding to the second field is

may be a DFT vector of , where D=2 ⁿ , where n is a positive integer. This is an additional field that shares the same set of characteristics as Rel-10 i ₁ .

The third field indicates, in azimuth dimension, co-phasing between the two polarizations. With all angles related to information broadband, the frequency selectivity of the channels must be captured by subband coefficients for L basis vectors. So, it is proposed that the UE feed back a set C={c _l } of L quantized coefficients per subband. It is noteworthy that in some cases only one of the coefficients of L for subbands is 1, and the other coefficients of L-1 are 0; In this case, the newly proposed CSI feedback is reduced to the Rel-10 8-transmission codebook.

Because the third field (used for co-paging) shares the same set of characteristics (sub-band trend and faster update) as the C feedback, reporting the third field jointly with the C feedback is It is possible. Also, it may be a separate report and C of the third field.

Example 2: Alternative Configurations

Instead of maximally reusing the Rel-10 codebook configuration, the following variants can also be considered.

상기

일부 예들의 값들 D 는 D=32, D=16, D=8 또는 D=4이다. D=32인 특별한 경우에, 모 집합에 포함된 베이시스 벡터들은 본 개시에서 위 첨자 D, 즉 {v₀,v₁,...,v₃₁}를 생략하여 기재된다.Considering the parent set of basis vectors,

remind

Some examples of values D are D=32, D=16, D=8 or D=4. In the special case of D=32, the basis vectors included in the parent set are described by omitting the superscript D, that is, {v ₀ ,v ₁ ,...,v ₃₁ } in this disclosure.

Depending on the user location and channel condition, different UEs may have different angular spreads. For some UEs with small angular spread in the azimuth domain, the parent set A _H ={v _2i , v _{2i +1} , v _{2i +2} , v _{2i +3} }, i=0,1,...,31 A set of basis vectors including continuous basis vectors in , which can be expressed as W1 (or i ₁ indication according to the Rel-10 8-transmission codebook with D=32 above) is sufficient to describe the channel matrix. Instead, for some other UEs with large angular spread, the continuous basis vector set A _H ={v _2i ,v _{2i + 1} ,v _{2i + 2} ,v _{2i + 3} } does not give a sufficient explanation.

Several methods for coping with these various UE channel conditions are proposed below.

의 모 집합 내에 균일하게 이격된 빔들의 집합을 포함하고, 상기 빔-간 간격(inter-beam spacing)으로 표시되는 s로 이격된 상기 집합에서 2개의 인접한 빔들이 나타내어지고, 여기서 s는 양의 정수이다.In one method, the basis vector set A _H is

Including a set of uniformly spaced beams within a parent set of , two adjacent beams are represented in the set spaced by s, denoted by the inter-beam spacing, where s is a positive integer. am.

For example, when s is configured as D=32, the UE selects a preferred basis vector set index i, where the basis vector set i is A _H (i)={v _2i , v _{2i +s} , v _{2i +2s} , v _2i+3s }, where i=0, 1, … , is 15.

Two alternatives are devised for configuring the processor of the UE of the basis vector set. In one alternative, the eNB may estimate the downlink angle of departure (AOD) spread from uplink sounding, and configure the inter-beam spacing as s. In another alternative, the UE selects the inter-beam spacing based on the channel estimate from the received reference signals and feeds it back to the UE. In some embodiments, the selected s is wideband, and only one value of s is fed back for the entire downlink frequency. In another embodiment, the selected s is reported less frequently (with a larger reporting period) than the basis vector set index i.

In this way, for signaling of s, a set S must be defined, and elements of the set S are candidate values of s that the eNB can select. In one example, S = {s: s = 1 or 2}, and in this case, the information size is 1 bit. In another example, S = { s : s = 1, 2, 3 or 4}, in which case the information size is 2 bits.

의 모 집합 내에 L개의 연속적인 빔들의 집합을 포함하고, 상기 D는 eNB에 의해 구성되거나 UE에 의해 선택된다. D가 UE에 의해 선택될 때, UE는 D에 관한 정보를 eNB로 피드백한다. 일부 실시 예들에서, 전체 하향링크 주파수(즉, D는 광대역 정보)에 대해 하나의 D값이 피드백된다.In another way, the basis vector set A _H is

Including a set of L consecutive beams in the parent set of , where D is configured by the eNB or selected by the UE. When D is selected by the UE, the UE feeds back information about D to the eNB. In some embodiments, one D value is fed back for the entire downlink frequency (ie, D is wideband information).

In one alternative, for this operation, a set of possible values for D and a parent set size are configured at the eNB and the UE. In one example, D∈{4,8,16,32}. In another alternative, a set of possible values of the oversampling factor x or O is configured at the eNB and the UE. In one example, x∈{1,2,4,8} and D=x×N or O×N, where N is the number of CSI-RS antenna ports corresponding to the CSI-RS resource or the two-dimensionality of FIG. 5 . One half of the number of antenna ports for M columns or horizontal arrangement in a rectangular arrangement. That is, it is the same as <Equation 17>.

This corresponds to the number of columns in the case of dual-polarized antenna systems.

The feedback information may indicate either D or x. In one example, D∈{4,8,16,32} (or x∈{1,2,4,8}), and the UE reports the selected parent set size using a 2-bit field.

In another example, the UE selects and reports the B basis vector set indices comprising the basis vector set. The basis vector set is indexed by i, B _i ={v _2i , v _{2i +1} , v _{2i +2} , v _{2i + 3} }, where i=0, 1, ..., 2 ^I -1. where I is the number of bits for encoding the selected basis vector set. In one example, I=4. In addition, v _m is the same as in <Equation 18>.

Some example values for D above are D=32 or D=16. By using these multiple sets, a wide spread of AOD or multiple AOD “cones” can be addressed. In this case, fields corresponding to different sets (eg, PMI) may be coded jointly or separately.

이다. 여기서 α₀<α₁<α₂<...<α_{L -1}은 다른 값들이다.In another method, the basis vector set includes a set of L beams,

am. where α ₀ <α ₁ <α ₂ <...<α _{L -1} are different values.

In one alternative, L is configured through higher layer (eg, radio resource control (RRC)) signaling, or to be included in an uplink grant that carries triggering for aperiodic CSI reporting. can Then, for a given L, the UE feeds back a field indicating the selection of α ₀ <α ₁ <α ₂ <...<α _L-1 .

In another alternative, the selection of L may be made at the eNB based on a record of the most recent value or i ₁ report. In this case, the choice of L by the eNB is left to the eNB implementation choice.

In another alternative, one of a field or a bitmap indicating a combination specifying a subset of the L precoding vectors is used.

In another method, the UE is configured to select and report a basis vector set A _H , the basis vector set comprising L basis vectors selected from a parent set.

이다. 여기서 α₀<α₁<α₂<...<α_{L - 1}는 정수 집합 {0, 1, …, D-1}로부터 선택된 다른 값들이고, v_m은 <수학식 19>와 같다.In another method, the basis vector set includes a set of L beams,

am. where α ₀ <α ₁ <α ₂ <...<α _{L - 1} is the set of integers {0, 1, … , D-1}, and v _m is the same as in <Equation 19>.

Some exemplary values for D above are D=32 or D=16.

The selected beam combination is mapped to a bit field, that is, a “beam combination indicator (BCI) field”, coded, and mapped to either PUSCH or PUCCH. The PUSCH may be referred to as a 'data channel', and the PUCCH may be referred to as a 'control channel'.

비트이다. 일부 실시 예에서, 필드에서 비트의 수를 줄이고 수신된 정보의 신뢰성을 향상시키기 위해, 1820개의 조합들의 부분집합은 BCI 필드에 의해 지시된다. In one example, D=16 and L=4, in which case the total number of combinations for selecting L=4 among the candidate beams with D=16 is 1820 (16 choose 4); At that time, the BCI field size is

it's a bit In some embodiments, to reduce the number of bits in the field and improve the reliability of the received information, a subset of 1820 combinations is indicated by the BCI field.

In some embodiments, the BCI field is carried less frequently than the corresponding coefficients.

In some embodiments, the set of L beams indicated by the BCI field is wideband information, which is used to calculate the CQI and corresponding coefficients in all subsets.

In some embodiments, only the BCI field is carried on the PUCCH without multiplexing any other uplink control information.

In some embodiments, the BCI field is coded and mapped on PUSCH in the same way that RI is coded and mapped; This better protects the contents of the field.

In some embodiments, the BCI field is co-coded and mapped with the RI on the PUSCH, in the same way that the RI is coded and mapped; This better protects the contents of the field.

In some embodiments, in the same way that CQI/PMI is coded and mapped, the BCI field is co-coded with the remaining CQI/PMI on PUSCH.

In some embodiments, in order to better protect the contents of the field, the BCI field is transmitted in the RI region of the PUSCH.

In some embodiments, the BCI field is carried on a single-PRB PUSCH, and the information is coded and mapped according to PUSCH channel coding and mapping.

Embodiment 3: Parent set restriction corresponding to indication of L beams or basis vectors

In some embodiments, the additional information, ie, the parent set restriction information, is configured in the UE in addition to the base set index i corresponding to the basis vector set A _H (i). The parent set restriction information may be either indicated by the eNB, selected by the UE, or fed back to the eNB.

을 고려하면, 여기서, v_m은 <수학식 20>와 같다.In one method, the parent set restriction information includes one of a (restricted) parent set size D, or an oversampling factor x. parent set of basis vectors

Considering , where v _m is the same as in <Equation 20>.

The D _M =32.

이 되고, 상기 d=D_M/D, d=D_M/(N_x)이고, 여기서 N은 도 5의 2차원 직사각형 배열에서 열 들의 수이거나, 수평 배열을 위한 안테나 포트들의 수의 절반이다(즉,

). N은 이중-편파된 안테나 시스템들의 경우에 열들의 수에 대응한다. 예를 들면, 제한된 모 집합 크기 D가 D=16으로 구성될 때, 또는 오버샘플링 인자 x가 x=4로 구성될 때, 제한된 모 집합은

이다. 다른 예를 들면, 제한된 모 집합 크기 D가 D=8로 구성될 때, 또는 오버샘플링 인자 x가 x=2로 구성될 때, 제한된 모 집합은

이 된다. In one example, when the constrained parent set size D is configured, or when the oversampling factor x is configured, the constrained parent set set is

, where d=D _M /D, d=D _M /(N _x ), where N is the number of columns in the two-dimensional rectangular array of FIG. 5 or half the number of antenna ports for a horizontal array ( in other words,

). N corresponds to the number of columns in the case of dual-polarized antenna systems. For example, when the constrained population set size D consists of D=16, or when the oversampling factor x consists of x=4, the constrained population set is

am. For another example, when the constrained population set size D consists of D=8, or when the oversampling factor x consists of x=2, the constrained population set is

becomes this

이고, 상기 d=D_M/D, d=D_M/(N_x)이다. In another method, the parent set restriction information includes an offset index f, as well as one of a (restricted) parent set size D or an oversampling factor x. In one example, when the offset index f is configured and the constrained parent set size D (or oversampling factor x) is configured, the constrained parent set is

and d=D _M /D, d=D _M /(N _x ).

이고, D가 8일 경우, 조합을 지시하는 비트들의 수는

비트이다.In these methods, the number of candidate basis vector sets may be configured differently depending on the selection of the constrained parent set. In some embodiments, the UE is configured to report any combination of the L basis vectors in the constrained parent set. The number of bits carrying the combination will be determined by the configured value of D. For example, when D is 16, the number of bits indicating the combination is

, and when D is 8, the number of bits indicating the combination is

it's a bit

In some embodiments, the UE is configured to report L consecutive basis vectors in the constrained parent set, and the number of bits for feedback information in the set of basis vectors is determined according to the size of the constrained parent set.

In some embodiments, the UE is configured to separately report the information of the parent set restriction information and the basis vector combination. In these embodiments, the parent set restriction information is wideband information, and only one value is fed back for the entire downlink frequency. In addition, the parent set restriction information is reported less frequently (with a larger reporting period) than the basis vector set index i.

In some embodiments, the UE is configured to jointly report the parent set restriction information and the coding information of the basis vector combination.

Some examples where L is 4 are as follows.

When D = 32 (or x = 8), the parent set is {v ₀ ,v ₁ ,...,v ₃₁ }, depending on the beam index, A _H (i)={v _2i ,v _{2i + 1} ,v _{2i + 2} ,v _{2i + 3} }, the UE is configured to report the set A _H (i) of four consecutive vectors in the constrained parent set, where i=0,1,..., 15. In this case, the UE is configured to use 4 bits to report information on the basis-vector combination.

When D = 16 (or x = 4), the parent set is {v ₀ , v ₂ ,...,v ₃₀ }, and depending on the beam index, A _H (i)={v _2i ,v _2i+2 ,v _2i+4 ,v _2i+6 }, the UE is configured to report the set A _H (i) of four consecutive vectors in the constrained parent set, where i=0,1,..., 15. In this case, the UE is configured to use 4 bits to report information on the basis-vector combination.

When D = 8 (or x = 2), the parent set is {v ₀ , v ₄ ,...,v ₂₈ }, and depending on the beam index, A _H (i)={v _4i ,v _4i+4 ,v _4i+8 ,v _4i+12 }, the UE is configured to report the set A _H (i) of four consecutive vectors in the constrained parent set. where i=0,1,...,7. In this case, the UE is configured to use 3 bits to report information on the basis-vector combination.

When D = 4 (or x = 1), the parent set is {v ₀ , v ₈ , v ₁₆ , v ₂₄ }, in which case the UE does not report A _H (i) and A _H (i) = {v ₀ ,v ₈ ,...,v ₂₄ }.

Another example where L is 4 is as follows.

When D = 32 (or x = 8), the parent set is {v ₀ , v ₁ ,...,v ₃₁ } and, depending on the beam index, A _H (i)={v _2i ,v _{2i + 1} ,v _{2i + 2} ,v _{2i + 3} }, the UE is configured to report the set A _H (i) of four consecutive vectors in the constrained parent set. where i=0,1,...,15. In this case, the UE is configured to use 4 bits to report information on the basis-vector combination.

When D = 16 (or x = 4), the parent set is {v ₀ , v ₂ ,...,v ₃₀ }, depending on the beam index, A _H (i)={v _4i ,v _4i+2 ,v _4i+4 ,v _4i+6 }, the UE is configured to report the set A _H (i) of four consecutive vectors in the constrained parent set. where i=0,1,...,7. In this case, the UE is configured to use 3 bits to report information on the basis-vector combination.

When D = 8 (or x = 2), the parent set is {v ₀ , v ₄ ,...,v ₂₈ }, and depending on the beam index, A _H (i)={v _8i ,v _8i+4 ,v _8i+8 ,v _8i+12 }, the UE is configured to report the set A _H (i) of four consecutive vectors in the constrained parent set. where i=0,1,...,4. In this case, the UE is configured to use two bits to report information on the basis-vector combination.

When D = 4 (or x = 1), the parent set is {v ₀ ,v ₈ ,v ₁₆ ,v ₂₄ }, in which case the UE does not report A _H (i) and A _H (i)= {v ₀ ,v ₈ ,...,v ₂₄ }.

인 비트 필드를 사용하여 코딩될 수 있다. 표 6은 이러한 일 예를 나타낸다.When the parent set constraint and the basis vector set are jointly coded, in this example the total number of states pointing to the basis vector set is (for D = 32) 16 + (for D = 16) 8 + (D = For 8) 4 = 28, which is

It can be coded using in-bit fields. Table 6 shows one such example.

Table 6 below shows the alternative basis vector set (or beam set) indicator mapping.

Basis Vector Set Indicator Index (5-bit) Population set size (D) or subsampling factor (x) basis vector combination index (i) Basis vector set (A _H (i)) 0, ..., 15 D=32 or x=8 0, ..., 15 {v _2i , v _{2i +1} , v _{2i +2} , v _{2i +3} } 16, ..., 23 D=16 or x=4 0, ..., 7 {v _4i , v _{4i +2} , v _{4i +4} , v _{4i +6} } 24, ..., 27 D=8 or x=2 0, ..., 3 {v _8i , v _{8i +4} , v _{8i +8} , v _8i+12 } 28 D=4 or x=1 0 {v ₀ , v ₈ , v ₁₆ , v ₂₄ } 29, 30, 31 reserved reserved

In some embodiments, in the same way that CQI/PMI is coded and mapped, the parent set and basis vector set indicator index are co-coded with the rest of the CQI/PMI on PUSCH.

In some embodiments, four different offset values f∈{0,2,4,6} are used when D = 4 (or x = 1), and the combination of the four basis vectors is {v associated with D = 4 _f , v _f+8 ,v _f+16 ,v _f+24 }, f∈{0,2,4,6}. In this case, a table for the base vector set indicator is constructed according to <Table 7>.

Table 7 below shows the alternative basis vector set (or beam set) indicator mapping.

Basis Vector Set Indicator Index (5-bit) Population set size (D) or subsampling factor (x) basis vector combination index (i) Basis vector set (A _H (i)) 0, ..., 15 D=32 or x=8 0, ..., 15 {v _2i , v _{2i +1} , v _{2i +2} , v _{2i +3} } 16, ..., 23 D=16 or x=4 0, ..., 7 {v _4i , v _{4i +2} , v _{4i +4} , v _{4i +6} } 24, ..., 27 D=8 or x=2 0, ..., 3 {v _8i , v _{8i +4} , v _{8i +8} , v _8i+12 } 28, 29, 30, 31 D=4 or x=1 0, ..., 3 {v _{2i +0} , v _{2i +8} , v _{2i +16} , v _2i+24 }

Example 4: H and V PMI configuration with indications corresponding to parent set restrictions and L basis vectors

In the case of a cross-polarized two-dimensional rectangular antenna array as shown in FIG. 5, the basis vectors A(i,k)={a _l (i,k):l=0,1,...,L-1} are It can have a formula like

The h _l (i)∈A _H (i) is configured according to some embodiments of the present disclosure.

1 벡터이다. In some embodiments, v _l (k)=v(k),l=0,1,...,L-1,k=0,...,K-1. In this case, information is coded for each k on a single vector v(k) by the UE and fed back to the eNB. In one example, the number of antenna ports for V-PMI feedback is two, and v(k) is two

1 is a vector.

In one example, v(k) is selected from the LTE 2-transmit rank-1 codebook. That is, v(k) is the same as in <Equation 22> when K=4.

In another example, v(k) is selected from an oversampled DFT codebook with an oversampling factor y. That is, v(k) is the same as <Equation 23>.

이다.Wherein y is a positive integer. The oversampling factor y may be indicated by the eNB to the UE, or configured by the UE and fed back to the eNB. The number of states for v(k) may vary depending on the configured value of y. In one example, the number of information bits is

am.

Example 5: Linear combination coefficient quantization

Linear combination (LC) coefficient quantization is one of the essential factors in determining the feedback overhead of the proposed method. A general radio channel state may follow the wideband and long-term feedback of the basis vector set. However, the channel condition requires that the quantization and reporting of the LC coefficients be implemented in a narrowband and short-term method. So, it is important to use a small number of bits for LC coefficient quantization.

In the Rel-10 8-transmit codebook, only very coarse quantization is supported. The UE can choose one of the basis vectors with L=4, its information only needs 2 bits of information ((4 choose 1) = 4 = 2 bits). With cross-polarization co-paging selection (2 bits), the Rel-10 8-transmit codebook allocates a total of 4 bits for i ₂ feedback, as shown in Tables 2 and 3.

In this embodiment, in order to increase the accuracy of the quantized channel matrix, it is proposed to use a larger number of quantization bits for coefficient quantization.

In one method, binary quantization is used to quantize each of the coefficients with L=4 for the basis vectors with L=4. In one example, a 4-bit bitmap is used to report (or indicate) coefficients with L=4. In another example, coefficients with L=4 are less than 4. In another example, a 3-bit field quantizes binary coefficients with L=4, and the 6 states of the 3-bit field indicate all 6 combinations of 2 basis vector selections (=4 choose 2). The six combinations are [1 1 0 0], [1 0 1 0], [1 0 0 1], [0 1 1 0], [0 1 0 1], [0 0 1 1].

In the case of a co-pol antenna, the resultant precoding vector w constructed according to this method is expressed by the following equation.

In the case of a cross-polarized antenna, the synthesis precoding vector w is constructed according to a method expressed by the following equation.

where c _l ∈{0,1}, l=0,1,2,3 and e ^jφ is cross-polarization co-phasing.

In the case of such cross-polarization, the quantization index of the linear-combination coefficients and the cross-polarization co-phasing can be encoded individually or jointly.

In one method, according to the LTE 4 transmit PMI codebook, the LC coefficients are quantized with a PMI precoding matrix or critically sampled with a 4-transmit DFT codebook. It should be noted that when the L basis vectors are constructed for linear combinatorial channel reconstruction, the L-transmit PMI codebook should be selected.

을 지시하는데 사용된다.In one method, we can have co-phasing between selected beams in addition to traditional cross-polarization co-phasing in the case of cross-polarization. In one example, a 5-bit field for quantizing binary coefficients with L=4, wherein the 3-bit selects two basis vectors ([1 e ^jα 0 0], [1 0 e ^jα 0], [1 0 0 e ^jα ], [0 1 e ^jα 0], [0 1 0 e ^jα ], [0 0 1 e ^jα ]) are used to indicate all 6 (=4 choose 2) combinations, and 2 bits are used to indicate the joint between the selected beams. - paging

used to indicate

In one method, for the case of a co-polarized antenna, the composite precoding vector w constructed according to this method is expressed by the following equation.

l=0,1,2,3이고, 교차-편파 안테나의 경우에 대해, 이러한 방법에 따라 구성된 합성 프리코딩 벡터 w는 다음의 식으로 표현된다.where c _l ∈{0,1},

l = 0,1,2,3, and for the case of a cross-polarized antenna, the synthesized precoding vector w constructed according to this method is expressed by the following equation.

l=0,1,2,3 이고, e^jφ 는 교차-편파 공동-페이징이다.where c _l ∈{0,1},

l=0,1,2,3 and e ^jφ is cross-polarization co-phasing.

In the case of cross-polarization, the quantization index of the linear-combination coefficients, beam co-phasing, cross-polarization co-phasing can be encoded individually or jointly.

In another way, the linear combination coefficients are allowed to take the magnitude value from the magnitude set. In one example, the size set may be {0.5,1,1.5,2}. In this example, 2 bits are used to indicate the magnitude of the linear combination coefficients. In this example, two bits indicate one common magnitude for all four linear coefficients. Alternatively, a 2-bit indication is allowed for each linear combination coefficient.

In one method, magnitudes and co-phasing are individually quantized for selected beams using separate codebooks. In another method, the magnitudes and co-phasing are jointly quantized using a joint codebook. The codebooks may be scalar codebooks or vector codebooks.

In another method, the four coefficients are quantized using a vector codebook of appropriate length (eg, a length-4 vector quantizer). Codebooks can be learning-based adaptive or universal and non-adaptive.

Example 6: Feedback construction for {a _l }: indication of L index tuples (i ₁ , i ₂ , i ₃ ) for L basis vectors.

의 분해에 따라 {a_l}을 구성하기 위해 구성되고, 상기 h_l 및 v_l는 주어진 방위 각 및 고도 각의 쌍에 대해, 각각 방위 및 고도 채널 응답을 나타내는 크기 N_H×1 및 N_V×1로 오버샘플링된 DFT 벡터들이다. 그리고

는 교차-편파 행렬의 공동-페이즈를 나타낸다. 인덱스 튜플 (i₁, i₂, i₃)는 베이시스 벡터 a_l을 지시한다.

와 연관된 인덱스는 i₁ 및 i₂로 표시되고, 이것의 집합은 8-송신 또는 4-송신에 대한 표 2 또는 표 4에 따른 특정 프리코더들에 맵핑된다. 게다가, v₁과 관련된 인덱스들은 i₂로 표시되고, 그것들은 길이 N_V의 Q_V 오버샘플링된 DFT 벡터들에 일대일 맵핑된다. 상기 Q_V는 고도 코드북 크기를 나타내는 양의 정수이고, 이것은 N_V의 함수로 결정될 수 있다.UE is

is constructed to _{construct {} a _{l }} according to the _{decomposition} of DFT vectors oversampled by 1. And

denotes the co-phase of the cross-polarization matrix. The index tuple (i ₁ , i ₂ , i ₃ ) points to the basis vector a _l .

The index associated with is denoted by i ₁ and i ₂ , a set of which is mapped to specific precoders according to Table 2 or Table 4 for 8-transmission or 4-transmission. Moreover, the indices associated with v ₁ are denoted by i ₂ , and they are of length N _V . Q _V One-to-one mapping to oversampled DFT vectors. The Q _V is a positive integer representing the height codebook size, which may be determined as a function of N _V .

Three options for feeding back L index tuples for L basis vectors are devised as follows. For convenience of explanation, i ₁ ∈ {0, 1, 2, 3} (ie, 4 bits of information), i ₂ ∈ {0, 1, 2, ... , 15} (ie, 4 bits of information), and i ₃ ∈ {0, 1, 2, 3} (ie, 2 bits of information).

1. Separate feedback of L index tuples for L basis vectors: 8 bits are used to transmit (i ₁ , i ₂ ); A total of 10 bits are used to transmit all three indexes per subband. If the UE is configured to report the index tuple for 10 subbands and L=4, the total number of bits for feedback is 400 bits (=10 subbands 4 basis vector ·(4+4+) 2) bit).

2. Wideband and basis-common feedback of i ₂ : The UE is configured to feedback a single wideband i ₃ value, which is also commonly used to construct all L=4 basis vectors. If the UE is further configured to report the index tuple for 10 subbands and L=4, then the total number of bits for feedback is 322 bits (=2 + 10 subbands·4 basis vector·(4+) 4) bit).

3. i ₁ and Wideband and basis-common feedback of i ₂ : The UE is configured to feedback single wideband i ₁ and i ₃ values, which are also commonly used to construct all L=4 basis vectors. For each subband, the four i ₂ values for the basis vectors with L=4 are 4k, 4k+1, 4k+2 and 4k+3, where k = 0, 1, 2, 3. To inform the BS of the determination of i ₂ , the UE is configured to feed back k = 0, 1, 2, 3 per subband. If the UE is further configured to report the index tuple for 10 subbands, the total number of bits for feedback is 26 bits (=4 + 2 + 10 subband 2 bits).

The rank-1 design in these embodiments may be extended to rank-2 transmission corresponding to Table 3 or Table 5 separately for 8-transmission and 4-transmission. The feedback mechanism for i ₁ and i ₂ is described in Rel. 12 It can be designed based on the procedure in LTE (one of the two submodes of PUSCH or PUCCH mode 1-1).

Example 7: Other Alternative Configurations

In some embodiments, the eNB configures the UE to feed back the preferred precoding vector/matrix according to the dual codebook structure, in which case the UE feeds back an index to indicate the precoder: i ₁ and i ₂ : i ₁ is used to indicate the set of basis vectors, that is, a _l ,l=1,...,L, and i ₂ is used to indicate the set of coefficients, that is, c _l ,l=1,. .., L.

In these embodiments, the eNB may further configure the UE regarding a set of coefficients configuring the precoder for CSI feedback. In one example, the eNB configures the UE to use one of many (eg, two) methods of mapping index i ₂ to a set of coefficients. The first method is a legacy 8-transmit codebook, ie Table 2, and the second method is a new mapping that facilitates better channel quantization for MU-MIMO operation. In this case, the first method for UEs that the eNB schedules using single-user MIMO (SU-MIMO); For UEs that the eNB schedules using multi-user MIMO (MU-MIMO), the eNB may configure the second method.

반면에, eNB는 UE에 대해 계수 양자화 방법을 더 구성할 수 있다.In one embodiment, the eNB configures 8 CSI-RSs for the UE, and configures the UE to feed back the preferred precoding vector/matrix according to the dual codebook structure; It further constructs to feed back the selected basis vectors and the coefficient vector corresponding to the two indices i ₁ and i ₂ . When Table 2 is used for basis vector quantization, the selected basis vectors are

On the other hand, the eNB may further configure the coefficient quantization method for the UE.

지시자 벡터에 의해 표현될 수 있고, 여기서 e_i 는 L×1 벡터이고, 그것의 i 번째 요소는 1이고, 모든 다른 요소들은 0이다. 이러한 경우, 공동-페이징 인자 φ_n, n=i₂mod4이고, 전체 프리코딩 벡터 (행렬)은 다음과 같이 표현된다.In this case, to feed back the CSI according to Table 2, the eNB further configures the legacy codebook and coefficient quantization for the UE. Then, the selected coefficient vector is

It can be represented by an indicator vector, where e _i is an L×1 vector, its i-th element being 1, and all other elements being 0. In this case, the co-phasing factor φ _n , n=i ₂ mod4, the entire precoding vector (matrix) is expressed as

In other cases, the eNB further configures the UE to feed back CSI according to the new LC coefficient mapping method (i ₂ to LC coefficients). The LC coefficients may be quantized according to any examples in Embodiment 3, and in this case, the entire precoding vector (matrix) is configured as follows.

는 공동으로 또는 개별적으로 코딩되고, 인덱스 i₂에 맵핑된다. φ₀=φ₁=φ₂=φ₃인 특별한 경우, 단지 하나의 공동-페이징 인자가 양자화되고, 피드백된다.In this case, the coefficient vector and the co-phasing factor

are jointly or individually coded and mapped to index i ₂ . In the special case of φ ₀ =φ ₁ =φ ₂ =φ ₃ , only one co-phasing factor is quantized and fed back.

6 illustrates an overall precoding operation 600 of a base station (base station, BS or enhanced node B (eNB)) according to embodiments of the present disclosure. The embodiment shown in FIG. 6 is merely for convenience of description. Other embodiments may be used without departing from the scope of the present disclosure.

The eNB configures the basis vector selection 620 and the CSI reconstruction 625 . CSI reconstruction 625 takes at least two inputs comprising L coefficients and L basis vectors, where L is a positive integer. The basis vectors are obtained by basis vector selection 620, while the coefficients are obtained by CSI feedback reception 615. Basis vector selection 620 uses a large number of conditions to determine L basis vectors for CSI reconstruction 625 . There are three candidate schemes for determining the set of L basis vectors.

Scheme 1: Estimated basis vectors that take UL SRS (or, generally, a set of arbitrary UL signals) as input (SRS Receive 605→ Basis Vector Est 610);

Method 2: CSI-RS precoding weight (CSI-RS precoder selection 615→CSI-RS configuration 640); and

Scheme 3: Feedback basis vectors (CSI feedback reception 615).

In the case of L=1 where only one basis vector is selected, the linear combination decreases in a single term, comprising the product of a single selected basis vector and a corresponding single LC coefficient. In this case, the single basis vector corresponds to either the precoding vector used for CSI-RS precoding or the precoding vector corresponding to the PMI reported by the UE. In addition, single LC coefficients correspond to channel quality according to the direction of the precoding vector. In this case, the eNB uses the precoding vector and channel quality for link adaptation, scheduling and precoding 630 .

For each UE, one of these three schemes may be selected to select the set of L basis vectors. In other words, the UE may be configured in one of these three ways. This selection depends on at least one state (eg related to deployment scenarios). Each of the three schemes is self-contained and thus can operate by itself, but also a combination of at least two schemes can be used for the UE. Details are described below.

The base station is equipped with a controller, and the controller performs linear combination (LC) coefficients c _l ,l=1, to reconstruct a channel state or a precoder vector/matrix according to Equation 30 below. ..,L can be handled.

The LC coefficients may be fed back by a subscriber station (or UE), w is a reconstructed channel vector (which may be a rank-1 precoding vector preferred by the UE), a _l ,l =1,...,L is the basis vector for the linear combination, and to determine the a _l ,l=1,...,L, the controller, based on many states, uses the following three methods At least one method may be selected. Each of the three methods corresponds to an operational mode.

7A shows a UE precoding block diagram 700 when the eNB uses method 1 . The embodiment shown in FIG. 7A is merely for convenience of description. Other embodiments may be used without departing from the scope of the present disclosure.

In method 1, the information on a _l ,l=1,...,L is configured in the UE, and the same a _l ,l=1,...,L configured in the UE is used for the linear combination. Selection of the L basis vectors (of the larger parent-set of basis vectors) is performed by the BS using SRS and UL/DL channel reciprocity (ie, scheme 1). This is the US Provisional Patent Application Serial No., filed Oct. 3, 2014, which is incorporated herein by reference. 62/059,664.

At block 710 , the UE receives the basis vectors (as part of the UE-specific eNB configuration) and, at block 715A, based on the set consisting of the L basis vectors received from block 710, estimate the LC coefficient (ie, LC coefficient calculations). Also, for LC coefficient estimation, block 720 takes a CSI-RS or CRS or any RS used for CSI estimation as an additional input for calculating LC coefficients. The LC coefficients are then quantized and fed back to the eNB, for example in the form of one PMI or multiple PMIs at block 725A.

7B shows a UE precoding block diagram 740 when the eNB uses method 2; The embodiment shown in FIG. 7B is merely for convenience of description. Other embodiments may be used without departing from the scope of the present disclosure.

In method 2, a _l ,l=1,...,L is the l-th precoding weight vector (precoding) applied to the antenna elements to configure the l-th CSI-RS beam (ie, scheme 2) for the UE. weight vector). The eNB configures the UE with L CSI-RSs. In this case, each CSI-RS is precoded with a corresponding precoding weight vector. This is US Patent Application Serial No., filed Jan. 7, 2014, which is incorporated herein by reference. 14/149,436.

At block 705a, the UE receives a precoded CSI-RS or CRS or any RS used for CSI estimation, and at block 715B calculates LC coefficients. So block 715B for basis vector estimation takes the received RS as input to compute the relevant LC coefficients and basis vectors. The LC coefficients are then quantized and fed back to the eNB at block 720 via 725B. In some embodiments, the precoding weight vectors applied to the CSI-RS are UE-specific, and they may be derived using UE CSI feedback (feedback basis vector) and/or UL channel estimation (estimated basis vectors). . In some embodiments, the precoding weight vectors are cell-specific and may create a grid of beams covering azimuth and elevation angular spaces.

7C illustrates UE operation 750 when the eNB uses method 3 according to embodiments of the present disclosure. The embodiment shown in FIG. 7C is merely for convenience of description. Other embodiments may be used without departing from the scope of the present disclosure.

다른 예에서, UE에 대해 4개의 CSI-RS를 갖는 eNB는 첫 번째 PMI 인덱스를 처리할 수 있고, 표 4에 따라, i₁ (또는 W1)은 a_l,l=1,...,L=4를 구성하기 위해 UE에 의해 피드백된다. 이러한 경우, 선택된 베이시스 벡터 집합은

CSI-RS 포트를 통해 안테나/TXRU 가상화가 수행될 수 있지만, CSI-RS 포트들은 일반적으로 프리코딩되지 않는다.In method 3, information for configuring a _l ,l=1,...,L is fed back by the UE (ie, method 3). In one example, an eNB with 8 CSI-RS configured for the UE may process the first PMI index, and according to Table 2, i ₁ (or W1) is a _l ,l=1,..., It is fed back by the UE to configure L=4. In this case, the chosen set of basis vectors is

In another example, an eNB with 4 CSI-RSs for a UE may process the first PMI index, and according to Table 4, i ₁ (or W1) is a _l ,l=1,...,L is fed back by the UE to configure =4. In this case, the chosen set of basis vectors is

Although antenna/TXRU virtualization may be performed through the CSI-RS port, the CSI-RS ports are generally not precoded.

At block 705c, the UE receives a CSI-RS used for CSI estimation, and at block 715c determines a subset of the L basis vectors. Block 715c for LC coefficient (or PMI) estimation takes the received CSI-RS as an input for calculating LC coefficients (or PMI). The LC coefficients are then quantized at block 720c and fed back to the eNB in the form of one PMI or multiple PMIs, depending on signaling corresponding to the selection of L basis vectors at block 725c.

In some embodiments, at least all of the above methods are supported by the eNB. At a given time within a given CSI process, the eNB configures each UE in one way depending on at least one switching or selection criterion. This configuration is UE-specific, although it is possible to write a cell-specific configuration. Some exemplary guidelines for dividing the switching criteria are given below.

The CSI-related operations that need to be calculated at the eNB and respective UEs are given in Tables 8 and 9.

Table 8 below shows CSI-related operations in transmission paths.

Method 1 Method 2 Method 3 eNB compute a subset of the L basis vectors;
Signaling subset selection to UE compute a subset of the L basis vectors;
Precoding L CSI-RS ports for UE -- UE Calculate L LC coefficients;
Coefficients feedback to eNB Calculate L LC coefficients;
Feedback the coefficients to the eNB compute a subset of the L basis vectors;
Calculate L LC coefficients;
Subset selection and feedback of coefficients to eNB

Table 9 below shows CSI-related operations in receive paths.

Method 1 Method 2 Method 3 eNB Receive and decode subset selection of L basis vectors Receive and decode subset selection of L basis vectors -- UE receive and decode L LC coefficients (feedback);
Channel or precoder reconfiguration receive and decode L LC coefficients (feedback);
Reconfigure channels or precoders receive and decode a subset selection of L basis vectors;
receive and decode L LC coefficients (feedback);
Reconfigure channels or precoders

Method 1 is suitable when the UL/DL channel reciprocity associated with long-period channel statistics (eg, profile(s) for departure angle) is reliable; For example, the UL/DL duplex interval is small and UE mobility is small. When UE-specific basis vectors are configured by RRC, one drawback is the RRC configuration delay, which can be in units of 100 mec: this delay is a method for UEs with medium to high mobility. makes it difficult to use. When the basis vectors are constructed via dynamic signaling, one problem is controlling the signaling overhead or reliability.

Method 2 is suitable when the channel pathloss is high (eg, for a high carrier frequency), or when the eNB does not want to incur any signaling overhead in both the UL or DL direction. One disadvantage is some potential increase in CSI-RS overhead when the number of active UEs served by the eNB is large enough. Therefore, this scheme is particularly suitable for cells with low loading. Similar to scheme 1, scheme 2 is suitable when the UL/DL channel reciprocity associated with long-period channel statistics is reliable.

Method 3 is suitable when UL/DL channel reciprocity is weak. So, when the UL-DL duplex interval is large enough, this method is suitable. This is a particularly suitable method when higher carrier frequencies are used along with legacy (lower) carrier frequencies. For example, the network may configure a DL carrier frequency in the mmWave domain, and may configure an associated (pair) UL carrier in the PCS band. One drawback is the additional feedback overhead that arises from the need to feed back the UE recommendation of the basis vectors.

Obviously, these methods have advantages and disadvantages: so the eNB controller may consider these tradeoffs to decide which method to use for DL link adaptation, scheduling and precoding. In real deployment scenarios, many different factors are considered in devising a set of switching criteria.

In some cases described above, the eNB may support multiple carrier frequency bands, and the carrier frequency is used as a selection criterion. Here, the plurality of carrier frequencies may be at least one frequency in a low band (up to 6 GHz), at least one frequency in a middle band (6 GHz to 60 GHz), and at least one frequency in a high band (60 GHz or more). can In one example, if the carrier frequency is lower than a particular carrier frequency, eg, 6 GHz or 30 GHz, the "Select Basis Vector" block selects either method 1 or 3 (estimate or feedback basis vectors), otherwise The block selects method 2 (precoding with CSI-RS weights). In another example, if the carrier frequency is higher than a particular carrier frequency, e.g., 6 GHz, the "Basis Vector Selection" block selects method 1 (estimated basis vectors), otherwise the block selects method 2 or method 2 ( feedback basis vectors or CSI-RS weighted precoding).

In a case other than the one described above, in other carrier frequency bands, the eNB may support multiple duplex schemes and a large number of serving cells. In this case, the type of duplex scheme is used as a selection criterion. For example, if the serving cell is time-division-duplex (TDD), the "basis vector selection" block selects method 1 (estimated basis vectors) for the serving cell, and the serving cell For this frequency-division duplex (FDD), the block selects method 3.

In some embodiments, the eNB explicitly configures the method(s) used for its basis vector selection to the UE, via higher-layer (eg RRC) signaling.

8 is a process 800 for configuring a basis vector of a UE according to an embodiment of the present disclosure. Although a flowchart describes a sequence of sequential steps, unless explicitly stated, the performance of a particular sequence of performance, performance steps, or portions thereof is not performed sequentially or overlappingly, independently without intervening or occurrence of intermediate steps. No inferences shall be made regarding the performance of the steps described. The processes described in the described examples are implemented in processing circuitry, such as, for example, mobile stations.

The UE may configure one basis vector selection method among multiple methods. In operation 805 , the UE is configured to select basis vectors by the eNB: (1) eNB configuration; and (2) UE estimation. (1) when the eNB is configured, the UE configures the basis vectors in operation 810 based on the basis vector configuration information of the eNB; (2) When UE estimation is configured, in operation 820, the UE estimates basis vectors using the received RS, ie, CSI-RS or CRS.

In some embodiments, the UE may support at least one of multiple duplex schemes, multiple carrier frequency bands and a large number of serving cells in different carrier frequency bands. According to FIG. 8 , the UE may further select one basis vector selection method among multiple methods.

Then, the UE may use the carrier frequency to configure the basis vector selection method.

In one example, the UE is configured with (a) the eNB configuration basis vectors for a serving cell with a critical carrier frequency, ie, a carrier frequency greater than or equal to 6 GHz; Otherwise, the UE is configured with (b) the UE estimate basis vectors for the serving cell with a carrier frequency lower than the threshold carrier frequency.

Instead, the UE may use a type of duplex scheme for configuring the basis vector selection method.

In one example, the UE is configured with (1) the eNB configuration basis vectors for the TDD serving cell; Otherwise, the UE is configured with (2) UE estimate basis vectors for the FDD serving cell.

In some embodiments, when the UE is capable of higher rank transmission (eg, rank 2), the basis vector selection block may calculate the number of "ranks" of the set of basis vectors, and the CSI reconstruction block is for channel state reconstruction, may receive a “rank” number of sets of channel co-coefficients.

9 illustrates an overall BS precoding operation 900 for a rank 2 channel according to embodiments of the present disclosure. The embodiment shown in FIG. 9 is only for convenience. Other embodiments may be used without departing from the scope of the present disclosure.

As shown in FIG. 9 , in one exemplary illustration, the basis vector selection block 620 is a set of one basis vectors, a _l ,i=1,2,... ,L is calculated, and the CSI reconstruction block 910 is a set of two channel coefficients from a rank-2 UE for channel state reconstruction, c _l ,l=1,2,... ,L, and d _l ,l=1,2,… ,L is received. The CSI reconstruction block reconstructs the rank-2 channel as in Equation 31 below.

10 illustrates an entire BS precoding operation 1000 for a rank 2 channel according to embodiments of the present disclosure. The embodiment shown in FIG. 10 is only for convenience of description. Other embodiments may be used without departing from the scope of the present disclosure.

As shown in FIG. 10 , in another exemplary illustration, the basis vector selection block 620 is a set of two basis vectors, a _l ,l=1,2, . . . ,L, and b _k ,k=1,2,... , to calculate K. Here, K and L may not be equal, and the CSI reconstruction block 1005 is a set of two channel coefficients, c _l ,l=1,2, ... from a rank-2 UE for channel state reconstruction. ,L, and d _k ,k=1,2,… , to receive K. The CSI reconstruction block reconstructs the rank-2 channel as in Equation 32 below.

11 illustrates a flowchart 1100 for basis vector selection according to embodiments of the present disclosure. The embodiment shown in FIG. 11 is merely for convenience of description. Other embodiments may be used without departing from the scope of the present disclosure.

In operation 1105, the eNB receives uplink signals, and in operation 1100 selects one of the three methods based on an uplink measurement such as SRS or PUSCH. Uplink measurement includes angular (angular), power-delay (power-delay), and Doppler estimation (doppler estimation). The operation of the basis vector selection block 1115 is described in detail below.

12 illustrates an example of a switching criterion for a basis vector selection block 1115 according to some embodiments of the present disclosure. The embodiment shown in FIG. 12 is only for convenience of description. Other embodiments may be used without departing from the scope of the present disclosure.

The basis vector selection block 1115 switches between methods 1 to 3, and combinations thereof, according to a criterion. When measuring the uplink channel characteristic, in operation 1200 the eNB controller checks how large the cluster angular spread is: if large, in operation 1215 the block selects method 3; And if it is small, the eNB further checks whether the duplex interval is large or small. If the duplex spacing is large, in operation 1205 the block selects method 1; If it is small, the basis vector selection block 1115 selects method 2 in operation 1210 . In complex situations, in operation 1220 the eNB may select a combination of these three methods. In such embodiments, in order for the eNB to determine “small” or “larger”, the eNB may set a threshold for comparison. For example, if the cluster angular spread is greater than a threshold value, the basis vector selection block 1115 may select method 3 .

These embodiments are modified by the following observations.

In method 1, the eNB may configure a set of L basis vectors for the UE. Such aggregation can be derived from uplink reception as well as feedback. For this approach to work well, the angular spread of each cluster channel needs not to be significantly high. Otherwise, it is difficult to effectively capture the power.

In method 2, W1 (or a set of L basis vectors) is not explicitly configured by the eNB; Instead, it precodes the CSI-RS based on uplink measurements. It may require uplink measurement to reflect the downlink channel well. When the duplex interval between the uplink and the downlink is not large, the angles of the multipaths are similar in the uplink and the downlink. Moreover, a small angular spread within the cluster (not distinct in the time domain) is required, otherwise there may not be a dominant direction that can be extracted from the uplink measurement.

In method 3, since the eNB mainly reconfigures the channel in UE feedback, excessive channel angle spread is not a problem. It is also possible to use a combination of methods 1, 2 and 3.

13 shows a flowchart for a process according to the present disclosure.

Referring to FIG. 13 , in step 1301, the base station transmits reference signals and information related to configurations for reporting a precoding matrix. In particular, the base station transmits information relating to a first configuration for reference signals and a second configuration for a precoding matrix report. The second configuration may include first and second numbers N ₁ and N ₂ . The second configuration may further include oversampling factors.

In step 1303, the base station transmits reference signals. That is, the base station transmits the reference signals according to the first configuration configuring the plurality of antenna ports. The number of the plurality of antenna ports may be equal to 2·N ₁ ·N ₂ .

In step 1305, the base station receives, from the terminal, indicators derived from reference signals. That is, the base station receives, according to the second configuration, feedback information including indicators derived from reference signals. One of the indicators indicates the azimuth channel, and one of the other indicators indicates the elevation channel. The feedback information further includes a CQI derived for using one of the predefined precoding matrices. The feedback information is transmitted aperiodically through the data channel or periodically through the control channel.

형식을 가진다. 여기서 φ는 공동-페이징 인자이고, h는 방위 채널을 나타내는 벡터이고, v는 고도 채널을 나타내는 벡터이다.Also, the base station may convert the indicators into one of predefined precoding matrices. Here, each of the predefined precoding matrices includes a first element and a second element. The first element comprises a product of a first value indicative of the azimuth channel and a second value indicative of the elevation channel, and the second element comprises a product of the first value and the second value that are phase-shifted. include Each of the predefined precoding matrices is composed of a linear combination of basis vectors. Basis vectors are determined based on each spread of one or more channels, uplink measurements, sounding reference signals, a precoding weight vector applied to the reference signals, and feedback information. For example, each of the predefined precoding matrices is

have a form where φ is the co-phasing factor, h is the vector representing the azimuth channel, and v is the vector representing the elevation channel.

14 shows a flowchart for an operating process of a UE according to the present disclosure.

Referring to FIG. 14 , in step 1401 , the UE receives reference signals and information related to configurations for precoding matrix reporting. In particular, the UE receives information relating to a first configuration for reference signals and a second configuration for a precoding matrix report. The second configuration may include first and second numbers N ₁ and N ₂ . The second configuration may further include oversampling factors.

In step 1403, the UE receives reference signals. That is, the UE receives the reference signals according to the first configuration configuring the plurality of antenna ports. The number of the plurality of antenna ports may be equal to 2·N ₁ ·N ₂ .

In step 1405, the UE transmits indicators derived from reference signals. That is, the UE transmits, according to the second configuration, feedback information including indicators derived from reference signals. One of the indicators indicates the azimuth channel, and one of the other indicators indicates the elevation channel. The feedback information further includes a CQI derived for using one of the predefined precoding matrices. The feedback information is transmitted aperiodically through the data channel or periodically through the control channel.

형식을 가진다. 여기서 φ는 공동-페이징 인자이고, h는 방위 채널을 나타내는 벡터이고, v는 고도 채널을 나타내는 벡터이다.The indicators are converted by the BS into one of the predefined precoding matrices. Here, each of the predefined precoding matrices includes a first element and a second element. The first component includes a product of a first value indicative of the azimuth channel and a second value indicative of the elevation channel, and the second component includes a product of the phase-shifted first value and the second value. Each of the predefined precoding matrices consists of a linear combination of basis vectors. Basis vectors are determined based on each spread of one or more channels, uplink measurements, sounding reference signals, a precoding weight vector applied to the reference signals, and feedback information. For example, each of the predefined precoding matrices is

have a form where φ is the co-phasing factor, h is the vector representing the azimuth channel, and v is the vector representing the elevation channel.

Although the present disclosure has been described in an exemplary embodiment, various changes and modifications may be suggested to those skilled in the art. It is intended that this disclosure cover such changes and modifications as fall within the scope of the appended claims.

Claims (28)

In a method of a base station (BS) in a wireless communication system,
Transmitting information related to a first configuration related to a plurality of antenna ports for reference signals and a second configuration related to a number of beams for precoding matrix reporting, the plurality of antenna ports comprising: antenna ports in a first dimension and a second dimension;
transmitting the reference signals according to the first configuration;
Receiving feedback information including a plurality of indicators obtained from the reference signals according to the second configuration;
From the plurality of indicators, comprising the process of obtaining a precoding matrix,
Each column of the precoding matrix is constructed according to a linear combination of a set of basis vectors and a set of coefficients,
The plurality of indicators includes at least one indicator indicating the set of base vectors and at least one indicator indicating the set of coefficients,
each of the basis vectors comprises a basis vector based on a first vector associated with the first dimension and a second vector associated with the second dimension;
The set of fundamental vectors is selected according to the number of beams,
The set of coefficients includes amplitude components and phase components according to the number of the beams.
The method according to claim 1, wherein the number of the plurality of antenna ports is 2·N ₁ ·N ₂ , N ₁ is the number of antenna ports in the first dimension, and N ₂ is the number of antenna ports in the second dimension. .
delete The method according to claim 1,
The feedback information is configured to be reported aperiodically through a physical uplink shared channel (PUSCH) or periodically through a physical uplink control channel (PUCCH).
A method of a terminal in a wireless communication system, comprising:
Receiving information related to a first configuration related to a plurality of antenna ports for reference signals and a second configuration related to a number of beams for precoding matrix reporting, the plurality of antenna ports comprising: antenna ports in a first dimension and a second dimension;
receiving the reference signals according to the first configuration;
Transmitting feedback information including a plurality of indicators obtained from the reference signals according to the second configuration;
The plurality of indicators are related to a precoding matrix,
Each column of the precoding matrix is constructed according to a linear combination of a set of basis vectors and a set of coefficients,
The plurality of indicators includes at least one indicator indicating the set of the base vectors and at least one indicator indicating the set of coefficients,
each of the basis vectors comprises a basis vector based on a first vector associated with the first dimension and a second vector associated with the second dimension;
The set of base vectors is selected according to the number of beams,
The set of coefficients includes amplitude components and phase components according to the number of the beams.
The method of claim 5 , wherein the number of the plurality of antenna ports is 2·N ₁ ·N ₂ , N ₁ is the number of antenna ports in the first dimension, and N ₂ is the number of antenna ports in the second dimension. .
delete 6. The method of claim 5,
The feedback information is configured to be reported aperiodically through a physical uplink shared channel (PUSCH) or periodically through a physical uplink control channel (PUCCH).
In a base station (BS) in a wireless communication system,
at least one transceiver;
at least one processor;
the at least one processor,
controlling the at least one transceiver to transmit information related to a first configuration related to a plurality of antenna ports for reference signals and a second configuration related to a number of beams for precoding matrix reporting, wherein the plurality of antenna ports include antenna ports in a first dimension and a second dimension;
controlling the at least one transceiver to transmit the reference signals according to the first configuration;
controlling the at least one transceiver to receive feedback information comprising a plurality of indicators obtained from the reference signals according to the second configuration;
and to obtain a precoding matrix from the plurality of indicators;
Each column of the precoding matrix is constructed according to a linear combination of a set of basis vectors and a set of coefficients,
The plurality of indicators includes at least one indicator indicating the set of base vectors and at least one indicator indicating the set of coefficients,
each of the basis vectors comprises a basis vector based on a first vector associated with the first dimension and a second vector associated with the second dimension;
The set of fundamental vectors is selected according to the number of beams,
The set of coefficients is a base station including amplitude components and phase components according to the number of beams.
The base station according to claim 9, wherein the number of the plurality of antenna ports is 2·N ₁ ·N ₂ , N ₁ is the number of antenna ports in the first dimension, and N ₂ is the number of antenna ports in the second dimension. .
delete 10. The method of claim 9,
The feedback information is a base station configured to be reported aperiodically through a physical uplink shared channel (PUSCH) or periodically through a physical uplink control channel (PUCCH).
In a terminal in a wireless communication system,
at least one transceiver;
at least one processor;
The at least one processor,
controlling the at least one transceiver to receive information related to a first configuration related to a plurality of antenna ports for reference signals and a second configuration related to a number of beams for precoding matrix reporting, wherein the plurality of antenna ports include antenna ports in a first dimension and a second dimension;
controlling the at least one transceiver to receive the reference signals according to the first configuration;
controlling the at least one transceiver to transmit feedback information comprising a plurality of indicators obtained from the reference signals according to the second configuration;
The plurality of indicators are related to a precoding matrix,
Each column of the precoding matrix is constructed according to a linear combination of a set of basis vectors and a set of coefficients,
The plurality of indicators includes at least one indicator indicating the set of base vectors and at least one indicator indicating the set of coefficients,
each of the basis vectors comprises a basis vector based on a first vector associated with the first dimension and a second vector associated with the second dimension;
The set of fundamental vectors is selected according to the number of beams,
The set of coefficients is a terminal including amplitude components and phase components according to the number of beams.
The terminal of claim 13 , wherein the number of the plurality of antenna ports is 2·N ₁ ·N ₂ , N ₁ is the number of antenna ports in the first dimension, and N ₂ is the number of antenna ports in the second dimension. .
delete 14. The method of claim 13,
The feedback information is configured to be reported aperiodically through a physical uplink shared channel (PUSCH) or periodically through a physical uplink control channel (PUCCH). delete delete delete delete delete delete delete delete delete delete delete delete

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