KR20170075794A - 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 including a plurality of antenna ports, From the terminal, feedback information including a plurality of indicators derived from the reference signals according to the second configuration. The base station includes a controller that converts the plurality of indicators into one of the pre-defined precoding matrices.

Description

[0001] CODEBOOK DESIGN AND STRUCTURE FOR ADVANCED WIRELESS COMMUNICATION SYSTEMS [0002]

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

Wireless communications is one of the most successful innovations in modern history. Recently, the number of subscribers of wireless communication services has surpassed 5 billion and is growing rapidly. The demand for wireless data traffic is driven by devices such as tablets, "note pad" net books, eBook readers, and machine types, Are rapidly growing due to the increased popularity among consumers and businesses of the same smart phones and other mobile data devices. Improvement of radio interface efficiency and coverage is important to meet high growth in mobile data traffic and to support new applications and deployments.

One 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 user equipment (UE) is provided. The base station transmits the CSI-RS according to a channel state information-reference signal (CSI-RS) configuration including a plurality of antenna ports, and transmits physical downlink shared channels (PDSCH) And a precoding-matrix configuration for a precoding matrix indicator (PMI), and transmits first and second oversampling factors O ₁ and O _2, the first and second numbers N ₁ and N ₂ , and transmits a pre-coding matrix configuration comprising a plurality of PMIs derived from the UE using CSI-RS according to a precoding- And a transceiver for receiving a link signal,

, Where φ is a co-phasing factor, h and v are the vectors of the magnitudes N ₁ × 1 and N ₂ × 1, respectively, / RTI >

상기 D1 = O1·N1 및 D2 = O2·N2, 이고 m1 및 m2는 양의 정수이다.In some embodiments, the N ₁ = 4 and N ₂ = _2, h and v are

D1 = O1N1 and D2 = O2N2, 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 transmitting a CSI-RS according to a CSI-RS configuration including a plurality of antenna ports, transmitting downlink signals including a CSI-RS configuration reporting on a PDSCH and a precoding-matrix configuration for a PMI Matrix configuration comprising the first and second oversampling factors O ₁ and O _2, the first and second numbers N ₁ and N ₂ , and transmitting the precoding-matrix configuration from the UE to the precoding-matrix configuration A step of receiving an uplink signal including a plurality of PMIs derived using CSI-RS,

With the format and comprising the step of converting one of the pre-defined pre-coding matrix, the φ is a co-factor, and paging, h and v are each of size ₁ × N 1 and N ₂ vectors of × 1.

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, receives the downlink signals including the CSI-RS configuration reporting on the PDSCH, the precoding-matrix configuration for the PMI, Th 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 , wherein O ₁ and O ₂ , Demodulates and decodes the downlink signals to obtain higher-layer configuration values for N ₁ and N ₂ , determines a plurality of PMIs derived using the CSI-RS according to the precoding-matrix configuration, And a controller that causes the transceiver to transmit an uplink signal comprising a plurality of PMIs, wherein the plurality of PMIs

Where? Is a co-paging factor and h and v are vectors of size N ₁ × 1 and N ₂ × 1, respectively.

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 is provided for a UE capable of communicating with a base station. The method includes receiving a CSI-RS according to a CSI-RS configuration including a plurality of antenna ports, receiving a downlink signal including a CSI-RS configuration reporting on a PDSCH and a precoding-matrix configuration for a PMI Matrix configuration including first and second oversampling factors O ₁ and O ₂ , first and second numbers N ₁ and N ₂ , and receiving a pre-coding matrix configuration including O ₁ and O ₂ , N hierarchy demodulate the downlink signal to obtain a value, and the decoding process and the pre-coding _to-1 and N ₂ the top of a process for determining a plurality of PMI-induced using a CSI-RS according to the matrix composition and, base station The method comprising transmitting a UL signal including a plurality of PMIs by a transceiver,

Where? Is a co-paging factor and h and v are vectors of size N ₁ × 1 and N ₂ × 1, respectively.

In a fifth embodiment, a base station is provided in a wireless communication system. The base station transmits information relating to a first configuration for reference signals and a second configuration for precoding matrix reporting and transmits reference signals according to a first configuration including a plurality of antenna ports, And a transceiver for receiving feedback information comprising a plurality of indicators derived from the reference signals in accordance with the configuration. The base station includes a controller that converts a plurality of indicators into pre-defined precoding matrices. Each of the predefined precoding matrices includes a first element and a second element. The first element includes a product of a first value representing an azimuth channel and a second value representing an elevation channel. The second element includes a product of a first value 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 a first configuration for reference signals and a second configuration for precoding matrix reporting, transmitting reference signals according to a first configuration including a plurality of antenna ports, Receiving feedback information including a plurality of indicators derived from reference signals according to a second configuration, and converting the plurality of indicators into pre-defined precoding matrices. Each of the predefined precoding matrices includes a first element and a second element. The first element includes a product of a first value representing an azimuth channel and a second value representing an altitude channel. The second element includes a product of a phase-shifted first value and a second value.

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

In an eighth embodiment, a method for a terminal in a wireless communication system is provided. The method includes receiving a first configuration for reference signals and a second configuration for precoding matrix reporting, receiving reference signals according to a first configuration including a plurality of antenna ports, And transmitting feedback information including a plurality of indicators derived from the reference signals according to the two configurations. By the base station, the plurality of indicators are converted into pre-defined precoding matrices. Each of the predefined precoding matrices includes a first element and a second element. The first element includes a product of a first value representing an azimuth channel and a second value representing an altitude channel. The second element includes a product of a phase-shifted first value and a second value.

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

Before entering the subject matter of the following disclosure, it may be advantageous to list the definitions of particular words and phrases used throughout this disclosure. The term " couple "and derivatives of the term 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 terms, the word " include ", " comprise ", " comprise ", as well as their derivatives. And associated therewith, as well as derivatives thereof, are included within, interconnect with, contain, contain, Be contained within, connect to or with, communicate with or with, be communicable with, communicate with, communicate with, communicate with, I will cooperate with you, interleave, juxtapose, be proximate to, We have to be bound to or with, have a property of, have a relationship to or with, and so on. The term "controller" is intended to encompass all types of devices, systems, or components thereof, which control at least one operation, which may be implemented in hardware and a combination of hardware and software and / The function associated with any particular control may be centralized or distributed, whether local or remote. The phrase "at least one of" refers to an item of items And other combinations of one or more items may be used, which may mean that only one item in the list may be required. For example, "at least one of A, B, and C" may comprise A, B, C, A and B, A and C, B and C, and A, B,

In addition, the various functions described below may be executed or supported by one or more computer programs. Each of the functions is formed from computer readable program code and is formed in a computer readable medium. The terms "application" and "program" are intended to refer to a computer program, a software component, a collection of instructions, a procedure, a function, an object, a class, an instance, related data, May refer to a portion thereof suitable for the implementation of the readable program 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" is intended to encompass all types of computer readable media including but not limited to read only memory (ROM), random access memory (RAM), hard disk drive, compact disc (CD), digital video disc or any other type of medium that can be connected by the same computer. A "non-transitory" computer-readable medium may exclude other communication links transmitting wired, wireless, optical, or transient electronic or other signals. Non-transitory computer readable media can include data such as rewritable optical discs or erasable memory devices that can be stored and media that can be overwritten thereafter, Lt; RTI ID = 0.0 > media. ≪ / RTI >

Definitions of particular words and phrases may be provided throughout this disclosure. It should be understood that, in most cases, ordinary descriptors can be applied to future uses as well as future uses of these definitions in defined words and phrases.

The performance of the communication system can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the present disclosure and the advantages of the present disclosure, the following description is made with reference to the accompanying drawings. In the drawings, like reference numerals denote like elements.
1 shows a wireless network according to the present disclosure;
Figures 2a and 2b show wireless transmit and receive paths in accordance with the present disclosure;
Figure 3A shows an example of a user equipment (UE) according to the present disclosure.
FIG. 3B shows an example of an evolved node B (eNB) according to the present disclosure.
Figures 4A and 4B show two-dimensional antenna arrays comprising sixteen dual-polarized antenna elements according to the present disclosure.
Figure 5 shows another numbering of the transmit antenna elements according to the present disclosure.
FIG. 6 shows the overall precoding operation according to the present disclosure.
Figures 7a, 7b and 7c show UE operations when the eNB according to the present disclosure uses the methods 1 to 3 separately.
Figure 8 is a process for the basis vector construction of a UE according to the present disclosure.
FIG. 9 illustrates the overall base station (BS) precoding operation for a rank 2 channel according to the present disclosure.
10 shows another full BS precoding operation for rank two channels according to the present disclosure.
11 shows a flow chart for basis vector selection according to the present disclosure.
Figure 12 shows an example of switching criteria for a basis vector selection block according to the present disclosure.
13 shows a flow chart of the operational process of the BS according to the present disclosure.
Figure 14 shows a scheme for the operational process of a UE according to the present disclosure.

It should be understood that the various embodiments utilized to illustrate the principles of the Figures 1 through 14 and the disclosure discussed below are for illustrative purposes only and are not to be construed in any way as limiting the scope of the present disclosure. Those of ordinary skill in the art will understand that the principles of the present disclosure may be implemented in wireless communication systems that are suitably deployed.

The following documents and standards are hereby incorporated into this disclosure as if fully set forth herein. (1) 3GPP (3 ^rd generation partnership project) TS 36.211, "E-UTRA, Physical channels and modulation", Relaease-12, , (3) 3GPP TS 36.213, "E-UTRA, Physical layer procedures", Release-12.

1 illustrates an example of a wireless network 100 in accordance with the present disclosure. The embodiment of the wireless network 100 shown in FIG. 1 is for illustrative convenience only. Other embodiments for wireless network 100 may be used, without departing from the scope of this 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 network, or other 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". For convenience, the terms "eNodeB" or "eNB" are used herein to describe a network infrastructure configuration that provides wireless connectivity to a remote terminal. Depending on the network type, other well known terms such as "mobile base station "," subscriber station ", "remote terminal "," wireless terminal ", and & . The term " user equipment "and" UE, "as used herein for convenience, refers to a remote radio device that wirelessly connects to an eNB in this document, wherein the UE is a mobile device (e.g., mobile phone or smartphone) For example, a desktop computer or a vending machine).

The eNB 102 provides a wireless broadband connection to the network 130 to a first plurality of UEs in the coverage area 120 of the eNB 102. The first plurality of UEs comprises a UE 111, which may be located in a small business, a UE 112, which may be located in a large enterprise, a UE 113, which may be located in a WiFi hot spot, UE 114 that may be located, UE 115 that may be located in a second residential area, and UE of UE 116, which may be a mobile device such as a cell phone, wireless laptop, wireless PDA, and so on. The eNB 103 provides a wireless broadband connection to the network 130 to a second plurality of UEs in the coverage area 125 of the eNB 103. The second plurality of UEs includes UE 115 and UE 116. In some embodiments, one or more of the eNBs 101 to eNBs 103 may communicate with each other, or may communicate with each other, or may communicate with each other via a 5G (5th generation), LTE (Long Term Evolution), LTE-A (advanced), WiMAX (worldwide interoperability for microwave access) And may communicate with UEs 111 through 116 using other advanced wireless communication technologies.

The dashed line represents the approximate range of coverage areas 120 and 125, which are depicted close to the circle for illustrative and illustrative purposes only. It should be clearly understood that the coverage areas associated with eNBs, such as coverage areas 120 and 125, may have other configurations, including irregular shapes depending on the configuration of the eNBs and the changes in radio environment due to natural and artificial obstructions do.

 As will be described in greater detail below, one or more of BS 101, BS 102 and BS 103 comprise 2D antenna arrays as described in the embodiments of the present disclosure. In some embodiments, one or more of BS 101, BS 102, and BS 103 support a codebook design and architecture for systems having 2D antenna arrays.

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

2A and 2B illustrate examples of wireless transmission and reception paths according to the present disclosure. In the following description, while the receive path 250 is described as being implemented in a UE (e. G., UE 116), the transmit path 200 may be described as being implemented in an eNB (eNB 102, for example). However, it will also be appreciated 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 a codebook design and structure for systems having 2D antenna arrays, as described in the embodiments of this disclosure.

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

In transmission path 200, channel coding and modulation block 205 receives a series of information bits, applies coding (e.g., low density parity check (LDPC) coding) and generates a sequence of frequency domain modulation symbols (e. g., quadrature phase shift keying (QPSK) or quadrature amplitude modulation (QAM)) of input bits to generate a serial-to- And transforms the serial modulated frequency domain symbols into parallel data to create parallel symbol streams of size N. The size N is the IFFT / FFT size used in eNB 102 and UE 116. The IFFT block 215 of size N is used to transform the time domain Serial conversion block 220 computes the IFFT for the parallel symbol streams of size N to produce the output signals of size N. To generate the serial time domain signals, (I.e., multiplexes) the received parallel time-domain output symbols, and CP add block 225 adds the CP to the time-domain signal. Up-converter block 230 receives the output of CP add block 225 (Such as up-converts) to an RF frequency. The signal may be filtered at the baseband before conversion to RF frequency.

The RF signal transmitted at the eNB 102 arrives at the UE 116 after passing through the radio channel and the reverse processes of the process performed at the eNB 102 are executed at 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. An FFT block 270 of size N performs an FFT algorithm to generate parallel N frequency domain signals. The parallel-to-serial conversion block 275 converts the parallel frequency domain signals into a sequence of modulated data symbols. The 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 on the downlink (DL) to the UEs 111 to 116 and may be similar to the uplink (UL) A receive path 250 may be implemented. Similarly, each of the UEs 111 to 116 can implement a transmission path 200 similar to the transmission in the uplink to the eNBs 101 to 103 and 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, the configuration of at least some of FIGS. 2A and 2B may be implemented in software, while the remaining configuration is implemented by hardware or by 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.

Further, this is merely an example, and should not be construed as limiting the scope of the present disclosure. Other types of transforms may be used, for example 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 (e.g., 1, 2, 3, 4, etc.), and using FFT or IFFT functions, (E.g., 1, 2, 4, 8, 16).

2A and 2B illustrate examples of wireless transmission and reception paths, but various modifications may be made to Figs. 2A and 2B. For example, the various configurations of FIG. 2A and FIG. 2B may be subdivided or omitted as well as combined, and additional configurations may be added according to specific needs. 2A and 2B are also examples of types of transmission and reception paths that may be used in a wireless network. Any other suitable structure for supporting wireless communication in a wireless network may be used.

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

The UE 116 includes an antenna 305, a radio frequency (RF) transceiver 310, a transmit (TX) processing circuit 315, a microphone 320 and a receive (RX) processing circuit 325. The UE 116 includes a speaker 330, a main processor 340, an input / output (I / O) interface 345, a keypad 350, a display 355, . 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, the 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 sent to receive (RX) processing circuitry 325, which filters, decodes, and / or digitizes the baseband or intermediate frequency signal to produce a processed baseband signal. The receive processing circuitry 325 sends the baseband signal processed by the speaker 330 (e.g., voice data) or the main processor 340 (e.g., web browsing data) to further process the processed baseband signal.

The transmit (TX) processing circuit 315 receives analog or digital voice data from the microphone 320 or receives outgoing baseband data (e.g., web data, e-mail or interactive video game data, etc.) from the main processor 340. The transmit processing circuit 315 encodes, multiplexes, and / or digitizes the external baseband data to produce 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 upconverts the baseband or intermediate frequency signal to an RF signal transmitted via the antenna 305.

The main processor 340 may include one or more processors or other processing devices and may execute a basic operating system (OS) program 361 stored in memory 360 to control the overall operation of the UE 116. For example, the main processor 340 may control the reception of the forward channel signals and the transmission of the reverse channel signals by the RF transceiver 310, the reception processing circuit 325, and the transmission processing circuit 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 operations for channel quality measurement, as described in the embodiments of this disclosure, and may report to systems having two-dimensional antenna arrays . The main processor 340 may store or output data required in an 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 run applications according to signals received from eNBs or operators. In addition, 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 notebook computers and portable computers. I / O interface 345 is the communication path between this accessory and main controller 340.

The main processor 340 may be coupled to the input device 350 and the display 355. The operator of the UE 116 may use the keypad 350 to input data to the UE 116. 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 have.

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

Although FIG. 3A illustrates an example of a UE 116, various modifications may be found in FIG. 3A. For example, the components shown in FIG. 3A can be combined or separated from one another according to a particular need, and added or omitted. For example, the main processor 340 may be separated into a plurality of processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). In addition, the UE 116 shown in FIG. 3A can be configured as a portable telephone or smart phone, and the UE 116 can be configured to operate with other types of mobile devices or fixed devices.

3B shows an example of an eNB 102 according to the present disclosure. The embodiment of eNB 102 shown in FIG. 3B is merely for convenience of description, and the other eNBs of FIG. 1 may have the same or similar configuration. However, the types of eNBs vary widely in their configurations, and Fig. 3b does not limit the scope of the present disclosure in 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 through 370n, a transmit processing unit 374, and a receive processing unit 376. In some embodiments, one or more of the plurality of antennas 370a through 370n may include two-dimensional antenna arrays. The eNB 102 may also include a controller / processor 378, memory 380, and a backhaul / network interface 382.

RF transceivers 372a through 372n may receive received RF signals from antennas 370a through 370n, such as signals transmitted by UEs or other eNBs. RF transceivers 372a through 372n may downconvert the received RF signal to produce intermediate frequency or baseband signals. 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 produce processed baseband signals. The receive processing circuit 376 transmits the processed baseband signals to the controller / processor 378 for further processing of the processed baseband signals.

Transmit processing circuit 374 receives analog or digital data (e.g., voice data, web data, e-mail, or interactive video game data) from controller / processor 378. The transmit processing circuit 374 encodes, multiplexes, and / or digitizes the outer baseband data to produce processed baseband or intermediate frequency signals. The RF transceivers 372a through 372n receive the externally processed baseband or intermediate frequency signals from the transmit processing circuit 374 and upconvert the baseband or intermediate frequency signals transmitted via the antennas 370a through 370n to RF signals.

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

Controller / processor 378 may also perform programs and other processes stored in memory 380, such as a base operating system. Controller / processor 378 may support channel quality measurements, as described in the embodiments of this disclosure, and may report measurements to systems having two-dimensional antenna arrays. In some embodiments, the controller / processor 378 supports communication between entities such as a real-time clock (RTC). The controller / processor 378 may store the necessary data in the execution process in the memory 380 or output it from the memory 380.

The controller / processor 378 is also coupled to a backhaul or network interface 335. The backhaul or network interface 382 may allow the eNB 102 to communicate with other devices or systems over a backhaul connection or network. The interface 382 may support communication over any wired or wireless connection. For example, if the eNB 102 can be implemented as part of a cellular communication system (e.g., 5G, LTE, or LTE-A, etc.), then the interface 382 allows the eNB 102 to communicate with another eNB Lt; / RTI > 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 to a larger wired or wireless network (e.g., the Internet). The interface 382 has any suitable structure to support over a wired or wireless connection, such as an ethernet or an RF transceiver.

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

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

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

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. Figures 4A and 4B are cross-sectional views,

Dimensional antenna arrays designed with sixteen dual-polarized antenna elements arranged in four rectangular formats. 4A shows an antenna port (AP)

4 dual-polarized antenna array 400, and Fig. 4b shows the same 4 < RTI ID = 0.0 >

4 dual-polarized antenna array 410. The dual- The embodiment shown in Figs. 4A and 4B is for convenience of explanation. Other embodiments may be utilized, 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 The dual polarization array is 16

2 = can be viewed as an array of 32 elements. In addition to azimuthal beamforming through a horizontal dimension, a vertical dimension (consisting of 4 rows) may utilize 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) precoding gain lt; RTI ID = 0.0 > gain. < / RTI > Although fixed beamforming (i.e., antenna virtualization) can be implemented through an elevation dimension, fixed beamforming can not exceed the potential gain provided by the spatial and frequency selective characteristics of the channel .

FIG. 5 illustrates another numbering of the transmit antenna elements 500 (or a transceiver unit (TXRU)) in accordance with the embodiments of the present disclosure. The embodiment shown in FIG. 5 is for convenience of description, and other embodiments may be used, so long as they do not depart 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 at P = 2, (m, n, p), and 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, (M, N) is (N _H , N _V ) or (N ₁ , N ₂ ) in the following embodiments (1D, 1D subarray partition) Can be indicated.

 In some embodiments, the UE is configured with CSI-RS resources including Q (Q = MNP) channel state information-reference signal (CSI-RS) The CSI-RS resource is associated with 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 comprising Q antenna ports (antenna ports A (1) through A (Q)) through an upper layer. The UE 116 may further include a CSI reporting configuration via a higher layer with respect to the CSI-RS configuration. The CSI reporting configuration includes an information element (IE) indicating the CSI-RS separation information (or component PMI port configuration).

One example of how to direct PMI reporting separation, as illustrated in Table 1 below, is to explicitly configure M, N, P and implicitly configure Q.

Component PMI Port Configuration M ... Select positive even numbers, for example, {1,2,4 ,,, 16}
N ... Select positive even numbers, for example, {1,2,4 ,,, 16}
P ... 1 or 2 one
Q = M? N? P ... Implicitly derived from explicitly constructed M, N, P

In conventional LTE, MIMO precoding is performed either as a CRS (see TS 36.211 section 6.3.4.2) or as a UE-specific reference signal (UE-RS) (see TS 36.211 section 6.3.4.4) . In each case, each UE operating in the spatial multiplexing mode is configured to report a CSI that may include a precoding matrix indicator (PMI) (i.e., 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 Tables 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 complies with 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 recommendation of the UE, the UE is configured to report the PMI according to the precoding codebook described above. Here, a PMI (which may be composed of a single index or a pair of indexes) may have a size N _c

N and _L is related to the size of the precoding matrix W, N _c is the number of antenna ports in a line (as in the number of columns), N _L is the number of transmission layers.

Rel . 12 LTE  8-transmission double codebook

Tables 2 and 3 are codebooks for reporting Rank-1 and Rank-2 (1-layer and 2-tier) CSI 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 these precoder expressions, the following two variables are used.

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

If the most recently reported RI is 1, according to Table 2, m and n are derived as two indices i ₁ and i ₂ , resulting 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, m, m ', and n are derived by two indices i ₁ and i ₂ according to Table 3, which is expressed by the following Equation (3) .

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

Is configured to be usable for two different types of channel conditions that facilitate rank-2 transmission.

i ₂ = {0, 1, ... , 7} comprises code words with m = m ', and the same beams (v _m ) comprise a code word with a code word m = m' .

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 two columns, due to the different signs to which? _N is applied, the two columns in the 2-layer precoder are orthogonal

These Rank-2 precoders can be used for UEs capable of receiving strong signals along two orthogonal channels generated by two antennas that are otherwise polarized.

Rel . 12 LTE  Alternative 4- Transmit double codebook

Based on a concept similar to 8-transmission, an alternative 4-transmit 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), high performance, scalable (with respect to the number and geometry of transmit antennas), flexible CSI feedback framework framework and structure of the system. In order to achieve high performance, more accurate CSI (preferably a quantized MIMO channel) is needed in the eNB. This is especially the case for FDD scenarios where short-term reciprocity is not feasible. In this case, the previous LTE (e.g., RE12) precoding framework (PMI-based feedback) may need to be replaced. However, feedback of the quantized channel coefficients may be excessive in terms of feedback requirements.

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

1. The use of large two-dimensional antenna arrays arranged close to a relatively small cluster (mainly aiming at a higher beamforming gain than spatial multiplexing) is spread to each UE: this is achieved by "compression " of quantized channel feedback quot; compression "or" dimensionality reduction ". In this case, a set of basic functions / vectors is used, and the quantization basically represents a MIMO channel in terms of linear combinations of these basic functions / vectors.

2. Low mobility as a target scenario for FD-MIMO: the possibility of updating the quantization parameters at a low rate (long-term channel statistics such as channel angular spread), for example, UE-specific high-layer signaling, and furthermore, CSI feedback can be used cumulatively.

3. Basic functions / vectors derived mainly from channel angular spreading characteristics, although time-varying basis functions / vectors can be used (e.g. derived from EVD or SVD and fed back from UE to eNB) Small channel angular spread ensures the use of a fixed master-set of vectors. For a given channel angular spreading characteristic, a subset of the fixed master-set (previously known to the UE and the eNB) is selected by the eNB and signaled to the UE.

The overall codebook configuration operation in accordance with some embodiments of the present disclosure is as follows (assuming a two-dimensional antenna array:

1. The UE receives N _P antenna ports and a CSI-RS (channel state information reference signals) configuration corresponding to the CSI-RS. N _P N _P is in accordance with the notation (notation) in the embodiments related to may be decomposed into N _{V H} · N. Fig. 5, N _H is the 2N and N is _V 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 for one column.

2. With the processed CSI-RS, the UE derives channel quality information (CQI), a precoding matrix indicator (PMI), and / or a 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 referring to 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 the set of basis vectors constituting L distinct basis vectors chosen apart from the mother set containing the large number of (? L) basis vectors, Each basis vector a ₁ is N _P

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

2.2.1.1. Constitution or reporting of the number of basis vectors L: In one method, L is organized into an upper-layer by the eNB. In another method, the UE reports a recommended value of L for the eNB.

2.2.1.2. Like the indexed antenna port 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 the magnitude N _{H, which} represents the azimuth and altitude channel response for a given pair of azimuth and elevation angles, respectively,

1 and N _V

1 < / RTI > DFT vectors, _hl and v _l Is oversampled.

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

2.2.1.2.2. For simplicity, the following mathematical description assumes the antenna port indexing given in FIG. 4B. Conventional descriptors may 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. Besides

_V? W _V ; And H = {h _l } _{l = 1,2,3,4} correspond to the four beams corresponding to i ₁ of the LTE Rel-10 8-transmit codebook (Tables 2 and 3). That is, H = {v _2i , v _{2i + 1} , v _{2i + 2} , v _{2i + 3} }, where v _m is as shown in 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 the magnitude N _{H, which} represents the azimuth and altitude channel responses for a given pair of elevation angles, respectively,

1 and N _V

Wherein with one of the DFT vector h _l v and _l Is oversampled; Then,? ₁ is expressed by Equation (12).

Represents the co-phase of the cross-polarization arrangement. In this case, the parent set can be a set of products 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, an index tuple (i ₁ , i ₂ , i ₃ ) indicates a basis vector a ₁

And associated indices are i ₁ and i ₂ represents an, <Table 2> are set is mapped to the specific pre-coder according to. In addition, the indices associated with v _l are represented as i ₃ , and they are mapped one-to-one to Q _v oversampled to _{D V} vectors of length N _v . The Q _V is a positive integer representing the height of the codebook and can 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. Besides

_V? W _V; And H = {h _l } _{l = 1,2,3,4} correspond to the four beams corresponding to i ₁ of the LTE Rel-10 8-transmit codebook (Tables 2 and 3). That _{is, H = {v 2i, v} 2i + 1, v 2i + 2, v 2i + 3}, wherein, v _m is as follows <Equation 14>.

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

1 is expressed as Equation (15) below.

Where D = 2 ⁿ , where n is a positive integer. DFT vectors oversampled to different magnitudes can similarly be constructed.

2.2.2. C = {c _l } is the set corresponding to the 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 individually quantized. N _Re is the quantization bit for the real dimension and N _Im is the quantization bit for the imaginary dimension. In one method, N _Re is N _Im .

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

2.2.2.3 Some details of the quantization methods are disclosed in US Patent Application No. &lt; RTI ID = 0.0 &gt; No. &lt; / RTI &gt; 14 / 593,711, which is incorporated herein by reference in its entirety.

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

2.4. The UE may select RI and PMI that allow the best (or best) CQI for PDSCH transmission with a certain (e.g., 0.1) error probability.

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

3.1. In one method, the PMI corresponding to the basis set A is broadband (i.e., only one set is reported in the aperiodic report), and the PMI corresponding to the coefficient set C is a subband (i.e., Aggregates, for example, one per subband is reported in the periodic report).

3.2. In one method, the PMI corresponding to h _l and v _l is broadband, and the coefficient set C and the co-phasing factor φ are subbands.

4. In a subframe having a period Q and a period P, in a subframe having a period Q, the UE transmits a 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 (i. E., Reported as a larger period) than the PMI corresponding to the coefficient set C.

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

4.3. In both methods (a) and (b) described above, less frequently reported PMIs are reported from the same PUCCH resource pool in the same manner and / or as 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 set {a _l } is reported less frequently (i.e., reported in a larger cycle) than the PMI corresponding to the set of coefficients {c _l }.

UE  Embodiments of feedback definitions

Example 1 Construction of Basis Vector A and Indication 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, utilizing the correlation of each piece of information over the frequency domain and the 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 at least in the following three fields to inform the selected L basis vectors: L vectors (A _H = {h _l : l = 0,1, ..., L-1}); A second field indicating a vector (denoted by v) representing the altitude domain channel directions; L co-paging factors &lt; RTI ID = 0.0 &gt;

&Lt; / RTI &gt; In this case, the corresponding basis vectors A = {a ₁ : 1 = 0,1, ..., L-1} are determined as follows.

Each field may have a correlation over frequency domain and basis vectors, which can 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 may be used for all L basis vectors, for feedback information generation, i. E.

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

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

Referring to these channel characteristics, the first and second fields are proposed as a wide band, and the third field is a subband. In one example where such 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 the K subband is (2K + 6) bits (= 4 bits + 2 bits + 2 bits K subband).

이다.For the indication of the first field, the first PMI (i ₁ ) of the Rel-10 8-transmit codebook (Table 2) can be reused and basically the first PMI indicates four oversampled DFT vectors. In this case, the number of basis vectors selected in subset L is fixed at four. With L = 4, the first field is an integer i = 0, 1, ... , 15, indicating the selection of four vectors v _2i , v _{2i + 1} , v _{2i + 2} , v _{2i +3} , and the Rel-10 8-transmit codebook One)

to be.

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

, D = 2 &^lt; ⁿ &^gt;, and n is a positive integer. This is an additional field that share the same set of characteristics as a Rel-10 i _1.

The third field, in the azimuthal dimension, indicates co-paging between the two polarizations. All angles associated with information are made broadband, and the frequency selectivity of the channels must be captured by the subband coefficients for the L basis vectors. Thus, it is proposed that the UE feed back the set of L quantized coefficients C = {c _l } per subband. In some cases it is noteworthy that only one of the coefficients of L for the subbands is 1 and the coefficients of the other L-1 are zero; In this case, the newly proposed CSI feedback is reduced to a Rel-10 8-transmit codebook.

Reporting the third field jointly with C feedback, because the third field (used for co-paging) shares the same set of characteristics (sub-band tendency and faster update) as C feedback It is possible. It can also be a separate report of the third field and C.

Example 2: Alternative configurations

Instead of reusing the Rel-10 codebook configuration as much as possible, the following variants can 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 set of basis vectors,

remind

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

Depending on the user location and channel conditions, other UEs may have different angular spreads. For some UEs with small angular spreading in the bearing domain, the model set A _H = {v _2i , v _{2i +1} , v _{2i +2} , v _{2i +3} }, i = 0,1, ..., 31 comprise a continuous basis vectors in and, W1 basis vector set that can be represented by (or according to the instruction i ₁ = 32 D in Rel-10 8- transmitted codebook) is sufficient to describe the channel matrix. Instead, for some other UEs with large angular spreading, the continuous basis vector set A _H = {v _2i , v _{2i + 1} , v _{2i + 2} , v _{2i + 3} } gives insufficient explanation.

Several methods for addressing 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

Wherein two adjacent beams are represented in the set spaced apart by s, denoted by the inter-beam spacing, where s is a positive integer &lt; RTI ID = 0.0 &gt; to be.

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

There are two alternatives designed to construct the processor of the basis set of UEs. In one alternative, the eNB may estimate the downlink departure angle (AOD) spread from the uplink sounding and constructs the inter-beam spacing in s. In another alternative, the UE selects an inter-beam interval based on channel estimates from received reference signals and feeds back to the UE. In some embodiments, the selected s is wideband and only one s value 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, the set S must be defined, and the elements of the set S are the candidate values of s that the eNB can select. In one example, S = {s: s = 1 or 2}, where the information size is one bit. In another example, S = {s: s = 1, 2, 3 or 4}, where 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 approach, the basis vector set A _H is

Lt; / RTI &gt; comprises a set of L consecutive beams in a parent set of &lt; RTI ID = 0.0 &gt; E, &lt; / RTI &gt; 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 (i.e., D is broadband information).

In one alternative, for this operation, the set of possible values for D and the aggregation size are configured in the eNB and UE. In one example, D? {4,8,16,32}. In another alternative, a set of possible values of the oversampling factor x or 0 is configured in the eNB and UE. In one example, x? {1,2,4,8} and D = xN or OXN, where N is the number of CSI-RS antenna ports corresponding to the CSI- Which is one half of the number of antenna ports for M columns or a horizontal array in a rectangular array. That is, Equation (17) is obtained.

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

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

In another example, the UE selects and reports a B basis set index comprising a basis vector set. The basis vector set is indexed (indexed) by i, B _i = {v _2i, v _{2i +1, +2} v _2i, v _{2i + 3},} wherein i = 0, 1, ..., 2 I -1. Where I is the number of bits for encoding the selected set of basis vectors. In one example, I = 4. In addition, v _m is expressed by Equation (18).

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

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

to be. Where α ₀ <α ₁ <α ₂ <... <α _{L -1} are other values.

In one alternative, L may be configured via higher layer (e.g., radio resource control (RRC)) signaling or included in an uplink grant that carries triggering for aperiodic CSI reporting . Then, for a given L, the UE feeds back a field indicating the choice of? ₀ <? ₁ <? ₂ <... <? _L-1 .

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

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

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

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,

to be. Where α ₀ <α ₁ <α ₂ <... <α _{L - 1} is the set of integers {0, 1, ... , D-1}, and v _m is given by Equation (19).

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

The selected beam combination is mapped to a bit field, i.e. a "beam combination indicator (BCI) field ", coded, and mapped to one of the 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, the total number of combinations that select L = 4 among D = 16 and L = 4 candidate beams with D = 16 in this case is 1820 (16 choose 4); At that time, the BCI field size is

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

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

In some embodiments, the set of L beams indicated by the BCI field is broadband information, which is used to calculate the corresponding coefficients and CQI 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, in the same manner that the RI is coded and mapped, the BCI field is coded and mapped on the PUSCH; This protects the content of the field better.

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

In some embodiments, in the same manner that CQI / PMI is coded and mapped, the BCI field is coded jointly with the remaining CQI / PMI on the 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.

Example 3: Restriction of the parent set corresponding to the indication of L beams or basis vectors

In some embodiments, additional information, i. E., Parent aggregation 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 aggregation restriction information may be one of the ones 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 aggregation constraint information includes one of (restricted) parent aggregate size D, or oversampling factor x. A set of basis vectors

, Where v _m is equal to Equation (20).

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 a restricted population size D is constructed, or when an oversampling factor x is constructed,

, 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 the horizontal array In other words,

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

to be. For another example, when the restricted population size D is composed of D = 8, or when the oversampling factor x is composed of x = 2,

.

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

D = D _M / D, and 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 choice of the restricted parent set. In some embodiments, the UE is configured to report any combination of L basis vectors in the restricted parent set. The number of bits conveying the combination will be determined by the configured value of D. For example, if D is 16, the number of bits indicating the combination is

And D is 8, the number of bits indicating the combination is

Bit.

In some embodiments, the UE is configured to report L consecutive basis vectors in a restricted model set, and the number of bits for feedback information in the set of basis vectors is determined by the size of the restricted model set.

In some embodiments, the UE is configured to separately report the information of the parent aggregation restriction information and the basis vector combination. In these embodiments, the parent aggregation restriction information is broadband information, and only one value is fed back for the entire downlink frequency. In addition, the parent aggregation constraint 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 coding information of the base vector combination with the parent aggregation restriction information.

L is 4, some examples are as follows.

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

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

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

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

Other examples where L is 4 are as follows.

When D = 32 (or x = 8), the parent set is _{{v 0, v 1, ...} , v 31} according to a 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 restricted parent set. Where i = 0, 1, ..., 15. In this case, the UE is configured to use four bits to report information on a basis-vector combination.

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

When D = 8 (or x = 2), the parent set is _{{v 0, v 4, ...} , v 28} , and, according to 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 a restricted set of cells. Where i = 0, 1, ..., 4. In this case, the UE is configured to use two bits to report information on a basis-vector combination.

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

인 비트 필드를 사용하여 코딩될 수 있다. 표 6은 이러한 일 예를 나타낸다.In this example, the total number of states indicating the basis vector set is 16 + (for D = 16) and 8 + (for D = 16) 8) &lt; / RTI &gt; 4 = 28,

Lt; / RTI &gt; bit field. Table 6 shows this example.

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

Basis Vector Set Indicator Index (5 bits) (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 { _v2i , _{v2i + 1} , _{v2i +2} , _{v2i + 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 { _v8i , _{v8i +4} , _{v8i +8} , _{v8i + 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 manner that CQI / PMI is coded and mapped, the parent set and basis vector set indicator index is coded jointly with the rest of the CQI / PMI on the 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 _f , v _{f + 8} , v _{f + 16} , v _{f + 24} }, f? {0, ₂ , ₄ , ₆ }. In this case, a table for the basic vector set indicator is constructed in accordance with Table 7.

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

Basis Vector Set Indicator Index (5 bits) (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 { _v2i , _{v2i + 1} , _{v2i +2} , _{v2i + 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 { _v8i , _{v8i +4} , _{v8i +8} , _{v8i + 12} } 28, 29, 30, 31 D = 4 or x = 1 0, ..., 3 {v _{+0 2i,} v _{2i +8, +16} v _2i, v _{2i + 24}}

Example 4: H and V PMI configurations with parent set limits and instructions corresponding to L basis vectors

In the case of the cross-polarized two-dimensional rectangular antenna array as shown in FIG. 5, the basic vectors A (i, k) = {a ₁ And so on.

The _{h l (i) ∈A H (} i) is configured in accordance with 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, the 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 2 and v (k) is 2

1 vector.

In one example, v (k) is selected from the LTE 2 -transmission rank-1 codebook. That is, v (k) is equal to Equation (22) when K = 4.

In another example, v (k) is selected from a DFT codebook oversampled with an oversampling factor y. That is, v (k) is expressed by Equation (23).

이다.Y is a positive integer. The oversampling factor y may be directed by the eNB to the UE or may be 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

to be.

Example 5: Linear combination coefficient quantization

Linear combination (LC) coefficient quantization is an essential element in determining the feedback overhead of the proposed method. A typical wireless channel condition may follow broadband and long-term feedback of a basis vector set. However, channel conditions require that the quantization and reporting of LC coefficients be performed in a narrowband and short-term manner. Thus, 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 select one of the basis vectors with L = 4, and its information requires only 2 bits of information ((4 choose 1) = 4 = 2 bits). With a cross-polarized 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 such an embodiment, it is proposed to use a larger number of quantization bits for coefficient quantization, in order to increase the accuracy of the quantized channel matrix.

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

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

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

Where c _l ∈ {0,1}, l = 0,1,2,3 and e ^jφ is cross-polarized co-paging.

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

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

을 지시하는데 사용된다.In one method, we can have co-paging between selected beams in addition to traditional cross-polarization co-paging in case of cross-polarization. In one example, a 5-bit field for quantizing binary coefficients with L = 4, where the 3 bits are selected from two basis vector selections ([1 e ^{j a} 0 0], [1 0 e ^{j a} 0], [1 0 0 e ^{j a ], [0 1 e jα 0} ], [0 1 0 e jα], [0 0 1 e jα]) of being used to indicate the combination of all the six (= 4 choose 2), 2 bits are common between the selected beams - Paging

Lt; / RTI &gt;

In one method, for the case of a co-polarized antenna, the composite precoding vector w constructed in accordance with 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 composite precoding vector w constructed in accordance with 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 ^{ej [phi]} is cross-polarization co-paging.

In the case of cross-polarization, the quantization index of the linear-combination coefficients, beam co-paging, cross-polarized co-paging may be encoded separately or jointly.

In another method, the linear combination coefficients are allowed to fetch magnitude values 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, the two bits indicate one common size for all four linear coefficients. Alternatively, a 2-bit indication is allowed for each linear combination factor.

In one method, sizes and co-paging are individually quantized for selected beams using individual codebooks. In another method, sizes and co-paging 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 an appropriate length vector codebook (e.g., a length-4 vector quantizer). The codebook can be either learning-based adaptive or universal and non-adaptive.

Embodiment 6: Feedback configuration 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.The UE

Of being configured to form a {a _l} in accordance with the decomposition, the h _l and v _l is the size N _H × 1, and N _V × represents the respective azimuth and elevation channel response for a given azimuth angle, and a pair of elevation angle 1 &lt; / RTI &gt; over-sampled DFT vectors. And

Represents the co-phase of the cross-polarization matrix. The index tuples (i ₁ , i ₂ , i ₃ ) indicate the basis vectors a ₁ .

Are indexed as i ₁ and i ₂ , and the set thereof is mapped to specific precoders according to Table 2 or Table 4 for 8-transmission or 4-transmission. In addition, the indices associated with v ₁ are denoted i ₂ , which are of length N _V Q _V One-to-one mapping to oversampled DFT vectors. The Q _V is a positive integer representing the altitude codebook size, which can be determined as a function of N _V.

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

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

2. The broadband and basis of ₂ i - common feedback: UE is configured to feed back the wideband single value i _3, and which is used in common to construct the basis vectors all L = 4. If the UE is further configured to report an index tuple for 10 subbands and L = 4, then the total number of bits for feedback is 322 bits (= 2 + 10 subbands · 4 basis vectors (4+ 4) bit).

3. i ₁ and The broadband and basis-common feedback of i ₂ : The UE is configured to feed back the single wideband i ₁ and i ₃ values, and this is 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 determination of i ₂ to the BS, UE is configured to feed back the k = 0, 1, 2, 3 per subband. If UE is further configured to report an index tuple for 10 subbands, the total number of bits for feedback is 26 bits (= 4 + 2 + 10 subbands 2 bits).

In these embodiments, the Rank-1 design may be extended to rank-2 transmissions that individually correspond to Table 3 or Table 5 for 8-transmission and 4-transmission. The feedback mechanism for i ₁ and i ₂ is Rel. 12 &lt; / RTI &gt; LTE (one of two sub-modes of PUSCH or PUCCH mode 1-1).

Example 7: Other alternative configurations

In some embodiments, the eNB configures the UE to feed back a preferred precoding vector / matrix according to a dual codebook structure, where the UE feeds back to the index to direct the precoder: i ₁ and i ₂ : i ₁ is used to indicate the set of basis vectors, i. E., A _l , l = 1, ..., L, and i ₂ are used to indicate the set of coefficients, i.e., c _l , l = 1,. .., L.

In these embodiments, the eNB may further configure the UE with respect to the set of coefficients constituting the precoder for CSI feedback. In one example, eNB has to map the number of index i ₂ as a set of coefficients: constitutes the one of the (e.g., 2) how to use UE. The first method is a legacy 8-transmit codebook, i.e., Table 2, and the second method is a new mapping that facilitates better channel quantization for MU-MIMO operation. In this case, a first method is used for the UEs to be scheduled by the eNB using single-user MIMO (SU-MIMO). An eNB may configure a second method for UEs that the eNB is scheduling using multi-user MIMO (MU-MIMO).

반면에, eNB는 UE에 대해 계수 양자화 방법을 더 구성할 수 있다.In one embodiment, the eNB configures eight CSI-RSs for the UE and configures the UE to feed back the preferred precoding vector / matrix according to the dual codebook structure; Further configured to feed back the selected basis vectors and the coefficient vectors corresponding to the two indices i ₁ and i ₂ . When Table 2 is used for basis vector quantization, the selected basis vectors &lt; RTI ID = 0.0 &gt;

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 a legacy codebook and coefficient quantization for the UE. Then, the selected coefficient vector is

, Where e _i is an L x 1 vector, its ith element is 1, and all other elements are zero. In this case, the co-paging factors φ _{n, n} = i ₂ mod4, and the whole pre-coding vector (matrix) is represented as:

In either case, eNB is further configured according to the new mapping coefficient LC method (LC to the coefficient from i ₂₎ the UE to feed back the CSI. The LC coefficients may be quantized according to any of the examples in Example 3, in which case the entire precoding vector (matrix) is constructed 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 co-paging factor

Jointly or separately, and coded in, it is mapped to the index i _2. In the special case where φ ₀ = φ ₁ = φ ₂ = φ ₃ , only one co-paging factor is quantized and fed back.

FIG. 6 illustrates an overall precoding operation 600 of a base station (BS) or enhanced Node B (eNB), in accordance with embodiments of the present disclosure. The embodiment shown in Fig. 6 is only for convenience of explanation. Other embodiments may be used, without departing from the scope of the present disclosure.

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

Method 1: Estimated basis vectors (SRS reception 605 → basis vector estimation 610) taking UL SRS (or, generally, a set of arbitrary UL signals) as an input;

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

Method 3: Feedback basis vectors (receiving CSI feedback 615).

In the case of L = 1 where only one basis vector is selected, the linear combination is reduced to a single term, including the product of the single selected basis vector and the corresponding single LC coefficient. In this case, the single basis vector corresponds to one of a precoding vector used for CSI-RS precoding or a precoding vector corresponding to the PMI reported by the UE. In addition, the single LC coefficients correspond to the 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 schemes. This choice depends on at least one state (e.g., related to deployment scenarios). Each of the three schemes is self-contained and thus can operate on its own, 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 which uses linear combination (LC) coefficients c _l , l = 1,... To reconstruct the channel state or 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 a basis vector for a linear combination and to determine the a ₁ , l = 1, ..., L, At least one of which can be selected. Each of the three methods corresponds to an operational mode.

FIG. 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 explanation. Other embodiments may be used, without departing from the scope of the present disclosure.

In method 1, information on a _l , l = 1, ..., L is configured in the UE and a _l , l = 1, ..., L equal to that configured in the UE is used for the linear combination. The selection of the L basis vectors (of the larger set of basis vectors) is performed by the BS using SRS and UL / DL channel reciprocity (i.e., scheme 1). This is incorporated herein by reference in its entirety, which is incorporated herein by reference in its entirety. 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 of L basis vectors received from block 710, LC coefficient calculations). Also, for LC coefficient estimation, block 720 takes any RS that is used for CSI estimation as an additional input to calculate CSI-RS or CRS or LC coefficients. The LC coefficients are then quantized and fed back to the eNB in the form of, for example, one PMI or multiple PMIs at block 725.

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 explanation. Other embodiments may be used, without departing from the scope of the present disclosure.

In method 2, a ₁ , l = 1, ..., L is an I-th precoding weight vector applied to the antenna elements to construct the 1 st CSI-RS beam (i.e., scheme 2) weight vector. The eNB constructs a UE with L CSI-RSs. In this case, each CSI-RS is precoded into a corresponding precoding weight vector. This is incorporated herein by reference in its entirety, such as in U.S. Patent Application Serial Nos. 14 / 149,436.

At block 705a, the UE receives the precoded CSI-RS or any RS used for CRS or CSI estimation and calculates LC coefficients at block 715B. Thus, block 715B for basis vector estimation takes the received RS as input to calculate the associated LC coefficients and basis vectors. The LC coefficients are then quantized and fed back to the eNB through blocks 720 through 725. In some embodiments, the precoding weight vectors applied to the CSI-RS are UE-specific and they can 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 can generate a grid of beams covering azimuth and altitude spaces.

7C illustrates a UE operation 750 when the eNB in accordance with the embodiments of the present disclosure uses Method 3. [ The embodiment shown in Fig. 7C is merely for convenience of explanation. 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, the information for configuring a _l , l = 1, ..., L is fed back (i.e., scheme 3) by the UE. In one example, eNB has eight CSI-RS is configured for the UE may process the first PMI index, in accordance with Table 2, i ₁ (or W1) is _{a l, l = 1, ...} , Lt; RTI ID = 0.0 &gt; L = 4. &Lt; / RTI &gt; In this case, the selected set of basis vectors

In another example, the eNB for the UE having four CSI-RS may process the first PMI index, in accordance with Table 4, i ₁ (or W1) is _{a l, l = 1, ...} , L Lt; RTI ID = 0.0 &gt; = 4 &lt; / RTI &gt; In this case, the selected set of basis vectors

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

In block 705c, the UE receives the CSI-RS used for CSI estimation and determines a subset of the L basis vectors in block 715c. Block 715c for LC coefficient (or PMI) estimation takes the received CSI-RS as an input to calculate the 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, according to the signaling corresponding to the selection of the L basis vectors at block 725c.

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

The CSI-related operations that need to be computed in the eNB and in each UE are given in Tables 8 and 9.

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

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

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

Method 1 Method 2 Method 3 eNB Receive and decode a subset selection of L basis vectors Receive and decode a subset selection of L basis vectors - UE Receiving and decoding L LC coefficients (feedback);
Reconfigure channel or precoder Receiving and decoding L LC coefficients (feedback);
Reconfigure channel or precoder Receiving and decoding a subset selection of L basis vectors;
Receiving and decoding L LC coefficients (feedback);
Reconfigure channel or precoder

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

Method 2 is suitable when the channel pathloss is high (e.g., for high carrier frequencies), or when the eNB does not want to generate any signaling overhead in both UL and DL directions. One drawback is a 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 UL / DL channel reciprocity associated with long-period channel statistics is reliable.

Method 3 is suitable when the UL / DL channel mutuality is weak. Thus, when the UL-DL duplex spacing is large enough, this method is suitable. This is particularly appropriate when higher carrier frequencies are used with legacy (lower) carrier frequencies. For example, the network may configure the DL carrier frequency in the mmWave region and the 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 can consider these tradeoffs to decide which method to use for DL link adaptation, scheduling and precoding. In actual deployment scenarios, many other factors are considered in devising a set of switching criteria.

In some of the above cases, the eNB may support multiple carrier frequency bands, and the carrier frequency is used as a selection criterion. Where the multiple carrier frequencies may be at least one frequency in the low band (up to 6 GHz), at least one frequency in the middle band (6 GHz to 60 GHz), at least one frequency in the high band . In one example, if the carrier frequency is lower than a particular carrier frequency, e.g., 6 GHz or 30 GHz, the "basis vector selection" block selects either method 1 or 3 (estimated or feedback basis vectors) The block chooses Method 2 (precoding to CSI-RS weight). In another example, if the carrier frequency is higher than a particular carrier frequency, for example, 6 GHz, the "basis vector selection" block selects method 1 (estimated basis vectors) Feedback basis vectors or CSI-RS weight precoding).

In other cases than the 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 the 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, If this is a frequency-division duplex (FDD), then the block chooses method 3.

In some embodiments, the eNB explicitly configures the method (s) used for selecting its basis vectors to the UE via higher-layer (e.g., RRC) signaling.

8 is a process 800 for basis vector construction of a UE according to an embodiment of the present disclosure. While the flowcharts illustrate a series of sequential steps, unless explicitly stated, the steps of performing a particular sequence of execution, steps of execution, or portions thereof may be performed independently, without intervening or intermediate steps, There should be no reasoning regarding the performance of the described steps. The process described in the described example is implemented in a processing circuit such as, for example, a mobile station.

The UE may configure one basis vector selection method among a plurality of methods. At operation 805, the UE is configured to select basis vectors by the eNB: (1) eNB configuration; And (2) UE estimation. (1) When an eNB is configured, the UE constructs basis vectors at operation 810 based on the eNB's basis vector configuration information; (2) When the UE estimate is configured, at operation 820, the UE estimates the basis vectors using the received RS, i.e., 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 of the plurality of methods for selecting a basis vector.

The UE may then use the carrier frequency to construct a basis vector selection method.

In one example, the UE is configured with (a) eNB configured basis vectors for a serving cell with a carrier frequency that is above a critical carrier frequency, i.e., 6 GHz; Otherwise, the UE is configured with (b) UE estimated basis vectors for a serving cell with a carrier frequency lower than the critical carrier frequency.

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

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

In some embodiments, the base vector selection block may yield a "rank" number of sets of basis vectors if the UE is capable of an upper rank transmission (e.g., rank 2), and the CSI reconstruction block may, Quot; number of sets of channel co-coefficients.

FIG. 9 illustrates a full BS precoding operation 900 for rank two channels, in accordance with embodiments of the present disclosure. The embodiment shown in Fig. 9 is merely for convenience. Other embodiments may be used without departing from the scope of the present disclosure.

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

10 illustrates a full BS precoding operation 1000 for rank two channels in accordance with embodiments of the present disclosure. The embodiment shown in Fig. 10 is only for convenience of explanation. Other embodiments may be used without departing from the scope of the present disclosure.

As shown in Figure 10, in another illustrative illustration, the basis vector selection block 620 includes sets of two basis vectors, a _l , l = 1, 2, ..., , L, and b _k , k = 1, 2, ... , K are calculated. Where K and L may not be the same and CSI reconstruction block 1005 may be used to derive from the rank-2 UE two sets of channel coefficients, c _l , l = 1, 2, ..., , L, and d _k , k = 1, 2, ... , K are received. The CSI reconstruction block reconstructs the rank-2 channel as shown in Equation (32) below.

11 shows a flowchart 1100 for basis vector selection according to embodiments of the present disclosure. The embodiment shown in Fig. 11 is only for convenience of explanation. Other embodiments may be used, without departing from the scope of the present disclosure.

At operation 1105, the eNB receives the uplink signals and selects one of the above three methods based on uplink measurements, such as SRS or PUSCH, at operation 1100. The uplink measurement includes angular, power-delay and 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 explanation. 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 criteria. When measuring the uplink channel characteristics, the eNB controller at operation 1200 checks how large the cluster angular spread is: if greater, then at block 1215 the block chooses Method 3; If so, the eNB further checks whether the duplex interval is large or small. If the duplex interval is large, the block selects Method 1 at operation 1205; If so, at operation 1210, the basis vector selection block 1115 selects method 2. In complex situations, at operation 1220, the eNB may select a combination of these three methods. In such embodiments, the eNB may set a threshold for comparison in order for the eNB to determine "small" or "large ". For example, if the cluster angular spread is greater than the threshold, the basis vector selection block 1115 may select method 3.

These embodiments are modified by the following observations.

In method 1, the eNB may construct a set of L basis vectors for the UE. This set can be derived from feedback as well as uplink reception. For this approach to work well, each spread of each cluster channel needs to be not very high. Otherwise, it is difficult to effectively capture 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 the uplink measurement. It may require uplink measurements to better reflect the downlink channel. 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. In addition, small angular spreads (not distinguished in the time domain) within the cluster are required, otherwise there may be no dominant direction that can be extracted from the uplink measurements.

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

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

Referring to FIG. 13, in step 1301, the base station transmits information related to reference signals and configurations for precoding matrix reporting. In particular, the base station transmits information relating to a first configuration for reference signals and a second configuration for precoding matrix reporting. 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 reference signals in accordance with a first configuration of a 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 the reference signals. That is, the base station receives feedback information including indicators derived from the reference signals, according to the second configuration. One of the indicators represents the bearing channel, and one of the other indicators represents the altitude channel. The feedback information further includes a CQI derived to use one of the pre-defined 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 base station may also convert the indicators to one of the 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 representing an azimuth channel and a second value representing an altitude channel and the second element comprises a product of a first value and a second value that are phase- . Each of the predefined precoding matrices consists of a linear combination of basis vectors. The basis vectors are determined based on the spreading of one or more channels, the uplink measurement, the sounding reference signals, the precoding weight vector applied to the reference signals, and the feedback information. For example, each of the predefined precoding matrices &lt; RTI ID = 0.0 &gt;

Format. Where phi is the co-paging factor, h is the vector representing the azimuth channel, and v is the vector representing the altitude channel.

Figure 14 shows a flow diagram of the operational process of the UE according to the present disclosure.

Referring to FIG. 14, in step 1401, the UE receives information related to reference signals and configurations for precoding matrix reporting. In particular, the UE receives information relating to a first configuration for reference signals and a second configuration for precoding matrix reporting. 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 reference signals in accordance with a first configuration that configures a 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 the reference signals. That is, according to the second configuration, the UE transmits feedback information including indicators derived from the reference signals. One of the indicators represents the bearing channel, and one of the other indicators represents the altitude channel. The feedback information further includes a CQI derived to use one of the pre-defined 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 to one of the pre-defined 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 representing an azimuth channel and a second value representing an altitude channel and the second element comprises a product of a phase-shifted first value and a second value. Each of the predefined precoding matrices consists of a linear combination of basis vectors. The basis vectors are determined based on the spreading of one or more channels, the uplink measurement, the sounding reference signals, the precoding weight vector applied to the reference signals, and the feedback information. For example, each of the predefined precoding matrices &lt; RTI ID = 0.0 &gt;

Format. Where phi is the co-paging factor, h is the vector representing the azimuth channel, and v is the vector representing the altitude channel.

While this disclosure has been described in terms of exemplary embodiments, various changes and modifications may be suggested to one of ordinary skill in the art. This disclosure is intended to cover such modifications and changes as fall within the scope of the appended claims.

Claims (14)

In a base station (BS) in a wireless communication system,
Transmitting information related to a first configuration for reference signals and a second configuration for precoding matrix reporting,
Transmitting the reference signals according to the first configuration including a plurality of antenna ports,
Comprising: a transceiver for receiving, from a terminal, feedback information including a plurality of indicators derived from the reference signals according to the second configuration;
And a controller for converting the plurality of indicators into one of pre-defined precoding matrices,
Wherein each of the predefined precoding matrices comprises a first element and a second element,
Wherein the first element comprises a product of a first value representing an azimuth channel and a second value representing an elevation channel,
Wherein the second element comprises a product of a first value and a second value that are phase-shifted.
In a wireless communication system, in a method of operating a base station (BS)
Transmitting information related to a first configuration for reference signals and a second configuration for precoding matrix reporting;
Transmitting the reference signals according to the first configuration including a plurality of antenna ports,
Receiving feedback information from a terminal, the feedback information including a plurality of indicators derived from the reference signals according to the second configuration;
And converting the plurality of indicators into one of pre-defined precoding matrices,
Wherein each of the predefined precoding matrices comprises a first element and a second element,
Wherein the first element comprises a product of a first value representing an azimuth channel and a second value representing an elevation channel,
Wherein the second element comprises a product of a first value and a second value that are phase-shifted.
A terminal in a wireless communication system,
Receiving information related to a first configuration for reference signals and a second configuration for precoding matrix reporting,
Receiving the reference signals according to the first configuration including a plurality of antenna ports,
A transceiver for transmitting feedback information including a plurality of indicators derived from the reference signals according to the second configuration;
By the base station, the plurality of indicators into one of pre-defined precoding matrices,
Wherein each of the predefined precoding matrices comprises a first element and a second element,
Wherein the first element comprises a product of a first value representing an azimuth channel and a second value representing an elevation channel,
Wherein the second element comprises a product of a first value and a second value that are phase-shifted.
A method of operating a terminal in a wireless communication system,
Receiving information related to a first configuration for reference signals and a second configuration for precoding matrix reporting,
Receiving the reference signals according to the first configuration including a plurality of antenna ports,
Transmitting feedback information including a plurality of indicators derived from the reference signals according to the second configuration,
By the base station, the plurality of indicators into one of pre-defined precoding matrices,
Wherein each of the predefined precoding matrices comprises a first element and a second element,
Wherein the first element comprises a product of a first value representing an azimuth channel and a second value representing an elevation channel,
Wherein the second element comprises a product of a first value and a second value that are phase-shifted.
The method according to any one of claims 1 to 4,
Each of the predefined precoding matrices

With format,
Wherein? Is a co-phasing factor, h is a vector representing an azimuth channel, and v is a vector representing an altitude channel.
The method of claim 5,
Said second configuration having first and second numbers N ₁ and N ₂ ,
When N ₁ = 4 and N ₂ = 2, h and v are

Wherein D ₁ = O ₁ .N ₁ , and D ₂ = O ₂ .N ₂ , wherein m ₁ and m ₂ are positive integers.
The method of claim 6,
Wherein the plurality of indicators are used to determine m ₁ and m ₂ .
The method of claim 5,
Wherein the number of the plurality of antenna ports is equal to 2 · N ₁ · N ₂ .
The method of claim 5,
Wherein the feedback information further comprises a channel quality indicator (CQI) derived using one of the predefined precoding matrices.
The method of claim 5,
Wherein the plurality of indicators each include at least two indicators for h and v, respectively.
The method according to claim 1, 2, 3, or 4,
Wherein each of the predefined precoding matrices comprises a linear combination of basis vectors.
The method of claim 5,
The basis vectors may include at least one of an angular spread of a channel, an uplink measurement, sounding reference signals, a precoding weight vector applied to the reference signals, and feedback information Base station, terminal or method.
The method according to any one of claims 1 to 4,
Wherein the feedback information is transmitted aperiodically through a data channel.
The method according to any one of claims 1 to 4,
Wherein the feedback information is transmitted periodically via a control channel.

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