KR20180087148A - Communication method and apparatus using multiple antennas in wireless communication system - Google Patents

Abstract

A communication method and apparatus using multiple antennas in a wireless communication system are disclosed. The communication method of a receiver includes the steps of: receiving reference signals from a transmitter of a communication system through beams to which hybrid beamforming is applied; selecting at least one analog beam with quality equal to or higher than a preset threshold value among analog beams which belong to the beams, based on the reference signals; and selecting at least one digital beam which corresponds to the at least one analog beam and has the quality equal to or higher than the preset threshold value among digital beams which belong to the beams, based on the reference signals. Therefore, the performance of the communication system can be improved.

Description

TECHNICAL FIELD [0001] The present invention relates to a communication method and apparatus using multiple antennas in a wireless communication system,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to wireless communication technology, and more particularly, to a wireless communication technique for providing enhanced communication service using multiple antennas.

BACKGROUND OF THE INVENTION [0003] In a wireless communication system, a user equipment typically can transmit and receive data units through a base station. For example, if there is a data unit to be transmitted to the second terminal, the first terminal can generate a message including the data unit to be transmitted to the second terminal, and transmit the generated message to the first base station Lt; / RTI > The first base station can receive the message from the first terminal and confirm that the destination of the received message is the second terminal. The first base station can transmit the message to the second base station to which the second terminal, which is the confirmed destination, belongs. The second base station can receive the message from the first base station and confirm that the destination of the received message is the second terminal. The second base station may transmit the message to the second terminal, which is the identified destination. The second terminal can receive the message from the second base station and obtain the data unit contained in the received message.

Meanwhile, as the users of the wireless communication system described above increase rapidly, an efficient communication method will be needed to improve the communication service. For example, communication based on multiple antennas may be considered for improving communication services. However, if communication based on multiple antennas is performed, an improvement plan for the following issues will be needed.

- Reduced transmission delay

- Reliability by improving data transmission / retransmission performance

Providing flexible and scalable services to reflect terminal (eg, user) and service characteristics

- Provide service considering frequency operation regulation and frequency characteristics

- Transfer of large data or high data rate according to user's demand

In order to solve the above problems, an object of the present invention is to provide a communication method and apparatus based on multiple antennas in order to provide an improved communication service.

According to a first aspect of the present invention, there is provided a communication method in a receiver of a communication system, the method comprising: receiving reference signals from a transmitter of the communication system through beams to which hybrid beamforming is applied; Selecting at least one analog beam having a quality higher than a preset threshold value among the analog beams belonging to the beams based on the reference signals, selecting one of the digital beams belonging to the beams from the at least one analog beam Selecting at least one digital beam corresponding to and having a quality that is equal to or greater than the preset threshold value and transmitting information indicating at least one of the at least one analog beam and the at least one digital beam to the transmitter .

Wherein the selecting of the at least one analog beam comprises selecting at least one horizontal analog beam having a quality above the preset threshold among the horizontal analog beams belonging to the analog beams, And selecting at least one vertical analog beam having a quality higher than the preset threshold value among the beams.

Here, the at least one vertical analog beam may be an analog beam vertically disposed with the at least one horizontal analog beam.

Wherein the selecting of the at least one digital beam comprises selecting at least one horizontal digital beam corresponding to the at least one horizontal analog beam among the horizontal digital beams belonging to the digital beams and having a quality above the predetermined threshold value And selecting at least one vertical digital beam corresponding to the at least one vertical analog beam among the vertical digital beams belonging to the digital beams and having a quality higher than or equal to the predetermined threshold value.

Here, the at least one vertical digital beam may be a digital beam vertically disposed with the at least one horizontal digital beam.

Here, the reference signals may be received via a combined beam of the transmitter.

Here, the digital beams can be generated by electrical tilting of the analog beams.

The selecting of the at least one digital beam may further comprise identifying a precoding vector of the at least one digital beam.

According to another aspect of the present invention, there is provided a method of communicating in a transmitter of a communication system, comprising: transmitting reference signals using analog beams and digital beams; Receiving from a receiver of the communication system information indicative of at least one of an analog beam and at least one digital beam and communicating with the receiver using at least one of the at least one analog beam and the at least one digital beam, Wherein the antenna module of the transmitter comprises a plurality of beam formers supporting different sectors, each of the plurality of beam formers includes a plurality of panels, each of the plurality of panels comprises a plurality And wherein said analog beams and said digital It is transmitted by a single beam former.

Here, the reference signals may be transmitted through a time-frequency resource other than a time-frequency resource set for interference measurement.

Wherein the at least one digital beam can be generated by electrical tilting of the at least one analog beam.

Here, the reference signals may be transmitted through a beam combining at least two of the analog beams and the digital beams.

Here, the combined beam can be generated by virtualizing the panels belonging to one beam former so that they have one orientation point.

In order to achieve the above object, a receiver of a communication system according to a third embodiment of the present invention includes a processor and a memory in which at least one instruction executed by the processor is stored, Receiving at least one analog beam having a quality higher than a predetermined threshold value among analog beams belonging to the beams based on the reference signals, receiving the reference signals from the transmitter of the communication system through the beams, Selecting at least one digital beam corresponding to the at least one analog beam among the digital beams belonging to the beams and having a quality above the predetermined threshold value, and selecting at least one of the at least one analog beam and the at least one At least one of the digital beams of And to transmit information indicating one to the transmitter.

Wherein the at least one command when selecting the at least one analog beam comprises selecting at least one horizontal analog beam having a quality higher than the preset threshold value among horizontal analog beams belonging to the analog beams, And to select at least one vertical analog beam having a quality above the predetermined threshold value among the vertical analog beams belonging to the analog beams.

Wherein the at least one command in the case of selecting the at least one digital beam comprises at least one command corresponding to the at least one horizontal analog beam among the horizontal digital beams belonging to the digital beams, And selecting at least one vertical digital beam corresponding to the at least one vertical analog beam among the vertical digital beams belonging to the digital beams and having a quality above the predetermined threshold value .

Wherein the at least one vertical analog beam may be an analog beam disposed in a vertical direction with the at least one horizontal analog beam and the at least one vertical digital beam may be a digital It can be a beam.

Here, the reference signals may be received via a combined beam of the transmitter.

Here, the digital beams can be generated by electrical tilting of the analog beams.

Here, in the case of selecting the at least one digital beam, the at least one instruction may be executed to identify a precoding vector of the at least one digital beam.

According to the present invention, an improved communication service in a communication system can be provided. Particularly, when communication is performed based on multiple antennas, the optimal beam (e.g., analog beam, digital beam) can be selected through a beam finding procedure, so communication performance can be improved. Further, the quality of the beam can be measured through a beam measurement procedure, and communication performance can be improved because communication can be performed using a beam having an optimum quality. Further, through the beam interference measurement procedure, the interference between the beams can be measured, and the interference can be controlled based on the measured result, so that the communication performance can be improved.

1 is a conceptual diagram showing a first embodiment of a communication system.
2 is a block diagram showing a first embodiment of a communication node constituting a communication system.
3 is a conceptual diagram showing a first embodiment of a beamforming-based transmission method.
4 is a conceptual diagram showing a first embodiment of an antenna module.
5A is a conceptual diagram showing a first embodiment of a horizontal sector in a service area.
5B is a conceptual diagram showing a first embodiment of a vertical sector in a service area.
5C is a conceptual diagram showing a first embodiment of the sector configuration in the service area.
6 is a conceptual diagram showing a second embodiment of the sector configuration in the service area.
7 is a conceptual diagram showing a third embodiment of the sector configuration in the service area.
8 is a conceptual diagram showing a fourth embodiment of the sector configuration in the service area.
Fig. 9 is a conceptual diagram showing a first embodiment of a panel in a beam former. Fig.
10 is a conceptual diagram showing a first embodiment of a 2D URA antenna disposed in a panel.
11 is a graph showing a first embodiment of an antenna gain and a beam pattern according to beam forming.
12 is a conceptual diagram showing a first embodiment of a beamforming operation state transition diagram.
13A is a conceptual diagram showing a first embodiment of a beam pattern in a service area served by one beamformer.
13B is a conceptual diagram showing a second embodiment of a beam pattern in a service area served by one beamformer.
14A is a graph showing a first embodiment of an antenna gain and a beam pattern according to the embodiment shown in FIG. 13A.
FIG. 14B is a graph showing a first embodiment of an antenna gain and a beam pattern according to the embodiment shown in FIG. 13B.
15 is a conceptual diagram showing a first embodiment of a beam pattern when hybrid beamforming is performed.
16 is a graph showing a first embodiment of an antenna gain and a beam pattern when hybrid beamforming is performed.
17A is a conceptual diagram showing a first embodiment of a panel-based beam transmission method.
17B is a conceptual diagram showing a second embodiment of the panel-based beam transmission method.
17C is a conceptual diagram showing a third embodiment of the panel-based beam transmission method.
17D is a conceptual diagram showing a fourth embodiment of the panel-based beam transmission method.
18A is a conceptual diagram showing a first embodiment of a beam transmission method through a repeater.
18B is a conceptual diagram showing a second embodiment of a beam transmission method through a repeater.
19 is a conceptual diagram showing a first embodiment of a beam pattern to which a virtual beam combining method is applied.
FIG. 20 is a conceptual diagram showing a first embodiment of a beam combined through a virtual beam combining method. FIG.
21 is a graph showing a first embodiment of an antenna gain and a beam pattern in an embodiment in which panel virtualization is applied.
22 is a graph showing a first embodiment of an antenna gain and a beam pattern according to a beam combining method.
23 is a graph showing a search delay according to the beam search method.
24 is a conceptual diagram showing a first embodiment of the beam measuring procedure.
25 is a conceptual diagram showing a second embodiment of the beam measuring procedure.
26A is a timing chart showing a first embodiment of a transmission method of a beam measurement signal.
Fig. 26B is a timing chart showing a second embodiment of a beam measurement signal transmission method. Fig.
27 is a conceptual diagram showing the setting of the beam measurement signal in the MRU.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be interpreted in an ideal or overly formal sense unless explicitly defined in the present application Do not.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In order to facilitate the understanding of the present invention, the same reference numerals are used for the same constituent elements in the drawings and redundant explanations for the same constituent elements are omitted.

A communication system to which embodiments of the present invention are applied will be described. The communication system may be a 4G communication system (e.g., a long-term evolution (LTE) communication system, an LTE-A communication system), a 5G communication system (e.g. The 4G communication system can support communication in a frequency band of 6GHz or less, and the 5G communication system can support communication in a frequency band of 6GHz or less as well as a frequency band of 6GHz or more. The communication system to which the embodiments according to the present invention are applied is not limited to the following description, and the embodiments according to the present invention can be applied to various communication systems. Here, the communication system can be used in the same sense as a communication network.

1 is a conceptual diagram showing a first embodiment of a communication system.

1, a communication system 100 includes a plurality of communication nodes 110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6. The communication system 100 also includes a core network (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway, a mobility management entity .

The plurality of communication nodes 110 to 130 may support a communication protocol (e.g., LTE communication protocol, LTE-A communication protocol, NR communication protocol, etc.) defined in the 3rd generation partnership project (3GPP) standard. The plurality of communication nodes 110 to 130 may be any one of a plurality of communication nodes such as a code division multiple access (CDMA) technology, a wideband CDMA (WCDMA) technology, a time division multiple access (TDMA) technology, a frequency division multiple access (OFDM) technology, an orthogonal frequency division multiple access (OFDMA) technique, an SC (single carrier) -FDMA (Frequency Division Multiplexing) Technology, a non-orthogonal multiple access (NOMA) technology, a generalized frequency division multiplexing (GFDM) technology, a filter bank multi-carrier (FBMC) technology, a universal filtered multi-carrier technology (UFMC) . Each of the plurality of communication nodes may have the following structure.

2 is a block diagram showing a first embodiment of a communication node constituting a communication system.

Referring to FIG. 2, the communication node 200 may include at least one processor 210, a memory 220, and a transceiver 230 connected to the network to perform communication. The communication node 200 may further include an input interface device 240, an output interface device 250, a storage device 260, and the like. Each component included in the communication node 200 may be connected by a bus 270 and communicate with each other. However, each component included in the communication node 200 may not be connected to the common bus 270 but may be connected to the processor 210 via an individual interface or a separate bus. For example, the processor 210 may be coupled to at least one of the memory 220, the transceiver 230, the input interface 240, the output interface 250 and the storage 260 via a dedicated interface .

The processor 210 may execute a program command stored in at least one of the memory 220 and the storage device 260. The processor 210 may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods in accordance with embodiments of the present invention are performed. Each of the memory 220 and the storage device 260 may be constituted of at least one of a volatile storage medium and a nonvolatile storage medium. For example, the memory 220 may comprise at least one of read-only memory (ROM) and random access memory (RAM).

Referring again to FIG. 1, the communication system 100 includes a plurality of base stations 110-1, 110-2, 110-3, 120-1, 120-2, a plurality of terminals 130- 1, 130-2, 130-3, 130-4, 130-5, and 130-6. Each of the first base station 110-1, the second base station 110-2 and the third base station 110-3 may form a macro cell. Each of the fourth base station 120-1 and the fifth base station 120-2 may form a small cell. The fourth base station 120-1, the third terminal 130-3 and the fourth terminal 130-4 may belong to the cell coverage of the first base station 110-1. The second terminal 130-2, the fourth terminal 130-4 and the fifth terminal 130-5 may belong to the cell coverage of the second base station 110-2. The fifth base station 120-2, the fourth terminal 130-4, the fifth terminal 130-5 and the sixth terminal 130-6 can belong to the cell coverage of the third base station 110-3 have. The first terminal 130-1 may belong to the cell coverage of the fourth base station 120-1. The sixth terminal 130-6 may belong to the cell coverage of the fifth base station 120-2.

Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1 and 120-2 includes an NB (NodeB), an evolved NodeB (eNB), a gNB, an advanced base station (ABS) A base transceiver station (BTS), a radio base station, a radio transceiver, an access point, an access node, a radio access station (RAS) ), A mobile multihop relay base station (MMR-BS), a relay station (RS), an advanced relay station (ARS), a high reliability relay station (HR-RS), a home NodeB (HNB), a home eNodeB A roadside unit (RSU), a radio remote head (RRH), a transmission point (TP), a transmission and reception point (TRP), and the like.

Each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5 and 130-6 includes a user equipment (UE), a terminal equipment (TE), an advanced mobile station (AMS) A high reliability-mobile station (HR-MS), a terminal, an access terminal, a mobile terminal, a station, a subscriber station, a mobile station, A mobile subscriber station, a node, a device, an on board unit (OBU), and the like.

Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may operate in different frequency bands, or may operate in the same frequency band. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1 and 120-2 may be interconnected via an ideal backhaul link or a non-idle backhaul link , An idle backhaul link, or a non-idle backhaul link. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to the core network via an idle backhaul link or a non-idle backhaul link. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 transmits a signal received from the core network to the corresponding terminals 130-1, 130-2, 130-3, 130 130-2, 130-3, 130-4, 130-5, and 130-6, and transmits the signals received from the terminals 130-1, 130-2, 130-3, 130-4, Lt; / RTI >

In addition, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 performs MIMO transmission (for example, SU (single user) -MIMO, MIMO, massive MIMO, etc.), coordinated multipoint (CoMP) transmission, carrier aggregation (CA) transmission, transmission in an unlicensed band, direct device to device communication (D2D) , Proximity services (ProSe), Internet of Things (IoT) communications, and dual connectivity (DC). Each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 includes base stations 110-1, 110-2, 110-3, and 120-1 , 120-2, and operations supported by the base stations 110-1, 110-2, 110-3, 120-1, and 120-2. For example, the second base station 110-2 can transmit a signal to the fourth terminal 130-4 based on the SU-MIMO scheme, and the fourth terminal 130-4 can transmit a signal based on the SU-MIMO scheme And may receive a signal from the second base station 110-2. Alternatively, the second base station 110-2 may transmit a signal to the fourth terminal 130-4 and the fifth terminal 130-5 based on the MU-MIMO scheme, the fourth terminal 130-4, And the fifth terminal 130-5 may receive signals from the second base station 110-2 by the MU-MIMO scheme.

Each of the first base station 110-1, the second base station 110-2 and the third base station 110-3 can transmit a signal to the fourth terminal 130-4 based on the CoMP scheme, The terminal 130-4 can receive signals from the first base station 110-1, the second base station 110-2, and the third base station 110-3 by the CoMP method. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 includes terminals 130-1, 130-2, 130-3, 130-4 , 130-5, and 130-6) and the CA scheme. Each of the first base station 110-1, the second base station 110-2 and the third base station 110-3 controls the D2D between the fourth terminal 130-4 and the fifth terminal 130-5 And each of the fourth terminal 130-4 and the fifth terminal 130-5 can perform the D2D under the control of each of the second base station 110-2 and the third base station 110-3 .

Meanwhile, in the embodiments of the present invention, an apparatus for providing enhanced communication services may be an enhanced mobile broadband (eMBB) device, a low latency enabled (LL) device, a coverage enhancement (CE) device, or a low complexity (LC) device. The eMBB device can support the transmission and reception of large amount of data. The LL device may support a function of reducing the transmission delay. The CE device can support the enhancement of transmission distance. The LC device can support the complexity improvement function. Devices (e.g., eMBB devices, LL devices, CE devices, LC devices, etc.) that provide enhanced communication services in the embodiments described below may be referred to as "S-devices".

The S-device may be a device supporting a transmission function (e.g., a base station in a downlink communication procedure, a terminal in an uplink communication procedure, etc.), a device supporting the receiving function (e.g., (E.g., a base station in a link communication procedure), a device supporting a relay function (e.g., a relay, etc.). Also, the S-device may be located in a mobile device (e.g., a car, a train, an airplane, a drone, etc.).

The meaning of the terms used in the following embodiments can be defined as follows.

- A _A : Array antenna pattern (dB)

- A _E : Composite array antenna pattern (dB)

- A _m : front-to-back ratio

: 방사 엘리먼트(radiation element)의 수평(horizontal) 패턴-

: A horizontal pattern of a radiation element

: 방사 엘리먼트의 수직(vertical) 방사 패턴(예를 들어, 어레이 안테나와 수직인 점과 90도의 오프셋(offset by 90° to point to perpendicular to array)을 가지는 방사 엘리먼트의 수직 방사 패턴)-

: A vertical radiation pattern of a radiating element (e.g., a vertical radiation pattern of a radiating element having a point perpendicular to the array antenna and an offset of 90 degrees to point to perpendicular to the array)

: RF(radio frequency) 체인(chain)에 의한 수평 커버 디그리(horizontal covered degree)-

: Horizontal covered degree by radio frequency (RF) chain.

: RF 체인(chain)에 의한 수직 커버 디그리(vertical covered degree)-

: Vertical covered degree by RF chain.

: 수평 방향에서 패널들(panels) 간의 거리-

: Distance between panels in horizontal direction

: 수직 방향에서 패널들 간의 거리-

: Distance between panels in vertical direction

: 섹터(sector)의 수평 커버 디그리-

: Vertical cover of sector sector

: 섹터의 수직 커버 디그리-

: Vertical Cover Degrees of Sectors

: 수평 방향에서 송신기(transmitter)의 안테나 엘리먼트들 간의 거리-

: Distance between the antenna elements of the transmitter in the horizontal direction

: 수직 방향에서 송신기의 안테나 엘리먼트들 간의 거리-

: Distance between the antenna elements of the transmitter in the vertical direction

: m번째 열(column)과 n번째 행(row)에서 방사 엘리먼트의 복소 이득(complex gain)(예를 들어, 어레이 안테나 배치에 따른 위상 시프트(shift)를 가지는 복소 이득)-

: The complex gain of the radiating element at the m-th column and the n-th row (e.g., the complex gain with phase shift according to array antenna placement)

: 방사 엘리먼트의 최대 방향성 이득(dB), 예를 들어, 최대 방향성 이득은 8dBi일 수 있음.-

: The maximum directional gain (dB) of the radiating element, for example, the maximum directional gain may be 8 dBi.

: 방위각(azimuth angle)(예를 들어, 수평축)에서 수평 섹터들의 개수-

: Number of horizontal sectors at an azimuth angle (e.g., horizontal axis)

: 천정각(zenith angle)(예를 들어, 수직축)에서 수직 섹터들의 개수-

: Number of vertical sectors in a zenith angle (e.g., vertical axis)

: 하나의 송신기에 의해 제공되는(served) 섹터들의 개수-

: The number of sectors served by one transmitter

: 빔포머(beamformer) 내의 패널들의 개수-

: Number of panels in a beamformer

: 빔포머 내의 수평 방향(행)에서 패널들의 개수 (>0)-

: The number of panels (> 0) in the horizontal direction (row)

: 빔포머 내의 수직 방향(열)에서 패널들의 개수 (>0)-

: Number of panels in vertical direction (column) in beam former (> 0)

: RF 체인에 의해 사용 가능한 빔들의 개수-

: Number of beams available by the RF chain

: 수평 방향에서 RF 체인에 의해 사용 가능한 빔들의 개수-

: Number of beams available by the RF chain in the horizontal direction

: 수직 방향에서 RF 체인에 의해 사용 가능한 빔들의 개수-

: Number of beams available by the RF chain in the vertical direction

: 수신기(receiver)의 RF 체인(예를 들어, 하나의 패널 내의 RF 체인)에 의해 연결되는 안테나 엘리먼트들의 개수-

: The number of antenna elements connected by the RF chain of the receiver (for example, the RF chain in one panel)

: 수신기의 하나의 패널 내의 수평 방향의 안테나 엘리먼트들의 개수 (>0) -

: Number of horizontal antenna elements in one panel of the receiver (> 0)

: 수신기의 하나의 패널 내의 수직 방향의 안테나 엘리먼트들의 개수 (>0)-

: The number of vertical antenna elements in one panel of the receiver (> 0)

: 송신기의 RF 체인(예를 들어, 하나의 패널 내의 RF 체인)에 의해 연결되는 안테나 엘리먼트들의 개수-

: The number of antenna elements connected by the RF chain of the transmitter (for example, the RF chain in one panel)

: 송신기의 하나의 패널 내의 수평 방향의 안테나 엘리먼트들의 개수 (>0) -

: Number of horizontal antenna elements in one panel of the transmitter (> 0)

: 송신기의 하나의 패널 내의 수직 방향의 안테나 엘리먼트들의 개수 (>0)-

: Number of vertical antenna elements in one panel of the transmitter (> 0)

: 엘리먼트 패턴의 크기(magnitude)-

: The magnitude of the element pattern

: 사이드-로브(side-lobe) 레벨 제한-

: Side-lobe level limit

: 방위각(예를 들어, 방위각은 -180° 내지 180° 사이에서 정의됨)-

: Azimuth angle (e.g., the azimuth angle is defined between -180 ° and 180 °)

: 한 방향의 고도각(elevation angle)(예를 들어, 고도각은 0° 내지 180° 사이에서 정의되고, 90°는 어레이 안테나에 수직인 것을 지시함)-

: An elevation angle in one direction (e.g., altitude angle defined between 0 [deg.] And 180 [deg.] And 90 [deg.] Indicating vertical to array antenna)

: 송신기에서 안테나의 수직 3dB 빔폭(beamwidth)-

: The vertical 3dB beamwidth of the antenna at the transmitter.

: 송신기에서 안테나의 수평 3dB 빔폭-

: Horizontal 3dB beamwidth of the antenna at the transmitter

: 동작 캐리어 주파수에 대응하는 파장-

: Wavelength corresponding to the operating carrier frequency

: 신호 상관 계수(signal correlation coefficient)-

: Signal correlation coefficient

■ How to Provide Improved Communication Services

At least one of the following methods may be used to provide enhanced communication services (e.g., communication services that support the transmission of large amounts of data, communication services that support high data rates, etc.) according to the user's needs.

- Method 1: Improve the transfer rate

- Method 2: Improve spectral efficiency

Method 3: Provide system bandwidth to service requirements

- Method 4: Provide a connection that meets your service needs

Method 5: Retransmissions to improve reliability, avoiding retransmissions through improved transmission procedures

- Method 6: Provide wide coverage

- Method 7: Transmission considering operating frequency characteristics

Improved transfer rate

The transmission rate can be improved through improved signal processing. Where there is a restriction on the use of spectrum according to the use of spectrum, communication services may be provided within a range satisfying the frequency operation regulation. For example, if a transmission based on a high modulation and coding scheme (MCS) level (e.g., 1024 QAM (quadrature amplitude modulation)) is performed, the transmission capacity can be increased. However, radio signals may suffer loss of free space, loss due to environment (for example, rain, atmosphere, etc.). In particular, it may be necessary to consider losses due to the environment (for example, rainfall, atmosphere, etc.) in a frequency band of 6 GHz or more (hereinafter referred to as "mmWave band").

Therefore, in order to use a high MCS level in the mmWave band, the MCS level can be adaptively adjusted according to the environment (e.g., rainfall, atmosphere, etc.). For example, whether to perform link adaptation based on rainfall probability (eg, 99.5%, 99.9%, 99.95%, 99.99%, 99.995%, 99.999%, etc.) based on a specific time , An MCS level (e.g., a maximum usable MCS level), and the like may be set.

Communication services can be provided by combining two or more radio links similar to a carrier aggregation scheme. For example, communication services can be provided by combining a low frequency link (e.g., a microwave link below 6 GHz) and a high frequency link (e.g., a mmWave link above 6 GHz). In this case, the radio links can be combined in consideration of the channel characteristics of each of the low-frequency link and the high-frequency link. Also, if the quality of one radio link (e.g., a high frequency link) is poor, a communication service may be provided using another radio link (e.g., a low frequency link). For example, a wireless link that is robust to changes in the environment among the combined wireless links may be used, and a wireless link (e.g., a low-frequency link in the case of long-distance transmissions) selected based on the transmission distance of the signal may be used.

Improved spectral efficiency

Spectral efficiency can be improved by multiplexing. Multiplexing may be performed over a plurality of layers / links. For example, multiplexing may be performed over multiple antennas or multiple transmission points. Proper placement (e.g., spacing between antennas) of multiple antennas to form multiple layers / links for multiplexing may be required. Control / cooperation between transmission points may also be required for multiplexing. Alternatively, the received signal quality can be improved through proper combination of the received signals according to the difference between the plurality of paths.

Provide appropriate system bandwidth

Large system bandwidth may be needed for large data transfers. Broad system bandwidth may be provided through a combination of multiple wireless links. Large amounts of data can be transmitted over wide system bandwidth in the license-exempt / public frequency band. However, the maximum system bandwidth may be limited to 1 to 2 GHz or less due to hardware limitations of the communication node (e.g., base station, terminal, S-device). For coexistence between communication systems or coexistence between communication nodes, the system bandwidth can be divided.

Provide many connections

In a communication system, point-to-point (P2P) communication and point-to-multipoint (P2MP) communication can be supported. In this case, many connections can be supported through limited radio resources.

Improved reliability

Data may not be successfully transmitted due to the characteristics of the wireless channel. To solve this problem, a robust and reliable transmission procedure, a transmission error correction procedure, and a data retransmission procedure can be performed. The transmitter may transmit data to the receiver and the receiver may transmit a response (e.g., ACK (acknowledgment), NACK (negative ACK)) to the data obtained from the transmitter to the transmitter, It is possible to determine whether to perform the retransmission procedure of the data. Alternatively, for improved reliability, the transmitter may retransmit the same data without a response (e.g., ACK, NACK). Reliability can be improved by transmitting data over a plurality of links or a plurality of transmission points.

Coverage  expansion

To provide wide coverage, the transmitter can transmit signals using high transmit power. As the transmission distance increases, the received signal strength can be reduced, and the receiver can provide wide coverage by processing signals with low received signal strength. Coverage can be extended through multi-hop transmission by repeaters. Coverage can be extended by transmitting the signal in a specific direction using high transmit power. In this case, a directional antenna (e.g., a directional antenna) may be used, and a plurality of antennas may be arranged such that the signal is transmitted in a specific direction. In addition, the communication performance can be improved by applying the interference cancellation technique.

Communication methods based on multiple antennas

Next, a method of improving spectral efficiency based on multiple antennas, a method of extending coverage, and the like will be described.

Beam forming ( 보형링 )

Beamforming can be performed through directional antennas, antenna placement, beam radiation, and the like. Through beamforming, the coverage for a particular direction can be extended. However, beamforming can be performed in all directions for a receiver having mobility. Also, since the communication performance due to beamforming may be degraded if the position of the receiver can not be accurately predicted, beamforming can be performed in all directions to solve this problem.

3 is a conceptual diagram showing a first embodiment of a beamforming-based transmission method.

Referring to FIG. 3, a communication node (e.g., a base station, a terminal, an S-device, etc.) may perform beamforming independently in each of the sectors. When the communication node includes one antenna, the communication node can perform beamforming in each of the sectors (e.g., sector # 0 to sector # 7) using one antenna. Alternatively, when the communication node includes a plurality of antennas, the communication node can simultaneously perform beamforming in a plurality of sectors (e.g., sector # 0 to sector # 7) using a plurality of antennas.

4 is a conceptual diagram showing a first embodiment of an antenna module.

4, an antenna module 400 for providing communication services in each of the sectors (e.g., sector # 0 to sector # 7 shown in Figure 3) includes a plurality of beam formers (e.g., Eighteen beamformers 410-1 through 410-18). One beamformer may be disposed on one surface of the antenna module 400. [ For example, the beam formers # 2 to # 6 (410-2 to 410-6) are arranged on the faces located on the horizontal axis (for example, the axis horizontal to the xy plane) and the beam former # 1 And beamformers # 7 to # 12 (410-7 to 410-12) are provided on the upper side of the plane on which the beam former # 1 (410-1) is disposed with respect to the vertical axis (for example, And beamformers # 13 to # 18 (410-13) are disposed on the lower surfaces of the beamformer # 1 410-1 on the basis of the vertical axis (for example, an axis perpendicular to the xy plane) To 410-18 may be disposed. One beamformer may form at least one beam and may be mapped to one sector. For example, one beamformer can provide communication services in one sector.

Each of the beam formers 410-1 through 410-18 may include at least one panel (e.g., an antenna panel), one panel may include at least one array antenna, And may include at least one antenna element. The arrangement of the panel, the array antenna and the antenna element may be the same in all the beam formers 410-1 through 410-18 belonging to the antenna module 400. Alternatively, the arrangement of the panel, array antenna, and antenna element may be independent of each of the beam formers 410-1 through 410-18. For example, beamformer # 1 410-1 may include four panels 410-1-1 through 410-1-4, and panel # 1-1 410-1-1 may include Two array antennas 410-1-1-1 and 410-1-1-2, and array antenna # 1-1-1 410-1-1-1 may include twenty four antenna elements Lt; / RTI >

On the other hand, a beamformer disposed on the horizontal axis may be referred to as a " horizontal beamformer ", and N _h horizontal beam formers may be disposed in the antenna module according to embodiments of the present invention. N _h horizontal beam formers may be used for communication with a communication node (e.g., base station, terminal, S-device, etc.) located at the same or similar height. The beam former disposed in the vertical axis may be referred to as "vertical beam former", may be N _v of the vertical beam former are placed in the antenna module according to embodiments of the present invention. N _v vertical beam formers may be used for communication with communication nodes (e.g., base stations, terminals, S-devices, etc.) located at different heights. Each of N _h and N _v may be an integer of 1 or more.

When the area where the antenna module provides the communication service (hereinafter referred to as the " service area "), the angle of the horizontal sector in which one horizontal beamformer provides communication service on the horizontal axis may be " 2 pi / Nh &_quot; , And the angle of the vertical sector in which one vertical beamformer provides communication services on the vertical axis may be " / N _{v. &} Quot; For example, when the reference point is 0 [deg.], The coordinates (e.g., an angle) of a horizontal sector can be defined based on Equation 1 below and the coordinates (e.g., 2 < / RTI >

FIG. 5A is a conceptual diagram illustrating a first embodiment of a horizontal sector in a service area, FIG. 5B is a conceptual diagram illustrating a first embodiment of a vertical sector in a service area, FIG. Fig.

5A through 5C, there may be three horizontal sectors in the service area, and three vertical sectors in the service area. According to the combination of three horizontal sectors and three vertical sectors, there may be nine sectors in the service area.

On the other hand, a plurality of beam formers can provide a communication service in one sector. Alternatively, one beamformer may provide communication services in a plurality of sectors. When beams are distinguished within one sector, if the beam change is required by movement of the terminal, the beam can be changed without changing the sector.

6 is a conceptual diagram showing a second embodiment of the sector configuration in the service area.

Referring to FIG. 6, an internal sector and an external sector may be set according to the transmission distance of the base station 600 in the service area. A separate beam former may be operated for each of the inner sector and the outer sector.

7 is a conceptual diagram showing a third embodiment of the sector configuration in the service area.

Referring to FIG. 7, the service area may be divided into a lower sector, a middle sector, and an upper sector according to the height of a receiver (e.g., a terminal). The base station 700 may provide communication services in the lower sector, the middle sector, and the upper sector, respectively.

8 is a conceptual diagram showing a fourth embodiment of the sector configuration in the service area.

8, when a plurality of beam formers (for example, beam formers # 1 and # 2) belonging to an antenna module of a transmitter provide communication service to one sector, a plurality of beams A beam ID (identification) for uniquely identifying each of the beams (for example, beams # 11 to # 14, beams # 21 to # 24) generated by the formers (for example, beam formers # 1 and # 2) ) Can be set.

Alternatively, a beam ID for uniquely identifying each of the beams in a sub-sector supported by one beamformer (e.g., one beamformer may be set.) For example, within a sub-sector # 1 A beam ID for uniquely identifying each of the beams # 11 to # 14 may be set, and a beam ID for uniquely identifying each of the beams # 21 to # 24 within the sub-sector # 2 may be set. The beams between the beamformers (e.g., beamformers # 1 and # 2) may be distinguished according to the sub-sectors supported by the beamformer.

Fig. 9 is a conceptual diagram showing a first embodiment of a panel in a beam former. Fig.

Referring to FIG. 9, the beamformer may include a plurality of panels, and the plurality of panels may be arranged independently. Each of the plurality of panels can generate independent beams and can provide communication services in different service areas. A plurality of service areas for each panel can be operated as follows. Here, the " service area " may indicate a " sector " and the " sub-service area "

- Method of Operation 1: A service area served by one beamformer is divided into sub-service areas that are served independently by each of the panels belonging to one beamformer.

- Operation 2: One service area is set up by the panels belonging to one beam former.

When the service area served by the beam former is set to the service area (for example, 2? / N _h ,? / N _v ) shown in FIGS. 5A to 5C, the corresponding service area is a service area (E.g., "service area of one beamformer = service area of one panel") or service area served by each of the panels (eg, "service area of one beamformer / Service area ").

On the other hand, the antenna elements in the panel can be arranged spatially independently, and the beams can be generated by the antenna elements disposed in one panel. By adjusting the spacing (dg _{, H} , dg _{, V} ) between the panels, the beams of each of the panels can be generated independently. Alternatively, the communication service can be provided through the combined beam between the panels by adjusting the spacing d _{g, H} , d _{g, V} between the panels. In this case, the arrangement of the antenna elements in the panels may be the same.

개의 패널들이 배치될 수 있고, 하나의 빔포머의 수직축에서

개의 패널들이 배치될 수 있다. 즉, 하나의 빔포머는

개의 패널들을 포함할 수 있다. 하나의 패널은 적어도 하나의 RF 체인과 연결될 수 있다. 이 경우, RF는 패널을 지칭할 수 있다. 하나의 패널의 수평축에서

개의 안테나 엘리먼트들이 배치될 수 있고, 하나의 패널의 수직축에서

개의 안테나 엘리먼트들이 배치될 수 있다. 즉, 하나의 패널은

개의 안테나 엘리먼트들을 포함할 수 있다. 인접한 패널들 간의 수평축 간격은 d_g,H일 수 있고, 인접한 패널들 간의 수직축 간격은 d_g,V일 수 있다. 인접한 안테나 엘리먼트들 간의 수평축 간격은

일 수 있고, 인접한 안테나 엘리먼트들 간의 수직축 간격은

일 수 있다. 전송률 향상을 위해 패널은 편파(polarisation)될 수 있다.

_max는 패널들 각각의 최대 수직 틸팅(tilting) 각도(예를 들어, 다운틸팅 각도, 업틸팅 각도)를 지시할 수 있다. 예를 들어,

_max는 102°일 수 있다.

_max는 패널들 각각의 최대 수평 틸팅 각도를 지시할 수 있다.On the horizontal axis of one beam former

≪ / RTI > panels can be arranged, and the vertical axis of one beam former

Lt; / RTI > panels can be placed. That is, one beam former

Lt; / RTI > panels. One panel may be connected to at least one RF chain. In this case, the RF can refer to the panel. On the horizontal axis of one panel

Antenna elements can be arranged, and the vertical axis of one panel

Antenna elements may be arranged. That is, one panel

RTI ID = 0.0 > antenna elements. ≪ / RTI > The horizontal axis spacing between adjacent panels can be _{dg, H} , and the vertical axis spacing between adjacent panels can be dg _{, V.} The horizontal axis spacing between adjacent antenna elements is

And the vertical axis spacing between adjacent antenna elements is

Lt; / RTI > The panel may be polarized to improve the transmission rate.

_max may indicate the maximum vertical tilting angle (e.g., down tilting angle, up tilting angle) of each of the panels. E.g,

_max may be 102 [deg.].

_max can indicate the maximum horizontal tilting angle of each of the panels.

Meanwhile, in the embodiments of the present invention, the beam width may be " HPBW (half-power beamwidth) " having a half intensity as compared to the main lobe. The antenna module can generate a radiation pattern based on Table 1 below.

10 is a conceptual diagram showing a first embodiment of a 2D URA (uniform rectangular array) antenna disposed in a panel.

개의 안테나 엘리먼트들이 배치될 수 있고, 2D URA 안테나의 수직축(예를 들어, xy 평면과 수직인 축)에서

개의 안테나 엘리먼트들이 배치될 수 있다. 인접한 안테나 엘리먼트들 간의 수평 간격은 d_H일 수 있고, 인접한 안테나 엘리먼트들 간의 수직 간격은 d_V일 수 있다.Referring to FIG. 10, in a horizontal axis (e.g., an axis horizontal to the xy plane) of a 2D URA antenna,

Antenna elements may be disposed and may be disposed on a vertical axis of the 2D URA antenna (e.g., an axis perpendicular to the xy plane)

Antenna elements may be arranged. The horizontal spacing between adjacent antenna elements may be d _H , and the vertical spacing between adjacent antenna elements may be d _V.

)가 적용될 수 있다. 2D URA 안테나에서 안테나 엘리먼트의 배치에 따라 아래 수학식 3에 따른 위상 변위가 ABF(analog beamforming)에 적용될 수 있다.Depending on the arrangement of the antenna elements, an array factor (

) May be applied. According to the arrangement of the antenna elements in the 2D URA antenna, the phase shift according to Equation (3) can be applied to ABF (analog beamforming).

(예를 들어, 0 <

)로 스티어링될 수 있고, 수직축에서 안테나 모듈(예를 들어, 안테나 모듈에 속한 패널, 어레이 안테나, 안테나 엘리먼트)은 지향점을 기준으로 수직축으로 최대

(예를 들어,

≤ π/2}로 스티어링될 수 있다.In the horizontal axis, an antenna module (e.g., a panel, an array antenna, or an antenna element belonging to an antenna module) has a maximum

(For example, 0 <

(E.g., a panel, an array antenna, or an antenna element belonging to an antenna module) can be steered to a vertical axis with a maximum

(E.g,

Lt; / 2 &gt;}.

On the other hand, when electric tilting is applied, the baseband signal can be processed based on the following equation (4).

On the other hand, the antenna gain and beam width according to beamforming may be as follows.

11 is a graph showing a first embodiment of an antenna gain and a beam pattern according to beam forming.

Referring to FIG. 11, each of the "1 × 1", "2 × 2", "4 × 4", "8 × 8", "16 × 16" The number of which can be specified. Beamforming can be performed through alignment of a plurality of antenna elements to improve the transmission rate. The greater the number of antenna elements used for beamforming, the more the antenna gain can be increased, and the beam width can be reduced. Therefore, a beam pattern for beamforming may be required, and beam tracking procedures may be required for rapid device / beam discovery, efficient antenna alignment, and data transmission / reception procedures.

Meanwhile, the data transmission / reception procedure according to beamforming may be performed based on the below-described beamforming operation state transition diagram.

12 is a conceptual diagram showing a first embodiment of a beamforming operation state transition diagram.

Referring to FIG. 12, a beam may be acquired through a search of a beam (e.g., a panel) in a beam sweeping state. For example, the beam can be acquired through a search of the beam in an initial access procedure, a handover (HO) procedure, a radio link failure (RLF) recovery procedure, and the like. A beam refinement procedure for maintaining the link (e.g., maintaining the data transmission / reception procedure) in the beam tracking state may be performed.

For data transmission and reception procedures based on beamforming, the receiver performs a beam measurement procedure, a beam identification procedure (e.g., a beam search procedure), a precoder selection procedure, a link adaptation procedure, a hybrid automatic repeat request (HARQ) A channel measurement procedure, an interference measurement procedure, and the like. For data transmission and reception procedures based on beamforming, the transmitter may perform beam selection / reselection / modification / assignment / cancellation operations based on measurement results obtained from the receiver. The operations performed at the transmitter may be performed in a beam sweeping state or a beam tracking state.

On the other hand, a system model can be defined based on the following Equations (5) to (8) according to antenna modeling and arrangement in a communication system using hybrid beamforming.

In Equation (6), R may be an array correlation matrix, and R may be defined based on Equation (7) below.

는 i번째 열과 j번째 행에서 신호들 간의 상관일 수 있고, 공간적으로 상관되는 안테나 엘리먼트들 간의 패스트 페이딩(fast fading)으로 추정될 수 있다. 또한, 수학식 7은 아래 수학식 8과 같이 간소화될 수 있다.In Equation (7)

May be a correlation between signals in the ith column and jth row and may be estimated as fast fading between spatially correlated antenna elements. Equation (7) can be simplified as Equation (8) below.

When hybrid beamforming is performed, the beam can be generated at the analog end and at the digital end. The beam pattern may be set based on a combination of at least one of the beam patterns of the analog stage and the digital stage. Here, the analog stage may be a component located before the analog-to-digital converter (ADC) among the components of the communication node (e.g., base station, terminal, S-device, etc.) Signal. The digital stage may be a component located after the ADC among the components of the communication node, and the beam of the digital stage may be a digital signal.

■ Analog beam pattern

One beamformer included in the antenna module may correspond to one sector, and the beamformer may include a plurality of panels (e.g., array antennas, antenna elements) that perform beamforming.

FIG. 13A is a conceptual view showing a first embodiment of a beam pattern in a service area served by one beamformer, and FIG. 13B is a schematic diagram showing a second embodiment of a beam pattern in a service area served by one beamformer It is a conceptual diagram.

13A and 13B, A _sector may indicate a service area served by a beamformer or a corresponding beam former, and A _RF may indicate a service area served by a panel or a corresponding panel in the beamformer. have. A _sector can be defined based on Equation (9) below.

는 하나의 빔포머에 의해 서빙되는 수평 영역일 수 있고,

는 하나의 빔포머에 의해 서빙되는 수직 영역일 수 있다. A_RF는 아래 수학식 10에 기초하여 정의될 수 있다.In Equation (9)

May be a horizontal region served by one beam former,

May be a vertical region served by one beam former. A _RF can be defined based on Equation (10) below.

는 하나의 패널에 의해 서빙되는 수평 영역일 수 있고,

는 하나의 패널에 의해 서빙되는 수직 영역일 수 있다. A_beam은 아래 수학식 11에 기초하여 정의될 수 있다.In Equation (10)

May be a horizontal region served by one panel,

May be a vertical region served by one panel. An A _beam can be defined based on Equation (11) below.

는 수평축으로 배치된 안테나 엘리먼트들에 의해 생성되는 HPBW일 수 있고,

는 수직축으로 배치된 안테나 엘리먼트들에 의해 생성되는 HPBW일 수 있다.

Lt; RTI ID = 0.0 &gt; HPBW &lt; / RTI &gt; generated by antenna elements disposed in the horizontal axis,

May be an HPBW generated by antenna elements arranged in a vertical axis.

If Equation (12) is satisfied, A _sector can be defined based on Equation (13) below, A _RF can be defined based on Equation (14) below and A _beam can be defined based on Equation . &Lt; / RTI &gt;

,

)는 아래 수학식 16에 기초하여 결정될 수 있다.The number of beams for the beam pattern (

,

) Can be determined based on the following equation (16).

는 수평축에서 빔들의 개수일 수 있고,

는 수직축에서 빔들의 개수일 수 있다.

는 안테나 엘리먼트(또는, 패널, 어레이 안테나)의 최대 스티어링 수평축 각도일 수 있고,

는 안테나 엘리먼트(또는, 패널, 어레이 안테나)의 최대 스티어링 수직축 각도일 수 있다. 패널의 지향점은 "

/2,

/2"에 대응하는 좌표로 설정될 수 있다.

은 아래 수학식 17에 기초하여 정의될 수 있고,

은 아래 수학식 18에 기초하여 정의될 수 있다.

Lt; / RTI &gt; may be the number of beams in the horizontal axis,

May be the number of beams in the vertical axis.

May be the maximum steering horizontal axis angle of the antenna element (or panel, array antenna)

May be the maximum steering vertical axis angle of the antenna element (or panel, array antenna). The panel's "

/2,

Quot; / 2 &quot;.

Can be defined based on Equation (17) below,

Can be defined based on Equation (18) below.

는 아래 수학식 20에 기초하여 정의될 수 있고,

는 아래 수학식 21에 기초하여 정의될 수 있다.If the following expression (19) is satisfied,

Can be defined based on Equation (20) below,

Can be defined based on the following equation (21).

는 아래 수학식 22에 기초하여 정의될 수 있고,

는 아래 수학식 23에 기초하여 정의될 수 있다.Also,

Can be defined based on Equation (22) below,

Can be defined based on Equation 23 below.

는 수평축에서 섹터들의 개수일 수 있고,

는 수직축에서 섹터들의 개수일 수 있다. "

×

"개의 섹터들이 존재할 수 있다.

는 수평축에서 패널들의 개수일 수 있고,

는 수직축에서 패널들의 개수일 수 있다. 하나의 빔포머 내에 "

×

"개의 패널들이 존재할 수 있다. 여기서,

,

,

및

각각은 1 이상의 정수일 수 있다. 또한, 아래 수학식 24가 정의될 수 있다.

May be the number of sectors in the horizontal axis,

May be the number of sectors in the vertical axis. "

×

&Quot;&lt; / RTI &gt; sectors may exist.

May be the number of panels on the horizontal axis,

May be the number of panels in the vertical axis. Within one beamformer,

×

&Quot;&lt; / RTI &gt;&lt; RTI ID = 0.0 &

,

,

And

Each may be an integer of 1 or more. In addition, the following equation (24) can be defined.

The orientation point coordinates (e.g., the steering angles) of the (i _h , i _v ) beams of the panels (j _h , j _v ) arranged at equal intervals in the service area according to the beam pattern and the number of beams are expressed by Equation 25 below Can be defined on the basis of. In Equation 25, " Alt1 " may be the first embodiment of the beam pattern in the service area served by one beamformer shown in Fig. 13A, and " Alt2 " may be represented by one beamformer shown in Fig. And may be a second embodiment of the beam pattern in the served service area.

On the other hand, when the sector is set to 60 占 60 占 in FIG. 13A, the beam pattern and the orientation point can be defined based on Table 2 below. In Table 2, " 1 RF " can indicate one panel.

13A, when the sector is set to 90 DEG x 90 DEG, the beam pattern and the orientation point can be defined based on Table 3 below. In Table 3, " 1 RF " can indicate one panel.

On the other hand, in Fig. 13B, when the sector is set to 60 占 60 占 the beam pattern and the orientation point can be defined based on Table 4 below. In Table 4, " 1 RF " can indicate one panel.

In Fig. 13B, when the sector is set to 90 占 90 占 the beam pattern and the orientation point can be defined based on Table 5 below. In Table 5, " 1 RF " can indicate one panel.

In the embodiments shown in FIGS. 13A and 13B, the antenna gain and the beam width may be as follows.

FIG. 14A is a graph showing a first embodiment of an antenna gain and a beam pattern according to the embodiment shown in FIG. 13A, FIG. 14B is a graph showing the antenna gain and beam pattern according to the first embodiment of the antenna gain and beam pattern according to the embodiment shown in FIG. FIG.

14A and 14B, each of " 2x2 ", " 4x4 ", " 8x8 ", and " 16x16 " may indicate the number of antenna elements, . In Fig. 14A, communication services can be provided throughout the sector by one beamformer. Communication services may be provided in sectors (e.g., some areas within a sector) by one panel in FIG. 14B. In this case, regions (e.g., sub-sectors) within a sector corresponding to each of the panels belonging to one beamformer can be set, and each panel can provide communication service in the corresponding sub-sector . According to the embodiment of FIG. 14A, a coverage hole in which no communication service is provided can be generated, and a beam pattern can be additionally generated to solve this problem. Alternatively, a beam can be generated at the digital end to resolve the coverage hole.

■ Analog Beam Codebook

는 양자화된 빔 스티어링 각도에 따른 {

,

}에 매핑되는 빔포밍 벡터일 수 있고, 송신기와 수신기에서 공유되는 아날로그 빔을 지시할 수 있다. 아날로그 빔 코드북(

)은 다음과 같이 정의될 수 있다.

Lt; RTI ID = 0.0 &gt; {

,

}, And may indicate an analog beam shared by the transmitter and the receiver. Analog beam codebook (

) Can be defined as follows.

는 수학식 27 또는 수학식 28에 기초하여 빔 패턴(예를 들어, 빔폭, 지향점)의 서비스 영역의 각도에 따라 양자화될 수 있다. 수학식 27 및 수학식 28에서,

_max 및

_max 각각은

및

에 대응할 수 있다.

May be quantized according to the angle of the service area of the beam pattern (e.g., beam width, orientation point) based on (27) or (28). In the equations (27) and (28)

_max and

_max each

And

.

■ Digital beam pattern

The beam generated through the phase shift at the analogue stage can be operated on the basis of the beam width, service area, and the like. However, if coverage holes occur between analog beams, fine beamforming may be required. Digital beamforming (e.g., digital beamforming (DBF), baseband precoding (BBP)) can be applied to solve this problem.

15 is a conceptual diagram showing a first embodiment of a beam pattern when hybrid beamforming is performed.

₁,

₂,

₃,

₄}을 가지는 4개의 빔들에 대한 빔 패턴에 전기적 틸팅(예를 들어,

_e)이 적용된 4개의 빔들에 대한 빔 패턴이 추가될 수 있다. 이 경우, 지향점 {

₁,

₁+

_e,

₂,

₂+

_e,

₃,

₃+

_e,

₄,

₄+

_e}을 가지는 8개의 빔들에 대한 빔 패턴이 생성될 수 있다. 전기적 틸팅에 기초하여 생성된 빔 패턴(예를 들어, 디지털 빔 패턴)의 성능은 지향점 {

₁+

_e,

₁+0,

₂+

_e,

₂+0,

₃+

_e,

₃+0,

₄+

_e,

₄+0}을 가지는 아날로그 빔 패턴의 성능과 동일할 수 있다. 빔 패턴은 아래 수학식 29에 기초하여 생성될 수 있다.Referring to FIG. 15,

₁ ,

₂ ,

₃ ,

₄ } to the beam pattern for the four beams (e.g.,

_e &lt; / RTI &gt; may be added. In this case,

₁ ,

₁ +

_e ,

₂ ,

₂ +

_e ,

₃ ,

₃ +

_e ,

₄ ,

₄ +

_e &lt; / RTI &gt; can be generated. The performance of a beam pattern (e. G., A digital beam pattern) generated based on electrical tilting depends on the orientation point {

₁ +

_e ,

₁ +0,

₂ +

_e ,

₂ +0,

₃ +

_e ,

₃ +0,

₄ +

_e ,

₄ +0}. &Lt; / RTI &gt; The beam pattern can be generated based on Equation 29 below.

_i 및

_i는 빔의 지향점일 수 있다.The array factor for electrical tilting can be set based on Equation 30 below. here,

_i and

_i may be the beam's point of orientation.

The spacing between panels in one beamformer can be defined based on Equation 31 below.

16 is a graph showing a first embodiment of an antenna gain and a beam pattern when hybrid beamforming is performed.

16, electrical tilting is applied to a 4x4 fixed beam pattern (e.g., a 4x4 analog beam pattern) at the digital end, thereby generating an 8x8 beam pattern (e.g., " 4x4 fixed beam pattern Quot; + " 4x4 electrically tilted beam pattern ") can be generated. The beam pattern and antenna gain of the embodiment shown in FIG. 16 may be the same as the beam pattern and antenna gain of the embodiment shown in FIG. 14B.

■ Digital beam codebook

는 양자화된 빔 스티어링 각도에 따른 {

,

}에 매핑되는 빔포밍 벡터일 수 있고, 송신기와 수신기에서 공유되는 디지털 빔을 지시할 수 있다. 디지털 빔 코드북(

)은 다음과 같이 정의될 수 있다.

Lt; RTI ID = 0.0 &gt; {

,

}, And may point to a digital beam shared by the transmitter and the receiver. Digital beam codebook (

) Can be defined as follows.

는 수학식 33에 기초하여 빔 패턴(예를 들어, 빔폭, 지향점)의 서비스 영역의 각도에 따라 양자화될 수 있다.

May be quantized according to the angle of the service area of the beam pattern (e.g., beam width, orientation point) based on equation (33).

■ Panel-based beam coupling

An independent RF (e.g., beam) may be generated for each panel, and the same number of beams as the maximum number of panels in the data transmission / reception procedure may be used.

FIG. 17A is a conceptual diagram showing a first embodiment of a panel-based beam transmission method, FIG. 17B is a conceptual view showing a second embodiment of the panel-based beam transmission method, FIG. FIG. 17D is a conceptual diagram showing a fourth embodiment of the panel-based beam transmission method. FIG.

17A, the base station 170 can provide communication services to the terminals 171-1 and 171-2 by transmitting different beams (e.g., beams having different beam indices) through a plurality of panels And the beams can be transmitted through different spaces. In the case where the terminals 171-1 and 171-2 are located adjacent to each other, the base station 170 in FIGS. 17B to 17D transmits beams to the terminals 171-1 and 171-2 through the same space, Service can be provided. Here, interference may occur when the time-frequency resources of the beams are the same.

17B, the base station 170 transmits communication services to the terminals 171-1 and 171-2 by transmitting different beams (for example, beams having different beam indices) through a plurality of panels to the same space . In FIG. 17C, the base station 170 transmits communication services to the terminals 171-1 and 171-2 by transmitting different beams (for example, beams having different beam indices) to the same space through one panel . Here, the transmission power of each of the two beams may be one-half of the total transmission power of the base station 170. In order to solve this problem, the base station 170 in FIG. 17D can provide communication services to the terminals 171-1 and 171-2 by transmitting one beam to the same space through one panel. Here, two or more beams can be combined. Also, a virtual beam combining scheme (e.g., a panel virtualization scheme) can be used. When a virtual beam combining method is used, one virtual panel can be set based on a plurality of panels instead of one panel, and one beam can be generated through one virtual panel.

FIG. 18A is a conceptual diagram showing a first embodiment of a beam transmission method through a repeater, and FIG. 18B is a conceptual diagram showing a second embodiment of a beam transmission method through a repeater.

Interference may occur between the beams of the base stations 180-1 and 180-2 in FIG. 18A, and communication service may be provided to the terminal 182 through the relay 181 in this case. Therefore, interference between beams can be reduced. When the change of the channel is small or the amount of data transmission increases, communication can be performed based on the beam combining method. For example, in FIG. 18B, the base station 180 may provide communication services using a combined beam.

FIG. 19 is a conceptual view showing a first embodiment of a beam pattern to which a virtual beam combining method is applied, and FIG. 20 is a conceptual diagram showing a first embodiment of a beam combined through a virtual beam combining method.

_c,

_c}일 수 있다. ABF/DBF에 기초하여 패널들 각각에 의해 생성된 빔의 지향점은 {

,

}일 수 있다.19 and 20, one virtual panel can be created based on a plurality of panels, and the orientation point of the beam generated by the virtual panel is {

_c ,

_c &lt; / RTI &gt; The orientation point of the beam generated by each of the panels based on ABF / DBF is {

,

}.

In the ABF step, an analog beam can be generated by antenna placement and phase shift of each of the panels, and precoding can be performed to generate one combined beam in the panels that perform beam combining in the DBF step. The beam combining method in the panels can be classified as follows.

- Beam coupling method 1: Beam coupling only at ABF level without panel virtualization

- Beam coupling method 2: Beam coupling through panel virtualization only at ABF level

Beam combining method 3: beam combining in the "ABF + DBF (eg, electrical tilting)" stage without panel virtualization

- Beam coupling method 4: Beam coupling through panel virtualization in "ABF + DBF"

- beam combining method 5: beam combining via panel virtualization in ABF step or DBF step

The array factor due to beam combining can be defined based on Equation (34) below.

)는 아래 수학식 35에 기초하여 정의될 수 있다.The array factor according to panel virtualization in equation (34)

) Can be defined based on the following equation (35).

)는 아래 수학식 36에 기초하여 정의될 수 있다.In the equation (34), the array factor

) Can be defined based on the following equation (36).

은 빔 결합을 위한 수평 패널 인덱스일 수 있고,

은 빔 결합을 위한 수직 패널 인덱스일 수 있고,

는 안테나 엘리먼트들의 개수일 수 있다. 패널들 간의 간격은 아래 수학식 37에 기초하여 정의될 수 있다.In Equation 34,

May be a horizontal panel index for beam combining,

May be a vertical panel index for beam combining,

May be the number of antenna elements. The interval between the panels can be defined based on the following equation (37).

&Quot; Beam combining scheme 1 (e. G., Weight and phase shift in beam combining scheme 1) " can be performed based on Equation (38) below.

는 안테나 엘리먼트들의 개수일 수 있고,

는 수평축에서 안테나 엘리먼트 인덱스일 수 있고,

는 수직축에서 안테나 엘리먼트 인덱스일 수 있고,

은 빔 결합을 위한 수평 패널 인덱스일 수 있고,

은 빔 결합을 위한 수직 패널 인덱스일 수 있다.In Equation 38,

May be the number of antenna elements,

May be an antenna element index on the horizontal axis,

May be an antenna element index on the vertical axis,

May be a horizontal panel index for beam combining,

May be a vertical panel index for beam combining.

는

를 위한 빔 스티어링 각도일 수 있고, 아래 수학식 39에 기초하여 정의될 수 있다.

The

And may be defined based on Equation 39 below.

는

를 위한 빔 스티어링 각도일 수 있고, 아래 수학식 40에 기초하여 정의될 수 있다.

The

And may be defined based on Equation 40 below.

&Quot; beam combining scheme 2 (e. G., Weight and phase shift in beam combining scheme 2) " can be performed based on Equation 41 below.

는 안테나 엘리먼트들의 개수일 수 있고,

는 수평축에서 안테나 엘리먼트 인덱스일 수 있고,

는 수직축에서 안테나 엘리먼트 인덱스일 수 있고,

은 빔 결합을 위한 수평 패널 인덱스일 수 있고,

은 빔 결합을 위한 수직 패널 인덱스일 수 있다.In Equation 41,

May be the number of antenna elements,

May be an antenna element index on the horizontal axis,

May be an antenna element index on the vertical axis,

May be a horizontal panel index for beam combining,

May be a vertical panel index for beam combining.

In Equation 41, m _c can be defined based on Equation 42 below, and n _c can be defined based on Equation 43 below.

는

를 위한 빔 스티어링 각도일 수 있고, 앞서 설명된 수학식 39에 기초하여 정의될 수 있다.

는

를 위한 빔 스티어링 각도일 수 있고, 앞서 설명된 수학식 40에 기초하여 정의될 수 있다.

The

And may be defined based on Equation 39 described above.

The

, And can be defined based on Equation (40) described above.

&Quot; beam combining scheme 3 (e. G., Weight and phase shift in beam combining scheme 3) " can be performed based on Equation (44) below.

는 안테나 엘리먼트들의 개수일 수 있고,

는 수평축에서 안테나 엘리먼트 인덱스일 수 있고,

는 수직축에서 안테나 엘리먼트 인덱스일 수 있고,

은 빔 결합을 위한 수평 패널 인덱스일 수 있고,

은 빔 결합을 위한 수직 패널 인덱스일 수 있다.

는

를 위한 빔 스티어링 각도일 수 있고, 아래 수학식 45에 기초하여 정의될 수 있다.In equation (44)

May be the number of antenna elements,

May be an antenna element index on the horizontal axis,

May be an antenna element index on the vertical axis,

May be a horizontal panel index for beam combining,

May be a vertical panel index for beam combining.

The

And may be defined based on Equation (45) below.

는

를 위한 빔 스티어링 각도일 수 있고, 아래 수학식 46에 기초하여 정의될 수 있다.

The

And may be defined based on Equation (46) below.

&Quot; beam combining scheme 4 (e. G., Weight and phase shift in beam combining scheme 4) " can be performed based on the following equation (47).

는 안테나 엘리먼트들의 개수일 수 있고,

는 수평축에서 안테나 엘리먼트 인덱스일 수 있고,

는 수직축에서 안테나 엘리먼트 인덱스일 수 있고,

은 빔 결합을 위한 수평 패널 인덱스일 수 있고,

은 빔 결합을 위한 수직 패널 인덱스일 수 있다.In Equation (47)

May be the number of antenna elements,

May be an antenna element index on the horizontal axis,

May be an antenna element index on the vertical axis,

May be a horizontal panel index for beam combining,

May be a vertical panel index for beam combining.

는

를 위한 빔 스티어링 각도일 수 있고, 앞서 설명된 수학식 45에 기초하여 정의될 수 있다.

는

를 위한 빔 스티어링 각도일 수 있고, 앞서 설명된 수학식 46에 기초하여 정의될 수 있다.m _c may be defined based on Equation 42 described above, and n _c may be defined based on Equation 43 described above.

The

And may be defined based on Equation 45 described above.

The

And may be defined based on Equation 46 described above.

On the other hand, when the panel virtualization is performed in the ABF step, "beam combining method 2" and "beam combining method 3" can be applied. &Quot; Beam coupling method 1 ", " Beam coupling method 3 ", and " Beam coupling method 4 " may be applied when panel virtualization is performed in the DBF step. When panel virtualization (e.g., beam combining) is performed, the antenna gain may be as follows.

21 is a graph showing a first embodiment of an antenna gain and a beam pattern in an embodiment in which panel virtualization is applied.

Referring to FIG. 21, the beam pattern and antenna gain generated by the 8x8 antenna elements in one panel can be identified and the 32x32 antenna elements generated by the 32x32 antenna elements formed through virtualization of 4x4 panels The beam pattern and antenna gain can be ascertained. When panel virtualization is applied, a relatively narrow beam can be generated and a relatively high antenna gain can occur. Here, a coverage hole (for example, a coverage hole in which a -3 dB antenna gain with respect to the orientation point occurs) can be compensated by the DBF.

22 is a graph showing a first embodiment of an antenna gain and a beam pattern according to a beam combining method.

Referring to Fig. 22, " Alt1 " may indicate " beam combining scheme 1 ", and " Alt2 " may indicate " beam combining scheme 2 ". In the embodiment where " Alt2 " is applied, the beam width may be narrower than the beam width in the embodiment where " Alt1 " The more the number of panels to be virtualized (e.g., 1 + 1, 2 + 2, 4 + 4, 8 + 8), the more the antenna gain can be increased.

■ the combined beam codebook according to the beam-forming of the panel base (combined beam codebook)

는 적어도 하나의 패널에서 {

,

}로 매핑되는 빔포밍 벡터일 수 있고,

는 아날로그 빔을 지시할 수 있고,

는 디지털 빔을 지시할 수 있다.

,

및

는 송신기와 수신기에서 공유될 수 있다. 빔 결합에 따른 빔 스티어링 각도(

,

)를 위한 코드북(

)은 아래 수학식 48에 기초하여 정의될 수 있다.

Lt; RTI ID = 0.0 &gt; {

,

}, &Lt; / RTI &gt; where &lt; RTI ID =

Lt; / RTI &gt; can direct an analog beam,

Can indicate a digital beam.

,

And

May be shared between the transmitter and the receiver. Beam steering angle according to beam combination (

,

) For the codebook (

) Can be defined based on the following equation (48).

는 수학식 49에 기초하여 빔 패턴(예를 들어, 빔폭, 지향점)의 서비스 영역의 각도에 따라 양자화될 수 있다.

Can be quantized according to the angle of the service area of the beam pattern (e.g., beam width, orientation point) based on equation (49).

■ Beam measurement procedure

In order to perform beam-related operations (e.g., beam selection operations, beam modification operations, HARQ retransmission operations, link adaptation operations, etc.), the receiver determines the channel conditions between the receiver and the transmitter based on the signals received from the transmitter , Beam state) can be measured. For example, the receiver may select an effective channel (h _eff ) based on the strength of a received signal (e.g., a reference signal, a synchronization signal) according to a beam pattern , And report the information of the beam corresponding to the selected effective channel h _eff to the transmitter. The effective channel h _eff may be determined based on Equation 50 below.

는 수평축에서 다중 전송 아날로그 빔들(multiple transmit analog beams)을 선택하기 위한 후보 집합을 지시할 수 있고,

는 수직축에서 다중 전송 아날로그 빔들을 선택하기 위한 후보 집합을 지시할 수 있다.

및

각각은 아래 수학식 51에 기초하여 정의될 수 있다.In equation (50)

May indicate a candidate set for selecting multiple transmit analog beams on the horizontal axis,

May indicate a candidate set for selecting multiple transmitted analog beams on the vertical axis.

And

Can be defined based on the following equation (51).

■ Beam search procedure

"번 수행될 수 있다. 수신기에서 수신 빔포밍이 적용되는 경우, 빔 검색 절차의 수행 횟수는 수신기의 빔들의 개수에 따라 증가할 수 있다. 예를 들어, 빔 검색 절차의 수행 횟수는

일 수 있다. 여기서, M_r은 수신기의 빔들의 개수일 수 있다. 빔 검색 절차는 아래 방식들에 기초하여 수행될 수 있다.The beam search procedure may include searching for an optimal beam among the beams (e.g., fixed beam, analog beam) generated at the analog stage and comparing the beam generated at the digital stage (e.g., a digital beam, an electronically tilted beam) And searching for an optimal beam among the plurality of beams. In order to search for the optimal beam through the measurement procedure of the beams received in different spaces,

If the receiver beamforming is applied at the receiver, the number of times the beam search procedure is performed may increase according to the number of beams of the receiver. For example, the number of times the beam search procedure is performed is

Lt; / RTI &gt; Where M _r may be the number of beams of the receiver. The beam search procedure can be performed based on the following methods.

Beam search method 1

When a beam pattern for an analog beam (hereinafter referred to as an "analog beam pattern") and a beam pattern for a digital beam (hereinafter referred to as a "digital beam pattern") are respectively defined, The digital beam can be retrieved later.

는 아날로그 빔 패턴에서 수평 아날로그 빔의 지향 각도를 지시할 수 있고,

는 빔 패턴에서 수직 아날로그 빔의 지향 각도를 지시할 수 있다.Step 1: The receiver may receive a signal (e.g., a reference signal, a synchronization signal, etc.) from the transmitter and may receive at least one of the analog beams (e.g., analog beam pattern) based on the quality of the received signal (Or select) an analog beam (e.g., an analog beam having a received signal strength greater than or equal to a predetermined threshold value). Step 1 may be performed based on the following equation (52). In Equation (52)

Can direct the directional angle of the horizontal analog beam in the analog beam pattern,

Can direct the directional angle of the vertical analog beam in the beam pattern.

각각은 단계 1에서 선택된

을 지시할 수 있다.Step 2: The receiver measures an optimal digital beam (e.g., a digital beam having a received signal strength above a predetermined threshold) among the beam pairs retrieved in step 1 (e.g., a digital beam corresponding to the retrieved analog beam) Search (or select). The optimal digital beam may be determined based on the quality of the signal received from the transmitter. Here, the digital beam corresponding to the analog beam may be an electronically tilted beam based on the analog beam. In addition, the receiver can retrieve the digital precoding vector for the optimal digital beam. Step 2 may be performed based on Equation 53 below,

Each selected in step 1

.

Beam search method 2

_i는 아날로그 빔 패턴에서 임의의 수평 아날로그 빔(예를 들어, 임의의 수평 아날로그 빔의 지향각)일 수 있다.Step 1: The receiver may receive a signal (e.g., a reference signal, a synchronization signal, etc.) from a transmitter and may determine, based on the quality of the received signal, at least one horizontal analog beam of horizontal analog beams (Or an analog beam having a received signal intensity equal to or greater than a preset threshold value). Step 1 may be performed based on Equation 54 below,

_i may be any horizontal analog beam (e.g., a directional angle of any horizontal analog beam) in the analog beam pattern.

각각은 수학식 54의

에 기초하여 선택된

일 수 있다.Step 2: The receiver searches (or selects) at least one vertical analog beam among the vertical analog beams based on the quality of the received signal (e.g., an analog beam having a received signal strength above a predetermined threshold) . Step 2 may be performed based on Equation 55 below,

Respectively,

Lt; RTI ID = 0.0 &

Lt; / RTI &gt;

- step 3: the receiver selects an optimal digital beam (e.g., a received signal above a predetermined threshold value) among the pairs of beams detected in steps 1 and 2 (e.g., the digital beam corresponding to the detected horizontal analog beam and vertical analog beam) (Or a digital beam having a certain intensity). The optimal digital beam may be determined based on the quality of the signal received from the transmitter. Here, the digital beam corresponding to the horizontal analog beam and the vertical analog beam may be an electronically tilted beam based on the corresponding analog beam. In addition, the receiver can retrieve the digital precoding vector for the optimal digital beam. Step 3 may be performed based on Equation (56) below.

Beam search method 3

Step 1: The receiver may receive a signal (e.g., a reference signal, a synchronization signal, etc.) from a transmitter and may determine, based on the quality of the received signal, at least one horizontal analog beam of horizontal analog beams (Or an analog beam having a received signal intensity equal to or greater than a preset threshold value). Step 1 may be performed based on Equation (54) described above.

Step 2: The receiver searches (or selects) at least one vertical analog beam among the vertical analog beams based on the quality of the received signal (e.g., an analog beam having a received signal strength above a predetermined threshold) . Step 2 may be performed based on Equation 55 described above.

각각은

에 기초하여 선택된

일 수 있고,

_e,i는 디지털 빔 패턴에서 임의의 수평 디지털 빔(예를 들어, 임의의 수평 디지털 빔의 지향각)일 수 있다.Step 3: The receiver selects an optimal horizontal digital beam (e.g., a digital signal having a received signal strength equal to or greater than a predetermined threshold value) out of the beam pairs retrieved in step 1 (e.g., a horizontal digital beam corresponding to the retrieved horizontal analog beam) Beam) can be searched (or selected). The optimal horizontal digital beam may be determined based on the quality of the signal received from the transmitter. Here, the horizontal digital beam corresponding to the horizontal analog beam may be an electronically tilted beam based on the corresponding analog beam. Step 3 may be performed based on the following equation (57). In Equation 57,

Each

Lt; RTI ID = 0.0 &

Lt; / RTI &gt;

_{e, i} may be any horizontal digital beam (e.g., a directional angle of any horizontal digital beam) in the digital beam pattern.

는

에 기초하여 선택된

_e일 수 있다.Step 4: The receiver measures the best vertical digital beam (e.g., digital with a received signal strength above a predetermined threshold) among the beam pairs retrieved in step 2 (e.g., a vertical digital beam corresponding to the retrieved vertical analog beam) Beam) can be searched (or selected). The optimal vertical digital beam may be determined based on the quality of the signal received from the transmitter. Here, the vertical digital beam corresponding to the vertical analog beam may be an electronically tilted beam based on the corresponding analog beam. Step 4 may be performed based on Equation 58 below,

The

Lt; RTI ID = 0.0 &

_e .

Meanwhile, according to the beam search method 1-3 described above, a search delay may occur. The search delay may be as follows:

23 is a graph showing a search delay according to the beam search method.

"일 수 있고, Alt1의 빔 검색 복잡도는 "

"일 수 있고, Alt2의 빔 검색 복잡도는 "

"일 수 있고, Alt3의 빔 검색 복잡도는 "

"일 수 있다.Referring to FIG. 23, "Alt1" can indicate "Beam search method 1", "Alt2" can indicate "Beam search method 2", and "Alt3" You can tell. A full search (FS) may indicate the manner in which all beams are searched. "A" can indicate "analog beam", and "D" can indicate "digital beam". The number of beam search attempts of FS may be greater than the number of beam search attempts of each of Alt1, Alt2 and Alt3, and the number of beam search times of Alt3 may be the smallest. For example, the beam search complexity of the FS (e.g., the number of beam seek attempts) is "

"And the beam search complexity of Alt1 is"

&Quot; and the beam search complexity of Alt2 is "

"And the beam search complexity of Alt3 is"

&Quot;

■ Beam measurement procedure

In a beam measurement procedure, a beam state (e.g., channel state) can be measured and the beam state can be measured in a measurement resource unit (MRU). The MRU may be a subcarrier allocated a signal (hereinafter referred to as a " beam measurement signal ") used for measuring the beam status among the subcarriers. The beam measurement signal may be a reference signal RS, a synchronization signal SS, a beam measurement-reference signal (BM-RS), a beam sweeping (BWS) signal, or the like. The beam measurement procedure can be classified as shown in Table 6 below.

In the beam measurement procedure, the measurement result can be converted in units of dB or dBm, and the receiver can report the converted value to the transmitter. Alternatively, the receiver can quantize the measurement results and report the quantized values to the transmitter. Alternatively, the receiver may report signal to interference plus noise ratio (SINR), received signal strength indicator (RSSI) or received signal strength (RSS) to the transmitter as a measurement result. In this case, the transmitter can estimate the SINR based on RSSI or RSS.

24 is a conceptual diagram showing a first embodiment of the beam measuring procedure.

개의 빔 측정 신호들이 전송될 수 있다. 수신기는 송신기로부터 수신된 빔 측정 신호에 기초하여 빔 측정을 수행할 수 있고, 측정 결과를 송신기에 보고할 수 있다. t_m 구간에서 측정 결과(

)는 아래 수학식 59에 기초하여 계산될 수 있다. 예를 들어, t_m 구간에서 측정 결과는 이전 구간(t_m-1)에서 측정 값과 현재 구간(t_m)에서 측정 값에 기초하여 계산될 수 있다.Referring to FIG. 24, a transmitter may transmit a beam measurement signal (e.g., reference signal, synchronization signal, BM-RS, BSW signal). The beam measurement signal may be transmitted based on a predetermined period. Here, each of m and n may be an integer of 1 or more. (Hereinafter referred to as " OS &quot;) corresponding to one n

Beam measurement signals may be transmitted. The receiver can perform beam measurement based on the beam measurement signal received from the transmitter and report the measurement results to the transmitter. Measurement results in t _m section (

) Can be calculated based on the following equation (59). For example, the measurement result in the period t _m may be calculated on the basis of the measurement value from the measurement value and the current period (t _m) in the preceding interval (t _m -1).

는 러닝 에버리징 파라미터(running averaging parameter)일 수 있다.

는 "t_m = m" 구간 내의 n 구간 동안의 빔 측정 신호의 측정 값일 수 있고, 아래 수학식 60에 기초하여 정의될 수 있다.

May be a running averaging parameter.

May be a measured value of the beam measurement signal during the interval n in the " t _m = m " interval, and may be defined based on Equation 60 below.

는 이전 구간(t_n = n-1)까지의 측정 값(

)과 현재 구간(t_n = n)에서 측정 값에 기초하여 계산될 수 있다. 예를 들어,

는 아래 수학식 61에 기초하여 계산될 수 있다. 여기서,

는 러닝 에버리징 파라미터일 수 있다.

Lt; _{RTI ID} = 0.0 &_gt; (t _n = n-1)

) And the current interval (t _n = n). E.g,

Can be calculated based on Equation (61) below. here,

May be a running averaging parameter.

은 "t_n = n" 구간 내의 적어도 하나의 빔 측정 신호에 기초하여 측정될 수 있으며, 아래 수학식 62에 기초하여 정의될 수 있다.

May be measured based on at least one beam measurement signal in the " t _n = n " interval and may be defined based on Equation 62 below.

는 이전 구간(t_os = OS - 1)까지의

와 현재 구간(t_os = OS)에서 측정 값에 기초하여 계산될 수 있다. 예를 들어,

는 아래 수학식 63에 기초하여 계산될 수 있다. 여기서,

는 러닝 에버리징 파라미터일 수 있다.

(T _os = OS - 1) to the previous period

And the current interval (t _os = OS). E.g,

Can be calculated based on the following equation (63). here,

May be a running averaging parameter.

는 "t_os = OS" 구간에서 빔 측정 신호의 측정 값일 수 있으며, 아래 수학식 64에 기초하여 계산될 수 있다.

May be a measurement value of the beam measurement signal in the " _tos = OS " interval, and may be calculated based on Equation 64 below.

는 송신기의 RF 체인을 위한 아날로그 빔별 빔 측정 신호 #j(즉, BM-RS #j)를 위해 할당된 OFMD 심볼들에서 서브캐리어들의 개수를 지시할 수 있고,

각각은 BM-RS #j의 측정을 위해 송신기와 수신기 간에 미리 설정된

일 수 있다.

는 수평축에서 다중 전송 아날로그 빔들을 선택하기 위한 후보 집합을 지시할 수 있고,

는 수직축에서 다중 전송 아날로그 빔들을 선택하기 위한 후보 집합을 지시할 수 있다.

및

각각은 아래 수학식 65에 기초하여 정의될 수 있다.

May indicate the number of subcarriers in the OFMD symbols allocated for the analog beam-specific beam measurement signal #j (i.e., BM-RS #j) for the RF chain of the transmitter,

Each of which is preset between the transmitter and the receiver for measurement of BM-RS #j

Lt; / RTI &gt;

Lt; / RTI &gt; may indicate a candidate set for selecting multiple transmission analog beams on the horizontal axis,

May indicate a candidate set for selecting multiple transmitted analog beams on the vertical axis.

And

Each can be defined based on Equation 65 below.

는 아래 수학식 66 내지 수학식 69에 기초하여 계산될 수 있다.or,

Can be calculated based on the following equations (66) to (69).

로 설정될 수 있다.

는 송신기의 RF 체인을 위한 아날로그 빔별 참조 신호(RS) #j를 위해 할당된 OFDM 심볼들에서 서브캐리어들의 개수를 지시할 수 있다.N _sc may indicate the number of subcarriers in OFDM symbols for measurement of physical channel state information at the transmitter. For example, N _sc may indicate the number of total subcarriers in one MRU or a plurality of MRUs (e.g., maximum system bandwidth). Alternatively, when a channel is measured based on the reference signal RS, N _sc

Lt; / RTI &gt;

May indicate the number of subcarriers in the OFDM symbols allocated for the analog beam-specific reference signal (RS) #j for the RF chain of the transmitter.

s [k] may indicate the transmit power of a signal (e.g., a reference signal (RS), sample, message) transmitted on the kth subcarrier. s [k] may be defined or dictated prior to transmission of the signal. r [k] may indicate the received power of a signal (e.g., a reference signal (RS), sample, message) received on the kth subcarrier. Here, r [k] may indicate the received power of the signal excluding interference and noise, and may be defined based on Equation 70 below.

각각은 참조 신호(RS) #j의 측정을 위해 송신기와 수신기 간에 미리 설정된

일 수 있고,

는 수평축에서 다중 전송 아날로그 빔들을 선택하기 위한 후보 집합을 지시할 수 있고,

는 수직축에서 다중 전송 아날로그 빔들을 선택하기 위한 후보 집합을 지시할 수 있다.

및

각각은 앞서 설명된 수학식 65에 기초하여 정의될 수 있다. RSSI[k]는 k번째 서브캐리어에서 수신되는 신호(예를 들어, RS, 샘플, 메시지)의 수신 전력을 지시할 수 있다. 여기서, RSSI[k]는 간섭 및 잡음을 포함하는 신호의 수신 전력을 지시할 수 있다.

Each of which is preset between the transmitter and the receiver for measurement of the reference signal RS #j

Lt; / RTI &gt;

Lt; / RTI &gt; may indicate a candidate set for selecting multiple transmission analog beams on the horizontal axis,

May indicate a candidate set for selecting multiple transmitted analog beams on the vertical axis.

And

Each can be defined based on Equation 65 described above. RSSI [k] may indicate the received power of a signal (e.g., RS, sample, message) received on the kth subcarrier. Here, RSSI [k] may indicate received power of a signal including interference and noise.

The receiver may comprise at least one antenna used for beam measurement, in which case the following equation (71) may be used.

는 빔 측정을 수행하는 수신기의 안테나 #r의

일 수 있고,

는 수신기에서 빔 측정을 수행하는 안테나들(예를 들어, 안테나 엘리먼트들)의 개수를 지시할 수 있다. 수신기는 빔 측정을 수행하는 모든 안테나들에서 측정된 평균값을 계산할 수 있고, 평균값을 송신기에 보고할 수 있다. 여기서, 평균값은 아래 수학식 72에 기초하여 계산될 수 있다.

Lt; RTI ID = 0.0 &gt;#r&lt; / RTI &gt; of the receiver performing beam measurement

Lt; / RTI &gt;

May indicate the number of antennas (e.g., antenna elements) that perform beam measurements at the receiver. The receiver can calculate the average value measured at all the antennas that perform the beam measurement and report the average value to the transmitter. Here, the average value can be calculated based on the following equation (72).

,

및

을 측정할 수 있고, 측정된 값을 송신기에 보고할 수 있다.On the other hand, when communication services are provided through a plurality of beams in a sector, interference between beams may occur. If one transmitter provides communication services in a plurality of sectors that are distinguished in the spatial domain, interference may occur between the sectors. If adjacent transmitters transmit signals, interference may occur between adjacent transmitters. The interference described above may be measured via a beam measurement-interference measurement (BM-IM), and a resource (e.g., resource element (RE), subcarrier, symbol) for the BM-IM may be set. The receiver can measure beam interference in the resource for BM-IM, and the transmitter may not transmit any signal through the resource configured for BM-IM. The receiver is configured to receive the

,

And

And report the measured value to the transmitter.

25 is a conceptual diagram showing a second embodiment of the beam measuring procedure.

25, the base station 2500 transmits a beam measurement signal (e.g., a reference signal, BM-1) through four beams (e.g., beam # 0, beam # 1, beam # 2, RS, sync signal, BSW signal). Here, the indices of the four beams may be different from each other, and the beam measurement signal may be transmitted in a beamforming manner. The beam measurement signal may be transmitted based on the following schemes.

26A is a timing chart showing a first embodiment of a transmission method of a beam measurement signal.

Referring to FIG. 26A, a BS 2500 may transmit a BSW signal and a BM-RS used for beam measurement. Each of the BSW signal and the BM-RS can be periodically transmitted, and the BM-RS can be transmitted in a beam-forming manner.

Fig. 26B is a timing chart showing a second embodiment of a beam measurement signal transmission method. Fig.

Referring to FIG. 26B, the BS 2500 may transmit a BSW signal, a BM-RS, and a combined BM-RS used for beam measurement. The combined BM-RS may be a BM-RS transmitted through the combined beam. Each of the BSW signal, the BM-RS and the combined BM-RS may be periodically transmitted, and the BM-RS and the combined BM-RS may be transmitted in a beamforming manner.

Referring again to FIG. 25, terminal 2510 may perform beam measurement based on a beam measurement signal received from a base station. For example, the terminal 2510 may select at least one beam whose beam measurement results meet predetermined criteria (e.g., at least one beam having a received signal strength above a predetermined threshold). If the beams meeting the preset criteria are beam # 1 and beam # 2, the terminal 2510 may transmit to the base station 2500 information (e.g. beam index) indicating beam # 1 and beam # 2 have.

The base station 2500 may receive the selected beam information (e.g., beam # 1, beam # 2) based on the beam measurement signal from the terminal 2510 and may use the beam # 1 and beam # 2510). In this case, the base station 2500 can provide the communication service to the terminal 2510 using the beams # 1 and # 2 having different indices. Alternatively, base station 2500 may provide communication services to terminal 2510 using combined beams (e.g., beam # 1 and beam # 2). For example, if a measurement result based on a combined BM-RS (e.g., BM-RS transmitted via combined beam # 1 and beam # 2) is received from terminal 2510, It can be seen that the measurement result is a measurement result based on the combined BM-RS, and the communication service can be provided to the terminal 2510 using the combined beam # 1 and beam # 2 indicated by the measurement result.

On the other hand, the beam measurement signal may be transmitted over some or all of the time-frequency resources. If the beam measurement signal is transmitted over a time-frequency resource or a separate time-frequency resource that is shared with another signal (e.g., control information, user data, another reference signal, another beam measurement signal) It must be able to recognize that the signal is a beam measurement signal.

Thus, a resource pool for the beam measurement signal can be established, and resources belonging to the resource pool can be mapped to each of the beam measurement signals. For example, each of the beam measurement signals can be mapped to different resources in the resource pool, and the base station can transmit a plurality of beam measurement signals using different resources in the resource pool, And can identify its beam measurement signal based on the mapping information.

The resource pool may be set to a time unit (e.g., a subframe, a transmission time interval (TTI), a slot, etc.), and may be periodically set in the time axis. Periodic beam measurement procedures can be performed based on the resource pool. When the beam measurement procedure is triggered by the transmitter, the message triggering the beam measurement procedure may include resource pool information. Also, the resource pool may be set to a frequency unit (e.g., physical radio unit or physical resource unit (PRU), subband, subchannel). For example, an entire frequency resource or some frequency resources may be allocated for a resource pool. In addition, the resource pool may be set on a time-frequency basis and may be set to a spatial unit (e.g., a beam index). A plurality of resource pools may be established and each of the plurality of resource pools may not be used for transmission of other signals (e.g., control information, user data, other reference signals, different beam measurement signals).

Within the resource pool, the beam measurement signal can be set to be distinguishable on the time axis and / or the frequency axis. For example, the beam measurement signal may be set in units of OFDM symbols (e.g., consecutive OFDM symbols) in the time axis and set in units of subcarriers (e.g., consecutive subcarriers) in the frequency axis . A particular resource (e.g., resource element (RE), tone, symbol, etc.) within a resource pool may be mapped to a beam measurement signal. When there are many beam measurement signals, a plurality of resource pools can be set. Further, when there are a plurality of receivers, a resource pool for each of a plurality of receivers can be set independently.

On the other hand, the beam measurement signal may be set in a resource pool (e.g., MRU) and the beam measurement signal in the MRU may be set as follows.

27 is a conceptual diagram showing the configuration of the beam measurement signal in the MRU.

27, at least one measurement period may be set in the measurement window, at least one measurement duration may be set in the measurement period, and at least one measurement period may be set within the measurement duration, One MRU may be set. The beam measurement procedure may be performed within the measurement duration, and the measurement duration may start after a predetermined offset from the start of the measurement period. The measurement report can be performed after the response delay from the end of the measurement duration.

The MRU may be the minimum resource unit set for the beam measurement procedure. The MRU may be composed of one OFDM symbol or successive OFDM symbols (e.g., frame, subframe, TTI, slot) on the time axis and may be composed of one subcarrier or successive subcarriers For example, an RB (resource block), a subband, a subchannel, and an entire frequency band). At least one beam measurement signal may be set in the MRU, and the beam measurement signals may be set to be distinguished in at least one of a time domain, a frequency domain, and a spatial domain.

The methods according to the present invention can be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer readable medium. The computer readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the computer readable medium may be those specially designed and constructed for the present invention or may be available to those skilled in the computer software.

Examples of computer readable media include hardware devices that are specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those generated by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate with at least one software module to perform the operations of the present invention, and vice versa.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. It will be possible.

Claims (20)

A communication method based on hybrid beamforming in a receiver of a communication system,
Receiving reference signals from a transmitter of the communication system through beams with the hybrid beamforming applied thereto;
Selecting at least one analog beam having a quality higher than a preset threshold value among analog beams belonging to the beams based on the reference signals;
Selecting at least one digital beam corresponding to the at least one analog beam among digital beams belonging to the beams and having a quality higher than or equal to the predetermined threshold value, based on the reference signals; And
And transmitting to the transmitter information indicating at least one of the at least one analog beam and the at least one digital beam. The method according to claim 1,
Wherein the step of selecting the at least one analog beam comprises:
Selecting at least one horizontal analog beam having a quality higher than the preset threshold value among horizontal analog beams belonging to the analog beams; And
Further comprising the step of selecting at least one vertical analog beam having a quality above said predetermined threshold among vertical analog beams belonging to said analog beams. The method of claim 2,
Wherein the at least one vertical analog beam is an analog beam disposed in a vertical direction with the at least one horizontal analog beam. The method of claim 2,
Wherein the step of selecting the at least one digital beam comprises:
Selecting at least one horizontal digital beam corresponding to the at least one horizontal analog beam among the horizontal digital beams belonging to the digital beams and having a quality higher than the preset threshold value; And
Further comprising selecting at least one vertical digital beam corresponding to the at least one vertical analog beam among the vertical digital beams belonging to the digital beams and having a quality above the preset threshold value. The method of claim 4,
Wherein the at least one vertical digital beam is a digital beam disposed in a vertical direction with the at least one horizontal digital beam. The method according to claim 1,
Wherein the reference signals are received via a combined beam of the transmitter. The method according to claim 1,
Wherein the digital beams are generated by electrical tilting of the analog beams. The method according to claim 1,
Wherein the step of selecting the at least one digital beam comprises:
Further comprising identifying a precoding vector of the at least one digital beam. A communication method based on hybrid beamforming in a transmitter of a communication system,
Transmitting reference signals using analog beams and digital beams;
Receiving from a receiver of the communication system information indicating at least one of at least one analog beam and at least one digital beam selected based on the reference signals; And
And communicating with the receiver using at least one of the at least one analog beam and the at least one digital beam,
The antenna module of the transmitter includes a plurality of beamformers that support different sectors and each of the plurality of beamformers includes a plurality of panels, Each comprising a plurality of antenna elements, wherein the analog beams and the digital beams are transmitted by a single beamformer. The method of claim 9,
Wherein the reference signals are transmitted over a time-frequency resource other than a time-frequency resource set for interference measurement. The method of claim 9,
Wherein the at least one digital beam is generated by electrical tilting of the at least one analog beam. The method of claim 9,
Wherein the reference signals are transmitted through a combined beam of at least two of the analog beams and the digital beams. The method of claim 12,
Wherein the combined beams are generated by virtualizing the panels belonging to one beam former to have a single point of orientation. A receiver of a communication system,
A processor; And
Wherein at least one instruction executed by the processor comprises a stored memory,
Wherein the at least one instruction comprises:
Receiving reference signals from a transmitter of the communication system through beams subjected to hybrid beamforming;
Selecting at least one analog beam having a quality higher than a predetermined threshold value among analog beams belonging to the beams based on the reference signals;
Selecting at least one digital beam corresponding to the at least one analog beam among the digital beams belonging to the beams and having a quality higher than or equal to the predetermined threshold value, based on the reference signals; And
And transmit information indicating at least one of the at least one analog beam and the at least one digital beam to the transmitter. 15. The method of claim 14,
Wherein the at least one command, when selecting the at least one analog beam,
Selecting at least one horizontal analog beam having a quality higher than the preset threshold value among horizontal analog beams belonging to the analog beams; And
And to select at least one vertical analog beam having a quality above the predetermined threshold value among vertical analog beams belonging to the analog beams. 16. The method of claim 15,
Wherein the at least one command, when selecting the at least one digital beam,
Selecting at least one horizontal digital beam corresponding to the at least one horizontal analog beam among the horizontal digital beams belonging to the digital beams and having a quality higher than the predetermined threshold value; And
And to select at least one vertical digital beam corresponding to the at least one vertical analog beam among the vertical digital beams belonging to the digital beams and having a quality above the predetermined threshold value. 18. The method of claim 16,
Wherein the at least one vertical analog beam is an analog beam disposed in a vertical direction with the at least one horizontal analog beam and the at least one vertical digital beam is a digital beam vertically disposed with the at least one horizontal digital beam, . 15. The method of claim 14,
Wherein the reference signals are received via a combined beam of the transmitter. 15. The method of claim 14,
Wherein the digital beams are generated by electrical tilting of the analog beams. 15. The method of claim 14,
Wherein the at least one command, when selecting the at least one digital beam,
And to identify a precoding vector of the at least one digital beam.

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