WO2021215566A1 - Device and method for transmitting signals through antenna array in wireless communication system - Google Patents

Abstract

According to various embodiments of the present disclosure, a device at the transmission end of a wireless communication system comprises: a transmission antenna array; at least one transceiver; and at least one processor. The at least one processor is configured to: acquire channel design information; set the transmission antenna array on the basis of the channel design information; and transmit a signal to the reception end through the at least one transceiver and the transmission antenna array. The channel design information may include a parameter value which is determined on the basis of at least one of the interval between antenna elements of the transmission antenna array, the interval between antenna elements of a reception antenna array of the reception end, information on the rotation of the transmission antenna array, and information on the rotation of the reception antenna array.

Description

Apparatus and method for transmitting a signal through an antenna array in a wireless communication system

BACKGROUND This disclosure relates generally to a wireless communication system, and more particularly to an apparatus and method for transmitting a signal via an antenna array in a wireless communication system.

A wireless network is being operated to increase a signal gain by using a beamforming technique. By applying precoding, adjusting a phase applied to each antenna, or controlling the number of transport streams, it is possible to design a channel between a transmitter and a receiver. In order to further increase the channel capacity according to the increasing requirements, various methods for designing an effective channel are required.

Based on the above discussion, the present disclosure provides an apparatus and method for designing an effective channel for increasing channel capacity in a wireless communication system.

In addition, the present disclosure provides an apparatus and method for channel design using a structure of an antenna array, a distance between a transmitting end and a receiving end, and channel quality in a wireless communication system.

In addition, the present disclosure provides an apparatus and method for configuring an optimal channel environment by changing a physical structure of an antenna array in a wireless communication system.

In addition, the present disclosure provides an apparatus and method for configuring an optimal channel environment through rotation of a uniform linear array (ULA) in a wireless communication system.

In addition, the present disclosure provides an apparatus and method for configuring a channel environment through signal processing at a transmitting end or a receiving end in a wireless communication system.

In addition, the present disclosure provides an apparatus and method for configuring a channel environment with low complexity through precoding using the characteristics of a line of sight (LOS) channel environment in a multi-antenna wireless communication system using ULA.

According to various embodiments of the present disclosure, the apparatus of the transmitting end in the wireless communication system includes a transmit antenna array, at least one transceiver, and at least one processor, wherein the at least one processor obtains channel design information, configured to set the transmit antenna array based on the channel design information, and transmit a signal to a receiving end through the at least one transceiver and the transmit antenna array, wherein the channel design information is between antenna elements of the transmit antenna array may include a value of a parameter determined based on at least one of an interval of , an interval between antenna elements of the receiving antenna array of the receiving end, rotation information of the transmitting antenna array, and rotation information of the receiving antenna array.

According to various embodiments of the present disclosure, the device of the receiving end in the wireless communication system includes a receiving antenna array, at least one transceiver, and at least one processor, wherein the at least one processor obtains channel design information, configured to set the receiving antenna array based on the channel design information, and to receive a signal from a transmitting end through the at least one transceiver and the receiving antenna array, wherein the channel design information includes an antenna of the transmitting antenna array of the transmitting end It may include a value of a parameter determined based on at least one of a spacing between elements, a spacing between antenna elements of the reception antenna array, rotation information of the transmission antenna array, and rotation information of the reception antenna array.

According to various embodiments of the present disclosure, a method performed by a transmitter in a wireless communication system includes a process of obtaining channel design information, a process of setting a transmit antenna array based on the channel design information, and the transmit antenna array and transmitting a signal to a receiving end through , a parameter value determined based on at least one of rotation information of the reception antenna array.

According to various embodiments of the present disclosure, in a method performed by a receiver in a wireless communication system, a process of acquiring channel design information, a process of setting a receive antenna array based on the channel design information, and the reception and receiving a signal from a transmitting end through an antenna array, wherein the channel design information includes: an interval between antenna elements of a transmitting antenna array of the transmitting end, an interval between antenna elements of the receiving antenna array, and a value of the transmitting antenna array It may include a value of a parameter determined based on at least one of rotation information and rotation information of the reception antenna array.

The apparatus and method according to various embodiments of the present disclosure allow high channel capacity to be provided through a channel design in consideration of an array structure, a distance between a transmitter and a receiver, and channel quality.

The apparatus and method according to various embodiments of the present disclosure enable efficient channel design through structural features of a uniform linear array (ULA).

Effects obtainable in the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned may be clearly understood by those of ordinary skill in the art to which the present disclosure belongs from the description below. will be.

1 illustrates a wireless communication system according to various embodiments of the present disclosure.

2A to 2C are diagrams for explaining the principle of channel design in a line of sight (LOS) multiple input multiple output (MIMO) environment according to various embodiments of the present disclosure;

3 illustrates an operation flow of a transmitter for configuring an adaptive antenna array according to various embodiments of the present disclosure.

4 illustrates an operation flow of a transmitter for rotation-based transmission of a uniform linear array (ULA) according to various embodiments of the present disclosure.

5A to 5C illustrate an example of rotation-based transmission of a uniform linear array (ULA) according to various embodiments of the present disclosure.

6A-6B illustrate examples of ULA rotation according to various embodiments of the present disclosure.

7A to 7C illustrate examples of ULA structures according to various embodiments of the present disclosure.

8 illustrates an example of sub-array selection according to ULA rotation according to various embodiments of the present disclosure.

9 illustrates an operation flow of a transmitter for precoding-based transmission according to various embodiments of the present disclosure.

10A illustrates an example of a functional configuration of a transmitter for precoding-based transmission according to various embodiments of the present disclosure.

10B illustrates an example of a functional configuration of a receiving end for precoding-based transmission according to various embodiments of the present disclosure.

11 illustrates an operation flow of a transmitter for phase information-based transmission according to various embodiments of the present disclosure.

12A illustrates an example of a functional configuration of a transmitter for phase information-based transmission according to various embodiments of the present disclosure.

12B illustrates an example of a functional configuration of a receiving end for phase information-based transmission according to various embodiments of the present disclosure.

13 illustrates an operation flow of a transmitter for rank information and phase information-based transmission according to various embodiments of the present disclosure.

14A illustrates an example of a functional configuration of a transmitter for rank information and phase information-based transmission according to various embodiments of the present disclosure.

14B illustrates an example of a functional configuration of a receiving end for rank information and phase information-based transmission according to various embodiments of the present disclosure.

15 illustrates a configuration of a base station in a wireless communication system according to various embodiments of the present disclosure.

16 illustrates a functional configuration of a terminal in a wireless communication system according to various embodiments of the present disclosure.

Terms used in the present disclosure are used only to describe specific embodiments, and may not be intended to limit the scope of other embodiments. The singular expression may include the plural expression unless the context clearly dictates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by one of ordinary skill in the art described in the present disclosure. Among the terms used in the present disclosure, terms defined in a general dictionary may be interpreted with the same or similar meaning as the meaning in the context of the related art, and unless explicitly defined in the present disclosure, ideal or excessively formal meanings is not interpreted as In some cases, even terms defined in the present disclosure cannot be construed to exclude embodiments of the present disclosure.

In various embodiments of the present disclosure described below, a hardware approach method will be described as an example. However, since various embodiments of the present disclosure include technology using both hardware and software, various embodiments of the present disclosure do not exclude a software-based approach.

Hereinafter, the present disclosure relates to an apparatus and method for designing an optimal effective channel using an array antenna in a wireless communication system. Specifically, the present disclosure relates to an apparatus and method for adaptively configuring an effective channel through a change in physical deployment of antennas of a reconfigurable antenna array in a wireless communication system.

Terms referring to signals (signal, symbol, stream, data, beamforming signal) used in the following description, terms related to beams (multi-beam, multiple beams, single beam, dual beam, quad-beam, beamforming) , terms referring to device components (antenna array, antenna element, communication unit, antenna), terms referring to network entities (eg, communication node, wireless A node (radio node), a radio unit (radio unit), a network node (network node), a transmission/reception point (transmission/reception point, TRP), etc. are exemplified for convenience of description. Accordingly, the present disclosure is not limited to the terms described below, and other terms having equivalent technical meanings may be used.

Signal-to-noise ratio (SNR) is exemplarily described as a metric for signal gain, communication quality, signal quality, etc. used in the following description, but embodiments of the present disclosure are not limited thereto. For example, in addition to SNR, beam reference signal received power (BRSRP), reference signal received power (RSRP), reference signal received quality (RSRQ), received signal strength indicator (RSSI), signal to interference and noise ratio (SINR), CINR (carrier to interference and noise ratio), EVM (error vector magnitude), BER (bit error rate), BLER (block error rate), etc. may be replaced with equivalent meanings . Of course, in addition to the above-described examples, other terms having an equivalent technical meaning or other metrics indicating signal quality may be used.

In addition, in the present disclosure, in order to determine whether a specific condition is satisfied or satisfied, an expression of more than or less than may be used, but this is only a description for expressing an example. It's not about exclusion. Conditions described as 'more than' may be replaced with 'more than', conditions described as 'less than', and conditions described as 'more than and less than' may be replaced with 'more than and less than'.

In addition, although the present disclosure describes various embodiments using terms used in some communication standards (eg, 3rd Generation Partnership Project (3GPP), Institute of Electrical and Electronics Engineers (IEEE)), this is an example for description. only Various embodiments of the present disclosure may be easily modified and applied in other communication systems.

1 illustrates a wireless communication system according to various embodiments of the present disclosure. 1 illustrates a base station 110 and a terminal 120 as some of nodes using a wireless channel in a wireless communication system.

In addition to the base station (base station), the base station 110 includes an 'access point (AP)', an 'eNodeB (eNodeB)', a 'gNB (next generation node B)', and a '5G node (5th generation node). ', '5G node ratio (5G NodeB, NB)', 'gNB (next generation node B)', 'wireless point', 'transmission/reception point (TRP)', 'central unit ( 'centralized unit (CU)', 'distributed unit (DU)', 'digital unit (DU)', 'radio unit (RU)', 'remote radio head (RRH)' )' or other terms having an equivalent technical meaning. Hereinafter, the present disclosure describes the base station 110 as one entity, but according to an embodiment, it may be implemented as distributed entities. For example, the base station 110 may be implemented by being divided into a DU and an RU. That is, a device that performs scheduling and a device that emits a signal according to the scheduling may be implemented at physically distinct locations. Also, for example, the base station 110 may be connected to one or more 'transmission/reception points (TRP)'. The base station 110 may transmit a downlink signal to the terminal or receive an uplink signal through one or more TRPs.

The terminal 120 is a device used by a user, and performs communication with the base station 110 through a wireless channel. In some cases, at least one of the terminals 120 may be operated without the user's involvement. That is, the terminal 120 is a device that performs machine type communication (MTC) and may not be carried by a user. The terminal 120 includes 'user equipment (UE)', 'mobile station', 'subscriber station', 'customer premises equipment' (CPE) other than a terminal. , 'remote terminal', 'wireless terminal', 'electronic device', or 'vehicle (vehicle) terminal', 'user device' or equivalent technical It may be referred to by other terms that have a meaning. A terminal (eg, terminal 120) according to various embodiments of the present disclosure is, for example, a cellular phone, a smartphone, a computer, a tablet PC, a mobile phone, a video phone, an e-book reader, a desktop PC, a laptop PC, a netbook computer , a workstation, a server, a PDA, a portable multimedia player (PMP), an MP3 player, a medical device, a camera, a wearable device, and at least one of a multimedia system capable of performing a communication function. In addition, the type of the terminal is not limited to the above example, of course.

In order to improve the channel gain, the base station 110 or the terminal 120 may perform beamforming. Here, the beamforming may include transmit beamforming and receive beamforming. That is, the base station 110 and the terminal 120 may impart directivity to a transmission signal or a reception signal. To this end, the base station 110 and the terminal 120 may select serving beams through a beam search or beam management procedure. After serving beams are selected, subsequent communication may be performed through a resource having a quasi co-located (QCL) relationship with a resource that has transmitted the serving beams. For example, the terminal 120 and the base station 110 may transmit and receive radio signals in millimeter wave (mmWave) bands (eg, 28 GHz, 30 GHz, 38 GHz, and 60 GHz).

If the large-scale characteristics of the channel carrying the symbol on the first antenna port can be inferred from the channel carrying the symbol on the second antenna port, then the first antenna port and the second antenna port are said to be in a QCL relationship. can be evaluated. For example, a wide range of characteristics include delay spread, Doppler spread, Doppler shift, average gain, average delay, spatial receiver parameter. may include at least one of

The terminal 120 may perform a synchronization procedure and a cell search procedure through a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH). Thereafter, the terminal 120 may perform an access procedure to complete the access to the network through the base station 110 . The terminal 120 transmits a preamble through a physical random access channel (PRACH) and receives a response message to the preamble through a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH). . After performing the procedure as described above, the UE may perform PDCCH/PDSCH reception and physical uplink shared channel (PUSCH)/physical uplink control channel (PUCCH) transmission as a general uplink/downlink signal transmission procedure. Such an access procedure may be variously used for initial access, uplink synchronization adjustment, resource allocation, handover, and the like.

A beamforming structure for increasing a signal gain according to an increasing frequency band is introduced. As one of the techniques for alleviating propagation path loss and increasing the propagation distance of radio waves, a beamforming technique is used. Beamforming, in general, uses a plurality of antennas to concentrate the arrival area of radio waves or to increase the directivity of reception sensitivity for a specific direction. Accordingly, in order to form beamforming coverage instead of using a single antenna to form a signal in an isotropic pattern, a communication node may have multiple antennas. In this case, a form in which a plurality of antennas are aggregated may be referred to as an antenna array, and each antenna included in the array may be referred to as an array element or an antenna element. Hereinafter, embodiments of a linear array are described as an example of the antenna array in the present disclosure, but may be configured in various forms such as a planar array and a cores-pol array.

The channel between the transmitting end and the receiving end may change due to various reasons such as time, frequency, or an obstacle between space, and accordingly, it may be required that the transmitting end and the receiving end process an appropriate signal in response to the changing channel. In particular, since it is affected by controllable characteristics such as time, frequency, or spatial resources, as well as communication distance, channel diversity according to a specific place, channel change due to obstacles (such as LOS environment), etc., the present disclosure is not limited to these factors also propose a considered channel design method. Specifically, the present disclosure proposes an apparatus and method for constructing an optimal effective channel by reconstructing the physical properties of the antenna of the structure of the array (eg, rotation of the array, selection of a sub-array, change of angle). In addition, the present disclosure also proposes a method for reducing the complexity by using techniques such as maximum ratio transmission (MRT) and maximum ratio combining (MRC).

As shown in FIG. 1, not only the downlink or uplink between the base station and the terminal, but also the communication between the terminal and the terminal (eg, Sidelink, V2X (vehicle to everything)), and the communication between the base station and the base station. Various embodiments of the present disclosure may be applied between a transmitting end and a receiving end in a communication environment.

Although not shown in FIG. 1 , various embodiments of the present disclosure may be applied to various types of communication nodes other than the base station and the terminal. For a stable design of a channel for a high data rate, various embodiments of the present disclosure may be applied to a field with relatively low mobility (eg, LOS MIMO).

In some embodiments, embodiments of the present disclosure may also be applied to wireless communication between distributed base stations. For example, embodiments of the present disclosure may be applied to wireless communication between a DU of a base station and an RU of a base station. As another example, embodiments of the present disclosure may be applied to wireless communication between a CU of a base station and a DU of a base station. Since the base station components (CU, DU, RU, etc.) have relatively low mobility compared to the terminal, it is easy to design a channel between the two components.

In some other embodiments, embodiments of the present disclosure may be applied to an electronic device (eg, CPE) in a fixed wireless access (FWA) or fixed wireless systems (FWS) environment. Since the electronic device transmits or receives a signal in a high frequency band and has relatively low mobility, it is easy to design a channel between the electronic device and a communication node (eg, a base station).

In some other embodiments, embodiments of the present disclosure may also be applied to an IAB node (integrated access and backhaul). The IAB node may perform communication through a backhaul connection with another IAB node or base station within a specified distance, or may perform communication through a radio access network (RAN). In order to increase the capacity of the cell and secure sufficient coverage capacity in the frequency band, one or more IAB nodes may be deployed for the base station. After deployment, since each IAB node has relatively low mobility, it is easy to design a channel between nodes in backhaul communication of the IAB node.

In some other embodiments, embodiments of the present disclosure may also be applied to vehicle-to-vehicle communication (eg, V2X, vehicle to vehicle (V2V)). A straight path between two vehicles on the road can be secured, and the range of height is limited, so it is easy to design channels between vehicles.

Hereinafter, embodiments of the present disclosure will be described by expressing, as a communication entity, a base station, a terminal, an electronic device, and a communication node as a communication entity as a transmitting end or a receiving end instead of a communication entity. Embodiments of the principle, operation, and structure for a reconfigurable antenna array are described with reference to FIGS. 2A to 8 .

2A to 2C are diagrams for explaining the principle of channel design in a line of sight (LOS) multiple input multiple output (MIMO) environment according to various embodiments of the present disclosure;

Referring to FIGS. 2A-2C , FIG. 2A shows a perspective view 201 of a channel model. The transmit antenna array may include a plurality of transmit antenna elements. As an example of the plurality of transmit antenna elements, a first antenna disposed at the mth position from the reference is illustrated. The first antenna may correspond to an _{md t length.} d _t denotes a spacing between elements on the array of the first antenna. The receiving end antenna array may include a plurality of receiving antenna elements. As an example of the plurality of receiving antenna elements, a second antenna disposed at the nth position from the reference is illustrated. The second antenna may correspond to _{nd r length.} d _r denotes an interval between elements on the second antenna. A distance between the first antenna and the second antenna may be D. The first antenna has a _{length of md t and} may be located on the xy plane. The first antenna may form an angle of _{θ t} with the x axis on the xz plane _{(eg, corresponding to (md t} , θ _t , 0) on the polar coordinate system). The second antenna has a _{length of nd r} and may form an angle of _{θ r with} the x-axis. Also, the second antenna projected on the yz plane may form an angle _{between the z axis and φ r} (eg, corresponding to _{(nd r} , θ _r , φ _{r ) in the polar coordinate system).}

2B shows a front view 203 of the channel model. The xz plane in the perspective view 201 is shown. 2C shows a top view 205 of the channel model. The yz plane in the perspective view 201 is shown. The distance between the two antenna elements, that is, the distance between the first antenna and the second antenna, may be defined as _{d n,m .} In this case, d _n,m may be determined by the following equation. The z-axis, x-axis, and y-axis distances between the two antennas may correspond to D+nd _r sinθ _r cosφ _r -md _t sinθ _t ,nd _r cosθ _r -md _t cosθ _t , md _r sinθ _r sinφ _r , respectively. In this case, the physical distance between the two antennas may be defined as follows.

<Equation 0>

Assume that there are N _t transmit antennas and N _{r receive antennas.} N _max is that the larger of N _t and N _r, N _max indicates the lesser of N _t and N _r. In the LOS communication system, the channel between the transmit antenna array and the receive antenna array is deterministic according to the positions of the antennas. In this case, the channel between the m-th transmit antenna and the n-th receive antenna may be expressed as follows.

Here, d _n,m is the distance between the m-th transmit antenna and the n-th receive antenna, G _t is the transmit antenna gain, G _r is the receive antenna gain, and λ represents the carrier wavelength.

는 m과 n에 상관이 없어지고 채널은 다음과 같이 단순화될 수 있다. In Equation 1, if the size of the antenna is sufficiently small compared to the communication distance,

is independent of m and n, and the channel can be simplified as

Here, h _n,m represents a channel between the m-th transmit antenna and the n-th receive antenna. D represents the communication distance, that is, the distance between the transmitting end and the receiving end.

The signal-to-noise ratio (SNR) is expressed as

Here, P _t is transmission power, B is bandwidth, and N ₀ is noise power density. G _t represents the transmit antenna gain, G _r represents the receive antenna gain, and λ represents the carrier wavelength. Using Equation 3, the LOS channel can be normalized as follows.

Here, h _n,m represents a channel between the m-th transmit antenna and the n-th receive antenna. d _n,m is the distance between the mth transmit antenna and the nth receive antenna, and λ represents the carrier wavelength.

Assuming that the nth singular value of the MIMO channel H is σ _n (H), the channel capacity is expressed as follows.

Not all channels are allocated the same power, but an appropriate power p _n is allocated to each stream n.

At this time, it is known that the upper limit of this channel capacity is as follows.

의 특이값을 가질 것이 요구된다. 여기서, ρ는 SNR에 의존적일 수 있다. ρ means the number of sub-channels (ie, transmission rank). In consideration of waterfilling, power expressed in SNR/ρ is allocated to each sub-channel,

It is required to have a singular value of Here, ρ may depend on the SNR.

개의 특이값으로

을 가져야하고 나머지 특이값으로 0을 가져야한다. 이러한 채널의 0이 아닌 서브채널에 동일한 전력을 할당하면 <수학식 6>의 상계가 달성될 수 있다. 여기서

은 다음과 같이 정의될 수 있다.In order to achieve the upper bound of <Equation 6>, the channel is approximately

as a singular value

should have 0 as the remaining singular values. If the same power is allocated to non-zero subchannels of such a channel, the upper bound of Equation (6) can be achieved. here

can be defined as

Here, c may be a specified value (eg, -1 - 2/W ₀ (-2/e ² )).

Various embodiments of the present disclosure propose an antenna structure for achieving the upper bound of Equation (6). That is, a channel is reconstructed through the structure of the antenna, and an antenna satisfying the upper bound condition of Equation (6) is proposed according to the reconstructed channel.

First, when a uniform linear antenna array is used in the transmitting and receiving end, the properties of the channel matrix in Equation 4 will be described.

It is assumed that a modelable uniform linear antenna array is disposed at a transmitting end and a receiving end as shown in FIGS. 2A to 2C . In the matrix of <Equation 4>, d _n,m may be replaced with <Equation 0>. At this time, assuming a relatively large communication distance D, h _n,m can be approximated by the following equation.

<Equation 7-0>

Referring to Equation <7-0>, the exponential function part may be composed of four parts. At this time, since the first component is the communication distance D, the second component is the parameters of the receiving end, and the fourth component is the parameters of the transmitting end, it does not have a dominant influence on the calculation of singular values. Accordingly, in order to calculate the channel condition of Equation 6 described above, the third component may be used to calculate the singular value of the channel matrix. That is, the channel matrix between the transmitting end and the receiving end may share a singular value with the following matrix.

where η is determined as

Due to the characteristics of the LOS MIMO channel using the ULA, the matrix H _ULA (η) has approximately ηN _min all of the same singular values, and the remaining singular values may be close to zero. Therefore, when the following equation is satisfied, the upper bound of <Equation 6> can be achieved.

A transmit/receive antenna array according to various embodiments may satisfy the following equation.

Here, d _t represents an interval between elements of the transmit antenna array. d _r represents an interval between elements of the receiving antenna array.

In this case, <Equation 10> can be simplified as follows through <Equation 9> and <Equation 11>.

_{That is, it can be seen that if the θ r} and θ _t values are adjusted to satisfy <Equation 12>, the upper bound of the above-mentioned <Equation 6> can be closely achieved. In an embodiment, as the simplest method, if θ _t = 0, the upper limit can be achieved only by rotation at the receiving end.

In the same way, _{by setting θ r} = 0, the purpose can be achieved only by the rotation (θ _{t ) at the transmitting end.} <Equation 11-13> is an example of the present disclosure, and an upper limit can be achieved in a specific SNR range through rotation even for an antenna array that does not satisfy this.

2A to 2C illustrate the principle of channel design for improving communication quality at the transmitting end and the receiving end. Here, the equations mentioned through FIGS. 2A to 2C are an example of a principle for designing channels of a transmitting end and a receiving end, which will be described later, and a specific equation is not intended to limit other embodiments of the present disclosure.

In addition, although parameters for designing a channel model through a linear array and achieving an upper bound have been described in FIGS. 2A to 2C , channel design according to various embodiments of the present disclosure is not limited to a linear array. The above results can be naturally extended to parallel uniform rectangular arrays (URA).

Width at the transmitting end distance d _{t, h} and vertical distance d _t, the N _{t, h} XN _{t, v} uniform rectangular antenna array having a _v, distance horizontally in the receiver d _{r, h} and vertical distance d _r, N _t with _{v ,h} XN _t,v It is known that the LOS channel created when using a uniform rectangular antenna array is as follows.

,

를 의미한다.

는 Kronecker product를 의미한다. H_URA(η_h, η_v)는 (η_h min(N_r,h, N_t,h))( η_v min(N_r,v, N_t,v))개의 모두 같은 값의 특이값을 가지고 나머지 특이값들은 0에 가깝게 될 수 있다. <수학식 10>과 같이, (η_h min(N_r,h, N_t,h))(η_v min(N_r,v, N_t,v))의 특이값들의 개수가

이 되도록 η_h와 η_v이 조절되면 균등 선형 어레이에서와 같이 채널 용량의 상계가 달성될 수 있다.here

,

means

stands for Kronecker product. H _URA (η _h , η _v ) gives (η _h min(N _r,h , N _t,h ))( η _v min(N _r,v , N _t,v )) all equal singular values and the remaining singular values can be close to zero. As in <Equation 10>, the number of singular values of _{(η h} min(N _r,h , N _t,h ))(η _v min(N _r,v , N _{t,v )) is}

When η _h and η _v are adjusted so that

A rank of a channel may mean the number of independent paths within a channel. The number of transport streams may be defined according to an independent path of a channel. In general, the maximum value of the rank is the minimum value of the number of transmit antennas (N _t ) and the number of receive antennas (N _r ). It is known that full-rank is suitable for obtaining high channel capacity at high SNR. However, at low SNR, full-rank may not be advantageous for obtaining high channel capacity. In order to reach a low SNR upper bound, it is necessary to determine an appropriate number of ranks, rather than always aiming for a full-rank. Accordingly, various embodiments of the present disclosure may consider signal quality as in Equation 7 when calculating a rank. The number of non-zero singular values may be defined as a rank.

Various embodiments of the present disclosure provide not only general channel capacity calculation, but also a method of determining the RI that is the basis of PMI and CQI calculation of CSI defined in 3GPP, or determining the number of data streams based on feedback information and applying precoding. It can be applied in various MIMO communication methods, such as a communication method. Based on the LOS MIMO channel principle described with reference to FIGS. 2A to 2C , the operations for the actual transmitting end and the receiving end to design an effective channel and transmitting a signal through the design are described with reference to FIGS. 3 to 8 .

Configuring an adaptive antenna array

3 illustrates an operation flow of a communication node for configuring an adaptive antenna array according to various embodiments of the present disclosure. The adaptive antenna array configuration refers to an operation for increasing the channel capacity by changing the physical arrangement of the antenna array. A communication node exemplifies a transmitting end or a receiving end. It may be the base station 110 of FIG. 1 , the terminal 120 , or other network entity.

Referring to FIG. 3 , in step 301 , the communication node may acquire channel design information based on the structure of the antenna array, the communication distance, and the communication quality. In the present disclosure, information on the values of parameters related to the physical arrangement of the antenna array, such as η, is referred to as channel design information and described. The parameters related to the physical arrangement include the number of transmit antenna elements in the antenna array of the transmitting end, the spacing between transmit antenna elements, the degree of rotation of the antenna array of the transmitting end, the number of receive antenna elements in the antenna array of the receiving end, and the number of receive antenna elements between the receive antenna elements. It may include at least one of an interval, a rotation degree of the antenna array of the receiving end, and a physical distance between the transmitting end and the receiving end. In this case, for example, the degree of rotation may be calculated based on an axis orthogonal to the communication direction.

The channel design information may be defined in various ways. In some embodiments, the channel design information may include a parameter (eg, η) defined by a combination of each parameter, rather than a value of each parameter. For example, the channel design information may include a value of a parameter defined as a product of an interval between receive antenna elements and an interval between transmit antenna elements. As another example, the channel design information may include a value of a parameter defined by an _{effective length (eg, d r} cosθ _{r ) of the receiving antenna elements.} As another example, the channel design information may include η of Equation (9).

In some embodiments, if some parameters at the transmitting end or the receiving end are fixed values or have already been obtained, the corresponding parameters may be excluded from the values of parameters of the channel design information to be newly calculated. As an example, according to the condition of Equation 11, the parameters of the channel design information may be simplified to _{θ r} and θ _{t as shown in Equation 12.} Also, as an example, as in <Equation 13>, the parameter may be simplified to _{θ r as the parameter of the channel design information.}

In some embodiments, when the electronic device is the transmitter, parameters related to the receiver may be determined based on a specified value or information fed back from the receiver. In some other embodiments, when the electronic device is the receiving end, parameters related to the transmitting end are based on a specified value or configuration information from the transmitting end (eg, radio resource control (RRC) of 3GPP, medium access control (MAC)) It can be determined by a control element (CE) or downlink control information (DCI).

In order to determine the value of the channel design information, it is required to satisfy an upper bound condition regarding the channel capacity (eg, <Equation 6> and <Equation 10>). In order to determine whether it is satisfied, the communication node may obtain information about channel quality (eg, SNR). The communication node may determine the number of sub-channels corresponding to the channel quality, that is, a transmission rank (hereinafter, an optimal rank). The transmission rank is not unconditionally set to full-rank (minimum number of antennas (N _min )). The communication node may identify a range according to channel quality, and identify the optimal number of ranks corresponding to the range. The communication node may determine the optimal number of ranks corresponding to each range according to the channel quality as a value of _{1 or more and N min or less.} According to an embodiment, the communication node includes the communication quality, the number of transmit antennas (that is, the number of antenna elements of the transmitting end participating in MIMO communication), and the number of receiving antennas (that is, participating in MIMO communication) within a certain range. An optimal rank value may be determined based on the number of antenna elements of the transmitter).

In step 303, the communication node may configure the antenna array based on the channel design information. The channel design information may include physical attitude control values of the antenna array. Various values may be defined according to a method for controlling the physical posture of the antenna array.

In some embodiments, since the channel design information includes information related to rotation of the transmit antenna array or the receive antenna array, the communication node may rotate the antenna array. In this case, for example, the rotation direction of the antenna array may be defined based on a plane orthogonal to the communication direction. Specific embodiments related to rotation are described with reference to FIGS. 4 to 7 .

In some other embodiments, since the channel design information is defined based on parameters related to the actual communication distance of the antenna element of the transmit antenna array and the antenna element of the receive antenna array, the communication node in the antenna array, Example: Under the conditions for satisfying <Equation 6> and <Equation 10>), an optimal sub-array may be selected. Specific embodiments related to rotation related to sub-array selection are described with reference to FIG. 8 .

In some other embodiments, the communication node may select a specific transmission unit when it includes a plurality of transmission units (eg, RUs in a distributed configuration of base stations). Since the channel design information includes the distance between the transmitting end and the receiving end as a parameter, it is possible to select a transmission unit that satisfies or is close to an upper bound condition of the channel capacity (eg, <Equation 6> and <Equation 10>). This principle can be applied in a similar way in installing a suitable communication unit to service a fixed terminal.

4 illustrates an operation flow of a transmitter for rotation-based transmission of a uniform linear array (ULA) according to various embodiments of the present disclosure. Although it is described as an operation of the transmitting end in FIG. 4, it goes without saying that the same principle is applicable to the receiving end. _{A method of adjusting θ r} and θ _{t when at least one of physical parameters d r} , d _t , N _r , N _t , λ and D is given in the channel model of FIGS. 2A to 2C described above, comprising: a transmit/receive antenna array There is a way to mechanically rotate the

Referring to FIG. 4 , in step 401 , the transmitting end may obtain rotation information from channel design information. The channel design information may include a value of rotation information. Here, the rotation information means the rotation angle of the transmitting end antenna array or the rotation angle of the receiving end antenna array required under the conditions for satisfying the upper bound condition of the channel capacity (eg, <Equation 6> and <Equation 10>) do. For convenience of design, either the rotation angle at the transmitting end or the rotation angle at the receiving end may be fixed. According to an embodiment, in the case of the transmitting end, rotation information of the receiving end may be omitted from the channel design information. The channel design information may include only rotation information of the transmitter. An operation according to the rotation information of the receiving end may be defined in the operation of the receiving end.

In step 403, the transmitting end may set the physical arrangement of the antenna array according to the rotation information. The rotation information may include a rotation angle. As an example, the rotation information may further include a rotation direction. As another example, the rotation direction of the rotation information may be fixed. The transmitting end may change the physical posture of the antenna array according to the rotation information. The transmitting end may rearrange the antenna array. In some embodiments, the rotation information may directly indicate a value for an angle requiring rotation of the transmitter. In some other embodiments, the rotation information may include an index indicating a predefined arrangement type of the antenna array. That is, the degree of rotation of the antenna array may be divided into a plurality of ranges, and rotation information may be indicated in the form of an index indicating a specific range.

In step 405 , the transmitting end may transmit a signal through an antenna array according to a physical arrangement. The transmitting end may transmit a signal through the rearranged antenna array.

5A to 5C illustrate examples of antenna reconstruction of a uniform linear array (ULA) according to various embodiments of the present disclosure.

Referring to FIG. 5A , the transmitter 510 may include a precoder 511 , a phase shifter 512 , and an antenna array 513 . For example, the precoder 511 may be a DFT precoder including a discrete fourier transform (DFT) matrix. An appropriate DFT precoding matrix may be constructed to construct an effective channel applied to multiple streams. The operation of the precoder 511 may correspond to digital beamforming. The phase shifter 512 is configured such that the antenna array 513 forms a beam by changing a phase appropriate to a signal input to each of the antenna elements of the antenna array or sub-array. The operation of the phase shifter 513 may correspond to analog beamforming. Although not shown in FIG. 5A , a power amplifier (PA) may also be included as an example of a beamforming implementation.

The receiving end 520 may include a receiver 521 and an antenna array 523 . The receiver 521 may perform an operation such as an equalizer to more effectively configure an effective channel with the transmitter 510 . The receiver 521 may restore signals through additional processing (eg, phase transformation, inverse DFT (IDFT), etc.) on signals received from the antenna array 523 . The receiver 521 may be configured as a maximum ratio combining (MRC) receiver according to various embodiments.

According to various embodiments, the antenna array 523 may be a reconfigurable linear array. In some embodiments, as shown in FIG. 5A , the receiving end 520 may rotate the antenna array 523 to design an effective channel. Here, it is assumed that the transmitter 510 does not rotate. The receiving end 520 may identify a singular value corresponding to a channel quality (eg, SNR) range. According to an embodiment, a mapping relationship corresponding to the channel quality and the singular value may be defined. The receiving end 520 may identify a range of channel quality. If it corresponds to a low quality, the optimal rank may be determined as 1. The receiving end 520 may obtain rotation information of the receiving end corresponding to the optimal rank. The receiving end 520 may transmit/receive data by selecting one of the structures configurable by the antenna array 523 . The receiving end 520 may reconfigure the antenna array 523 based on the rotation information. By rotating the antenna array, the receiving end 520 can achieve the same effect as using several equal antenna arrays.

In some other embodiments, as shown in FIG. 5B , the receiving end 520 may select a sub-array for effective channel design. A sub-array may be defined according to a range of channel quality. For example, as shown in FIG. 5C , the antenna array 523 may include sub-arrays corresponding to each channel quality range. In the case of low channel quality, the arrangement of the antenna array 523 may correspond to the first arrangement. The receiving end 520 may identify the first sub-array 541 corresponding to the first arrangement. The receiving end 520 may communicate with the transmitting end 510 through the first sub-array 530 . When the channel quality corresponds to the intermediate range, the arrangement of the antenna array 523 may correspond to the second arrangement. The receiving end 523 may obtain preferred angle information based on the channel quality and identify the second sub-array 542 corresponding to the antenna arrangement of the corresponding angle information (eg, the intermediate range of Equation 7). The receiving end 520 may communicate with the transmitting end 510 through the second sub-array 542 . In the case of high channel quality, the arrangement of the antenna array 523 may correspond to the third arrangement. The receiving end 520 may identify the third sub-array 543 corresponding to the third arrangement. The receiving end 520 may communicate with the transmitting end 510 through the third sub-array 543 . The receiving end 520 identifies and changes the sub-array of the antenna array 523 corresponding to the angle based on the angle information, or maintains the current communication sub-array (when the same sub-array is identified) with the transmitting end 510 You can keep it in optimal condition.

5A to 5C, a situation in which the channel quality range is 3 and the number of sub-arrays is 3 has been described as an example, but various embodiments of the present disclosure are not limited thereto. In some embodiments, the transmitting end 510 or the receiving end 520 may define more than three number of channel quality ranges, and may include more than three sub-arrays. Conversely, in some embodiments, the transmitting end 510 or the receiving end 520 may determine a reference value and define only high and low channel quality. The transmitting end 510 or the receiving end 520 may include a sub-array corresponding to high quality and a sub-array corresponding to low quality.

Example implementation of ULA rotation

6A-6B illustrate examples of ULA rotation according to various embodiments of the present disclosure. 6A shows an example of a rotation structure of a reconfigurable antenna array for transmitting or receiving a signal by applying the rotation information of FIGS. 4 to 5C . Referring to FIG. 6A , a front view 601 of the rotating structure is shown. Referring to FIG. 6B , a perspective view 603 of the rotating structure is shown. The rotation structure may include a structure in which the ULA is attached to a plane and rotatable in a clockwise or counterclockwise direction.

7A to 7C illustrate examples of ULA structures according to various embodiments of the present disclosure. 7A-7C illustrate exemplary implementations of a reconfigurable antenna array for transmitting or receiving a signal by applying the rotation information of FIGS. 4-5C . According to an embodiment, the rotation axis of the antenna array may be located at the center of the array antenna ( 701 ). It may be easy to design a channel according to rotation information. According to another embodiment, the rotation axis of the antenna array may be located at a location other than the center of the array antenna (eg, the end of the antenna array) (703). According to another embodiment, the rotation axis of the antenna array may be located in a different part from the array antenna array ( 705 ). By not necessarily limiting the arrangement of the rotation axis on the antenna array, more diverse design scenarios can be covered.

6A to 6B and 7A to 7C illustrate an antenna array structure for reconstructing an effective channel through ULA rotation between a transmitting end and a receiving end. However, these structures are only examples for implementation, and other exemplary embodiments of the present disclosure are not limited thereto. Not only the method of simply applying the rotation information value through physical rotation, but also the method of selecting sub-arrays in the antenna array (eg, in FIG. 8 ) that have been opportunistically rotated (that is, in a state that already forms a rotation angle from a channel point of view) By applying rotation information, an effective channel can be designed.

Selection example of ULA sub-array

8 illustrates an example of sub-array selection according to ULA rotation according to various embodiments of the present disclosure. _{As a method of adjusting θ r} and θ _t when physical parameters d _r , d _t , N _r , N _t , λ, and D are given, there is a method of selecting a suitable component from among a plurality of transmit/receive antenna components. . Hereinafter, a method of selecting a sub-array of an antenna array is described in FIG. 8 .

Referring to FIG. 8 , the antenna array 800 may include three sub-arrays. The antenna array 800 may include a first sub-array 801 , a second sub-array 803 , and a third sub-array 805 . For example, the first sub-array 801 may correspond to a high SNR, the second sub-array 803 may correspond to a mid-range SNR, and the third sub-array 805 may correspond to a low SNR. High and low may be defined according to a specified range (eg, <Equation 7>).

Each sub-array has the same length, but may have different effective lengths based on high SNR. Considering the first sub-array 801 corresponding to the high SNR as a reference axis, if the length of the first sub-array 801 is L and the degree of rotation is θ _i , the effective length will be defined as _{L i} =Lcosθ _i can The effective length 811 of the first sub-array 801 may be L. The effective length 815 of the second sub-array 803 may be L _mid-SNR = Lcosθ _mid-SNR . The effective length 815 of the third sub-array 805 may be L _low-SNR = Lcosθ _low-SNR . Since the number of antenna elements included in each sub-array is equal and equally spaced, the effective length of each sub-array may correspond to an interval (eg, d _{r , d t} ) between antenna elements.

According to various embodiments of the present disclosure, in a wireless communication system, a transmitter may receive feedback channel information and acquire channel design information. The transmitter may select one sub-array from among a plurality of sub-arrays through the channel design information. The transmitting end may transmit to the receiving end using the selected sub-array. According to various embodiments of the present disclosure, in a wireless communication system, a receiving end may select one sub-array from among a plurality of sub-arrays through estimated channel information. The receiving end may receive a signal transmitted from the transmitting end through the selected sub-array.

The design and operation methods of a reconfiguration antenna for achieving a high data transmission rate in a LOS MIMO environment have been described with reference to FIGS. 2A to 8 . The apparatus and method according to various embodiments of the present disclosure may achieve a high data transmission rate by selecting an array or arrangement having an appropriate beamforming gain and a multiplexing gain. In particular, the maximum channel capacity, that is, the maximum transmission speed, is achieved even at a low SNR, so that high communication efficiency can be described in various environments.

2A to 8, the ULA type antenna array or the URA type antenna array is referred to, but the reconfigurable UCA (uniform circular array) type antenna is also referred to as a reconfigurable UCA type antenna in the form of adjusting the radius to optimize the channel capacity according to the distance. It may be understood as an embodiment of the present disclosure.

Efficient effective channel design

In order to calculate the parameters having the maximum channel capacity, it is necessary to determine whether the above-described equations of <Equation 6> and <Equation 11> and the condition of the corresponding effective channel are satisfied, so the amount of computation may be considerable. Accordingly, the present disclosure proposes an effective channel design method for low-complexity. It is assumed that the channel matrix H=H _ULA (η) of Equation 8 and the transmitting end 510 and the receiving end 520 shown in FIGS. 5A to 5C.

A precoding matrix (eg, a DFT precoder) of the precoder 511 of the transmitter 510 may be F. At this time, if the MRC precoding in the receiver 521 is H ^* and the IDFT precoding F ^{*, the} following equation may be satisfied.

That is, by configuring the channel between the transmitting end and the receiving end to be close to a diagonal matrix, as an effective channel, interference-free subchannels can be obtained. Also, the same effect can be obtained by performing IDFT precoding at the transmitting end 510 and MRC precoding and DFT precoding at the receiving end 520 as follows.

In addition, the same effect can be achieved by MRT precoding at the transmitting end instead of MRC precoding at the receiving end. DFT precoding F and MRT precoding H ^* may be applied at the transmitting end, and IDFT precoding F ^* may be applied at the receiving end.

Conversely, IDFT precoding F ^* and MRT precoding H ^* may be applied at the transmitting end, and DFT precoding F may be applied at the receiving end.

In the beamforming environment, both sides of the channel matrix of <Equation 8> must be multiplied by the diagonal matrix D that rotates the phase so that it becomes the same as the actual channel matrix expressed in <Equation 7-0>, as shown in FIGS. 5A to 5C Phase shifters may be required. In this case, MRC/MRT precoding and DFT/IDFT precoding at the receiving end/transmitting end may be considered as precoding of one block, and this may be considered as MRC/MRT for an effective channel. In other words, the precoding for the low-complexity design described through <Equation 15> to <Equation 18> does not need to be performed only in the digital stage, and may be performed in the analog stage according to an embodiment. For effective channel design according to F, H, H ^* , F ^* and D, D ^* described above, at least some components may be applied at the analog stage. In some embodiments, the precoding for low complexity may be implemented in the form of hybrid beamforming (or hybrid precoding) in which digital beamforming and analog beamforming are combined. In this case, the number of necessary RF chains may be smaller than the number of antennas.

According to the above embodiment, D corresponding to the beamforming matrix before and after H may be defined. An effective channel matrix for forming a diagonal matrix as shown in <Equation 15> to <Equation 18> is F ^* D ^* H ^* HDF, FD ^* H ^* HDF ^* , F ^* D ^* HH ^* DF, or FD ^* It may consist of HH ^* DF ^*.

개의 특이값들에 대한 정보(예: largest right singular vector들)만을 송신단에게 피드백할 수도 있다. 또 다른 일부 실시 예들에서, 수신단은

개의 특이값들을 결정하기 위한 다른 정보들을 송신단에게 피드백할 수 있다. 일 실시 예에 따라, 3GPP의 LTE 혹은 NR 시스템의 CSI(channel state information)에 포함되는 파라미터들(예: CRI(CSI-RS resource indicator), RI(rank indicator), CQI(channel quality indicator), PMI(precoding matrix indicator), LI(layer indicator), RSRP, SINR 등)이 상술된 랭크 및 특이값 중 적어도 하나를 결정하기 위해 이용될 수 있다.In order to achieve high channel capacity, precoding (eg, SVD (Singular Value Decomposition)) is required. In order to select an appropriate precoder, the receiving end receives a signal transmitted from the transmitting end (e.g., as a reference signal, SS/PBCH block, CSI -RS, CRS, etc.) may generate channel information and feed back channel information to the transmitter In this case, in some embodiments, the receiver may feed back all channel information H to the transmitter. Alternatively, in some other embodiments In examples, the receiving end

Only information on singular values (eg, largest right singular vectors) may be fed back to the transmitter. In some other embodiments, the receiving end

Other information for determining singular values of n may be fed back to the transmitter. According to an embodiment, parameters included in CSI (channel state information) of LTE or NR system of 3GPP (eg, CRI (CSI-RS resource indicator), RI (rank indicator), CQI (channel quality indicator), PMI) (precoding matrix indicator, LI (layer indicator), RSRP, SINR, etc.) may be used to determine at least one of the above-described rank and singular value.

The receiving end can more accurately grasp the channel environment by estimating the channel based on the signal transmitted from the transmitting end. The transmitter may more accurately identify the channel between the receivers through signaling. By accurately identifying the channel at the transmitting end, the receiving end, or both the transmitting end and the receiving end, it is possible to reconfigure the above-described antenna array and design a low-complexity channel. Hereinafter, examples of signaling and precoding of a transmitter and a receiver for effective channel design in a feedback environment (eg, closed loop (CL)-MIMO) will be described with reference to FIGS. 9 to 14B .

9 illustrates an operation flow of a transmitter for precoding-based transmission according to various embodiments of the present disclosure. Although it is described as an operation of the transmitting end in FIG. 9, it goes without saying that the corresponding operation is also applicable to the receiving end.

Referring to FIG. 9 , in step 901 , the transmitter may receive feedback information including singular value information. Here, the singular value information means information related to singular value vectors (or matrices) obtained based on the channel estimation result at the receiving end. For example, the singular value information may refer to information informing the transmitter to configure an effective channel according to the channel matrix H in a diagonal matrix at the receiver. In some embodiments, the receiving end may feed back information on the desired precoding at the transmitting end according to MRC precoding, IDFT precoding, or receive beamforming matrix to be applied at the receiving end. As an example, the feedback information may include PMI or CRI of CSI.

According to various embodiments, the feedback information may further include rank information. The rank information may mean the number of ranks preferred by the receiving end. As an example, the feedback information may include an RI of CSI. In this case, according to an embodiment, the effective channel design (eg, satisfying the conditions of Equation 6 and Equation 10) of the present disclosure may be applied to a method for calculating a rank at the receiving end.

According to various embodiments, the feedback information may include information on a preferred channel in addition to singular value information. According to an embodiment, the receiving end may feed back information about a modulation scheme or a coding rate desired by the receiving end. Such information may indirectly indicate communication quality. As an example, the rank may be indicated in the form of RI of CSI. As an example, the feedback information may include a CQI of CSI. The transmitting end obtains the SNR from the CQI, and may derive an appropriate rank and singular values to achieve the upper bound of Equation (6).

In step 903, the transmitting end may perform precoding. Through effective channel design together with precoding applied to the receiving end, the transmitting end may select a precoder for constructing the diagonal matrix exemplified in Equations 15 to 18. In some embodiments, the transmitter may derive a precoding matrix obtained through singular value decomposition of a channel. The transmitter may derive a precoding matrix based on the feedback information received in step 901 . In this case, the transmitter may apply the precoding matrix according to the feedback information as it is. In this case, according to an embodiment, the effective channel design (eg, <Equation 15> to <Equation 18>) of the present disclosure may also be applied to a method of calculating the recommended precoder at the receiving end.

In step 905, the transmitting end may transmit a signal. The transmitter may reconfigure the antenna array based on given channel information (eg, channel quality (SNR)). In the LOS MIMO channel environment, for effective channel design (eg, satisfying the conditions of Equation 6 and Equation 10) to achieve the optimal channel capacity, the transmitting end obtains the values of the channel design information from the feedback information. can decide Values of such channel design information may depend on channel quality (eg, SNR). According to an embodiment, the transmitting end may acquire a range of channel quality desired by the receiving end based on the feedback information. The transmitting end may determine the number of singular values (ie, the number of transmission ranks) and the singular value based on the acquired channel quality range. The antenna array can be reconfigured in a variety of ways. In some embodiments, the transmitter may obtain rotation information based on the number of singular values and rotate the antenna array to correspond thereto. In some other embodiments, the transmitter may obtain angle information based on the number of singular values and select a sub-array of the antenna array to correspond thereto.

10A illustrates an example of a functional configuration of a transmitter for precoding-based transmission according to various embodiments of the present disclosure. 10B illustrates an example of a functional configuration of a receiving end for precoding-based transmission according to various embodiments of the present disclosure.

10A and 10B , the transmitter 1000 may include a plurality of antennas. The receiving end 1050 may include a plurality of antennas. The receiving end 1050 may perform channel estimation. The receiving end may acquire information on H through channel estimation. Let the channel matrix be H. In this case, in the SVD technique, H may be expressed in the form ^{of UΣV *.} Here, U may be referred to as left singular vectors (or left singular matrix), and V may be referred to as right singular vectors (or right singular matrix). U and V may be calculated in consideration of a rank in which a condition for the maximum channel capacity (eg, <Equation 6> and <Equation 10>) is satisfied. The receiving end 1050 feeds back information related to V to the transmitting end 1000 , and the receiving end 1050 as an equalizer may apply ^{U * to the SVD precoder.}

In addition to an appropriate precoding design, information related to a preferred channel (eg, channel quality, channel index) and rank information may be additionally transmitted to the transmitter 1000 for reconfiguration of the antenna array. The transmitter 1000 may determine the number of transport streams based on rank information. The transmitter 1000 may determine the size of the precoding matrix according to the number of transport streams. The transmitter 1000 may determine the number of singular values based on the channel quality and derive each singular value. The transmitter 1000 may activate antenna elements or RF chains according to the derived number. The transmitter 1000 may select a precoder based on the feedback information. When the transmitting end 1000 applies the precoding related to V, ^{along with U *} of the receiving end 1050, a diagonal matrix of all effective channels can be designed.

The transmitter 1000 may select a sub-array of the antenna array to which the selected transmission rank and precoder are to be applied. The transmitter 1000 may transmit data streams through the selected sub-array. The receiving end 1050 may select a sub-array for receiving data streams. The receiver 1050 may select a sub-array to which the selected equalizer or the like is applied based on the above-described channel estimation result. The receiving end 1050 may obtain data to be transmitted from the transmitting end 1000 by processing and demodulating the received streams.

10A and 10B show that the sub-array is selected, embodiments of the present disclosure are not limited thereto. Increasing the channel capacity by rotating the antenna array may also be understood as an embodiment of the present disclosure.

11 illustrates an operation flow of a transmitter for phase information-based transmission according to various embodiments of the present disclosure. Although it is described as an operation of the transmitting end in FIG. 11, it goes without saying that the corresponding operation is also applicable to the receiving end.

Referring to FIG. 11 , in step 1101 , the transmitter may receive feedback information including phase information. Here, the phase information may mean information related to phase transformation values of elements of the antenna array. The receiving end may transfer feedback information for recommending phase shift values suitable for the transmitting end to the transmitting end in order to increase the channel capacity with the transmitting end. In this case, according to an embodiment, the effective channel design (eg, <Equation 15> to <Equation 18>) of the present disclosure may also be applied to a method of calculating the recommended phase information at the receiving end.

In some embodiments, the phase information may include an indicator. According to an embodiment, the transmitter may transmit signals through a plurality of beams, and the receiver may generate feedback information in the form of indicating a preferred beam among the plurality of beams. The receiving end may transmit feedback information including an indicator indicating a preferred beam to the transmitting end. As an example, this indicator may include a CSI-RS resource indicator (CRI) or an SS/PBCH block resource indicator (SSBRI). In some other examples, the phase information may include a beamforming weight to be applied at the transmitting end. The phase information may indicate a phase transformation matrix (or phase transformation values) indicating a specific beamforming weight among a plurality of beamforming weight matrices.

According to various embodiments, the feedback information may include information on a preferred channel in addition to phase information. According to an embodiment, the receiving end may feed back information about a modulation scheme or a coding rate desired by the receiving end. Such information may indirectly indicate communication quality. As an example, the feedback information may include a CQI of CSI. The transmitting end obtains the SNR from the CQI, and may derive an appropriate rank and singular values to achieve the upper bound of Equation (6).

In step 1103, the transmitting end may perform a phase transformation. The transmitting end may select beamforming weights for constructing the diagonal matrix exemplified in Equations 15 to 18 through effective channel design together with receive beamforming applied to the receiving end. The transmitter may perform phase transformation based on the feedback information received in step 1101 .

In step 1105, the transmitting end may transmit a signal. In the LOS MIMO channel environment, for effective channel design (eg, satisfying the conditions of Equation 6 and Equation 10) to achieve the optimal channel capacity, the transmitting end obtains the values of the channel design information from the feedback information. can decide The description of step 905 of FIG. 9 may be applied in the same or similar manner.

12A illustrates an example of a functional configuration of a transmitter for phase information-based transmission according to various embodiments of the present disclosure. 12B illustrates an example of a functional configuration of a receiving end for phase information-based transmission according to various embodiments of the present disclosure.

12A and 12B , the transmitter 1200 may include a plurality of antennas. The receiving end 1250 may include a plurality of antennas. The receiving end 1250 may perform channel estimation. The receiving end 1250 may obtain information on H through channel estimation.

The receiving end 1250 may calculate a rank suitable for a channel estimated through channel information. The receiving end 1250 may determine a rank for achieving the maximum capacity based on the channel quality obtained from the channel. The receiving end 1250 may determine an optimal rank through the effective channel design (eg, satisfying the conditions of Equations 6 and 10) of the present disclosure. The receiving end 1250 may transmit the information on the channel quality to the transmitting end 1200 by including it in the feedback information.

The receiving end 1250 may obtain first phase information to be applied by the receiving end 1250 and second phase information to be applied by the transmitting end 1250 through the channel information. The receiving end 1250 may feed back the second phase information to the transmitting end 1200 . The first phase information may correspond to a reception beamforming weight, and the second phase information may correspond to a transmission beamforming weight. In addition to appropriate phase information, information related to a preferred channel (eg, channel quality, channel index) may be additionally transmitted for reconfiguration of the antenna array.

The transmitter 1200 may determine the number of singular values based on the channel quality and derive each singular value. The transmitter 1200 may activate antenna elements or RF chains according to the derived number. The transmitter 1200 may determine phase transformation values to be applied (ie, beamforming weight) based on the phase information. According to an embodiment, since the transmitter 1250 applies the phase information according to the feedback result of the receiver 1250 , a diagonal matrix of an effective channel may be designed according to the feedback from the receiver 1250 . The transmitter 1200 may select a sub-array of the antenna array to which the selected transmission rank and phase information are to be applied. The transmitter 1200 may transmit data streams through the selected sub-array.

The receiving end 1250 may select a sub-array for receiving data streams. The receiver 1250 may select a sub-array to which the selected equalizer or the like is applied based on the above-described channel estimation result. The receiving end 1250 may process the received streams through MRC precoding. Specifically, the receiving end 1250 may obtain the processed signals through MRC precoding and phase transformation. The receiving end 1250 may acquire data to be transmitted from the transmitting end 1200 by demodulating the processed signals. Meanwhile, the receiving end 1250 may use the rank obtained from the channel estimation result for sub-array selection or MRC precoding. The number of antenna elements in the sub-array may depend on the obtained transmission rank. Also, the matrix size of MRC precoding may depend on the obtained transmission rank.

12A and 12B show that the sub-array is selected, embodiments of the present disclosure are not limited thereto. Increasing the channel capacity by rotating the antenna array may also be understood as an embodiment of the present disclosure.

13 illustrates an operation flow of a transmitter for rank information and phase information-based transmission according to various embodiments of the present disclosure. Although it is described as an operation of the transmitting end in FIG. 13, it goes without saying that the corresponding operation is also applicable to the receiving end.

Referring to FIG. 13 , in step 1301 , the transmitter may receive feedback information including phase information and rank information.

The transmitting end may receive feedback information including phase information. Here, the phase information may mean information related to phase transformation values of elements of the antenna array. The description of the phase information may be applied in the same or similar manner as the description of the phase information of FIG. 11 . The transmitter may receive feedback information including rank information. Here, the rank information may mean the number of ranks preferred by the receiving end. As an example, the feedback information may include an RI of CSI. The description of the rank information may be applied in the same or similar manner to the description of the rank information of FIG. 9 .

In step 1303, the transmitting end may identify the number of transport streams. The transmitting end may determine the number of singular values (ie, the number of transmission ranks) and the singular value based on the acquired channel quality range. The transmitting end may activate as many antennas as the number corresponding to the rank among the number of transmit antennas.

In step 1305, the transmitting end may perform a phase transformation. The transmitting end may select beamforming weights for constructing the diagonal matrix exemplified in Equations 15 to 18 through effective channel design together with receive beamforming applied to the receiving end. The transmitter may perform phase transformation based on the feedback information received in step 1301 .

In step 1305, the transmitting end may transmit a signal. In the LOS MIMO channel environment, for effective channel design (eg, satisfying the conditions of Equation 6 and Equation 10) to achieve the optimal channel capacity, the transmitting end obtains the values of the channel design information from the feedback information. can decide The description of step 905 of FIG. 9 may be applied in the same or similar manner.

The transmitting end may determine the number of singular values (ie, the number of transmission ranks) and the singular value based on the acquired channel quality range. The antenna array can be reconfigured in a variety of ways. In some embodiments, the transmitter may obtain rotation information based on the number of singular values and rotate the antenna array to correspond thereto. In some other embodiments, the transmitter may obtain angle information based on the number of singular values and select a sub-array of the antenna array to correspond thereto.

14A illustrates an example of a functional configuration of a transmitter for rank information and phase information-based transmission according to various embodiments of the present disclosure. 14B illustrates an example of a functional configuration of a receiving end for rank information and phase information-based transmission according to various embodiments of the present disclosure.

14A and 14B , the transmitter 1400 may include a plurality of antennas. The receiving end 1450 may include a plurality of antennas. The receiving end 1450 may perform channel estimation. The receiving end 1450 may obtain information on H through channel estimation. The receiving end 1250 may calculate a rank suitable for a channel estimated through channel information. The receiving end 1250 may transmit information indicating the calculated rank by including it in the feedback information. The receiving end 1450 may transmit information on the channel quality obtained through channel estimation to the transmitting end 1400 by including it in the feedback information.

The receiving end 1450 may obtain first phase information to be applied by the receiving end 1450 and second phase information to be applied by the transmitting end 1450 through the channel information. The receiving end 1450 may feed back the second phase information to the transmitting end 1400 . The first phase information may correspond to a reception beamforming weight, and the second phase information may correspond to a transmission beamforming weight. In addition to appropriate phase information, information related to a preferred channel (eg, channel quality, channel index) may be additionally transmitted for reconfiguration of the antenna array.

The transmitter 1400 may determine the number of singular values based on the channel quality and derive each singular value. The transmitter 1400 may activate antenna elements or RF chains according to the derived number. The transmitter 1400 may determine phase transformation values to be applied (ie, beamforming weight) based on the phase information. According to an embodiment, since the transmitting end 1450 applies the phase information according to the feedback result of the receiving end 1450 , a diagonal matrix of an effective channel may be designed according to the feedback of the receiving end 1450 . The transmitter 1400 may select a sub-array of the antenna array to which the selected transmission rank and phase information are to be applied. The transmitter 1400 may transmit data streams through the selected sub-array.

The receiving end 1450 may select a sub-array for receiving data streams. The receiving terminal 1450 may select a sub-array to which the selected equalizer or the like is applied based on the above-described channel estimation result. The receiving end 1450 may process the received streams through MRC precoding. Specifically, the receiving end 1450 may obtain the processed signals through MRC precoding and phase transformation. The receiving end 1450 may acquire data to be transmitted from the transmitting end 1400 by demodulating the processed signals.

14A and 14B show that the sub-array is selected, embodiments of the present disclosure are not limited thereto. Increasing the channel capacity by rotating the antenna array may also be understood as an embodiment of the present disclosure.

In a wireless communication system according to various embodiments, the method of operation of the transmitting end may identify an array for achieving the maximum transmission rate using information about channel quality (eg, received SNR) among a plurality of subarrays. have. In this case, the transmitter may identify the sub-array based on <Equation 10> to <Equation 13>.

In a wireless communication system according to various embodiments, the method of operation of the receiving end may use information about channel quality (eg, received SNR) among a plurality of subarrays to identify an array for achieving a maximum transmission rate. have. In this case, the receiving end may identify the sub-array based on <Equation 10> to <Equation 13>.

In a wireless communication system according to various embodiments of the present disclosure, an operation method of a transmitter may acquire rotation information for achieving a maximum transmission rate by using information on channel quality (eg, received SNR). The transmitting end may rotate the antenna array according to the angle determined based on the rotation information and <Equation 10> to <Equation 13>.

In a wireless communication system according to various embodiments of the present disclosure, the method of operation of the receiving end may obtain rotation information for achieving the maximum transmission rate by using information on channel quality (eg, received SNR). The receiving end may rotate the antenna array according to the angle determined based on the rotation information and <Equation 10> to <Equation 13>.

A method of operating a transmitter in a wireless communication system according to various embodiments may include a precoding process in which DFT precoding F and diagonal precoding D are combined. At this time, in some embodiments, DFT precoding F are IDFT precoding F ^* can be optionally substituted with, IDFT precoding of the receiver F ^* can be substituted with DFT precoding F.

A method of operating a receiving end in a wireless communication system according to various embodiments ^{may include performing precoding using IDFT precoding F *} , diagonal precoding D and channel matrix information H. In this case, in some embodiments, IDFT precoding F ^* may be substituted with DFT precoding F, and DFT precoding F of the transmitting end may be substituted with IDFT precoding F ^* .

A method of operating a transmitter in a wireless communication system according to various embodiments may include precoding using DFT precoding F, diagonal precoding D, and channel matrix information H. At this time, in some embodiments, DFT precoding F are IDFT precoding F ^* can be optionally substituted with, IDFT precoding of the receiver F ^* can be substituted with DFT precoding F.

A method of operating a receiving end in a wireless communication system according to various embodiments of the present disclosure may include precoding by combining ^{IDFT precoding F * and diagonal precoding D.} In this case, in some embodiments, IDFT precoding F ^* may be substituted with DFT precoding F, and DFT precoding F of the transmitting end may be substituted with IDFT precoding F ^* .

The transmitting end and the receiving end performing the above-described operations may be communication nodes performing wireless communication in the LOS MIMO environment. The transmitting end or the receiving end may be the base station 110 or the terminal 120 . Hereinafter, functional configurations of the base station 110 and the terminal 120 will be described with reference to FIGS. 15 and 16 . Meanwhile, the transmitting end or the receiving end may be another network entity that supports wireless communication other than the base station 110 or the terminal 120 .

15 illustrates a configuration of a base station in a wireless communication system according to various embodiments of the present disclosure. Terms such as '... unit' and '... group' used below mean a unit that processes at least one function or operation, which may be implemented as hardware or software, or a combination of hardware and software. have.

Referring to FIG. 15 , the base station 110 includes a wireless communication unit 1501 , a backhaul communication unit 1503 , a storage unit 1505 , and a control unit 1507 .

The wireless communication unit 1501 performs functions for transmitting and receiving signals through a wireless channel. For example, the wireless communication unit 1501 performs a conversion function between a baseband signal and a bit stream according to a physical layer standard of a system. For example, when transmitting data, the wireless communication unit 1501 generates complex symbols by encoding and modulating the transmitted bit stream. In addition, when receiving data, the wireless communication unit 1501 restores the received bit stream by demodulating and decoding the baseband signal. In addition, the wireless communication unit 1501 up-converts the baseband signal into a radio frequency (RF) band signal, transmits the signal through the antenna, and downconverts the RF band signal received through the antenna into a baseband signal.

To this end, the wireless communication unit 1501 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a digital to analog converter (DAC), an analog to digital converter (ADC), and the like. Also, the wireless communication unit 1501 may include a plurality of transmission/reception paths. Furthermore, the wireless communication unit 1501 may include at least one antenna array composed of a plurality of antenna elements. In terms of hardware, the wireless communication unit 1501 may be composed of a digital unit and an analog unit, and the analog unit includes a plurality of sub-units according to operating power, operating frequency, etc. can be composed of

The wireless communication unit 1501 may transmit and receive signals. To this end, the wireless communication unit 1501 may include at least one transceiver. For example, the wireless communication unit 1501 may transmit a synchronization signal, a reference signal, system information, a message, control information, or data. Also, the wireless communication unit 1501 may perform beamforming.

The wireless communication unit 1501 transmits and receives signals as described above. Accordingly, all or part of the wireless communication unit 1501 may be referred to as a 'transmitter', 'receiver', or 'transceiver'. In addition, in the following description, transmission and reception performed through a wireless channel are used in the meaning of including processing as described above by the wireless communication unit 1501 .

The backhaul communication unit 1503 provides an interface for communicating with other nodes in the network. That is, the backhaul communication unit 1503 converts a bit string transmitted from the base station 110 to another node, for example, another access node, another base station, an upper node, a core network, etc. into a physical signal, and is received from another node. Converts a physical signal into a bit string.

The storage unit 1505 stores data such as a basic program, an application program, and setting information for the operation of the base station 110 . The storage unit 1505 may include a memory. The storage unit 1505 may be configured as a volatile memory, a non-volatile memory, or a combination of a volatile memory and a non-volatile memory. In addition, the storage unit 1505 provides the stored data according to the request of the control unit 1507 .

The controller 1507 controls overall operations of the base station 110 . For example, the control unit 1507 transmits and receives signals through the wireless communication unit 1501 or through the backhaul communication unit 1503 . In addition, the control unit 1507 writes and reads data in the storage unit 1505 . In addition, the control unit 1507 may perform functions of a protocol stack required by the communication standard. To this end, the controller 1507 may include at least one processor. The operations according to the control unit 107 are the instruction set or code stored in the storage unit 1505, at least temporarily resident in the control unit 1507 (resided) instruction / code or a storage space storing the instruction / code, or, It may be a part of circuitry constituting the control unit 1507 . According to various embodiments, the controller 1507 may control the base station 110 to perform operations according to the above-described various embodiments.

The configuration of the base station 110 shown in FIG. 15 is only an example of the base station, and examples of the base station performing various embodiments of the present disclosure from the configuration shown in FIG. 15 are not limited thereto. That is, according to various embodiments, some configurations may be added, deleted, or changed.

In FIG. 15 , the base station is described as one entity, but the present disclosure is not limited thereto. The base station according to various embodiments of the present disclosure may be implemented to form an access network having a distributed deployment as well as an integrated deployment. According to an embodiment, the base station is divided into a central unit (CU) and a digital unit (DU), and the CU is an upper layer function (eg, packet data convergence protocol (PDCP)). The DU is a lower layer function. (lower layers) (eg, MAC (medium access control), PHY (physical)) may be implemented to perform. The DU of the base station may form beam coverage on the radio channel.

16 illustrates a functional configuration of a terminal in a wireless communication system according to various embodiments of the present disclosure. Terms such as '... unit' and '... group' used below mean a unit that processes at least one function or operation, which may be implemented as hardware or software, or a combination of hardware and software. have.

Referring to FIG. 16 , the terminal 120 includes a communication unit 1601 , a storage unit 1603 , and a control unit 1605 .

The communication unit 1601 performs functions for transmitting and receiving signals through a wireless channel. For example, the communication unit 1601 performs a function of converting between a baseband signal and a bit stream according to a physical layer standard of a system. For example, when transmitting data, the communication unit 1601 generates complex symbols by encoding and modulating the transmitted bit stream. In addition, when receiving data, the communication unit 1601 restores the received bit stream by demodulating and decoding the baseband signal. Also, the communication unit 1601 up-converts the baseband signal into an RF band signal, transmits the signal through the antenna, and downconverts the RF band signal received through the antenna into a baseband signal. For example, the communication unit 1601 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like. According to various embodiments, the communication unit 1601 performs a signature for distinguishing a specific UE from a corresponding resource even if orthogonality between resources is not satisfied (eg, signals of multiple UEs overlap in the same time-frequency resource). (eg, codeword, sequence, pattern, etc.) can be applied to transmit a signal.

Also, the communication unit 1601 may include a plurality of transmission/reception paths. Furthermore, the communication unit 1601 may include an antenna unit. The communication unit 1601 may include at least one antenna array composed of a plurality of antenna elements. In terms of hardware, the communication unit 1601 may include a digital circuit and an analog circuit (eg, a radio frequency integrated circuit (RFIC)). Here, the digital circuit and the analog circuit may be implemented as one package. Also, the communication unit 1601 may include a plurality of RF chains. The communication unit 1601 may perform beamforming. The communication unit 1601 may apply a beamforming weight to a signal to be transmitted/received in order to give a direction according to the setting of the control unit 1605 to the signal. According to an embodiment, the communication unit 1601 may include a radio frequency (RF) block (or RF unit). The RF block may include first RF circuitry associated with the antenna and second RF circuitry associated with baseband processing. The first RF circuit may be referred to as an RF-A (antenna). The second RF circuit may be referred to as RF-B (baseband).

Also, the communication unit 1601 may transmit/receive signals. To this end, the communication unit 1601 may include at least one transceiver. The communication unit 1601 may receive a downlink signal. The downlink signal includes a synchronization signal (SS), a reference signal (RS) (eg, a cell-specific reference signal (CRS), a demodulation (DM)-RS, and a channel state information-reference signal (CSI-RS)). )), system information (eg, MIB, SIB, RMSI (remaining system information), OSI (other system information)), a configuration message, control information, or downlink data. . Also, the communication unit 1601 may transmit an uplink signal. The uplink signal includes a random access-related signal (eg, a random access preamble (RAP) (or Msg1 (message 1)), Msg3 (message 3)), a reference signal (eg, a sounding reference signal (SRS), DM). -RS), or a power headroom report (PHR), and the like.

Also, the communication unit 1601 may include different communication modules to process signals of different frequency bands. Furthermore, the communication unit 1601 may include a plurality of communication modules to support a plurality of different wireless access technologies. For example, different wireless access technologies are Bluetooth low energy (BLE), Wi-Fi (Wireless Fidelity), WiGig (WiFi Gigabyte), cellular networks (eg, LTE (Long Term Evolution), NR (new radio), etc. In addition, different frequency bands are a super high frequency (SHF) (eg, 2.5GHz, 5Ghz) band, a millimeter wave (eg, 38GHz, 60GHz, etc.) band. Also, the communication unit 1601 performs the same method of wireless access on different frequency bands (eg, an unlicensed band for licensed assisted access (LAA), citizens broadband radio service (CBRS) (eg, 3.5 GHz)). You can also use technology.

The communication unit 1601 transmits and receives signals as described above. Accordingly, all or part of the communication unit 1601 may be referred to as a 'transmitter', 'receiver', or 'transceiver'. In addition, in the following description, transmission and reception performed through a wireless channel are used to mean that the above-described processing is performed by the communication unit 1601 .

The storage unit 1603 stores data such as a basic program, an application program, and setting information for the operation of the terminal 120 . The storage unit 1603 may be configured as a volatile memory, a non-volatile memory, or a combination of a volatile memory and a non-volatile memory. In addition, the storage unit 1603 provides the stored data according to the request of the control unit 1605 .

The controller 1605 controls overall operations of the terminal 120 . For example, the control unit 1605 transmits and receives signals through the communication unit 1601 . In addition, the control unit 1605 writes and reads data in the storage unit 1603 . In addition, the control unit 1605 may perform the functions of the protocol stack required by the communication standard. To this end, the controller 1605 may include at least one processor. The controller 1605 may include at least one processor or microprocessor, or may be a part of the processor. Also, a part of the communication unit 1601 and the control unit 1605 may be referred to as CPs. The control unit 1605 may include various modules for performing communication. According to various embodiments, the controller 1605 may control the terminal to perform operations according to various embodiments to be described later.

Methods according to the embodiments described in the claims or specifications of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. One or more programs stored in the computer-readable storage medium are configured to be executable by one or more processors in an electronic device (device). One or more programs include instructions for causing an electronic device to execute methods according to embodiments described in a claim or specification of the present disclosure.

Such programs (software modules, software) include random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable ROM (electrically erasable programmable read only memory, EEPROM), magnetic disc storage device, compact disc-ROM (CD-ROM), digital versatile discs (DVDs), or other It may be stored in an optical storage device or a magnetic cassette. Alternatively, it may be stored in a memory composed of a combination of some or all thereof. In addition, each configuration memory may be included in plurality.

In addition, the program is transmitted through a communication network consisting of a communication network such as the Internet, an intranet, a local area network (LAN), a wide area network (WAN), or a storage area network (SAN), or a combination thereof. It may be stored on an attachable storage device that can be accessed. Such a storage device may be connected to a device implementing an embodiment of the present disclosure through an external port. In addition, a separate storage device on the communication network may be connected to the device implementing the embodiment of the present disclosure.

In the specific embodiments of the present disclosure described above, components included in the disclosure are expressed in the singular or plural according to the specific embodiments presented. However, the singular or plural expression is appropriately selected for the context presented for convenience of description, and the present disclosure is not limited to the singular or plural element, and even if the element is expressed in plural, it is composed of the singular or singular. Even an expressed component may be composed of a plurality of components.

Meanwhile, although specific embodiments have been described in the detailed description of the present disclosure, various modifications are possible without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments and should be defined by the claims described below as well as the claims and equivalents.

Claims (32)

A method performed by a transmitting end in a wireless communication system, the method comprising: The process of acquiring channel design information; The process of setting a transmit antenna array based on the channel design information; Transmitting a signal to a receiving end through the transmit antenna array, The channel design information is based on at least one of an interval between antenna elements of the transmission antenna array, a spacing between antenna elements of a reception antenna array of the receiving end, rotation information of the transmission antenna array, and rotation information of the reception antenna array A method including a value of a parameter determined by The method according to claim 1, wherein the obtaining of the channel design information comprises: obtaining a channel quality between the transmitting end and the receiving end; identifying the number of singular values corresponding to the channel quality; and determining a value of the parameter based on the number of singular values. 3. The method according to claim 2, The transmit antenna array is a uniform linear array (ULA) having equal spacing between antenna elements, The receiving antenna array is a ULA having equal spacing between antenna elements, The parameter is determined based on at least one of a rotation degree of the transmitting antenna array with respect to a communication direction of the transmitting end or a rotation degree of the receiving antenna array with respect to a communication direction of the receiving end, The number of singular values is determined based on an upper bound condition for the capacity of the channel. 4. The method according to claim 3, The capacity of the channel is defined by the following equation,

Here, N _min is the minimum value of the number of antenna elements of the transmit antenna array and the number of antenna elements of the receive antenna array, p _n is the transmit power used to transmit data symbols in each stream n, σ _n (H ) means the nth singular value of the channel H, The upper bound condition corresponds to the following equation,

SNR is the channel quality, ρ is the number of singular values, N _t is the number of antenna elements in the transmit antenna array, and N _r is the number of antenna elements in the receive antenna array. The method according to claim 4, wherein the m-th transmit antenna is (md _t cosθ _t , 0, -md _t sinθ _t ) in a Cartesian xyz coordinate space, and the n-th receive antenna is (nd _r cosθ _r , nd _r sinθ _r) sinφ _r , D+ nd _r sinθ _r cosφ _r ) and the parameter corresponds to the following equation,

Here, d _t represents an interval between elements of the transmit antenna array, d _r represents an interval between elements of the receive antenna array, and λ represents a carrier wavelength. D is a communication distance between the transmitting end and the receiving end, and N _max represents a maximum value of the number of antenna elements of the transmit antenna array and the number of antenna elements of the receive antenna array. 6. The method of claim 5, The number of singular values is determined as an integer between _{1 and N min} according to a channel range to which the channel quality corresponds among a plurality of channel quality ranges _{, and N min} is the number of antenna elements of the transmit antenna array and the receive antenna A method that is the minimum of the number of antenna elements in the array. The method according to claim 1, For receiving beamforming at the receiving end, based ^{on the effect channel matrix (D *} H ^{* HD) generated using the conjugate transpose (H *} ) and the phase shift matrix (D) of the channel matrix, A method in which an eigenvector is used or some column vector of a discrete fourier transform (DFT) matrix or an inverse DFT (IDFT) matrix is used. The method according to claim 1, generating an ^{effect channel matrix (D *} HH ^* D) using the conjugate transpose (H ^* ) and phase shift matrix (D) of the channel matrix; Based on the effect channel matrix, using an eigenvector of the effect channel matrix, or using a discrete fourier transform (DFT) matrix or a partial column vector of an IDFT (inverse DFT) matrix, the method further comprising the step of performing transmit beamforming. Way. A method performed by a receiving end in a wireless communication system, the method comprising: The process of acquiring channel design information; The process of setting a receiving antenna array based on the channel design information; Receiving a signal from a transmitting end through the receiving antenna array, The channel design information is based on at least one of a distance between antenna elements of the transmit antenna array of the transmitting end, a distance between antenna elements of the receive antenna array, rotation information of the transmit antenna array, and rotation information of the receive antenna array A method including a value of a parameter determined by The method of claim 9, wherein the obtaining of the channel design information comprises: obtaining a channel quality between the transmitting end and the receiving end; identifying the number of singular values corresponding to the channel quality; and determining a value of the parameter based on the number of singular values. 11. The method of claim 10, The transmit antenna array is a uniform linear array (ULA) having equal spacing between antenna elements, The receiving antenna array is a ULA having equal spacing between antenna elements, The parameter is determined based on at least one of a rotation degree of the transmitting antenna array with respect to a communication direction of the transmitting end or a rotation degree of the receiving antenna array with respect to a communication direction of the receiving end, The number of singular values is determined based on an upper bound condition for the capacity of the channel. 12. The method of claim 11, The capacity of the channel is defined by the following equation,

Here, N _min is the minimum value of the number of antenna elements of the transmit antenna array and the number of antenna elements of the receive antenna array, p _n is the transmit power used to transmit data symbols in each stream n, σ _n (H ) means the nth singular value of the channel H, The upper bound condition corresponds to the following equation,

SNR is the channel quality, ρ is the number of singular values, N _t is the number of antenna elements in the transmit antenna array, and N _r is the number of antenna elements in the receive antenna array. The method according to claim 12, wherein the m-th transmit antenna is in (md _t cosθ _t , 0, -md _t sinθ _t ) in a Cartesian xyz coordinate space, and the n-th receive antenna is (nd _r cosθ _r , nd _r sinθ _r) sinφ _r , D+ nd _r sinθ _r cosφ _r ) and the parameter corresponds to the following equation,

Here, d _t represents an interval between elements of the transmit antenna array, d _r represents an interval between elements of the receive antenna array, and λ represents a carrier wavelength. D is a communication distance between the transmitting end and the receiving end, and N _max represents a maximum value of the number of antenna elements of the transmit antenna array and the number of antenna elements of the receive antenna array. 14. The method of claim 13, The number of singular values is determined as an integer between _{1 and N min} according to a channel range to which the channel quality corresponds among a plurality of channel quality ranges _{, and N min} is the number of antenna elements of the transmit antenna array and the receive antenna A method that is the minimum of the number of antenna elements in the array. 10. The method of claim 9, The process of generating an ^{effect channel matrix (D *} H ^* HD) using the conjugate transpose (H ^* ) and phase shift matrix (D) of the channel matrix; Based on the effect channel matrix, using an eigenvector of the effect channel matrix, or using a discrete fourier transform (DFT) matrix or a partial column vector of an IDFT (inverse DFT) matrix, the method further comprising: performing receive beamforming Way. 10. The method of claim 9, For transmit beamforming at the transmitting end, based ^{on the effect channel matrix (D *} HH ^* D) ^{generated using the conjugate transpose (H *} ) of the channel matrix and the phase shift matrix (D), A method in which an eigenvector is used or some column vector of a discrete fourier transform (DFT) matrix or an inverse DFT (IDFT) matrix is used. In the apparatus of a transmitting end in a wireless communication system, a transmit antenna array; at least one transceiver; at least one processor; the at least one processor Acquire channel design information, setting the transmit antenna array based on the channel design information, and transmit a signal to a receiving end through the at least one transceiver and the transmit antenna array; The channel design information is based on at least one of an interval between antenna elements of the transmission antenna array, a spacing between antenna elements of a reception antenna array of the receiving end, rotation information of the transmission antenna array, and rotation information of the reception antenna array A device including a value of a parameter determined by The method of claim 17 , wherein to obtain the channel design information, the at least one processor comprises: obtaining a channel quality between the transmitting end and the receiving end, identify the number of singular values corresponding to the channel quality; and determine a value of the parameter based on the number of singular values. 19. The method of claim 18, The transmit antenna array is a uniform linear array (ULA) having equal spacing between antenna elements, The receiving antenna array is a ULA having equal spacing between antenna elements, The parameter is determined based on at least one of a rotation degree of the transmitting antenna array with respect to a communication direction of the transmitting end or a rotation degree of the receiving antenna array with respect to a communication direction of the receiving end, The number of singular values is determined based on an upper bound condition for the capacity of the channel. 20. The method of claim 19, The capacity of the channel is defined by the following equation,

Here, N _min is the minimum value of the number of antenna elements of the transmit antenna array and the number of antenna elements of the receive antenna array, p _n is the transmit power used to transmit data symbols in each stream n, σ _n (H ) means the nth singular value of the channel H, The upper bound condition corresponds to the following equation,

SNR is the channel quality, ρ is the number of singular values, N _t is the number of antenna elements in the transmit antenna array, and N _r is the number of antenna elements in the receive antenna array. The method of claim 20, wherein the m-th transmit antenna is (md _t cosθ _t , 0, -md _t sinθ _t ) in a Cartesian xyz coordinate space, and the n-th receive antenna is (nd _r cosθ _r , nd _r sinθ _r) sinφ _r , D+ nd _r sinθ _r cosφ _r ) and the parameter corresponds to the following equation,

Here, d _t represents an interval between elements of the transmit antenna array, d _r represents an interval between elements of the receive antenna array, and λ represents a carrier wavelength. D is a communication distance between the transmitting end and the receiving end, and N _max is the maximum value of the number of antenna elements of the transmit antenna array and the number of antenna elements of the receive antenna array. 22. The method of claim 21, The number of singular values is determined as an integer between _{1 and N min} according to a channel range to which the channel quality corresponds among a plurality of channel quality ranges _{, and N min} is the number of antenna elements of the transmit antenna array and the receive antenna A device that is the minimum of the number of antenna elements in the array. The method according to claim 17, for reception beamforming at the receiving end, based ^{on the effect channel matrix (D *} H ^* HD) ^{generated using the conjugate transpose (H *} ) of the channel matrix and the phase shift matrix (D), An apparatus in which an eigenvector of the effect channel matrix is used, or a partial column vector of a discrete fourier transform (DFT) matrix or an inverse DFT (IDFT) matrix is used. The method of claim 17 , wherein the at least one processor comprises: ^{Create an effect channel matrix (D *} HH ^* D) using the conjugate transpose (H ^* ) and phase shift matrix (D) of the channel matrix, The apparatus is further configured to perform transmit beamforming by using an eigenvector of the effect channel matrix or using a discrete fourier transform (DFT) matrix or some column vector of an inverse DFT (IDFT) matrix based on the effect channel matrix. In the device of the receiving end in a wireless communication system, a receiving antenna array; at least one transceiver; at least one processor; the at least one processor Acquire channel design information, setting the receiving antenna array based on the channel design information, and receive a signal from a transmitting end via the at least one transceiver and the receiving antenna array; The channel design information is based on at least one of an interval between antenna elements of the transmitting antenna array of the transmitting end, a distance between antenna elements of the receiving antenna array, rotation information of the transmitting antenna array, and rotation information of the receiving antenna array A device including a value of a parameter determined by The method of claim 25 , wherein to obtain the channel design information, the at least one processor comprises: obtaining a channel quality between the transmitting end and the receiving end, identify the number of singular values corresponding to the channel quality; and determine a value of the parameter based on the number of singular values. 27. The method of claim 26, The transmit antenna array is a uniform linear array (ULA) having equal spacing between antenna elements, The receiving antenna array is a ULA having equal spacing between antenna elements, The parameter is determined based on at least one of a rotation degree of the transmitting antenna array with respect to a communication direction of the transmitting end or a rotation degree of the receiving antenna array with respect to a communication direction of the receiving end, The number of singular values is determined based on an upper bound condition for the capacity of the channel. 28. The method of claim 27, The capacity of the channel is defined by the following equation,

Here, N _min is the minimum value of the number of antenna elements of the transmit antenna array and the number of antenna elements of the receive antenna array, and p _n is the transmit power used to transmit data symbols in each stream n, σ _n (H ) means the nth singular value of the channel H, The upper bound condition corresponds to the following equation,

SNR is the channel quality, ρ is the number of singular values, N _t is the number of antenna elements in the transmit antenna array, and N _r is the number of antenna elements in the receive antenna array. The method according to claim 28, wherein the m-th transmit antenna is (md _t cosθ _t , 0, -md _t sinθ _t ) in a Cartesian xyz coordinate space, and the n-th receive antenna is (nd _r cosθ _r , nd _r sinθ _r) sinφ _r , D+ nd _r sinθ _r cosφ _r ) and the parameter corresponds to the following equation,

Here, d _t represents an interval between elements of the transmit antenna array, d _r represents an interval between elements of the receive antenna array, and λ represents a carrier wavelength. D is a communication distance between the transmitting end and the receiving end, and N _max is the maximum value of the number of antenna elements of the transmit antenna array and the number of antenna elements of the receive antenna array. 30. The method of claim 29, The number of singular values is determined as an integer between _{1 and N min} according to a channel range corresponding to the channel quality among a plurality of channel quality ranges _{, and N min} is the number of antenna elements of the transmit antenna array and the receive antenna A device that is the minimum of the number of antenna elements in the array. 26. The method of claim 25, wherein the at least one processor comprises: ^{Create an effect channel matrix (D *} H ^* HD) using the conjugate transpose (H ^* ) and phase shift matrix (D) of the channel matrix, and perform receive beamforming by using an eigenvector of the effect channel matrix or using a discrete fourier transform (DFT) matrix or some column vector of an inverse DFT (IDFT) matrix based on the effect channel matrix. 26. The method of claim 25, For transmit beamforming at the transmitting end, based ^{on the effect channel matrix (D *} HH ^* D) ^{generated using the conjugate transpose (H *} ) of the channel matrix and the phase shift matrix (D), A device in which an eigenvector is used or some column vector of a discrete fourier transform (DFT) matrix or an inverse DFT (IDFT) matrix is used.

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