KR20140076509A - Antenna apparatus and method for switching baem using the antenna apparatus - Google Patents

Abstract

Disclosed are an antenna apparatus and a hand over method using the antenna apparatus. The antenna apparatus includes multiple antenna devices forming multiple beams at a specific service area, and various antenna devices are arranged in multiple rows. The uppermost row of the multiple rows includes a smaller number of antenna devices than the lowermost row has, and a separation angle between beams formed by each antenna device included in the lowermost row is wider than a separation angle between the beams formed by each antenna device included in the uppermost row. Therefore, inter-beam interference can be minimized, and service disconnection can be prevented during the high speed movement of a terminal.

Description

TECHNICAL FIELD [0001] The present invention relates to a handover method using an antenna apparatus and an antenna apparatus,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication technology, and more particularly, to an antenna device and a handover method using an antenna device that can maintain a wide service coverage while minimizing inter-beam interference.

Currently, Long Term Evolution (LTE) -Advanced and Worldwide Interoperability for Microwave Access (WiMAX), which is currently under development with the goal of developing a 4G mobile communication system, uses a frequency band of less than 6 GHz, 8 x 8 Multiple-Input Multiple-Output (MIMO), Carrier Aggregation (CA), Coordinated Multi-Point Transmission (CoMP), and Relay In order to secure the transmission capacity of the mobile station.

According to mobile data usage forecasts of wireless service providers and traffic prediction research organizations including mobile communication service providers, mobile data usage is estimated to reach 1,000 times in 2020. This means that mobile data usage rate is gradually changing from video and text services to video services that require higher data rates, and the use of smart phones such as smart phones and tablets is increasing exponentially It is a reasonable prediction considering the fact that

As the traffic usage increases exponentially and the frequency efficiency improvement in the current cellular frequency band reaches the limit as described above, the frequency of the millimeter wave (mmWave) frequency band corresponding to 10 GHz to 300 GHz It is possible to consider a method of constructing a new cellular network by using the network.

When a millimeter wave frequency band is used for mobile communication, a wide bandwidth of 1 GHz or more can be obtained. In addition to linearity, which is a physical propagation characteristic of a signal having a millimeter wave frequency band, a beamforming technique that is inevitable for communication using a millimeter wave frequency band is utilized to utilize radio resources and space resources such as time, frequency, and code The wireless capability can be dramatically increased.

Examples of utilizing the millimeter wave frequency band for wireless communication are a wireless personal area network (WPAN) system for a recent distance of about 10 m around a 60 GHz frequency band, a point-to-point communication for a wireless backhaul in a 70 to 80 GHz band In some cases. However, until now, the millimeter-wave frequency band has been limited to specific fields.

When a cellular network (or a cellular mobile communication system) using a millimeter-wave frequency band is implemented, it can meet the demand of mobile traffic that explodes explosively through the use of frequency bandwidth resources and the recycling of space resources, It is expected that next generation application services such as ultra-definition (UD) video service can be easily provided with a high-quality service quality.

However, a solution to the problems that may occur when using the millimeter wave frequency band has not been presented so far, and thus the use of the millimeter wave frequency band is not widely used.

For example, when a multi-beam is formed using a millimeter-wave frequency band, a problem of inter-beam interference or a service disconnection due to a high-speed movement of a terminal in a handover may occur. Therefore, do.

SUMMARY OF THE INVENTION An object of the present invention is to provide an antenna device capable of minimizing inter-beam interference.

It is another object of the present invention to provide a handover method using an antenna device capable of preventing a service disconnection in inter-beam handover in a mobile communication system that provides a service using multiple beams.

Other objects and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which: FIG.

According to an aspect of the present invention, there is provided an antenna apparatus including a plurality of antenna elements for forming a plurality of beams in a specific service area, Wherein the uppermost row among the plurality of rows includes less than the lowest row antenna elements and the inter-beam spacing angle formed by each antenna element included in the lowest row is greater than a distance between each antenna element included in the uppermost row Is formed to be wider than the spacing between beams formed.

Here, the horizontal beam angles formed by the antenna elements included in each of the plurality of rows may be configured to be the same.

Here, the vertical beam angles of the beams formed by the respective antenna elements included in the lowermost row among the plurality of rows may be configured to be wider than the vertical beam angles of the beams formed by the respective antenna elements included in the uppermost row.

Here, each antenna element may be installed in the antenna device such that the angle of inclination of the central angle of the beam formed by each of the antenna elements included in each row increases from the uppermost row to the lowermost row.

Here, the antenna device may be composed of a first row, a second row, a third row and a fourth row each including a plurality of antenna elements, and the horizontal direction of each antenna element included in the first and second rows And the vertical beam angles of the respective antenna elements included in the fourth row may be configured to be wider than the vertical beam angles of the respective antenna elements included in the first and second rows.

Here, the inter-beam spacing formed by the antenna elements in the third row is wider than the inter-beam spacing formed by the antenna elements in the first and second rows, and the spacing between the beams formed by the antenna elements belonging to the fourth row And the angle may be made wider than the spacing between beams formed by the antenna elements belonging to the third row.

According to another aspect of the present invention, there is provided a handover method performed by a base station, the method comprising: acquiring movement information of a mobile station; Constructing a candidate cooperation beam set to be applied to the terminal, and providing the configured candidate cooperation beam set information to the terminal.

The handover method includes the steps of receiving measurement information on the candidate cooperative beam set from the terminal, configuring an active cooperative beam set to be applied to the terminal based on the measurement information, And providing the aggregation information to the terminal.

Here, the step of acquiring the movement information of the terminal may acquire the movement information based on the position information that the terminal includes in the predefined message.

Here, the step of acquiring the movement information of the terminal may include: allocating a specific physical channel to the terminal; acquiring movement information of the terminal based on a signal transmitted from the terminal on the physical channel at every predetermined period; .

According to another aspect of the present invention, there is provided a handover method performed by a mobile station, comprising: reporting mobile information to a base station; And receiving data via the beams included in the candidate cooperative beam set.

In the step of reporting the movement information to the base station, GPS (Global Positioning System) information may be included in a predefined message and transmitted to the base station.

In the step of reporting the movement information to the base station, a signal may be transmitted to the base station at predetermined intervals using the physical channel allocated by the base station.

The handover method includes: performing measurements on the beams included in the candidate cooperative beam set; transmitting measurement information on the candidate cooperative beam set to the base station; Receiving the corresponding active cooperative beam aggregation configuration information, and receiving data via the beams included in the active cooperative beam aggregation.

According to the handover method using the antenna device and the antenna device as described above, it is possible to form a three-dimensional beam while minimizing inter-beam interference by optimizing the arrangement of antenna elements in a mobile communication environment using a millimeter frequency band.

In addition, until the active cooperative beam set (ACBS) of the terminal is constructed, a candidate cooperative beam set (CCBS) is constructed in consideration of the mobility of the terminal, a service is provided to the terminal using the composed candidate cooperative beam set, When the aggregation is formed, service disconnection can be prevented even in an environment where the mobile station moves at a high speed by providing a service to the mobile station using the active cooperative beam set.

1 and 2 are conceptual diagrams showing an example of an antenna device applied to a mobile communication system.
3 is a conceptual diagram illustrating an arrangement of an antenna device according to an embodiment of the present invention.
Fig. 4 is a conceptual diagram for explaining the arrangement of beams formed by the antenna device shown in Fig. 3. Fig.
5 is a conceptual diagram showing a configuration of a communication system using a millimeter wave frequency band.
6 is a conceptual diagram for explaining a handover method performed in a wireless communication system using a millimeter-wave frequency band.
7 is a conceptual diagram illustrating an example of handover performed in a wireless communication system using a millimeter wave frequency band.
8 is a flowchart illustrating a handover method performed in a wireless communication system using a millimeter wave frequency band.
9 is a flowchart illustrating a handover method performed in a base station according to an embodiment of the present invention.
10 is a flowchart illustrating a handover method performed in a terminal according to an embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail.

It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

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

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

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

Embodiments of the present invention described below may be applied to standard documents disclosed in at least one of IEEE (Institute of Electrical and Electronics Engineers) 802 system, 3rd Generation Partnership Project (3GPP) system, 3GPP LTE system and 3GPP2 system . In other words, steps or portions of embodiments of the present invention which are not described in order to clearly illustrate the technical idea of the present invention can be supported by the above-mentioned standard documents. In addition, all terms used in the present invention can be described by the standard document.

The term 'terminal' used in the present application includes a mobile station (MS), a user equipment (UE), a machine type communication (MTC) device, a mobile terminal (MT) A wireless terminal, an access terminal (AT), a subscriber unit, a subscriber station (SS), a wireless device, a wireless communication device, a wireless transmit / receive unit (WTRU) Receive Unit), mobile node, mobile, or some other terminology.

The term 'base station' used in the present application is used to mean a control device for controlling one cell. However, in an actual wireless communication system, a physical base station can control a plurality of cells, in which case the physical base station can be regarded as including at least one base station used in the present application. For example, it should be understood that parameters assigned differently for each cell in the present application assign different values to each base station. The 'base station' includes a base station, a Node-B, an eNode-B, a BTS (Base Transceiver System), an access point, It can be called another term.

Hereinafter, embodiments of the present invention provide a technique for constructing a new mobile communication network using a millimeter wave frequency band (for example, 10 GHz to 300 GHz). However, the technical idea of the present invention is not limited to the millimeter wave frequency band, but can be applied to a mobile communication system using a conventional cellular mobile communication frequency band.

In order to construct a cellular network using a millimeter-wave frequency band, a high path loss problem due to a high frequency must be solved, and a shadowing phenomenon caused by a propagation signal being blocked by an obstacle due to the straight- shadowing) problem, and it is required to efficiently support a mobile station (MS) while providing a wide coverage.

In order to overcome the high path loss, which is a propagation characteristic of a signal having a frequency in the millimeter wave band, it is necessary to obtain a high transmit and receive antenna gain considering the limited transmit / receive power. This requirement can be regarded as a characteristic of a communication system using a millimeter wave frequency different from the conventional cellular mobile communication system.

In general, a plurality of antennas are required to form a single transmit / receive beam. In general, the larger the number of antennas, the narrower the transmit / receive beam width and the higher antenna gain can be obtained.

Meanwhile, since a beam formed through a plurality of antennas transmits a signal only in a specific predetermined direction, in order to transmit a signal to a wide area, a plurality of different beams are formed in directions other than the specific direction, , In which case the signal can be transmitted using the same frequency resource at the same time.

When a plurality of beams are generated using a plurality of antennas at a base station, the service capacity of a system capable of providing more beams is increased, but the inter-beam interference also increases. In particular, when a beam is formed in a three-dimensional (3D) manner, an individual beam region can be formed in the horizontal and vertical directions. By using an antenna that provides a narrow beam width, more beams can be formed. However, . In order to eliminate inter-beam interference, the center angles of neighboring beams may be spaced apart, but coverage holes may occur in the regions where the beams are spaced apart.

Therefore, the system designer should design the beam width, beam-to-beam spacing, and antenna placement structure of the antenna to be used in consideration of the capacity of the system, the service coverage, and the installation height of the antenna.

1 and 2 are conceptual diagrams showing an example of an antenna device applied to a mobile communication system.

The antennas shown in FIGS. 1 and 2 can be applied to a base station in a cellular network using millimeter wave frequencies.

1 and 2, FIG. 1 illustrates a configuration of an antenna supporting one cell of a total area of three antennas 110 and serving as a service area of 120 degrees, FIG. 2 is a cross- One surface of the antenna 120 serves as a service area of 60 degrees and is composed of a total of six surfaces to illustrate the shape of an antenna supporting all the cells.

Referring first to FIG. 1, the antenna 110 may be configured to have a triangular cross-section, and a plurality of antenna elements 111 may be installed on each side so that each side is responsible for a service area of 120 degrees. have.

Specifically, the antenna elements 111 constituting each surface can be arranged in a plurality of rows and columns. For example, the antenna elements 111 constituting each surface may be composed of three rows and twelve columns as shown in FIG. 1, and each antenna element 111 may form a separate beam.

In addition, the antenna 110 can be configured by fixing the horizontal angle and the vertical angle of the beam formed by the individual antenna elements 111 constituting each surface to a predetermined angle. For example, the horizontal angles of the beams formed by the individual antenna elements 111 may be fixed at 10 degrees. The vertical angles of the beams formed by the individual antenna elements 111 can be configured to have different angles depending on the row in which the antenna elements 111 are installed. For example, the vertical angles of the beams formed by the individual antenna elements 111 are 10 degrees for the antenna elements included in the first row from the top of each plane, 30 degrees for the antenna elements included in the second row, May be configured to form a beam at 50 degrees.

Accordingly, in order for one side of the antenna 110 to support a region of 120 degrees horizontally, it is possible to arrange the individual antenna elements so that the centers of their horizontal angles are spaced apart by 10 degrees from each other, have.

2, the antenna 120 may have a hexagonal cross section, and a plurality of antenna elements 121 may be installed on each side of the antenna 120 so that each side may serve as a service area of 60 degrees.

Specifically, the antenna elements 121 constituting each surface can be configured in three rows and six columns, each row including six antenna elements, and a total of eighteen antenna elements 121 arranged on each surface . Here, the horizontal angle formed by the antenna elements 121 constituting each row may be set to be fixed at 10 degrees as in the case of the antenna elements 111 shown in FIG. The vertical angles of the beams formed by the respective antenna elements 121 are the same as those of the antenna elements 111 shown in FIG. 1, and the antenna elements included in the first row from the top of each plane are 10 degrees, The included antenna elements can be configured to form a beam at 30 degrees, and the antenna elements included in the third row form a beam at 50 degrees.

Here, the horizontal and vertical beam angles of the respective antenna elements 111 and 121 are angles representing the half power beam width (HPBW).

In FIGS. 1 and 2, antenna elements are arranged in three rows and six columns and three rows and six columns in each sector. The horizontal and vertical beam angles of each row are 10 degrees-10 degrees in one row and 10 degrees -30 degrees in two rows. And the third row is composed of 10 degrees to 50 degrees.

In the case of the antenna configured as shown in FIGS. 1 and 2, interference between neighboring beams among the beams formed by the antenna elements belonging to the same row becomes severe, so that even in the center of the horizontal and vertical angles formed by a specific beam, Technology alone can not be applied, thereby reducing the capacity of the system.

The above-described phenomenon is deepened in the lower row among the rows constituted by the plurality of antenna elements provided in each antenna. This is because the total beam area formed by the antenna elements included in the lower row in the sector- Because the spacing between the beams formed by the antenna elements included in the lower row is reduced by providing a region narrower than the entire beam region formed by the antenna elements constituting the lower layer.

The present invention provides an antenna device for solving inter-beam interference as described above.

3 is a conceptual diagram illustrating an arrangement of an antenna device according to an embodiment of the present invention. 4 is a conceptual diagram for explaining the arrangement of the beams formed by the antenna device shown in Fig.

1, an antenna device 300 according to an embodiment of the present invention includes a total area of three sides (i.e., three sectors) And can be configured in a supporting shape.

In addition, the antenna device 300 according to an embodiment of the present invention may be configured such that each side is composed of four rows, each row includes a plurality of antenna elements, and each antenna element included in each row forms a respective beam .

Specifically, each surface of the antenna device 300 may be composed of 12 antenna elements 311 and 312, respectively, from the top, and the first row 301 and the second row 302 may be composed of 12 antenna elements 311 and 312, respectively, May be composed of ten antenna elements 313 and the fourth row 304 may be composed of six antenna elements 314.

Each antenna element 311 constituting the first row 301 is set to have a horizontal to vertical half value beam width HPBW of 5 to 5 degrees and to provide a service for a sector of 120 degrees, The separation angle can be set to 10 degrees. The inter-beam spacing angle refers to a separation angle when each of the antenna elements 311 is oriented horizontally. 4, when the height H of the antenna is 50 m and the coverage is 1000 m, the antenna elements 311 constituting the first row 301 are arranged in the vertical direction of the beam center angle < RTI ID = 0.0 > Can be set so that the position at which the central angle travels is located at the boundary of the coverage by setting the angle horizontally at an angle inclined by 3 degrees.

Each antenna element 312 constituting the second row 302 may be set to a horizontal-vertical half-width beam width of 5 to 5 degrees and a horizontal beam spacing angle to 10 degrees. In addition, the vertical center of beam of the antenna elements 312 constituting the second row 302 can be set to be inclined by 15 degrees from the horizontal. The spacing between the beams formed by the antenna elements 312 constituting the second row 302 may be smaller than that of the first row 301, The interference between the beams formed by the elements 311 may be somewhat larger.

Each of the antenna elements 313 constituting the third row 303 is set to have a horizontal-vertical flank width of 5 to 5 degrees as in the case of the antenna elements 311 and 312 of the first and second rows 302, The number of the antenna elements 313 is set to 10 smaller than the first and second rows 302 and the vertical distance between the antenna elements 313 in the horizontal direction is extended by 12 degrees, It can be set to be inclined by 27 degrees from the horizontal. The reason for reducing the number of antenna elements 313 constituting the third row 303 to be smaller than the number of the antenna elements of the first and second rows 302 and extending the central angle separation distance in the horizontal direction is that the third row 303 And reflects the narrowed beam region as the vertical beam center angle of the constituent antenna elements 313 is set to 27 degrees.

The horizontal-vertical half-width beam width of each antenna element 314 constituting the fourth row 304 is set to 5 to 20 degrees, the vertical distance of the beam central angle of each antenna element 314 is set to 20 degrees, The beam center angle in the direction may be set to an angle tilted by 57 degrees from the horizontal.

The beam formed by each antenna element in the antenna device 300 shown in FIG. 3 may adjust the beam forming direction through an adjustment value (for example, an antenna adjustment parameter), and the direction of the beam formed by each antenna element may be Or may be configured to be fixed.

In the case where the direction of the beam formed by each antenna element is adjustable, it may include an additional digital circuit corresponding to the direction of the beam formed by each antenna element, There is an advantage that the antenna can be relatively simply implemented since additional circuitry for adjusting the beam direction is not needed.

In the antenna device 300 according to the embodiment of the present invention shown in FIG. 3, the antenna device 300 has three sides and one side covers a coverage of 120 degrees. However, The technical idea is not limited to the structure of the antenna device 300 illustrated in Fig. That is, the overall shape of the antenna device, the arrangement of the antenna elements constituting each side of the antenna device, the number of the antenna elements, the horizontal angle and the vertical angle of the beams formed by the respective antenna elements may be various forms can be changed.

Each of the antenna elements shown in FIG. 3 may be implemented by various types of antenna elements. For example, each antenna element may be implemented as a horn antenna or a patch array antenna (PAA).

Generally, in a mobile communication system that forms a plurality of beams, there is a problem that a gain of a signal beam including a signal in a boundary region of a beam formed by the antenna elements is lowered or a quality of the signal beam is lowered due to interference of peripheral beams Lt; / RTI >

In order to solve the above problem, the signal quality of a signal beam can be improved by using a macro diversity transmission (MDT) method in which a signal beam and peripheral beams of a signal beam simultaneously transmit signals to the terminal .

The macro diversity transmission method can be applied to support the mobility of the terminal.

5 is a conceptual diagram showing a configuration of a communication system using a millimeter wave frequency band.

5, a communication system using a millimeter-wave frequency band includes a central base station (CBS) 510 that performs a base station function and at least one relay base station (RBS) Relay Base Stations 521 and 523 and may provide services to the terminal 530 by connecting the beams using the central base station 510 and at least one relay base station 521 and 523. [

5, a wireless backhaul link may be formed between the central base station 510 and the relay base station 521 or between the central base station 510 and the relay base station 521. In addition, a radio access link may be formed between the relay base station 523 or the central base station to which the terminal 530 is directly connected. Here, the beam in the uplink direction among the beams transmitted from each relay base station 521, 523 may be referred to as a wireless backhaul beam 541, and the beam in the downlink direction may be referred to as a radio access beam 543 .

FIG. 6 is a conceptual diagram for explaining a handover method performed in a wireless communication system using a millimeter wave frequency band, in which the central and / or relay base stations cooperate to form multiple beams dynamically in the terminal according to the movement path of the terminal A low latency handover-distributed beam system (hereinafter referred to as LH-DBS), which is a technique for enabling inter-beam handover with very low latency while transmitting different data or the same data, Quot;).

In order to enable LH-DBS technology, distributed multi-beam based multi-flow / inter-site MIMO should be supported, and the terminal should support LH-DBS demodulation Method, and high-speed handover (or beam-to-beam fast switching) between the beams must be possible. Here, a known technique can be used for the demodulation method supporting LH-DBS.

6 illustrates a first cell 610 including a plurality of first relay base stations 612, 613, and 614 connected to a first base station 611 and a first base station 611 via a wireless backhaul link, A second cell 620 including a plurality of second relay base stations 622, 623 and 624 connected to a central base station 621 and a second central base station 621 via a wireless backhaul link, (LH-DBS) process when the UE 601 moves along a specific path in a wireless communication system using a wireless communication band.

6, when a terminal 601 receives a service in a first cell 610 and then moves to a second cell 620, the terminal 601 transmits a service to the second cell 620 through a central base station and / Can receive or transmit data over a plurality of forming radio access links, and as the terminal moves, the radio access links (or beams) available to the terminal change.

Hereinafter, the LH-DBS method will be described in more detail.

7 is a conceptual diagram illustrating an example of handover performed in a wireless communication system using a millimeter wave frequency band. 8 is a flowchart illustrating a handover method performed in a wireless communication system using a millimeter wave frequency band.

First, terms used in the process of describing the LH-DBS method are defined.

A Measurement Beam Set (MBS) is information informed to a terminal by a Head CBS of a terminal. The measurement beam set (MBS) is a measurement beam set (MBS) Means a list. Here, the Head CBS means a serving base station of a terminal.

A downlink candidate cooperative beam set (DL CCBS) refers to a downlink cooperative beam candidate set and can be a subset of the MBS.

The DL Active Cooperated Beam Set (DL ACBS) refers to a set of beams for transmitting data on the downlink according to a predetermined method in the LH-DBS, It can be a subset of DL CCBS.

An uplink candidate beam set (UL CCBS, hereinafter referred to as 'UL CCBS') refers to an uplink cooperative beam candidate set, which may be the same as the DL CCBS and perform uplink synchronization with the corresponding beams .

An uplink ACBS (UL ACBS) is a set of beams for transmitting data on the uplink according to a predetermined method in the LH-DBS, and a subset of the UL CCBS And a round trip time (RTT) value with respect to the MS is satisfied.

N_RXB denotes the number of beams that can be simultaneously received by the UE.

N_TXB denotes the number of beams that can be simultaneously transmitted by the UE.

7 and 8, FIG. 7 illustrates a logical set of beams for performing the LH-DBS function, and candidate beams and active beams are configured before movement of the mobile station. And the candidate beams and the active beams are changed as the terminal moves.

Table 1 shows the beam sets according to the position of the UE in the cellular network using the millimeter wave frequency band shown in FIG.

For example, as shown in FIG. 6, when the terminal 751 is located at the first position P1 in the first cell 760, the terminal 751 transmits data to the base station (Beam1-n, Beam1-1-m) formed by the base station 761 and the relay base station 762 among the candidate beams formed by the CBS1 761 and the relay base stations 762, 763, To transmit and receive data.

Then, when the terminal 751 moves from the first cell 760 to the second position P2, the DL ACBS transmits the Beam 1-n and the Beam 2-5-n formed by the base station 761 and the relay base station 773, a. When the terminal 751 moves from the second position P2 to the third position P3 which is the boundary point between the first cell 760, the second cell 770 and the third cell 780, the terminal 751 The DL ACBS and the UL ACBS used for transmission and reception are transmitted to the relay base stations 762, 763 and 764 of the first cell 760, the relay equipment stations 772, 773 and 774 of the second cell 770, The relay base station 764 and the second cell 770 of the first cell 760 among the plurality of candidate beams formed by the relay base stations 782 and 783 of the first cell 780 and the base station 781 of the third cell 780, (Beam1-3-r, Beam2-5-a) formed by the relay base station 773 of Fig.

Hereinafter, the LH-DBS function will be described with reference to FIGS. 7 and 8. FIG. The LH-DBS function shown in FIG. 8 can be performed by a terminal that is served by a communication system using a millimeter-wave frequency band.

First, the terminal 751 registers itself with the serving central base station 761 (S801). At this time, the terminal 751 can report N_RXB and N_TXB information, which are specifications for its own transmission and reception beams, to the serving central base station 761.

7 and 8, after the terminal 751 registers itself in the serving central base station 761, the terminal 751 transmits a beam (Beam1-n) of the central base station 761 to the relay base station 762 Assuming that UL ACBS is the same as the DL ACBS, it is assumed that a beam (Beam1-1-m) of the DL ACBS is DL ACBS and receives a DL service. Thus, the central base station 761 becomes a Head CBS.

Meanwhile, the terminal can also receive the beams Beam1-1-2-o and Beam 1-3-q from the relay base station 763 and the relay base station 764. [ Therefore, the DL CCBS of the UE can be composed of Beam1-n, Beam1-1-m, Beam1-1-2-o, and Beam1-3-q.

The base station 761 can determine the DL ACBS of the UE by determining the N_RXB reported by the UE and the link state measured by the UE and the traffic load states of the BSs forming the beam belonging to the DL CCBS in the DL CCBS of the UE .

Meanwhile, there may be three modes in which the terminal receives data from beams belonging to the DL ACBS. That is, a single-flow cooperative reception mode for receiving the same data from two or more beams belonging to the DL ACBS, a multi-flow cooperative reception for receiving different data from two or more beams belonging to the DL ACBS, Mode, and a general reception mode used when there is one beam belonging to DL ACBS.

Here, assuming that DL ACBS is composed of two beams, the UE can receive data through a single-flow cooperative reception mode or a multi-flow cooperative reception mode.

The base station 761, which is the head CBS, can configure the MBS, which is information on the neighboring beams, based on the location of the corresponding terminal 751, and can notify the terminal 751 of the configured MBS information through Beam1-n . Here, the central base station 761 may transmit MBS information through an arbitrary beam among the beams constituting the DL ACBS. However, using a reliable MCS (Modulation and Coding Scheme) generally improves transmission reliability. Therefore, it is preferable to select one beam in terms of resource utilization efficiency. One beam carrying a control message is referred to as a primary beam. The control message may be transmitted via beams belonging to the DL ACBS in addition to the primary beam.

As the base station 761 transmits the MBS to the terminal 751 through the primary beam, the terminal 751 receives the MBS information from the base station 761 (S803).

The terminal 751 adjusts the weight vector of the antenna based on the MBS information received from the base station 761 to find the beams corresponding to the MBS. Then, the terminal 751 measures the preamble of each beam or reference signal received power (RSRP: hereinafter referred to as 'RSRP') for the detected beams and updates the DL CCBS (S805). At this time, the UE 751 may selectively transmit a radio resource (e.g., a frequency and / or a time resource, a resource block (RB)) to the beam newly added to the DL CCBS through the DL ACBS, ) And an average noise plus interference power indicator (ANIPI) of the reference signal. The RSRP of another reference signal may be measured in the same direction. Generally, in a cellular network, a reference signal having the highest RSRP measured for one beam direction is generated (for example, the reference signals may be transmitted at different frequencies) If another reference signal RSRP is measured for the same direction and this signal can be added to the DL CCBS, this signal can be judged as an interfering signal source for a beam having the highest RSRP, which is referred to as ANIPI_RS, The interference to the block can be called ANIPI_RB.

The ANIPI is a parameter for determining the degree of the interference signal on the added beam, and the base station 761 can later use it as a reference for determining DL ACBS. That is, the smaller the measured ANIPI, the better the link quality.

The terminal 751 performs RSRP measurement on MBSs as well as RSRP measurement on the existing DL CCBSs as described above. Herein, the terminal 751 may delete, in the DL CCBS, existing beams that do not satisfy the predetermined criteria according to the measurement result of the DL CCBS.

That is, the terminal 751 measures the RSRP (or ANIPI) for the beams included in the MBS and / or the existing DL CCBS, compares the measurement result with a preset reference value (S807) A beam having a received power (or ANIPI) equal to or greater than the set reference value may be added to the DL CCBS in step S809, and the beams RSRP (or ANIPI) among the beams included in the existing DL CCBS may be deleted from the DL CCBS in step S811 ). As described above, the DL CCBS can be configured based on the reference value, but it is also possible to configure the DL CCBS by selecting the maximum N (where N is a design parameter) of the measured RSRP values.

On the other hand, the terminal 751 may report to the central base station 761 whenever the DL CCBS is changed, or may report according to a predetermined period. Here, in the case where the terminal 751 is configured to report the change of the DL CCBS according to a predetermined period, the terminal 751 may be configured to determine the reporting period through the operation of the timer T_rep. In step S803 of FIG. 8, the terminal 751 drives the timer T_rep. In step S813, the terminal 751 determines whether the timer has expired. When the timer expires, the terminal 751 reports the DL CCBS to the serving base station 761 (S815).

The terminal 751 moving to the third position P3 in the step S815 calculates the DL CCBS (Beam1-3-r, Beam2-5-a, Beam2-7-e, Beam3- -b and Beam 3-6-c, and then report the configured DL CCBS information to the central base station 761 via the primary beam Beam1-n. In the case of a beam added in parallel thereto, To perform uplink synchronization.

On the other hand, the central base station 761 compares the DL CCBS information reported from the terminal 751 with the previously stored DL CCBS to check for changes in the DL CCBS, and for the removed beams in the DL CCBS, To the base station and / or the relay base station, whether the base station and / or the relay base stations delete the resources associated with the terminal 751 and whether the terminal 751 can be accommodated for the newly added beams in the DL CCBS Contact us.

The central base station 761 extracts beams capable of accommodating the terminal 751 in the DL CCBS reported from the terminal 751 as described above and outputs the received signals to the terminal 751 based on the reference signal measurement values and the ANIPI values of the extracted beams. ), And then transmits the configured DL ACBS information to the terminal 751. The DL ACBS information is transmitted to the terminal 751 through the DL ACBS. For example, in the case of FIG. 7, DL ACBS can be composed of Beam1-3-r and Beam2-5-a. Here, Beam1-3-r may be the next primary beam according to the movement of the terminal 751. [ The DL ACBS information may be transmitted only to Beam1-n, which is currently the primary beam, or may be transmitted to the UE more securely with Beam2-5-a. At this time, the Head CBS can signal to the terminal that the primary beam is changed from Beam1-n to Beam1-3-r, and informs the UE of the downlink reception mode.

The terminal 751 receives the DL ACBS information configured as described above and the downlink receiving mode information of the terminal from the Head CBS 761 (S817).

Here, the downlink reception scheme of the UE may be any one of a multi-flow cooperation reception mode S819, a general reception mode S821, and a single-flow cooperation reception mode S823, And receives the downlink data based on the mode information. For example, if the downlink reception scheme of the UE is a multi-flow cooperative reception mode, the UE can perform the MMSE-SIC reception setup, and in the normal reception mode, . Also, if the downlink reception scheme of the UE is the single-flow cooperative reception mode, the UE can receive the downlink data after performing the MRC reception setup.

Meanwhile, the UE 751 may perform uplink synchronization whenever possible with respect to the DL CCBS beams. In addition, when receiving the DL ACBS information from the central base station, the terminal 751 may set DL CCBS to DL ACBS and preferentially perform uplink synchronization on the beams included in the DL ACBS (S825). Here, if the UE 751 performs uplink synchronization with respect to the DL CCBS, the UE 751 may perform synchronization with respect to the beams included in the received DL ACBS, for which uplink synchronization has not been performed.

As described above, when the uplink synchronization is attempted from the corresponding terminal 751, the corresponding base station and / or the relay base station transmits the round trip delay values obtained through the uplink synchronization process of the terminal 751 to the base station 761 Can be reported.

The Head CBS 761 can determine the optimal UL ACBS from the UL CCBS based on the reported round trip delay values as described above and can transmit it to the terminal 751 through the current DL ACBSs, 751 can receive the UL ACBS information from the Head CBS 761 and can update the UL ACBS based on the received information (S827). Here, the UL ACBS may have a value of N_TXB or less as reported from the terminal 751.

Then, the UE can transmit uplink data using the beams included in the UL ACBS (S829).

The DL ACBS and the UL ACBS configured as described above may be identical to or different from each other. Downlink reception through the DL ACBS in the UE 751 can achieve a more reliable downlink reception effect by using a diversity scheme such as Maximal Ratio Combining (MRC) for single-flow cooperative reception In the case of multi-flow cooperative reception, the reception frequency efficiency may be improved by effectively receiving different data through an interference cancellation receiver module such as a Minimum Mean Square Error-Successive Interference Cancellation (MMSE-SIC). Transmission through the UL ACBS from the terminal 751 can improve reception efficiency through various techniques such as selection diversity in the Head CBS via different base stations.

The LH-DBS shown in FIG. 7 and FIG. 8 performs a macro-diversity transmission (MDT) scheme using beams belonging to ACBS.

However, in the case of forming a three-dimensional beam in the LH-DBS, the area of each beam becomes relatively narrow, and if the mobile speed of the mobile station is high, the mobile station may be out of the area of the signal beam before constructing the ACBS to be applied to the mobile station Thereby causing service disconnection to the terminal.

In order to solve the service disconnection problem, the handover method according to an embodiment of the present invention uses available beams among peripheral beams (i.e., CCBS) to be transmitted to the mobile station before constructing the ACBS to be applied to the mobile station And performs macro-diversity transmission. The macro diversity transmission using the CCBS continues until the ACBS is configured. When the ACBS configuration is completed, the macro diversity transmission is performed using the ACBS.

Here, it is important to accurately configure the CCBS in order to minimize the resource waste due to the application of the macro diversity transmission, and it is important that the base station constituting the CCBS transmits the movement information of the terminal (for example, ), It is possible to optimize the beams to perform the macro-diversity transmission.

9 is a flowchart illustrating a handover method performed in a base station according to an embodiment of the present invention.

Referring to FIG. 9, the BS acquires movement information of a mobile station (S901). Here, the movement information of the terminal may include, for example, the movement speed and / or the movement direction information of the terminal. In addition, the base station may acquire movement information of the mobile station based on the location information of the mobile station included in the predefined message transmitted by the terminal having the GPS (Global Positioning System) reception function, and may allocate a specific physical channel And may acquire movement information of the mobile station by receiving a signal transmitted through a physical channel allocated from the mobile station according to a predetermined period and measuring a DOA (Direction of Arrival) and / or an arrival time of the received signal.

The base station constructs a CCBS to be applied to the terminal based on the acquired movement information of the terminal (S903). In this case, the BS may configure a CCBS composed of available beams among the beams formed around the signal beam transmitted to the MS, considering the moving speed and moving direction of the MS. Alternatively, in step S903, the base station may configure the MBS to be applied to the terminal based on the movement information of the terminal instead of configuring the CCBS to be applied to the terminal.

Thereafter, the base station notifies the terminal of the CCBS configuration information (S905). Alternatively, if the MBS is configured instead of the CCBS in step S903, the base station may notify the terminal of the MBS configuration information instead of the CCBS configuration information. In addition, the base station may notify the base station forming each beam included in the configured CCBS to CCBS configuration information so that the corresponding base stations form a corresponding beam on the terminal.

As described above, when the base station constitutes the CCBS and notifies the terminal of the CCBS configuration information, the terminal can receive signals through the beams belonging to the CCBS based on the CCBS configuration information received from the base station. The terminal may also perform measurements on the individual beams included in the CCBS (e.g., measure the preamble or reference signal received power of each beam) and report the CCBS measurement information to the base station.

Alternatively, when the terminal receives the MBS information from the base station, it finds the beams corresponding to the MBS as shown in FIG. 8, updates the CCBS by measuring the preamble or reference signal reception power of each beam with respect to the detected beams, The CCBS update information may be provided to the base station.

The base station acquires CCBS measurement information (or CCBS update information) reported from the terminal (S907), and configures ACBS based on the acquired information (S909).

Thereafter, the base station notifies the terminal of the ACBS configuration information (S911). 8, the base station can provide the downlink reception scheme to the terminal along with the ACBS configuration information, and the terminal can perform uplink synchronization and downlink data reception based on the provided information, Transmission can be performed.

10 is a flowchart illustrating a handover method performed in a terminal according to an embodiment of the present invention.

Referring to FIG. 10, the terminal reports its movement information to the base station (S1001). Here, the movement information may include movement speed and direction information of the terminal. If the terminal has a GPS receiving function, the terminal may transmit a message including the GPS information of the terminal to the base station, or may transmit a specific signal to the base station according to a predetermined period using the allocated physical channel.

As described above, the base station acquires the movement information of the terminal based on the movement information or the signal transmitted by the terminal, configures the CCBS based on the acquired movement information, and notifies the terminal of the CCBS configuration information. Alternatively, the base station may configure the MBS based on the movement information of the terminal, and then notify the terminal of the MBS configuration information.

The terminal receives the CCBS configuration information (or MBS configuration information) from the base station (S1003), and receives the downlink data through the beams (or beams belonging to the MBS configuration information) belonging to the received CCBS configuration information (S1005). Here, the UE performs measurements on the individual beams belonging to the CCBS configuration information (for example, measuring the preamble of each beam or the received power of the reference signal), or measures the individual beams belonging to the MBS To update the CCBS.

Thereafter, the terminal reports the CCBS measurement information (or CCBS update information) to the base station (S1007).

After configuring the ACBS based on the report of the terminal as described above, the ACBS configuration information may be notified to the terminal, and the terminal may receive the ACBS configuration information from the base station (S1009).

Thereafter, the UE can receive the downlink data through the beams belonging to the ACBS based on the ACBS configuration information received from the base station (S1011). Here, as shown in FIG. 8, the UE can receive the downlink reception scheme together with the ACBS configuration information from the base station. In this case, the UE receives the downlink data based on the received downlink reception scheme, It is possible to perform data transmission through the uplink.

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

110: antenna 111: antenna element
120: antenna 121: antenna element
300: antenna device 301: first row
302: second row 303: third row
304: fourth row 311, 312, 313, 314: antenna element
510: CBS 521, 523: Relay Station (RBS)
530: MS 541: Wireless backhaul beam
543 wireless access beam 601 terminal
610: first cell 611: first base station
612, 613, 614: first relay base station
620: second cell 621: second central base station
622, 623, 624: the second relay base station
751: Terminal 760: First cell
761: Central BTS 762, 763, 764:
770: Second cell 771:
772, 773: Relay base station 780: Third cell
781: Central base station 782:
783: relay base station

Claims (14)

An antenna device comprising a plurality of antenna elements forming a plurality of beams in a specific service area,
Wherein the plurality of antenna elements are arranged in a plurality of rows and the uppermost row among the plurality of rows includes less than the lowest row antenna elements, Wherein a distance between the first and second antenna elements is larger than a distance between the first and second antenna elements. The method according to claim 1,
Wherein the horizontal beam angles formed by the antenna elements included in each of the plurality of rows are all the same. The method according to claim 1,
Wherein a vertical beam angle of a beam formed by each antenna element included in a lowest row among the plurality of rows is wider than a vertical beam angle of a beam formed by each antenna element included in the uppermost row. The method according to claim 1,
Wherein each of the antenna elements is provided such that the angle of inclination of the central angle of the beam formed by each of the antenna elements included in each row becomes larger from the top row to the bottom row. The method according to claim 1,
Wherein the antenna device comprises a first row, a second row, a third row and a fourth row each comprising a plurality of antenna elements, the horizontal and vertical beam angles of each antenna elements included in the first and second rows Wherein the vertical beam angles of the respective antenna elements included in the fourth row are wider than the vertical beam angles of the respective antenna elements included in the first and second rows. The method of claim 5,
The spacing between beams formed by the antenna elements belonging to the third row is wider than the spacing between beams formed by the antenna elements belonging to the first and second rows and the spacing between beams formed by the antenna elements belonging to the fourth row is Wherein the second antenna element has a larger spacing between beams formed by the antenna elements belonging to the third row. In a handover method performed by a base station,
Obtaining movement information of the terminal;
Constructing a candidate cooperation beam set to be applied to the terminal based on the acquired movement information; And
And providing the configured candidate cooperative beam aggregation information to the terminal. The method of claim 7,
The handover method
Receiving measurement information on the candidate cooperative beam set from the terminal;
Constructing an active cooperative beam set to be applied to the terminal based on the measurement information; And
And providing the configured active cooperative beam aggregation information to the mobile station. The method of claim 7,
The step of acquiring the movement information of the terminal comprises:
Wherein the mobile terminal acquires the movement information based on location information included in a predefined message transmitted by the terminal. The method of claim 7,
The step of acquiring the movement information of the terminal comprises:
Assigning a specific physical channel to the terminal; And
And acquiring movement information of the mobile station based on a signal transmitted from the mobile station over the physical channel every predetermined period. In a handover method performed in a terminal,
Reporting movement information to a base station;
Receiving candidate cooperation beam set configuration information corresponding to the movement information from the base station; And
And receiving data via beams included in the candidate cooperative beam set. The method of claim 11,
Wherein the step of reporting the movement information to the base station comprises:
Wherein the global positioning system (GPS) information is included in a predefined message and transmitted to the base station. The method of claim 11,
Wherein the step of reporting the movement information to the base station comprises:
And a signal is transmitted to the base station at a predefined period using a physical channel allocated from the base station. The method of claim 11,
The handover method includes:
Performing measurements on the beams included in the candidate cooperative beam set;
Transmitting measurement information of the candidate cooperative beam set to the base station;
Receiving active collaboration beam set configuration information corresponding to the measurement information to the base station; And
≪ / RTI > further comprising receiving data via beams included in the active cooperative beam set.

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