KR101533712B1 - Appratus and method for tracking beam - Google Patents

Abstract

Disclosed is a receiving apparatus capable of tracking a receiving beam and a transmitting apparatus capable of tracking the transmitting beam. The receiving apparatus selects a reception candidate beam in a direction adjacent to the direction of the reception beam and compares the quality of the reference signal received using the reception beam with the quality of the received reference signal using the reception candidate beam, Followed by beam tracking. The transmission apparatus selects a transmission candidate beam in a direction adjacent to the direction of the transmission beam and receives from the reception apparatus the quality of the reference signal transmitted using the transmission beam and the quality of the reference signal transmitted using the transmission candidate beam. The transmitting apparatus performs beam tracking according to the comparison result.

Description

[0001] APPARATUS AND METHOD FOR TRACKING BEAM [0002]

The following embodiments are directed to a technique for forming a beam using a plurality of antenna elements and transmitting and receiving data using the formed beam, specifically for tracking the direction of the beam.

The propagation in the tens of gigahertz band, referred to as the millimeter wave band, experiences high path loss and has a high directivity with a short wavelength. For this reason, directional beamforming technology, which can effectively utilize the LOS (Line-of-Sight) or NLOS (Non-Line-of-Sight) components, has been proposed as an effective way to increase capacity and extend coverage. However, due to hardware complexity, analog beamforming (ABF) technology or switched beamforming technology, which is relatively less complex than digital beamforming (DBF) technology, is mainly used.

In the millimeter wave band, it is possible to construct a small array antenna having many antenna elements due to a short wavelength. When an antenna array having a plurality of antenna elements is used, a plurality of small A beam can be formed. In this case, a very large gain can be obtained when a pair of beams that maximize the transmission beam and the reception beam, that is, the signal-to-noise ratio (SNR), are aligned. However, Which is greatly deteriorated.

In a switched beamforming system, a beam training process for finding an optimal beam between a base station and a terminal is essential at the beginning of communication. In this process, the BS and the UE search for the optimal pair of TX and RX beams in each uplink and downlink among all possible beam combinations, and the beam training process takes a very long time because all possible beam combinations are tested.

The mobile station must start a communication using a pair of beams detected through a beam training process but continuously perform a beam tracking process for maintaining a new optimal transmission / reception beam pair whenever a power factor is experienced. In the present invention, beam training refers to a process of finding an optimal transmission beam and a reception beam pair among all possible beam combinations between a base station and a terminal, and beam tracking is performed after beam training is performed, In this case, it means that the beam is updated to fit the change. In the switched beamforming system, the reception beam mismatch resulting from the direction change of the terminal is the biggest factor causing the reception beam tracking, and the transmission beam mismatch caused by the movement of the terminal is a factor for performing transmission beam tracking.

The following embodiments are intended to quickly track a beam even when the receiving apparatus moves or rotates and the direction of the transmitting / receiving beam is shifted.

According to an exemplary embodiment of the present invention, there is provided a receiving apparatus including a receiving unit that receives a reference signal transmitted from a transmitting apparatus using a receiving beam, a candidate beam selecting unit that selects a beam in a direction adjacent to the receiving beam as a receiving candidate beam, A comparison unit for comparing the quality received using the reception beam with the quality received using the reception candidate beam and a beam tracking unit for updating the reception candidate beam with the reception beam according to the comparison result Is provided.

Here, the quality may include at least one of a power value of the received reference signal, an SNR of the received reference signal, and an error rate of the received reference signal.

The reference signal may correspond to each of a plurality of transmission beams that can be formed by the transmission apparatus, and may be selected from a plurality of reference signals orthogonal to each other.

Also, the reference signal may be multiplexed with the data signal and transmitted from the transmission apparatus.

Here, the receiver may form a plurality of reception beams, receive the reference signals using the plurality of reception beams, and combine the received reference signals.

The transmission apparatus may further include a transmission unit that transmits a control signal for changing a direction of a transmission beam of the transmission apparatus that transmits the reference signal to the transmission apparatus.

Also, the receiving unit receives the second reference signal using the transmission candidate beam in the direction adjacent to the direction of the transmission beam, the comparing unit compares the quality of the reference signal with the quality of the second reference signal, And the quality of the first reference signal and the quality of the second reference signal are transmitted to the transmission apparatus and the quality of the second reference signal and the quality of the second reference signal are compared with each other, The beam may be updated with the transmit beam

According to yet another exemplary embodiment, there is provided a receiver comprising a transmitter for transmitting a reference signal to a receiver using a transmit beam, wherein the receiver receives the reference signal using a receive beam of the receiver and the quality is less than a predetermined threshold Wherein the reference signal is received using a receiving candidate beam in a direction adjacent to the direction of the receiving beam and the receiving candidate beam is updated with the receiving beam based on quality received using the receiving candidate beam, Is provided.

Here, the quality may include at least one of a power value of the received reference signal, an SNR of the received reference signal, and an error rate of the received reference signal.

The receiving apparatus may further include a receiving unit that receives a control signal for changing the direction of the transmission beam for transmitting the reference signal from the receiving apparatus.

The transmission unit may further include a receiving unit, a comparing unit, and a beam tracking unit. The transmitting unit transmits a second reference signal using a transmission candidate beam in a direction adjacent to the direction of the transmission beam. Wherein the comparing unit compares the quality of the reference signal with the quality of the second reference signal and the beam tracking unit adjusts the quality of the reference signal according to the quality of the reference signal and the quality of the third reference signal. The transmission candidate beam may be updated with the transmission beam.

According to yet another exemplary embodiment, there is provided a method of receiving a reference signal transmitted from a transmitting apparatus using a receiving beam, selecting a beam in a direction adjacent to the receiving beam as a receiving candidate beam, Comparing the quality received using the receive beam with the received quality using the receive candidate beam and updating the receive candidate beam with the receive beam in accordance with the comparison result; Is provided.

Here, the quality may include at least one of a power value of the received reference signal, an SNR of the received reference signal, and an error rate of the received reference signal.

The reference signal may correspond to each of a plurality of transmission beams that can be formed by the transmission apparatus, and may be selected from a plurality of reference signals orthogonal to each other.

Also, the reference signal may be multiplexed with the data signal and transmitted from the transmission apparatus.

The method may further include transmitting to the transmission apparatus a control signal for changing a direction of a transmission beam of the transmission apparatus that transmits the reference signal.

Receiving a second reference signal using a transmission candidate beam in a direction adjacent to the direction of the transmission beam and transmitting the quality of the first reference signal and the quality of the second reference signal to the transmission apparatus; And the transmission candidate beam may be updated with the transmission beam according to the quality of the reference signal and the quality of the second reference signal.

According to another exemplary embodiment, there is provided a method for transmitting a reference signal to a receiving device, the method comprising transmitting a reference signal using a transmitting beam to a receiving device, wherein if the quality received using the receiving beam of the receiving device is less than a predetermined threshold Wherein the reference signal is received using a receiving candidate beam in a direction adjacent to the direction of the receiving beam and the receiving candidate beam is updated with the receiving beam based on quality received using the receiving candidate beam, Is provided.

Here, the quality may include at least one of a power value of the received reference signal, an SNR of the received reference signal, and an error rate of the received reference signal.

The method may further include receiving from the receiving apparatus a control signal for changing a direction of the transmission beam for transmitting the reference signal.

The method may further include transmitting a second reference signal using a transmission candidate beam in a direction adjacent to the transmission beam direction, receiving quality of the reference signal and quality of the second reference signal, Comparing the quality of the second reference signal and updating the transmission candidate beam with the transmission beam according to the quality of the reference signal and the quality of the third reference signal, do.

According to the embodiments described below, the beam can be quickly tracked even when the receiving apparatus moves or rotates and the direction of the transmission / reception beam is shifted.

Fig. 1 is a diagram showing a specific example in which beam tracking is required.
FIG. 2 is a flowchart illustrating a step of a reception beam tracking method according to an exemplary embodiment.
FIG. 3 is a flowchart illustrating a step of a transmission beam tracking method according to an exemplary embodiment.
4 is a block diagram illustrating a structure of a receiving apparatus for performing reception beam tracking using a URS.
FIG. 5 is a diagram for explaining a soft switching beam tracking method using a plurality of antenna arrays, frame by frame.
FIG. 6 is a view for explaining a soft switching beam tracking method using a single antenna array according to a frame.
7 is a diagram illustrating a state change of a transmission beam according to a movement of a receiving apparatus.
8 is a diagram showing a tracking state of a transmission beam according to the movement of the receiving apparatus.
FIG. 9 is a diagram illustrating a hard switching transmission beam tracking method frame by frame.
10 is a diagram showing a resource block for transmitting a reference signal.
11 is a diagram illustrating a soft switching transmission beam tracking method frame by frame.
FIG. 12 is a view for explaining a hybrid transmission beam tracking method according to a frame.
13 is a block diagram showing the structure of a receiving apparatus according to an exemplary embodiment.
14 is a block diagram illustrating the structure of a transmission apparatus according to an exemplary embodiment.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.

Fig. 1 is a diagram showing a specific example in which beam tracking is required.

1 (a), a base station 110 forms a transmission beam 121 in the direction of a terminal 130 by using a plurality of base station antennas 120. The terminal 130 also forms a receive beam 131 in the direction of the base station 110. The data transmission performance is maximized when the transmission beam 121 faces the direction of the terminal 130 and the reception beam 131 faces the direction of the base station 110. [

However, when the terminal 140 rotates, the direction of the reception beam 141 also changes. Therefore, the reception beam 141 is not directed in the direction of the base station 110, and the data transmission performance is reduced. In this case, reception beam tracking is required so that the modified reception beam 141 is directed toward the base station 110 again.

1B, the base station 150 forms a transmission beam 161 in the direction of the terminal 170 using a plurality of base station antennas 160. [ The terminal 170 also forms a receive beam 171 in the direction of the base station 150. When the terminal 180 moves, the transmission beam 161 no longer faces the direction of the terminal 180, and the data transmission performance decreases. In this case, transmission beam tracking is required so that the transmission beam 161 is directed to the direction of the terminal 180 on which the transmission beam 161 has moved.

Hereinafter, the present invention will be described by taking the case where the present invention is applied to a downlink of a mobile communication system. That is, the base station of the mobile communication system operates as a transmission apparatus, and the terminal can operate as a reception apparatus. However, the present invention can also be applied to an uplink of a mobile communication system.

FIG. 2 is a flowchart illustrating a step of a reception beam tracking method according to an exemplary embodiment.

In step 210, the receiving device receives a reference signal from the transmitting device. According to one aspect, a receiving apparatus can receive a reference signal using a reception beam formed using a plurality of reception antennas. Here, the receiving apparatus can form a reception beam using a switched beamforming technique. The switched beam forming technique is a technique for selecting one of a plurality of predetermined beams as a reception beam or a transmission beam.

In step 220, the receiving apparatus compares the quality of the received reference signal with the predetermined threshold using the receive beam. Here, the quality of the reference signal may include at least one of the power value of the received reference signal, the SNR of the received reference signal, and the error rate of the received reference signal.

If the quality of the reference signal received using the receive beam is greater than or equal to a predetermined threshold value, the receiving apparatus can determine that the receive beam is directed to the transmitting apparatus and can maintain the receive beam.

However, if the quality of the reference signal received using the receiving beam is below a predetermined threshold, the receiving apparatus can determine that the direction of the receiving beam is not directed to the transmitting apparatus, and can track the receiving beam.

In step 230, the receiving apparatus selects the beam in the direction adjacent to the direction of the receiving beam as the receiving candidate beam. Further, the receiving apparatus receives the reference signal transmitted from the transmitting apparatus using the receiving candidate beam.

In step 240, the receiving apparatus compares the quality of receiving the reference signal using the receiving beam and the quality of receiving the reference signal using the receiving candidate beam. The receiving apparatus can update the receiving candidate beam to the receiving beam in accordance with the comparison result.

More specifically, if the quality received using the receiving candidate beam is better, the receiving device compares the received quality with a predetermined threshold value using the receiving candidate beam in step 270. If the quality received using the receiving candidate beam is greater than or equal to the predetermined threshold, the receiving device updates the receiving candidate beam to the receiving beam in step 280. [

If, in step 270, the quality received using the receiving candidate beam is below a predetermined threshold, then the receiving device may determine that it is not sufficient to update the receiving candidate beam to the receiving beam. In this case, the receiving apparatus determines in step 250 whether another beam can be selected.

If, in step 240, the received quality using the receive beam is better, then the receiving device determines in step 250 whether another beam can be selected.

In step 250, if it is determined that another beam can be selected because it has not yet attempted for all beams, the receiving apparatus may change the receiving candidate beam in step 260 and try to track the beam again.

If it is determined in step 250 that the trial has been completed for all the beams, the receiving apparatus can determine that the data transmission performance can not be increased by the use of the received beam tracking. In this case, the receiving apparatus may transmit, in step 290, a control signal to the transmitting apparatus, which controls to change the direction of the transmitting beam of the transmitting apparatus.

FIG. 3 is a flowchart illustrating a step of a transmission beam tracking method according to an exemplary embodiment.

In step 310, the transmitting apparatus receives a control signal from the receiving apparatus. Here, the control signal can include a meaning of performing transmission beam tracking because the control signal can no longer increase the data transmission performance by the reception beam tracking.

In step 320, the transmitting apparatus selects the beam in the direction adjacent to the direction of the transmission beam as the transmission candidate beam. Further, the transmission apparatus transmits the second reference signal to the reception apparatus using the selected transmission candidate beam.

The receiving device receives the second reference signal and transmits the quality of the second reference signal to the transmitting device.

In step 330, the transmitting apparatus receives the quality of the second reference signal from the receiving apparatus.

In step 340, the transmitting device compares the quality of the second reference signal with the quality of the reference signal.

If the quality of the second reference signal is better, then in step 370 the transmitting apparatus updates the transmit candidate beam to a transmit beam.

If the quality of the reference signal is better, at step 350, the transmitting apparatus determines whether it has attempted for all beams. If it is not yet attempted for all the beams, the transmission candidate beam is changed in step 360.

If an attempt is made for all beams, the transmitting apparatus performs beam training in step 380. [

Hereinafter, the reception beam tracking method and the transmission beam tracking method, which are schematically illustrated in FIGS. 2 to 3, will be described in detail.

1. Receive beam tracking

The reception performance of the reception beam deteriorates because the angle of arrival (AoA) of the reception beam is changed and the reception beam is not aligned in the direction of the transmission apparatus or the direction in which the signal is transmitted. Generally, this occurs when the direction of the receiving apparatus is changed or when the receiving apparatus is moved. In this case, it is necessary to track the receiving beam.

Tracking of the reception beam occurs more frequently than tracking of the transmission beam, and can be performed by the reception apparatus alone without feedback to the transmission apparatus. According to one aspect, tracking of the receive beam may be performed using a reference signal transmitted from the transmitting apparatus. According to one aspect, the reference signal may be a DRS (Dedicated Reference Signal) transmitted on a separate channel for beam tracking, or a UE Specific Reference Signal (URS) multiplexed with data. Here, URS is a signal widely used in LTE systems.

(1) Receive beam tracking using DRS

DRS is a signal transmitted from a transmitting apparatus to a receiving apparatus for beam tracking, and the transmitting apparatus can continuously transmit DRS in a short period. Since the DRS is transmitted irrespective of the data transmission, if the beam tracking is performed using DRS, the reception beam can be tracked even when there is no data transmission.

The DRS is continuously and repeatedly transmitted, and the transmitting apparatus can transmit multiple DRSs. When a transmitting apparatus transmits a plurality of DRSs, each DRS corresponds one-to-one to one transmission beam. In this case, each DRS is transmitted using a corresponding transmission beam. When a plurality of receiving apparatuses use the same transmission beam, a plurality of receiving apparatuses can use the same DRS. When a plurality of terminals use different transmission beams, a plurality of DRSs can be allocated to the same channel resource. In this case, the DRSs can be allocated while maintaining orthogonality with each other.

According to one aspect, as shown in Equation (1), it is possible to transmit the DRS in which the orthogonality between the beams is maintained using the Chu sequence and the ID of the transmission beam is encoded.

[Equation 1]

이다.

는 Chu 시퀀스의 길이를 나타내며 홀수이다.

는 루트인덱스로 빔 ID를 구분하는 파라미터이고, b는 루트인덱스에 대응된다.

는 루트인덱스의 총 수를 나타낸다. n과 a는 Chu 시퀀스를 주파수 영역에서 순환이동시키는 s를 구성하며, s는 Chu시퀀스를 순환이동시킴으로서 셀 ID와 부어레이 ID를 구분한다.

는 셀 ID의 총 수를 나타내고,

는 부어레이 ID의 총 수를 나타낸다.Here, k represents an index of a subcarrier in the OFDM system,

to be.

Represents the length of the Chu sequence and is odd.

Is a parameter for identifying the beam ID with the root index, and b corresponds to the root index.

Represents the total number of root indexes. n and a constitute s that circulatively shifts the Chu sequence in the frequency domain, and s separates the cell ID and the pseudo-random ID by cyclically shifting the Chu sequence.

Represents the total number of cell IDs,

Represents the total number of the subarea IDs.

Using the DRS described in Equation (1), the PAPR performance is excellent due to the characteristics of the Chu sequence, and a relatively large number of the beam IDs and the number of the sub-array IDs can be distinguished. In addition, it is easy to distinguish beam IDs in multi-beam and multi-user environments with excellent correlation properties.

According to one aspect, as shown in Equation (2), it is possible to transmit the DRS in which the orthogonality between the beams is maintained using the Chu sequence and the ID of the transmission beam is encoded.

&Quot; (2) "

이다.

는 Chu 시퀀스의 길이를 나타내며 홀수이다.

는 루트인덱스로 셀 ID를 구분하는 파라미터이고, q는 루트인덱스에 대응된다.

는 셀 ID의 총 수를 나타낸다.

는 빔 탐색 구간으로, 검출과정에서 이 구간 내에서 높은 상관값을 가질 경우 해당 구간에 대응되는 빔 ID와 부 어레이 ID를 검출한다. s는 이 구간을 빔 ID와 부 어레이 ID의 수만큼 구분하는 파라미터이다.

는 빔 ID의 총 수를 나타내며

는 부어레이 ID의 총 수를 나타낸다.Here, k represents an index of a subcarrier in the OFDM system,

to be.

Represents the length of the Chu sequence and is odd.

Is a parameter that distinguishes the cell ID from the root index, and q corresponds to the root index.

Represents the total number of cell IDs.

Is a beam search interval. When a correlation value is high in this interval during the detection process, a beam ID and a sub-array ID corresponding to the corresponding interval are detected. s is a parameter that divides this interval by the number of beam IDs and subarray IDs.

Represents the total number of beam IDs

Represents the total number of the subarea IDs.

이 1보다 큰 자연수가 되도록

의 값ㅇ르 결정한다. 이 방법은 시간영역에서 빔 탐색을 수행하므로, 푸리에 변환을 하지 않아 복잡도가 낮고, 채널의 영향을 크게 받지 않는다. 또한, 타이밍 옵셋이 CP 보다 작을 경우 타이밍 옵셋에 의한 영향을 받지 않는 장점이 있다.Here, particularly

To be a natural number greater than 1

The value of Since this method performs beam search in the time domain, the Fourier transform is not performed, so that the complexity is low and the influence of the channel is not greatly affected. Further, when the timing offset is smaller than the CP, there is an advantage that it is not affected by the timing offset.

When DRS is used, the receiving apparatus can receive data using one receiving beam in a single receiving antenna array. Thus, changing the receive beam may use a hard beam switching method.

(2) Receive beam tracking using URS

The URS is a reference signal that is multiplexed with data and transmitted together with the data to demodulate the data transmitted from the transmission apparatus to the reception apparatus. When receiving beam tracking is performed using URS, data reception is possible using different beams in a plurality of antenna arrays. Therefore, it is possible to individually measure the quality of the URS using each beam, or to combine the received URS or data appropriately (e.g., Maximal Ratio Combine) using each beam to improve performance Switching).

4 is a block diagram illustrating a structure of a receiving apparatus for performing reception beam tracking using a URS. The receiving apparatus according to the exemplary embodiment includes a receiving antenna 410, a plurality of antenna arrays 421 and 422, a plurality of beam formers 431 and 432, a plurality of power measuring units 441 and 442, ), And a demodulation unit 460.

Each antenna array 421, 422 and beam formers 431, 432 receive URS from a transmitting device using different beams.

The power measurement units 441 and 442 measure the reception power corresponding to each beam. The data transmitted together with the URS is combined in the combining unit 450 and demodulated in the demodulating unit 460. [

Equation (3) represents Maximal Ratio Combined and demodulated data.

&Quot; (3) "

는 복조된 데이터,

는 수신 안테나 입력,

는 i 번째 수신 안테나서 수신 빔포밍후의 데이터,

는 전송된 데이터를 각각 나타낸다. 또한,

는 수신 안테나 입력단의 레퍼런스 신호,

는 i 번째 수신 안테나에서 수신 빔포밍 후의 레퍼런스 신호,

는 레퍼런스 신호에 실린 송신 신호를 나타낸다.

는 i 번째 수신 안테나의 가중치 벡터를 나타내고,

는 수신 AoA(Angle of Arrival)에 해당하는 어레이 벡터를 나타낸다.

는 채널 상수이고,

는 송신 빔포밍 이득을 나타내는 상수이다.

는 전송 빔의 가중치 벡터이고,

는 송신 AoD(Angle of Departure)에 해당하는 어레이 벡터를 각각 나타낸다.
here,

Demodulated data,

A receive antenna input,

Is the data after reception beamforming at the i < th > reception antenna,

Represents the transmitted data, respectively. Also,

Is a reference signal at the input terminal of the receiving antenna,

Is the reference signal after reception beamforming at the i < th > reception antenna,

Represents a transmission signal contained in the reference signal.

Represents the weight vector of the i < th > receive antenna,

Represents an array vector corresponding to the received AoA (Angle of Arrival).

Is a channel constant,

Is a constant indicating the transmission beamforming gain.

Is a weight vector of the transmission beam,

Represents an array vector corresponding to the transmission AoD (Angle of Departure).

Equation (4) represents the reception power of the URS received using each beam.

&Quot; (4) "

를 추정한다. 그리고 추정된 채널 상수 값을 이용하여 각각의 빔에서 수신된 데이터를 최대비 결합(수학식 3의 첫 번째 식 참조)하여 신호를 복조할 수 있다.
Referring to Equations (3) and (4), for soft switching beam tracking with a plurality of antenna arrays, the received power is measured using a reference signal at each receiving antenna,

. And demodulate the signal by using the maximum ratio combining (see the first expression of Equation (3)) of the data received from each beam using the estimated channel constant value.

FIG. 5 is a diagram for explaining a soft switching beam tracking method using a plurality of antenna arrays, frame by frame.

(512)를 이용하여 데이터 및 레퍼런스 신호를 수신하고, 수신된 레퍼런스 신호의 전력을 측정한다. 수신 빔(511, 513)은 활성화 되지 않았다.At t = k-1 < RTI ID = 0.0 > 510,

(512) to receive data and a reference signal, and measures the power of the received reference signal. The receiving beams 511 and 513 are not activated.

(522)에 인접한 수신 후보 빔

+1(521)을 이용하여 데이터 및 레퍼런스 신호를 수신하고, 각 빔(521, 522)을 이용하여 수신된 레퍼런스 신호의 전력을 측정한다. 수신 빔(523)은 활성화 되지 않았다.At t = k 520,

Lt; RTI ID = 0.0 > 522 < / RTI &

+1 521, and measures the power of the received reference signal using each of the beams 521 and 522. The receive beam 523 is not activated.

(532)에 인접한 수신 후보 빔

-1(533)을 이용하여 데이터 및 레퍼런스 신호를 수신하고, 각 빔(532, 533)을 이용하여 수신된 레퍼런스 신호의 전력을 측정한다. 수신 빔(531)은 활성화 되지 않았다.At t = k + 1 530,

RTI ID = 0.0 > 532 < / RTI >

-1 533, and measures the power of the received reference signal using each of the beams 532 and 533. The receiving beam 531 is not activated.

(543)에 인접하지 않은 빔을 수신 후보 빔(541)로 선택하여 데이터 및 레퍼런스 신호를 수신하고, 각 빔(541, 543)을 이용하여 수신된 레퍼런스 신호의 전력을 측정한다. 수신 빔(542, 544)은 활성화 되지 않았다. t=k+2(540)과 같은 트래킹 절차는 수신한 레퍼런스 신호의 품질이 미리 결정된 임계값 이상인 우수한 수신 후보 빔을 찾을 때까지 진행될 수 있다.At t = k + 2 540,

Selects a beam not adjacent to the beam 543 as a reception candidate beam 541, receives data and a reference signal, and measures the power of the received reference signal using each beam 541 and 543. The receive beams 542 and 544 are not activated. A tracking procedure such as t = k + 2 540 may be performed until an excellent received candidate beam whose quality of received reference signal is higher than a predetermined threshold value is found.

+1(551)을 새로운 수신 빔으로 이용하여 데이터 및 레퍼런스 신호를 수신한다. 다른 빔들(552, 553)은 활성화 되지 않았다.
At t = k + n (550), the receive beam tracking procedure has been completed. The receiving device

+1 551 as a new receive beam to receive data and reference signals. The other beams 552 and 553 were not activated.

FIG. 6 is a view for explaining a soft switching beam tracking method using a single antenna array according to a frame.

(612)를 이용하여 데이터 및 레퍼런스 신호를 수신하고, 수신된 레퍼런스 신호의 전력을 측정한다. 빔(611, 613)은 활성화 되지 않았다.At t = k-1 610, the receiving device receives the received beam < RTI ID = 0.0 >

(612), and measures the power of the received reference signal. Beams 611 and 613 were not activated.

+1(621)을 이용하여 데이터 및 레퍼런스 신호를 수신하고, 수신된 레퍼런스 신호의 전력을 측정한다. 빔(622, 623)은 활성화 되지 않았다.At t = k 620, the receiving apparatus receives the reception candidate beam < RTI ID = 0.0 &

+1 621 to receive the data and the reference signal, and measures the power of the received reference signal. Beams 622 and 623 were not activated.

-1(633)을 이용하여 데이터 및 레퍼런스 신호를 수신하고, 수신된 레퍼런스 신호의 전력을 측정한다. 빔(631, 632)은 활성화 되지 않았다.At t = k + 1 630,

-1 633, and measures the power of the received reference signal. Beams 631 and 632 were not activated.

+2 (641)을 이용하여 데이터 및 레퍼런스 신호를 수신하고, 수신된 레퍼런스 신호의 전력을 측정한다. 수신 빔(642, 643, 644)은 활성화 되지 않았다. t=k+2(640)과 같은 트래킹 절차는 수신한 레퍼런스 신호의 품질이 미리 결정된 임계값 이상인 우수한 수신 후보 빔을 찾을 때까지 진행될 수 있다.At t = k + 2 (640), the receiving device receives

+2 641, and measures the power of the received reference signal. The receive beams 642, 643, and 644 are not activated. A tracking procedure such as t = k + 2 640 may be performed until a good received candidate beam whose quality of received reference signal is above a predetermined threshold value is found.

+1(651)을 새로운 수신 빔으로 이용하여 데이터 및 레퍼런스 신호를 수신한다. 다른 빔들(652, 653)은 활성화 되지 않았다.
At t = k + n (650), the receive beam tracking procedure has been completed. The receiving device

+1 651 as the new receive beam to receive the data and the reference signal. The other beams 652 and 653 were not activated.

2. Transmission beam tracking

7 is a diagram illustrating a state change of a transmission beam according to a movement of a receiving apparatus.

The Angle of Departure (AoD) of the transmission beam is defined as the angle 731, 741 between the direction 720 of the transmission beam 710 and the direction of the receiving device 730, 740. As the receiving devices 730 and 740 move, the AoD change 750 occurs.

The Angle of Arrival (AoA) of the receive beam is defined as the angle 732, 742 between the direction 733, 743 of the receiving device and the direction of the transmitting device 710. As receiving apparatuses 730 and 740 move, AoA also changes.

When the receiving apparatus moves from the position 730 to the position 740, the transmission gain is changed according to the AoD (Angle of Departure) change of the transmission beam, and the reception gain is changed in accordance with the change of AoA (Angle of Arrival). That is, since the transmission gain and the reception gain are changed at the same time, the power of the reference signal received by the receiving device sharply decreases.

The transmission beam tracking is a technique for searching a transmission beam for switching to a beam capable of providing a higher quality when the receiving apparatus is located at the boundary of the beam while moving and the quality of the reference signal is degraded. For this, the average reception power of the transmission candidate beam adjacent to the transmission beam and the direction of the transmission beam should be continuously estimated.

8 is a diagram showing a tracking state of a transmission beam according to the movement of the receiving apparatus. The transmission device may form four beams 810, 820, 830, 840. Regions 850, 860, 870, and 880 corresponding to the beams 810, 820, 830, and 840 each having a gain greater than that of other beams are associated with each beam 810, 820, 830,

The first receiving device 811 can move from the current transmitting beam 810 and the second receiving device 812 can move from the current transmitting beam 830 to the area of the same adjacent beam 820. [ The receiving apparatus receives the reference signal transmitted using the beam and measures the quality of the received reference signal. The receiving apparatus can determine whether or not the receiving apparatus has moved away from the center of the transmitting beam based on the quality of the reference signal.

If the receiving device determines that it is away from the center of the transmitting beam, the receiving device may receive the reference signal using the transmitting candidate beam around the transmitting beam to perform beam tracking. The receiving apparatus can update the transmission candidate beam to the transmission beam according to the quality of the reference signal received using the transmission candidate beam.

(1) transmission beam tracking using DRS, (2) transmission beam tracking using URS, and (3) transmission beam tracking using a hybrid scheme will be described.

(1) transmission beam tracking using DRS

DRS is a signal transmitted from a transmitting apparatus to a receiving apparatus for beam tracking, and may be transmitted only in a transmission beam tracking period for a receiving apparatus requiring transmission beam tracking. The transmitting device can transmit multiple DRSs. When a transmitting apparatus transmits a plurality of DRSs, each DRS corresponds one-to-one to one transmission beam. In this case, each DRS is transmitted using a corresponding transmission beam. When a plurality of receiving apparatuses use the same transmission beam, a plurality of receiving apparatuses can use the same DRS. The DRS may be sequentially assigned one frame at a time, or may include a plurality of frames at the same time in the same frame. In the latter case, all DRSs must be allocated with orthogonality maintained. It is assumed that the resource to which the DRS is allocated is known between the transmitting apparatus and the receiving apparatus in advance.

Transmission beam tracking using DRS is performed according to the following procedure.

1) When the receiving apparatus requests the transmission beam tracking, the transmitting apparatus transmits a message to the receiving apparatus about the allocation of the DRS. The DRS allocation message may include a field indicating an allocation region of a DRS channel resource corresponding to each beam, a beam index, and an attribute of an orthogonal code corresponding to each index.

2) The receiving apparatus can receive the DRS allocation message and measure the quality of the received reference signal using each beam using the allocated DRS channel.

3) The receiving device feeds back the quality of the reference signal to the transmitting device. The transmitting apparatus can determine whether to switch to the adjacent beam using the quality of the reference signal. Here, the transmission and the quality measurement of the reference signal can be continuously performed until the beam switching is performed.

4) If it is determined that either the current transmission beam or the transmission candidate beams are not enough to transmit data, the transmission beam can be determined again through the beam training procedure.

FIG. 9 is a diagram illustrating a hard switching transmission beam tracking method frame by frame.

In FIG. 9, a data transmission beam for data transmission and a reference transmission beam for transmitting a reference signal are separated. Data transmission is performed using the previous data transmission beam until an optimal beam is selected using DRS.

At t = k-1 910, the data is transmitted using beam 912. Adjacent beams 911 and 913 are not activated. In this case, the reference signal is transmitted using beam 915. Adjacent beams 914 and 916 are not activated.

At t = k 920, the data is transmitted using beam 922. The adjacent beams 921 and 923 are not activated. The reference signal is transmitted using a beam 925 and a candidate beam 924 adjacent to beam 925. The adjacent other beam 926 is not activated.

At t = k + 1 930, the data is transmitted using beam 932. Adjacent beams 931 and 933 are not activated. The reference signal is transmitted using a beam 935 and a candidate beam 936 adjacent to beam 935. The adjacent other beam 934 is not activated.

At t = k + 2 940, the data is transmitted using beam 942. Adjacent beams 941 and 943 are not activated. The reference signal is transmitted using beam 945 and candidate beam 944 adjacent to beam 945. [ The adjacent other beam 946 is not activated. The transmission apparatus can compare the case of t = k and the case of t = k + 1 to select a new transmission beam.

At t = k + n 950, the transmission beam is changed. Data is transmitted using beam 951. The other beams 952 and 953 are not activated. The reference signal is transmitted using beam 954, and the other beams 955 and 956 are not activated.

At t = k + n + 1 960, the transmission beam tracking procedure is completed. Data is transmitted using beam 961. The other beams 962 and 963 are not activated. The reference signal is no longer transmitted, and all beams are deactivated.

(2) transmission beam tracking using URS

The transmission beam tracking using URS is performed according to the following procedure.

과 전송 후보 빔

+1)을 통하여 데이터를 전송할 수 있다. 이 경우에, 수신 장치는 전송 후보 빔

+1을 이용하여 수신한 레퍼런스 신호의 품질을 측정한다.1) When the receiving apparatus transmits a beam tracking request, the base station transmits two beams

And the transmission candidate beam

+1). ≪ / RTI > In this case, the receiving apparatus transmits the transmission candidate beam

The quality of the reference signal received using +1 is measured.

-1을 선택하고, 전송 빔

와 전송 후보 빔

-1을 이용하여 데이터를 전송한다. 수신 장치는 전송 후보 빔

-1을 이용하여 수신한 레퍼런스 신호의 품질을 측정한다.2) In the next frame, another transmission candidate beam

-1 is selected, and the transmission beam

And the transmission candidate beam

-1 to transmit the data. The receiving apparatus transmits the transmission candidate beam

-1 to measure the quality of the received reference signal.

3) The receiving apparatus transmits, to the transmitting apparatus, the index of the transmission candidate beam having the superior quality of the reference signal among the two transmission candidate beams.

와 전송 후보 빔

+1을 이용하여 데이터를 전송하며, 수신 장치는 빔 스위칭 여부를 결정한다.
4)

And the transmission candidate beam

+1, and the receiving apparatus determines whether to switch the beam.

In the transmission beam tracking method using URS, data may be transmitted using a separate resource corresponding to each beam, or data may be transmitted using only one resource. This will be described in detail with reference to FIG.

10 is a diagram showing a resource block for transmitting a reference signal.

10A is an example of data and URS allocation for demodulating power and data of each beam when two beams are superimposed on one resource and transmitted. One resource block is divided into a data area and two URS areas 1011 to 1014 and 1015 to 1018. The data area is beamformed using a weight vector that is the sum of the two beam weight vectors, and the two URS areas are beamformed using two different weight vectors to enable separate measurement of the power of each beam.

In this case, the reception signal at the receiving apparatus can be expressed by the following equation (5).

&Quot; (5) "

는 데이터,

는 제1 빔을 이용하여 수신한 레퍼런스 신호,

는 제2 빔을 이용하여 수신한 레퍼런스 신호를 나타낸다.here,

Data,

A reference signal received using the first beam,

Represents a reference signal received using the second beam.

는 데이터,

는 i 번째 전송 빔을 이용하여 전송되는 레퍼런스 신호이다.

은 수신 빔포밍 이득을 나타내는 상수이며,

는 수신 신호의 방향을 나타내는 어레이 벡터,

는 수신단의 가중치 벡터이다.

는 전송 빔을 형성하는 가중치 벡터이고,

는 전송 후보 빔을 형성하는 가중치 벡터이다.

는

에 해당하는 어레이 벡터이다.

는 전송 빔과 전송 후보 빔을 중첩하여 전송된 신호의 채널 상수이고,

은 전송 빔을 이용하여 전송된 신호의 채널 상수,

는 전송 후보 빔을 이용하여 전송된 신호의 채널 상수이다.

Data,

Is a reference signal transmitted using the i < th > transmission beam.

Is a constant indicating the reception beamforming gain,

An array vector indicating the direction of the received signal,

Is the weight vector of the receiving end.

Is a weight vector forming a transmission beam,

Is a weight vector that forms a transmission candidate beam.

The

. ≪ / RTI >

Is a channel constant of a signal transmitted by superimposing a transmission beam and a transmission candidate beam,

Is a channel constant of a transmitted signal using a transmission beam,

Is the channel constant of the transmitted signal using the transmitted candidate beam.

Referring to Equation (5), the received power of the reference signal received using each beam is individually measured. When demodulating the data, the sum of the estimated values of the reference signals is given as an estimate of the channel constant of the data area. The received power of the channel estimation value and the reference signal received using each beam can be calculated by Equation (6).

&Quot; (6) "

는 데이터 복조를 위한 채널 추정치,

는 각 빔의 추정 전력을 나타낸다.
here,

A channel estimate for data demodulation,

Represents the estimated power of each beam.

FIG. 10B shows a resource block and a URS structure when data is allocated to two resources. In this case, separate resource blocks 1020 and 1030 are allocated to the transmission beam and the transmission candidate beam, respectively. Each resource block 1020 and 1030 includes URS areas 1021 to 1024 and 1031 to 1034. The same data is transferred to the data areas of the resource blocks 1020 and 1030.

를 이용하여 최대비 결합한 데이터

는 하기 수학식 7과 같이 나타낼 수 있다.
After receiving beamforming, a received signal corresponding to the data of each resource block

The maximum non-combined data

Can be expressed by the following Equation (7).

&Quot; (7) "

The received signal of each reference signal is expressed by Equation (5), and the received power is represented by Equation (6).

Referring to Equation (7), when two resource blocks are used, the received power of each reference signal is measured using Equation (6), and a channel constant of each beam is estimated. Then, the maximum ratio combining can be performed by multiplying the estimated channel constant value by the reception signal corresponding to the data area of each resource block.

11 is a diagram illustrating a soft switching transmission beam tracking method frame by frame. When URS is used, both data transmission and reference signal transmission are performed.

At t = k-1 1110, the data and reference signals are transmitted using beam 1112. [ Adjacent beams 1111 and 1113 are not activated.

At t = k 1120, the data and reference signals are transmitted using beams 1121 and 1122. Beam 1123 is not activated.

At t = k + 1 1130, the data and reference signals are transmitted using beams 1132 and 1133. Beam 1131 is not activated.

The receiving apparatus measures the reception power of the reference signal transmitted using the beam 1121 at t = k 1120 and the reception power of the reference signal transmitted using the beam 1133 at t = k + 1 1130 Measure power.

At t = k + 2 1140, the data and reference signals are transmitted using beams 1141 and 1142. [ The beam 1143 is not activated. The transmission apparatus can select a transmission beam among the beams 1121 and 1141 and the beam 1133. [

At t = k + n 1150, the transmitting apparatus can change the transmit beam with beam 1151. Even in this case, the transmitting apparatus can transmit the data and the reference signal using both the beam 1151 and the beam 1152. [

At t = k + n + 1 1160, if the received power of the reference signal transmitted using the beam 1162 is very small, the transmitting apparatus can stop the data transmission using the beam 1162. In this case, the data and the reference signal are transmitted using only the beam 1161. [ Beam 1163 is deactivated.

At t = k + n + 2 (1170), the transmitting device stops transmitting data.

(3) transmission beam tracking using hybrid technique

The hybrid scheme combines DRS and URS to perform transmission beam tracking. In the hybrid scheme, DRS is used to find the optimal transmission candidate beam, and data is transmitted using the current transmission beam and the optimal transmission candidate beam. Also, the URS multiplexed with the data is transmitted using each beam, and the received power of the transmitted URS is measured. With this method, it is not necessary to limit the candidate transmission beam to a beam adjacent to the transmission beam, and beam switching in a wider range can be performed. In addition, since data is transmitted using two beams, data transmission performance is improved.

The transmission beam tracking using the hybrid technique proceeds according to the following procedure.

1) Upon receiving a transmission beam tracking request from the receiving apparatus, the transmitting apparatus transmits DRS. The receiving apparatus measures the received power of the DRS and selects a transmission candidate beam. The receiving apparatus transmits the ID of the selected transmission candidate beam to the transmitting apparatus.

2) The transmitting apparatus stops the DRS transmission and transmits the data using the transmission beam and the transmission candidate beam. The receiving device measures the received power of the URS multiplexed into the data.

3) The receiving apparatus determines whether the beam is switched using the received power of the transmitted URS using each beam

FIG. 12 is a view for explaining a hybrid transmission beam tracking method according to a frame.

At t = k-1 1210, the data is transmitted using beam 1212. Adjacent beams 1211 and 1213 are not activated. In this case, the DRS is transmitted using the beam 1215. Adjacent beams 1214 and 1216 are not activated.

At t = k 1220, the data is transmitted using beam 1222. [ Adjacent beams 1221 and 1223 are not activated. DRS is transmitted using beam 1225 and beam 1224. [ The adjacent other beam 1226 is not activated.

At t = k + 1 1230, the data is transmitted using beam 1232. Adjacent beams 1231 and 1233 are not activated. DRS is transmitted using beam 1235 and beam 1236. [ Adjacent beams 1234 are not activated.

At t = k 1220 and t = k + 1 1230, the receiving apparatus measures the reception quality of the DRS and selects the transmission candidate beam according to the measurement result.

At t = k + 2 1240, the data and URS are transmitted using beam 1241 and beam 1242. The beam 1241 is a beam selected as a transmission candidate beam. Beam 1243 is not activated. The receiving apparatus can measure the reception quality of the received URS using each of the beams 1241 and 1242.

At t = k + n 1250, the data and URS are transmitted using beam 1251 and beam 1252. The beam 1253 is not activated. The transmitting or receiving device may decide to switch to beam 1251.

At t = k + n + 1 1260, the data and URS are transmitted using beam 1261. Beams 1262 and 1263 are not activated.

At t = k + n + 2 1270, the transmitting device stops transmitting data.

Although the present invention has been described above with reference to the case where the present invention is applied to a downlink of a mobile communication system, the present invention can be applied to an uplink of a mobile communication system. When the present invention is applied to the uplink of a mobile communication system, the DRS may be replaced with a random access channel (RACH) of the uplink. Also, the URS may be replaced with a DMRS (DeModulation RS) of the uplink.

13 is a block diagram showing the structure of a receiving apparatus according to an exemplary embodiment.

The receiving apparatus 1300 according to the exemplary embodiment includes a receiving unit 1310, a candidate beam selecting unit 1320, a comparing unit 1330, a beam tracking unit 1340, and a transmitting unit 1350.

Receiver 1310 Receives a reference signal from transmitter 1360. According to one aspect, the receiving apparatus 1300 can receive a reference signal using a reception beam formed using a plurality of reception antennas.

The comparing unit 1330 compares the quality of the received reference signal with the predetermined threshold using the reception beam. Here, the quality of the reference signal may include at least one of the power value of the received reference signal, the SNR of the received reference signal, and the error rate of the received reference signal.

If the quality of the reference signal received using the receive beam is less than a predetermined threshold, then the receiving device may determine that the direction of the receive beam is not directed to the direction of the transmission and may track the receive beam.

The candidate beam selector 1320 selects a beam in a direction adjacent to the direction of the reception beam as a reception candidate beam. In this case, the receiving unit 1310 receives the reference signal transmitted from the transmitting apparatus 1360 using the receiving candidate beam.

The comparing unit 1330 compares the quality of the reference signal received using the receive beam and the received quality of the reference signal using the receive candidate beam. The beam tracking unit 1340 can update the reception candidate beam to the reception beam in accordance with the comparison result.

More specifically, if the quality received using the receiving candidate beam is better, the receiving device compares the received quality with a predetermined threshold value using the receiving candidate beam in step 270. If the quality received using the receiving candidate beam is greater than or equal to the predetermined threshold, the receiving device updates the receiving candidate beam to the receiving beam in step 280. [

If the quality received using the receiving candidate beam is less than a predetermined threshold or is lower than the quality received using the receiving beam, then the receiving apparatus may determine that it is insufficient to update the receiving candidate beam to the receiving beam . In this case, the candidate beam selector 1320 determines whether another beam can be selected.

If it is not possible to select another beam by completing the attempt for all beams, the receiving apparatus may decide to perform tracking of the transmission beam. In this case, the transmission unit 1350 may transmit a control signal to the transmission apparatus to change the direction of the transmission beam of the transmission apparatus.

When tracking of the transmission beam is performed, the reception unit 1310 can receive the second reference signal transmitted from the transmission apparatus 1360 using the transmission candidate beam in the direction adjacent to the transmission beam.

In this case, the transmitting unit 1350 can transmit the quality of the reference signal and the quality of the second reference signal to the transmitting apparatus 1360. The quality of the reference signal and the quality of the second reference signal may be compared in transmitting apparatus 1360 and used to update the transmit beam.

14 is a block diagram illustrating the structure of a transmission apparatus according to an exemplary embodiment.

The transmitting apparatus 1400 according to the exemplary embodiment includes a receiving unit 1410, a candidate beam selecting unit 1420, a transmitting unit 1430, a comparing unit 1440, and a beam tracking unit 1450.

The receiving unit 410 receives a control signal from the receiving apparatus.

The candidate beam selector 1420 selects a beam in the direction adjacent to the direction of the transmission beam as a transmission candidate beam according to the control signal. The transmission unit 1430 transmits the second reference signal to the reception device using the selected transmission candidate beam do.

The receiving device receives the second reference signal and transmits the quality of the second reference signal to the transmitting device.

The receiving unit 1410 receives the quality of the second reference signal and the quality of the reference signal from the receiving apparatus.

The comparing unit 1440 compares the quality of the second reference signal with the quality of the reference signal. If the quality of the second reference signal is better, the beam tracking unit 1450 updates the transmission candidate beam to the transmission beam.

If the quality of the reference signal is better, the candidate beam selector 1420 determines whether or not all the beams have been tried. If not all the beams have been tried yet, the candidate beam selector 1420 changes the transmission candidate beam and retries the beam tracking again.

If an attempt is made for all beams, the transmitting apparatus performs beam training.

The method according to an embodiment may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions to be recorded on the medium may be those specially designed and configured for the embodiments or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. For example, it is to be understood that the techniques described may be performed in a different order than the described methods, and / or that components of the described systems, structures, devices, circuits, Lt; / RTI > or equivalents, even if it is replaced or replaced.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

110: Transmission device
120: Transmission antenna
121: transmission beam
130, 140: receiving device
131, 141: receiving beam

Claims (22)

A receiving unit for receiving a reference signal transmitted from a transmitting apparatus using a receiving beam;
A candidate beam selector for selecting a beam in a direction adjacent to the direction of the reception beam as a reception candidate beam;
A comparison unit for comparing the quality of the reference signal received using the reception beam and the reception quality of the reference signal received using the reception candidate beam; And
And a beam tracking unit for updating the reception candidate beam with the reception beam according to the comparison result,
.
The method according to claim 1,
Wherein the quality comprises at least one of a power value of the received reference signal, an SNR of the received reference signal, and an error rate of the received reference signal.
The method according to claim 1,
Wherein the reference signal corresponds to each of a plurality of transmission beams that can be formed by the transmission apparatus, and is selected from among a plurality of reference signals orthogonal to each other.
The method according to claim 1,
Wherein the reference signal is multiplexed with a data signal and transmitted from the transmission apparatus.
The method according to claim 1,
Wherein the receiving unit forms a plurality of reception beams, receives the reference signals using each of the plurality of reception beams, and combines the received reference signals.
The method according to claim 1,
A transmission unit for transmitting a control signal for changing a direction of a transmission beam of the transmission apparatus that transmits the reference signal to the transmission apparatus;
Further comprising:
The method according to claim 6,
Wherein the receiving unit receives the second reference signal using the transmission candidate beam in the direction adjacent to the direction of the transmission beam,
Wherein the comparing unit compares the quality of the reference signal with the quality of the second reference signal,
Wherein the transmission unit transmits the comparison result or the quality of the first reference signal and the quality of the second reference signal to the transmission apparatus,
And the transmission candidate beam is updated with the transmission beam according to the comparison result or the quality of the reference signal and the quality of the second reference signal.
A transmitting unit for transmitting a reference signal to a receiving apparatus using a transmission beam,
Lt; / RTI >
When the quality of the reference signal received using the receiving beam of the receiving apparatus is less than a predetermined threshold value, the reference signal is received using a receiving candidate beam in a direction adjacent to the direction of the receiving beam, And the reception candidate beam is updated with the reception beam based on quality received using the beam.
9. The method of claim 8,
Wherein the quality comprises at least one of a power value of the received reference signal, an SNR of the received reference signal, and an error rate of the received reference signal.
9. The method of claim 8,
A receiver for receiving a control signal for changing the direction of the transmission beam for transmitting the reference signal from the receiver;
Further comprising:
11. The method of claim 10,
A receiving unit;
A comparator;
The beam-
Further comprising:
Wherein the transmission unit transmits a second reference signal using a transmission candidate beam in a direction adjacent to the transmission beam,
Wherein the receiving unit receives the quality of the reference signal and the quality of the second reference signal,
Wherein the comparing unit compares the quality of the reference signal with the quality of the second reference signal,
Wherein the beam tracking unit updates the transmission candidate beam with the transmission beam according to the quality of the reference signal and the quality of the second reference signal. Receiving a reference signal transmitted from a transmitting apparatus using a receiving beam;
Selecting a beam in a direction adjacent to the direction of the reception beam as a reception candidate beam;
Comparing the received quality of the reference signal using the received beam and the received quality of the reference signal using the received candidate beam; And
Updating the reception candidate beam to the reception beam in accordance with the comparison result
The method comprising the steps of:
13. The method of claim 12,
Wherein the quality comprises at least one of a power value of the received reference signal, an SNR of the received reference signal, and an error rate of the received reference signal.
13. The method of claim 12,
Wherein the reference signal corresponds to each of a plurality of transmission beams that can be formed by the transmission apparatus, and is selected from among a plurality of reference signals that are orthogonal to each other.
13. The method of claim 12,
Wherein the reference signal is multiplexed with a data signal and transmitted from the transmission apparatus.
13. The method of claim 12,
And transmitting a control signal for changing a direction of a transmission beam of the transmission apparatus that transmits the reference signal to the transmission apparatus.
17. The method of claim 16,
Receiving a second reference signal using a transmission candidate beam in a direction adjacent to the direction of the transmission beam;
Transmitting the quality of the first reference signal and the quality of the second reference signal to the transmitting apparatus;
Further comprising:
Wherein the transmission candidate beam is updated with the transmission beam according to the quality of the reference signal and the quality of the second reference signal.
Transmitting the reference signal to the receiving device using the transmission beam
Lt; / RTI >
When the quality of the reference signal received using the receiving beam of the receiving apparatus is less than a predetermined threshold value, the reference signal is received using a receiving candidate beam in a direction adjacent to the direction of the receiving beam, Wherein the receiving candidate beam is updated with the receiving beam based on quality received using the beam.
19. The method of claim 18,
Wherein the quality comprises at least one of a power value of the received reference signal, an SNR of the received reference signal, and an error rate of the received reference signal.
19. The method of claim 18,
Further comprising receiving from the receiving apparatus a control signal for changing a direction of the transmission beam transmitting the reference signal.
21. The method of claim 20,
Transmitting a second reference signal using a transmission candidate beam in a direction adjacent to the direction of the transmission beam,
Receiving the quality of the reference signal and the quality of the second reference signal;
Comparing the quality of the reference signal with the quality of the second reference signal; And
Updating the transmission candidate beam with the transmission beam according to the quality of the reference signal and the quality of the second reference signal
Further comprising the steps of: A computer-readable recording medium on which a program for executing the method according to any one of claims 12 to 21 is recorded.

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