KR20180089371A - Synchronization signal receiving apparatus and method - Google Patents

Abstract

According to the present invention, disclosed are an apparatus for receiving a synchronization signal and a method thereof which can increase the overall beamforming synchronization performance by quickly performing beam tracking in a receiving apparatus in performing timing synchronization and beamforming synchronization between transmitting/receiving apparatuses communicating based on a beamforming technology.

Description

Technical Field [0001] The present invention relates to a synchronous signal receiving apparatus and a synchronous signal receiving method.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synchronization technique in a MIMO system, and more particularly, to a technique for performing timing synchronization and beamforming synchronization between transmitting and receiving devices in a MIMO system, To improve overall beamforming synchronization performance.

In recent years, by performing communication based on beamforming technology on the premise that the number of antennas of a transmitting apparatus and the number of antennas of a receiving apparatus are provided, A variety of techniques have been developed that can expect a transmission capacity gain, and MIMO (Multiple Input Multiple Output) technology is a typical technique.

The greatest part of obtaining a transmission capacity gain in a communication system of a MIMO technology (hereinafter referred to as a MIMO system) is a diversity gain and a multiplexing gain through beamforming.

For this purpose, beamforming techniques used in MIMO systems are divided into analog beamforming, digital beamforming, and hybrid beamforming. In the MIMO system, the hybrid beamforming technique combining the two beamforming techniques is mainly used because of the disadvantages of the digital beamforming technique in which the RF chain is required for the number of antennas and the installation cost is increased and the analog beamforming technique in which the performance gain is limited .

Between the transmitting / receiving apparatuses communicating based on the beam-forming technique, various direction / type antenna beams which can be formed by the transmitting apparatus and antenna beams of various directions / shapes which can be formed by the receiving apparatus are used, It is very important to select and synchronize.

However, in the conventional beamforming technique, a method of performing timing synchronization and beamforming synchronization between transmitting / receiving devices has not been proposed in detail.

Accordingly, there is a need for a concrete method capable of rapidly tracking beam tracking in a receiving apparatus, thereby reducing the failure rate of beam forming synchronization between transmitting and receiving apparatuses and improving overall beam forming synchronization performance.

Accordingly, the present invention proposes a method of improving the overall beamforming synchronization performance by enabling fast beam tracking in a receiving apparatus.

SUMMARY OF THE INVENTION It is an object of the present invention to provide timing synchronization and beamforming synchronization between transmitting and receiving apparatuses in a MIMO system, ) To improve overall beamforming synchronization performance.

According to an aspect of the present invention, there is provided an apparatus for receiving a synchronization signal by a base station in a MIMO system, comprising: a base station for receiving a first synchronization signal for frequency synchronization and a second synchronization signal for frame synchronization from a base station, A timing synchronization performing unit for performing timing synchronization with the base station; And a beamforming synchronization performing unit for receiving a third synchronization signal from the base station through two or more antenna beams formed in different directions and performing beamforming synchronization with the base station.

Specifically, the BS configures a plurality of radio resource blocks, each of which is a combination of two or more neighbors among unit radio resources classified in a specific unit, in a designated radio resource for synchronization between devices, It is possible to transmit the beam synchronization signal as the third synchronization signal through the antenna beams in different directions.

Specifically, the radio communication apparatus may further include a radio resource configuration unit configured to configure at least two reception blocks in which a unit radio resource designated in each of the plurality of radio resource blocks is combined in the radio resource; The beamforming synchronization performing unit may receive a beam synchronization signal as the third synchronization signal through the at least two antenna beams formed for the at least two reception blocks.

Specifically, the number of unit radio resources to be combined in the reception block can be determined according to the number of antenna beams that can be formed in the base station.

Specifically, the base station configures an information transmission block for transmitting information related to the communication system between each radio resource block in the radio resource, and transmits information allocated to the information transmission block to a neighboring 2 Through the antenna beam formed in any one of the radio resource blocks.

In particular, in each of the two or more antenna beams, the information transmitted through at least one antenna beam of the base station may be received.

According to a second aspect of the present invention, there is provided a method for receiving a synchronization signal by a base station in a MIMO system, the method including receiving a first synchronization signal for frequency synchronization and a second synchronization signal for frame synchronization from a base station, Performing timing synchronization with a base station; And a beamforming synchronization performing unit that receives a third synchronization signal from the base station through two or more antenna beams formed in different directions and performs beamforming synchronization with the base station.

Specifically, the BS configures a plurality of radio resource blocks, each of which is a combination of two or more neighbors among unit radio resources classified in a specific unit, in a designated radio resource for synchronization between devices, It is possible to transmit the beam synchronization signal as the third synchronization signal through the antenna beams in different directions.

Specifically, the method further includes a radio resource configuration step of configuring at least two reception blocks, each of which is a combination of unit radio resources assigned to each of the plurality of radio resource blocks, in the radio resource; The step of performing the beamforming synchronization may receive the beam synchronization signal as the third synchronization signal through the at least two antenna beams formed for each of the at least two reception blocks.

Specifically, the base station configures an information transmission block for transmitting information related to the communication system between each radio resource block in the radio resource, and transmits information allocated to the information transmission block to a neighboring 2 Through the antenna beam formed in any one of the radio resource blocks.

In particular, in each of the two or more antenna beams, the information transmitted through at least one antenna beam of the base station may be received.

According to the synchronization signal transmitting apparatus and the synchronization signal transmitting method of the present invention, in timing synchronization and beamforming synchronization between transmitting and receiving apparatuses in a MIMO system, it is possible to perform fast beam tracking in a receiving apparatus Thereby achieving an effect of improving overall beamforming synchronization performance.

1 is an exemplary diagram showing a MIMO system using a beamforming technique to which the present invention is applied.
2 is an exemplary diagram illustrating a configuration of a synchronization signal transmission apparatus according to an embodiment of the present invention.
3 is an exemplary diagram illustrating a configuration of a synchronization signal receiving apparatus according to an embodiment of the present invention.
4 is an exemplary diagram illustrating a radio resource structure of a downlink synchronization channel according to an embodiment of the present invention.
5 is an exemplary diagram illustrating a flow of a synchronization signal receiving method according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

1 is an exemplary diagram showing a MIMO system using a beamforming technique to which the present invention is applied.

The MIMO (Multiple Input Multiple Output) technique is a technique that can expect a transmission capacity gain proportional to the number of transmission antennas and the number of reception antennas even if no additional frequency or power is used. And a diversity gain and a multiplexing gain.

For this purpose, beamforming techniques used in MIMO systems are divided into digital beamforming, analog beamforming, and hybrid beamforming.

In the case of digital beamforming, the number of beams that can be formed is determined by the number of RF chains, and a plurality of beams formed by digital beamforming improves the diversity of the receiving end to improve the signal to interference ratio (SINR) ), And can also be used for multiplexing to separate multiple receivers into different beams, each receiving a different signal.

On the other hand, in the case of the analog beamforming, a plurality of beams formed by the analog beamforming can be used only as means for improving the diversity of the receiving end and increasing the signal quality (SINR).

As a result, in the MIMO system, due to the disadvantages of the digital beamforming technique in which an RF chain is required for the number of antennas and the installation cost is increased and the analog beamforming technique in which the performance gain is limited, the hybrid beam Foaming technology is mainly used.

Hereinafter, the present invention will be described with reference to a hybrid beam forming technique.

As shown in FIG. 1, in a MIMO system using a beamforming technique such as a hybrid beamforming technique to which the present invention is applied, antenna beams of various directions / shapes that can be formed in a transmitting device, It is very important to select and synchronize the optimal beam having the best channel environment among the antenna beams of various directions / types that can be formed.

At this time, the transmitting apparatus corresponds to the base station 100 shown in FIG. 1, and the receiving apparatus corresponds to each terminal shown in FIG.

Therefore, in the following description, a transmitting apparatus for transmitting a synchronizing signal for timing synchronization and beam forming synchronization will be collectively referred to as a base station 100, and a receiving apparatus for receiving a synchronizing signal and performing timing synchronization and beam forming synchronization, (10).

The transmitting apparatus, that is, the base station 100 has a plurality of antennas.

The receiving apparatus, that is, the terminal 10, has two or more antennas.

Here, the synchronization signal transmission apparatus proposed in the present invention transmits a first synchronization signal for frequency synchronization and a second synchronization signal for frame synchronization to a terminal for timing synchronization, and transmits a plurality of antennas (Hereinafter referred to as a beam synchronization signal), which are formed in different directions through the first and second synchronization signals.

In this case, the synchronization signal transmission apparatus proposed in the present invention is capable of transmitting two or more neighboring unit radio resources identified by a specific unit in a radio resource designated for synchronization between a transmitting / receiving apparatus, that is, the base station 100 and the terminal 10. [ A plurality of combined radio resource blocks are configured and a beam synchronization is performed based on a beam synchronization signal in a manner of transmitting a beam synchronization signal through antenna beams of different directions formed for a plurality of radio resource blocks.

The synchronization signal transmission apparatus of the present invention is preferably the same as the base station 100 and the terminal 10 performing the timing synchronization and beamforming synchronization. I will explain it.

Particularly, the synchronization signal receiving apparatus proposed in the present invention is a device for receiving a combination of unit radio resources assigned to each of a plurality of radio resource blocks in a radio resource designated for synchronization between a transmitting / receiving apparatus, that is, And performs a beamforming synchronization based on the beam synchronization signal in a manner of receiving a beam synchronization signal as the third synchronization signal through the at least two antenna beams formed for two or more reception blocks.

The synchronous signal receiving apparatus of the present invention is preferably the same as the performing entity that performs synchronization and beamforming synchronization with the base station 100 of the transmitting / receiving apparatus, that is, the base station 100 and the terminal 10. Hereinafter, (10).

That is, in the present invention, the base station 100 as a synchronous signal transmission apparatus constitutes a plurality of radio resource blocks that combine two or more neighboring unit radio resources identified by specific units in radio resources designated for synchronization between devices.

The base station 100 forms antenna beams in different directions for each of a plurality of radio resource blocks through each of a plurality of antennas that the base station 100 has.

The base station 100 performs beamforming synchronization based on a beam synchronization signal with the terminal 10 in such a manner that a beam synchronization signal is transmitted through antenna beams of different directions formed for a plurality of radio resource blocks .

At this time, the number of unit radio resources constituting each radio resource block constituted by the base station 100 may be determined according to the number of antenna beams that can be formed in the apparatus for receiving the beam synchronization signal, i.e., the terminal 10. [

In the present invention, the terminal 10 as the synchronous signal receiving apparatus, that is, the terminal 10, receives a combination of unit radio resources designated for each of a plurality of radio resource blocks constituted by the base station 100, Configure two or more blocks.

Then, the terminal 10 forms antenna beams in different directions through each of the two or more antennas that the terminal 10 has.

The terminal 10 receives a beam synchronization signal through two or more antenna beams in different directions formed for each of two or more reception blocks and performs beamforming synchronization based on a beam synchronization signal with the base station 100 do.

In the present invention, when beam-forming synchronization based on a beam-synchronous signal is performed between the base station 100 and the terminal 10 in the above-described manner, beam-forming synchronization is performed between the base station 100 and the terminal 10, tracking can be performed quickly, thereby reducing the failure rate of the beamforming synchronization and improving the overall beamforming synchronization performance.

Hereinafter, a method of performing the synchronization proposed in the present invention will be described in more detail, and a process of deriving the effects as described above will be described.

2, a synchronization signal transmission apparatus 100 according to an embodiment of the present invention includes a first synchronization signal for frequency synchronization and a second synchronization signal for frame synchronization, And a beamforming synchronization performing unit 120 for transmitting a third synchronization signal formed in different directions through a plurality of antennas to the terminal for beamforming synchronization.

In addition, the synchronization signal transmission apparatus 100 includes a radio resource configuration unit 110 (hereinafter, referred to as a radio resource configuration unit 110) that configures a plurality of radio resource blocks in which two or more neighboring radio resource blocks are combined, ).

As described above, the synchronous signal transmission apparatus of the present invention is described as being the same as the base station 100, and will be described with reference to the same reference numerals.

The synchronous signal transmission apparatus 100 of the present invention, that is, the base station 100 includes a plurality of antennas A, B, ..., N. Hereinafter, for convenience of explanation, it is assumed that the base station 100 includes eight antennas.

The radio resource configuration unit 110 configures a plurality of radio resource blocks in which two or more neighboring unit radio resources among unit radio resources classified in a specific unit are combined in a designated radio resource for synchronization between the apparatuses.

Here, the radio resource designated for the synchronization between apparatuses means one of a plurality of symbols in a downlink synchronization channel subframe periodically allocated.

More specifically, in the MIMO system to which the present invention is applied, a synchronization signal for timing synchronization between devices and beam-forming synchronization is periodically transmitted through a downlink synchronization channel.

For example, as shown in Fig. 4, a subframe (0, 25) at a designated position for every frame (e.g., subframes 0 to 49, 10 ms) of the downlink synchronization channel is divided into subframes a), it is possible to periodically transmit a synchronization signal for synchronization between devices via the downlink synchronization channel every 5 ms.

Hereinafter, for convenience of description, a subframe (a) for synchronization between devices will be referred to as a synchronization subframe.

Here, as shown in FIG. 4, the synchronization subframe (a) is composed of a plurality of symbols, for example, 14 ODFM symbols.

Hereinafter, a function (method) for configuring the radio resource (OFDM symbol in the synchronization subframe) of the downlink synchronization channel in the radio resource configuration unit 110 will be described in detail.

First, the radio resource configuration unit 110 allocates radio resources of a designated radio resource, that is, an OFDM symbol in the synchronization subframe (a), to a timing synchronization frequency region for timing synchronization with a beam And can be divided (configured) into a synchronous frequency domain.

The timing synchronization performing unit 130 transmits a first synchronization signal for frequency synchronization and a second synchronization signal for frame synchronization through a plurality of antenna beams formed in the timing synchronization frequency region to perform timing synchronization .

In this case, the first synchronization signal may be a primary synchronization signal (PSS), and the second synchronization signal may be a secondary synchronization signal (SSS). In addition, the timing synchronization performing unit 130 may transmit (transmit) more synchronization signals such as ESS (Enhanced Sync Signal) for timing synchronization.

Meanwhile, the beamforming synchronization performing unit 120 transmits a third synchronization signal for beamforming synchronization through a plurality of antenna beams formed in the beam synchronization frequency region, and performs beamforming synchronization.

At this time, the third synchronization signal is a beam synchronization signal, and may be specifically a beam reference signal (BRS).

Hereinafter, the beam synchronization frequency region among the radio resources (OFDM symbols in the synchronization subframe) of the downlink synchronization channel will be described in detail.

The radio resource configuration unit 110 divides the radio resources of the OFDM symbol into specific units in the OFDM symbols in the synchronization subframe (a) of the designated radio resource, i.e., periodically allocated downlink synchronization channel, for synchronization between the devices.

Here, the specific unit is preferably a minimum frequency unit of radio resources required to form one antenna beam in the receiving apparatus, i.e., the terminal 10. [

The specific unit may be a unit defined on the basis of an RB (Radio Block), or a unit defined on a carrier basis constituting an RB.

Hereinafter, for the sake of convenience of explanation, it is assumed that the specific unit is a unit defined by the RB standard and is one RB.

In this case, the radio resource configuration unit 110 divides the radio resources of the OFDM symbol into one RB unit in the OFDM symbol in the synchronization subframe (a) of the periodically allocated downlink synchronization channel. In this case, the radio resources of the OFDM symbol in the synchronization subframe (a) of the synchronization channel will be divided into several unit radio resources in units of 1 RB.

Then, the radio resource configuration unit 110 allocates a plurality of radio resource blocks that combine two or more neighboring ones among several unit radio resources classified in units of 1 RB, in the OFDM symbol in the synchronization subframe (a) of the downlink synchronization channel .

At this time, the number of unit radio resources constituting each radio resource block may be determined according to the number of antenna beams that can be formed in the receiving apparatus, i.e., the terminal 10, which receives the beam synchronizing signal, i.e., BRS.

More specifically, assuming that the UE 10 is capable of forming four antenna beams with four antennas, the radio resource configuration unit 110 generates OFDM symbols in the synchronization subframe a of the downlink synchronization channel A plurality of radio resource blocks combining four neighboring radio resource units (or a number related to 4, such as 8 or 12, etc.) among a plurality of unit radio resources may be configured.

In addition, the radio resource configuration unit 110 configures a plurality of radio resource blocks in the OFDM symbol in the synchronization subframe (a) of the downlink synchronization channel as described above, It is preferable to configure a radio resource block as many as the number of antenna beams that can be formed in the base station 100. [

Hereinafter, it is assumed that the base station 100 includes eight antennas. In the OFDM symbol in the synchronization subframe (a) of the downlink synchronization channel, I will explain that it constitutes a resource block.

In this case, in the OFDM symbol in the synchronization subframe (a) of the downlink synchronization channel, the radio resource configuration unit 110 may configure eight radio resource blocks in the form of combining four neighboring unit radio resources.

As described above, since the number of unit radio resources in the radio resource block depends on the number of antennas of the receiving apparatus, that is, the terminal 10, the number of unit radio resources constituting the radio resource block becomes smaller as the number of antennas of the terminal 10 And the number of antennas of the terminal 10 increases.

Therefore, the radio resource configuration unit 110 grasps the number of antennas per terminal for all terminals (mobile phones, notebooks, etc.) existing in the cell coverage of the base station 100, calculates the minimum number of antennas per terminal, It is also possible to flexibly adjust the number of unit radio resources in the radio resource block according to the result obtained by applying the maximum number of antennas per terminal or the minimum number and the maximum number of antennas per terminal to a separately defined algorithm .

The radio resource configuration unit 110 maps a plurality of radio resource blocks, that is, eight radio resource blocks, to each of eight antennas included in a plurality of transmission antennas, that is, the base station 100, So that antenna beams of different directions can be formed for each radio resource block.

Meanwhile, in the present invention, a radio resource of a designated radio resource, that is, an OFDM symbol in a synchronization subframe (a) is divided into a timing synchronization frequency region for timing synchronization and a beam synchronization frequency region for beamforming synchronization 4, the radio resource of the OFDM symbol in the synchronization subframe (a) is divided into two beam synchronization frequency regions and a timing synchronization frequency region located between the two beam synchronization frequency regions Can be configured.

In this case, in the OFDM symbol in the synchronization subframe (a) of the downlink synchronization channel, the radio resource configuration unit 110 constitutes eight radio resource blocks in the form of combining four neighboring unit radio resources, # 4, # 2, # 3, and # 4 in one area of the beam synchronization frequency domain and the remaining four radio resource blocks # 5, # 6, # 7, . ≪ / RTI >

For convenience, only four radio resource blocks # 1, # 2, # 3, and # 4 are shown in FIG.

In addition, the radio resource configuration unit 110 includes an information transmission block (hereinafter, referred to as a PBCH) for transmitting communication system related information, such as MIN (Master Information Block) and SIB (System Information Block) (Physical Broadcasting Channel)).

Of course, the information transmission block, that is, the PBCH, will belong to the beam synchronization frequency domain according to the premise of being located between radio resource blocks.

4, the radio resources of the OFDM symbol in the synchronization subframe (a) of the downlink synchronization channel are allocated to the radio resource blocks # 1 and # 2 in which four unit radio resources (b) are combined , A PBCH between radio resource blocks # 1 and # 2, a PBCH between radio resource blocks # 2 and # 3, and a PBCH between radio resource blocks # 3 and # 4, And a timing synchronization frequency region for timing synchronization.

Although the radio resources of the OFDM symbol in the synchronization subframe a of the downlink synchronization channel are multiplexed into the radio resource blocks # 5, # 6, A PBCH between radio resource blocks # 5 and # 6, a PBCH between radio resource blocks # 7 and # 8, a PBCH between radio resource blocks # 7 and # do.

The timing synchronization performing unit 130 transmits timing synchronization synchronization signals PSS, SSS, and ESS through a plurality of antenna beams formed in the timing synchronization frequency region to perform timing synchronization.

That is, the base station 100 forms a plurality of antenna beams toward the entire area of the cell coverage of the base station 100 through each of the eight antennas that the base station 100 has.

The timing synchronization performing unit 130 receives synchronization signals PSS, SSS, and ESS for timing synchronization through a plurality of antenna beams toward the entire area of the cell coverage of the base station 100 formed in the timing synchronization frequency domain, The terminal 10 can perform timing synchronization with the terminal 10. [

The beamforming synchronization performing unit 120 transmits a beam synchronization signal or BRS through antenna beams of different directions formed for the plurality of radio resource blocks # 1 to # 8 to perform BRS-based beamforming synchronization.

That is, the base station 100 forms antenna beams in different directions for each of the eight radio resource blocks # 1 to # 8 mapped to each antenna through each of the eight antennas that the base station 100 has.

Accordingly, the beamforming synchronization performing unit 120 transmits the BRS through antenna beams A, B, C, D, ..., H of different directions formed for each of the eight radio resource blocks # 1- # 8 , It is possible to perform BRS-based beamforming synchronization with the terminal 10. [

That is, the base station 100 as a synchronous signal transmission apparatus proposed in the present invention forms antenna beams A, B, C, D, ..., H as many as the number of antennas of its own, From the viewpoint, four neighboring unit radio resources in one radio resource block are grouped to form the same antenna beam.

In each OFDM symbol in the synchronization subframe (a) of the downlink synchronization channel, the base station 100 transmits, for each of the eight radio resource blocks # 1 to # 8, To form an antenna beam.

The beamforming synchronization performing unit 120 performs BRS in a direction different from the previous OFDM symbol for each of the eight radio resource blocks # 1 to # 8 in each OFDM symbol in the synchronization subframe (a) of the downlink synchronization channel Can be transmitted.

On the other hand, information allocated to the PBCH, for example, MIB and SIM, is preferably transmitted through an antenna beam formed by one of two radio resource blocks neighboring the PBCH.

For this, the radio resource configuration unit 110 preferably maps each of the PBCHs to a transmission antenna to which one of the two radio resource blocks adjacent to the PBCH are mapped, that is, the antenna of the base station 100. [

For example, in the case of a PBCH between radio resource blocks # 1 and # 2, the information of the PBCH is transmitted through an antenna beam formed in one of two neighboring radio resource blocks # 1 and # 2 .

To this end, if the PBCH is a PBCH between radio resource blocks # 1 and # 2, the radio resource configuration unit 110 allocates the PBCH to the base station 100 to which the two radio resource blocks # 1 and # 2 are mapped, Lt; RTI ID = 0.0 > antenna.

4, the information in the PBCH between the radio resource blocks # 1 and # 2 is transmitted to the radio resource blocks # 1 and # 2, respectively, by predefining transmission of the preceding radio resource block among the two radio resource blocks neighboring the PBCH. The information in the PBCH between the radio resource blocks # 2 and # 3 is transmitted through the same antenna beam B as the radio resource block # 2, and the information in the PBCH between the radio resource blocks # 3 and # Information may be transmitted via antenna beam C, such as radio resource block # 3.

In other words, when information related to the communication system, that is, MIB and SIM, is configured between radio resource blocks in the radio resources of the OFDM symbol in the synchronization subframe (a) of the downlink synchronization channel, The same MIB and SIM are simultaneously transmitted through B, C, D, E, F, and G, thereby achieving frequency diversity gain through beamforming.

Hereinafter, a synchronization signal receiving apparatus 10 according to an embodiment of the present invention will be described with reference to FIG.

At this time, as assumed in the foregoing description, the synchronous signal receiving apparatus of the present invention is described as being the same as the terminal 10, and will be described with reference to the same reference numerals.

The synchronization signal receiving apparatus 10 of the present invention or the terminal 10 receives a first synchronization signal for frequency synchronization and a second synchronization signal for frame synchronization from the base station 100, A timing synchronization executing unit 13 that performs synchronization with the base station 100 and a third synchronization signal from two or more antenna beams formed in different directions from the base station 100 and performs beamforming synchronization with the base station 100 And a beamforming synchronization performing unit 12.

In addition, the synchronization signal receiving apparatus 10 of the present invention, that is, the terminal 10 may further include a radio resource configuration unit 11. [

The synchronous signal receiving apparatus 10 of the present invention, that is, the terminal 10 includes two or more antennas 1, 2, ..., N. Hereinafter, for convenience of explanation, it is assumed that the terminal 10 is provided with four antennas.

The radio resource configuration unit 11 configures at least two reception blocks in which the unit radio resources specified in each of the plurality of radio resource blocks constituted by the base station 100 are combined in the radio resources designated for the synchronization between the apparatuses .

Here, the radio resource designated for the synchronization between apparatuses means one of a plurality of symbols in a downlink synchronization channel subframe periodically allocated.

In the MIMO system, as shown in Fig. 4, a subframe (0, 25) at a designated position for every frame (e.g., subframes 0 to 49, 10 ms) of the downlink synchronization channel is divided into subframes a), it is possible to periodically transmit a synchronization signal for synchronization between devices via the downlink synchronization channel every 5 ms.

At this time, a subframe (a) for synchronization between devices, that is, a synchronization subframe (a) is composed of a plurality of symbols, for example, 14 ODFM symbols.

Hereinafter, a function (method) for configuring the radio resource (OFDM symbol in the synchronization subframe) of the downlink synchronization channel in the radio resource configuration unit 11 will be described in detail.

First, the radio resource configuration unit 11 transmits radio resources of a designated radio resource, i.e., an OFDM symbol in the synchronization subframe (a), to a timing synchronization frequency region for timing synchronization with a beam for beam- And can be divided (configured) into a synchronous frequency domain.

The timing synchronization performing unit 13 receives the first synchronization signal for frequency synchronization and the second synchronization signal for frame synchronization through two or more antenna beams formed in the timing synchronization frequency region, Lt; / RTI >

In this case, the first synchronization signal may be a primary synchronization signal (PSS), and the second synchronization signal may be a secondary synchronization signal (SSS). In addition, the timing synchronization performing unit 13 may receive more synchronization signals such as ESS (Enhanced Sync Signal) for timing synchronization.

Meanwhile, the beamforming synchronization performing unit 12 receives the third synchronization signal for beamforming synchronization through two or more antenna beams formed in the beam synchronization frequency region, and performs beamforming synchronization with the base station 100 .

At this time, the third synchronization signal is a beam synchronization signal, and may be specifically a beam reference signal (BRS).

Hereinafter, the beam synchronization frequency region among the radio resources (OFDM symbols in the synchronization subframe) of the downlink synchronization channel will be described in detail.

The radio resource configuration unit 11 divides the radio resources of the OFDM symbol into specific units in the OFDM symbols in the synchronization subframe (a) of the designated radio resource, that is, the periodically allocated downlink synchronization channel.

Here, the specific unit is preferably a minimum frequency unit of radio resources required to form one antenna beam in the terminal 10. [

The specific unit may be a unit defined on the basis of an RB (Radio Block), or a unit defined on a carrier basis constituting an RB.

Hereinafter, for the sake of convenience of explanation, it is assumed that the specific unit is a unit defined by the RB standard and is one RB.

In this case, the radio resource configuration unit 11 divides the radio resources of the OFDM symbol into one RB unit in the OFDM symbol in the synchronization subframe (a) of the periodically allocated downlink synchronization channel. In this case, the radio resources of the OFDM symbol in the synchronization subframe (a) of the synchronization channel will be divided into several unit radio resources in units of 1 RB.

The radio resource configuring unit 11 combines the unit radio resources assigned to each of the plurality of radio resource blocks constituted by the base station 100 in the OFDM symbol in the synchronization subframe a of the downlink synchronization channel Configure two or more receive blocks.

At this time, the number of unit radio resources to be combined in each receiving block can be determined according to the number of antenna beams that can be formed in the base station 100.

More specifically, assuming that the base station 100 is capable of forming eight antenna beams with eight antennas, the radio resource configuration unit 11 generates OFDM symbols in the synchronization subframe a of the downlink synchronization channel Two or more receiving blocks may be configured by combining eight unit radio resources (or the number related to 8) assigned to each of eight radio resource blocks.

In addition, the radio resource configuration unit 11 constructs two or more reception blocks in the OFDM symbol in the synchronization subframe (a) of the downlink synchronization channel as described above, and determines the number of antennas that the terminal 10 has, It is preferable to configure a receiving block as many as the number of antenna beams that can be formed in the terminal 10. [

Hereinafter, as described above, assuming that the UE 10 includes four antennas, the radio resource configuration unit 11 sets, in the OFDM symbol in the synchronization subframe (a) of the downlink synchronization channel, four reception I will explain it as a block.

In this case, the radio resource configuration unit 11 determines the number of radio resource blocks allocated to each of the eight radio resource blocks that are configured by the base station 100 in the OFDM symbol in the synchronization subframe a of the downlink synchronization channel, And four receiving blocks of a combination of resources can be configured.

As described above, since the number of unit radio resources in the receiving block depends on the number of antennas of the transmitting apparatus, that is, the base station 100, the number of unit radio resources to be combined with the receiving block becomes smaller as the number of antennas of the base station 100 decreases And the number of antennas of the base station 100 increases.

Therefore, the radio resource configuration unit 11 can flexibly change the number of unit radio resources to be used in combining / configuring the received blocks according to the number of antenna beams that can be formed in the base station 100 of the cell coverage in which the terminal 10 is located It is also possible to adjust.

The radio resource configuration unit 11 maps two or more reception blocks, i.e., four reception blocks, to two or more reception antennas, that is, four antennas included in the terminal 10, So that antenna beams of different directions can be formed for each block.

Meanwhile, in the present invention, a radio resource of a designated radio resource, that is, an OFDM symbol in a synchronization subframe (a) is divided into a timing synchronization frequency region for timing synchronization and a beam synchronization frequency region for beamforming synchronization 4, the radio resource of the OFDM symbol in the synchronization subframe (a) is divided into two beam synchronization frequency regions and a timing synchronization frequency region located between the two beam synchronization frequency regions Can be configured.

In this case, in the OFDM symbol in the synchronization subframe (a) of the downlink synchronization channel, the radio resource configuration section 11 generates four radio resource blocks # 1 and # 2 (# 4, # 4, # 4, and # 8) of the radio resource blocks # 5, # 6, # 7, # a, # b, # c, # d).

In this case, the method of designating a unit radio resource of each of the radio resource blocks for combining each receiving block in the synchronous signal receiving apparatus of the present invention, i.e., the terminal 100, may be a random method or a sequential method.

In FIG. 4, a unit radio resource of each radio resource block is designated in a sequential manner for each reception block.

Referring to FIG. 4, the radio resource block # 1 in the radio resource of the OFDM symbol in the synchronization subframe (a) of the downlink synchronization channel will be described, The wireless resource 1-1 is used for the reception block #a combination, the sequentially designated unit radio resource 1-2 of the radio resource block # 1 is used for the reception block #b combination, and the sequentially designated unit The radio resources 1-3 may be used for the combination of the reception block #c and the sequentially specified unit radio resources 1-4 of the radio resource block # 1 may be used for the combination of the reception block #d.

The terminal 10 transmits the unit radio resource 1-1 of the radio resource block # 1 and the unit radio resource 2-1 of the radio resource block # 2 and the radio resource block # 3 of the radio resource block # The unit radio resource 3-1 and the unit radio resource 4-1 of the radio resource block # 4 and the unit radio resource 5-1 of the radio resource block # 5 and the unit radio resource 6-1 and the radio resource block # 7 and the unit radio resource 8-1 of the radio resource block # 8 can be used in combination.

Therefore, the radio resource configuration unit 11 maps each of the four reception blocks #a, #b, #c, and #d to each of the four antennas of the terminal 10, And antenna beams 1, 2, 3, and 4 of different directions can be formed for each of the reception blocks # a, # b, # c, and # d.

In this case, each of the four antenna beams 1, 2, 3, and 4 formed by the UE 10 is allocated to the eight radio resource blocks # 1 to # 4 in the OFDM symbol in the synchronization subframe a of the downlink synchronization channel, 8 < / RTI >

In this manner, the terminal 10 forms four antenna beams 1, 2, 3, and 4 in different directions, and receives the BRS through the antenna beams 1, 2, 3, 100 based on the BRS-based beamforming synchronization.

That is, in the present invention, the synchronous signal receiving apparatus, that is, the terminal 10 forms antenna beams 1, 2, 3, and 4 as many as the antennas, (Combining) the eight unit radio resources specified in each of the eight radio resource blocks to be formed in the radio resource block to form the same antenna beam.

Further, in each of the two or more antenna beams formed by the synchronization signal receiving apparatus of the present invention, i.e., the terminal 10, it is preferable that information related to the communication transmitted through at least one antenna beam of the base station 100 is received Do.

As described above, the base station 100 inserts a PBCH (information related to a communication system, i.e., MIB, SIM, etc.) between radio resource blocks in the radio resources of the OFDM symbol in the synchronization subframe a of the downlink synchronization channel (MIB and SIM) through several antenna beams A, B, C, D, E, F, and G at the same time.

As shown in FIG. 4, the synchronous signal receiving apparatus or terminal 10 is interleaved between radio resource blocks to generate antenna beams A, B, C, D, H through each of the antenna beams 1, 2, 3, and 4.

At this time, as shown in FIG. 4, the UE 10 can randomly use each interleaved PBCH between the radio resource blocks when the antenna beams 1, 2, 3, and 4 are formed, It can be used sequentially when antenna beams 1, 2, 3, and 4 are formed.

For example, when sequentially used, the UE 10 uses the first OFDM symbol for forming the antenna beam 1 in the case of the PBCH between the radio resource blocks # 1 and # 2, and the radio resource blocks # The PBCH between the radio resource blocks # 5 and # 6 is used for forming the antenna beam 4, and the PBCH between the radio resource blocks # 3 and # 4 is used for forming the antenna beam 3, The PBCH between the radio resource blocks # 6 and # 7 is used for forming the antenna beam 1, and the PBCH between the radio resource blocks # 7 and # 8 is used for forming the antenna beam 2.

In the next OFDM symbol, the terminal 10 uses the antenna beam 3 to form the antenna beam 3 in the case of the PBCH between the radio resource blocks # 1 and # 2, and the antenna beam 4 in the case of the PBCH between the radio resource blocks # The PBCH between the radio resource blocks # 3 and # 4 is used for forming the antenna beam 1, the PBCH between the radio resource blocks # 5 and # 6 is used for forming the antenna beam 2, The PBCH between # 6 and # 7 may be used for forming the antenna beam 3, and the PBCH between the radio resource blocks # 7 and # 8 may be used for forming the antenna beam 4. [

As a result, in the present invention, the synchronization signal receiving apparatus or the terminal 10 transmits, in the radio resources of the OFDM symbol in the synchronization subframe (a) of the downlink synchronization channel, information related to the communication system, that is, MIB and SIM, The MIB and the SIM are simultaneously received through the plurality of antenna beams 1, 2, 3, and 4, thereby obtaining frequency diversity gain through beamforming.

As described above, the base station 100 serving as a synchronous signal transmission apparatus proposed by the present invention forms antenna beams A, B, C, D, ..., H as many as the number of antennas thereof, Based on the radio resource structure (OFDM symbol in the synchronization subframe) of the downlink synchronization channel that forms the same antenna beam by grouping four neighboring unit radio resources in one radio resource block in view of the antenna beam, Perform synchronization.

In addition, the terminal 100 as a synchronous signal receiving apparatus proposed in the present invention forms antenna beams 1, 2, 3, and 4 as many as the number of antennas included therein, Based on the radio resource structure (OFDM symbol in the synchronization subframe) of the downlink synchronization channel, which forms the same antenna beam by combining (combining) the eight unit radio resources specified in each of the eight radio resource blocks to be configured in the radio resource block 100, Beamforming synchronization is performed.

As described above, if beamforming synchronization is performed based on the radio resource structure of the downlink synchronization channel according to the present invention, the receiving apparatus, that is, the terminal 10 can rapidly perform beam tracking in the process of performing synchronization, Will not be able to track the optimal beam and will fail to fail the beamforming synchronization.

As a result, according to the present invention, in performing timing synchronization and beamforming synchronization between the base station 100 and the terminal 10, it is possible to perform fast beam tracking in the terminal 10 to perform overall beamforming synchronization performance Can be improved.

Hereinafter, a synchronization signal receiving method according to an embodiment of the present invention will be described in detail with reference to FIG.

For convenience of explanation, the terminal 10 will be described as a synchronous signal receiving apparatus in accordance with the above description.

When the synchronous signal receiving method of the terminal 10 according to the present invention reaches a preset period (S10), the synchronous signal receiving method of the terminal 10 starts to perform synchronization between the devices.

At this time, reaching the preset period means the transmission time point of the synchronization subframe (a) of the periodically allocated downlink synchronization channel as described above with reference to FIG.

When the predetermined period is reached (S10), the synchronization signal receiving method of the terminal 10 according to the present invention is a method for synchronizing the radio resources of the OFDM symbol in the synchronization subframe (a) of the downlink synchronization channel with the timing And may be divided into a synchronous frequency domain and a beam synchronous frequency domain for beamforming synchronization (S11).

The method for receiving the synchronization signal of the terminal 10 according to the present invention is a method for receiving a plurality of radio resources constituting the base station 100 in the beam synchronization frequency domain in the OFDM symbol in the synchronization subframe a of the downlink synchronization channel, At least two receiving blocks are formed by combining the unit radio resources designated in each block (S12).

Assuming the above-described example, the base station 100 transmits, in the OFDM symbol in the synchronization subframe (a) of the downlink synchronization channel, a wireless combination of four neighboring unit radio resources divided in units of 1 RB Eight resource blocks can be configured.

The base station 100 maps each of the eight radio resource blocks # 1 to # 8 to each of the eight antennas included in the base station 100 so that eight radio resource blocks So that antenna beams A, B, ..., H can be formed.

In this case, the synchronization signal receiving method of the terminal 10 according to the present invention is a method for receiving synchronization signals of eight radio resource blocks # 1 to #n configured by the base station 100 in the OFDM symbol in the synchronization subframe a of the downlink synchronization channel, (# A, # b, # c, # d) of a combination of eight unit radio resources specified in each of # 8 and # 8 (S12).

The method of receiving a synchronization signal of the terminal 10 according to the present invention maps two or more reception blocks, that is, four reception blocks, to each of four antennas of two or more reception antennas, i.e., the terminal 10, So that antenna beams of different directions can be formed for each of the four receiving blocks in each of the antennas.

A method of receiving a synchronization signal of a terminal 10 according to the present invention includes receiving a timing synchronization signal (e.g., PSS, SSS, and ESS) for timing synchronization in an OFDM symbol in a synchronization subframe a of a downlink synchronization channel, And a beam synchronization signal (e.g., BRS) for beamforming synchronization, and performs timing synchronization and beamforming synchronization with the base station 100 (S13).

Specifically, the synchronization signal receiving method of the terminal 10 according to the present invention is a method for synchronizing signals for timing synchronization through two or more antenna beams of the terminal 10 formed in the timing synchronization frequency domain of the OFDM symbol in the synchronization subframe (a) Synchronization performance information (e.g., signal reception strength, availability of synchronization, results of synchronization, etc.) for the received synchronization signals (e.g., PSS, SSS, and ESS) (S14), it is possible to perform timing synchronization with the base station 100. [

Meanwhile, the synchronization signal receiving method of the terminal 10 according to the present invention is performed for each of at least two receiving blocks #a, #b, #c and #d in the beam synchronization frequency domain of the OFDM symbol in the synchronization subframe (a) (Eg, signal reception intensity, whether or not to perform synchronization, the result of synchronization, etc.) with respect to the received beam synchronization signal (eg, BRS) through the antenna beam in different directions (S14), the base station 100 performs BRS-based beamforming synchronization.

That is, in the method of receiving the synchronization signal of the terminal 10 according to the present invention, the four reception blocks #a, #b, #c, #d The antenna beams of different directions are formed.

The method of receiving a synchronization signal of the terminal 10 according to the present invention is a method of receiving a synchronization signal through antenna beams 1, 2, 3, and 4 of different directions formed for each of four reception blocks #a, #b, #c, BRS-based beamforming synchronization with the base station 100 in a manner of receiving BRS.

That is, in the method of receiving a synchronization signal of the terminal 10 according to the present invention, antenna beams 1, 2, 3, and 4 corresponding to the number of antennas of the terminal 10 are formed, (8) unit radio resources allocated to each of the eight radio resource blocks to be combined in the radio resource block to form the same antenna beam.

In this case, the synchronization signal receiving method of the terminal 10 according to the present invention includes interleaving between radio resource blocks from the base station 100 to generate antenna signals A, B, C, D, H through each of the antenna beams 1, 2, 3, and 4 (S13).

Then, the synchronization signal receiving method of the terminal 10 according to the present invention checks whether radio resources of the downlink synchronization channel, that is, OFDM symbols in the synchronization subframe (a) are all used (S15). In other words, it is checked whether all 14 OFDM symbols in the synchronization subframe (a) are used.

The synchronization signal reception method of the terminal 10 according to the present invention resets the above-described steps S13 and S14 to the terminal 10 if all 14 OFDM symbols in the synchronization subframe a have not been used (S15 No) Lt; RTI ID = 0.0 > beamforming < / RTI >

Meanwhile, if all 14 OFDM symbols in the synchronization subframe (a) are used (Yes in S15), the synchronization signal receiving method of the terminal 10 according to the present invention is a method of receiving the synchronization signal and the beamforming synchronization And determine the timing and optimal beam between the base station 100 and the terminal 10 based on the received signal.

As described above, in the method of receiving a synchronous signal of the terminal 10 according to the present invention, antenna beams 1, 2, 3, and 4 corresponding to the number of antennas included in the terminal 10 are formed, (OFDM symbol in the synchronization subframe) of the downlink synchronization channel that forms the same antenna beam by combining (combining) the eight unit radio resources specified in each of the eight radio resource blocks constituted by the base station 100 To perform beamforming synchronization.

5, the base station 100 serving as a synchronous signal transmission apparatus proposed by the present invention has antenna beams A, B, C, and D corresponding to the number of antennas that the base station 100 itself has, ,..., H are formed, and the radio resource structure of the downlink synchronization channel for forming the same antenna beam by grouping four neighboring unit radio resources in one radio resource block from the viewpoint of each antenna beam Frame OFDM symbol) based on the OFDM symbol.

As described above, when timing synchronization and beamforming synchronization are performed based on the radio resource structure of the downlink synchronization channel according to the present invention, the receiving apparatus, i.e., the terminal 10, can quickly perform beam tracking in the process of performing synchronization Which will not be able to track the optimal beam, thereby reducing the failure of beamforming synchronization.

As a result, according to the present invention, in performing synchronization between the base station 100 and the terminal 10, it is possible to perform fast beam tracking in the terminal 10, thereby improving overall beamforming synchronization performance.

The method of receiving a sync signal according to an exemplary embodiment of the present invention 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 recorded on the medium may be those specially designed and constructed for the present invention 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 present invention, 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, but, on the contrary, 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 by the appended claims.

According to the synchronization signal receiving apparatus and the synchronization signal receiving method according to the present invention, it is possible to perform fast beam tracking in a receiving apparatus in performing synchronization between transmitting and receiving apparatuses, thereby improving overall beamforming synchronization performance , And proposes a radio resource structure of a downlink synchronization channel which enables this. In addition, as the technology overcomes the limitations of the existing technology, it is not only possible to use commercially available devices, It is an invention that can be used industrially because it is practically possible to carry out clearly.

100: base station (synchronous signal transmission device)
10: terminal (synchronous signal receiving apparatus)
11: Radio resource configuring unit 12: Beamforming synchronization performing unit
13: Timing synchronization performing unit

Claims (11)

An apparatus for receiving a synchronization signal by a terminal apparatus in a MIMO system,
A timing synchronization performing unit for receiving a first synchronization signal for frequency synchronization and a second synchronization signal for frame synchronization from a base station and performing timing synchronization with the base station; And
And a beamforming synchronization performing unit for receiving a third synchronization signal from the base station through at least two antenna beams formed in different directions and performing beamforming synchronization with the base station. The method according to claim 1,
The base station comprises:
A plurality of radio resource blocks in which two or more neighbors of unit radio resources separated by a specific unit are combined in a designated radio resource for synchronization between devices,
And transmits a beam synchronization signal as the third synchronization signal through antenna beams of different directions formed for each of the plurality of radio resource blocks. 3. The method of claim 2,
Further comprising a radio resource configuration unit configured to configure at least two reception blocks in which the unit radio resources specified in each of the plurality of radio resource blocks are combined in the radio resource;
Wherein the beamforming synchronization performing unit comprises:
And receives the beam synchronization signal as the third synchronization signal through the at least two antenna beams formed for the at least two reception blocks. The method of claim 3,
Wherein the number of unit radio resources to be combined in the reception block,
And the number of antenna beams that can be formed in the base station. The method of claim 3,
The base station comprises:
An information transmission block for transmitting communication system related information between each radio resource block in the radio resource,
Wherein the information transmission block transmits information allocated to the information transmission block through an antenna beam formed in one of two radio resource blocks adjacent to the information transmission block. 6. The method of claim 5,
In each of the two or more antenna beams,
Wherein the information to be transmitted through at least one antenna beam of the base station is received. A method for receiving a synchronization signal by a terminal apparatus in a MIMO system,
A timing synchronization step of receiving a first synchronization signal for frequency synchronization and a second synchronization signal for frame synchronization from a base station and performing timing synchronization with the base station; And
And a beamforming synchronization performing unit that receives a third synchronization signal from the base station through two or more antenna beams formed in different directions and performs beamforming synchronization with the base station. 8. The method of claim 7,
The base station comprises:
A plurality of radio resource blocks in which two or more neighbors of unit radio resources separated by a specific unit are combined in a designated radio resource for synchronization between devices,
And a beam synchronization signal as the third synchronization signal is transmitted through antenna beams of different directions formed for each of the plurality of radio resource blocks. 9. The method of claim 8,
Further comprising: a radio resource configuration step of configuring at least two reception blocks, each of which is a combination of unit radio resources assigned to each of the plurality of radio resource blocks, in the radio resource;
Wherein the step of performing beamforming synchronization comprises:
And a beam synchronization signal as the third synchronization signal is received through the at least two antenna beams formed for each of the at least two reception blocks. 10. The method of claim 9,
The base station comprises:
An information transmission block for transmitting communication system related information between each radio resource block in the radio resource,
Wherein information to be allocated to the information transmission block is transmitted through an antenna beam formed in one of two radio resource blocks adjacent to the information transmission block. 11. The method of claim 10,
In each of the two or more antenna beams,
Wherein the information transmitted through at least one antenna beam of the base station is received.

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