KR20170096929A - Method and apparatus for beam reference signal transmission, broadcast signal transmission and the associated reference signal transmission in mmWave beamforming systems - Google Patents

Abstract

The present disclosure relates to communication method and system in which a 5G communication system for supporting a higher data transmission rate than a 4G system is converged with IoT technology. The disclosure can be applied to an intelligent service (for example, smart home, smart building, smart city, smart car or connected car, health care, digital education, retail business, security and safety related service, and the like) based on the 5G communication technology and IoT related technology. The present invention relates to operating method and apparatus necessary to transmit information by broadcasting such as system information to support a system capable of expecting dramatic increase of communication capacity by using beam forming in a broad frequency band in the next generation communication supporting a millimeter wave (mmWave) band.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a beam reference signal transmission method, a broadcast signal transmission method, and a corresponding reference signal design method and apparatus for a mmWave beamforming communication system,

In order to support a system capable of expecting a remarkable increase in communication capacity by using beam forming on a wide frequency band in a next generation communication supporting a millimeter wave (mmWave) band, To an operation method and apparatus necessary for transmitting information.

Efforts are underway to develop an improved 5G or pre-5G communication system to meet the growing demand for wireless data traffic after commercialization of the 4G communication system. For this reason, a 5G communication system or a pre-5G communication system is called a system after a 4G network (Beyond 4G network) communication system or after a LTE system (Post LTE). To achieve a high data rate, 5G communication systems are being considered for implementation in very high frequency (mmWave) bands (e.g., 60 gigahertz (60GHz) bands). In order to mitigate the path loss of the radio wave in the very high frequency band and to increase the propagation distance of the radio wave, in the 5G communication system, beamforming, massive MIMO, full-dimension MIMO (FD-MIMO ), Array antennas, analog beam-forming, and large scale antenna technologies are being discussed. In order to improve the network of the system, the 5G communication system has developed an advanced small cell, an advanced small cell, a cloud radio access network (cloud RAN), an ultra-dense network, (D2D), a wireless backhaul, a moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation Have been developed. In addition, in the 5G system, the Advanced Coding Modulation (ACM) scheme, Hybrid FSK and QAM Modulation (FQAM) and Sliding Window Superposition Coding (SWSC), the advanced connection technology, Filter Bank Multi Carrier (FBMC) (non-orthogonal multiple access), and SCMA (sparse code multiple access).

On the other hand, the Internet is evolving into an Internet of Things (IoT) network in which information is exchanged between distributed components such as objects in a human-centered connection network where humans generate and consume information. IoE (Internet of Everything) technology, which combines IoT technology with big data processing technology through connection with cloud servers, is also emerging. In order to implement IoT, technology elements such as sensing technology, wired / wireless communication, network infrastructure, service interface technology and security technology are required. In recent years, sensor network, machine to machine , M2M), and MTC (Machine Type Communication). In the IoT environment, an intelligent IT (Internet Technology) service can be provided that collects and analyzes data generated from connected objects to create new value in human life. IoT is a field of smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart home appliance, and advanced medical service through fusion of existing information technology . ≪ / RTI >

Accordingly, various attempts have been made to apply the 5G communication system to the IoT network. For example, technologies such as a sensor network, a machine to machine (M2M), and a machine type communication (MTC) are implemented by techniques such as beamforming, MIMO, and array antennas It is. The application of the cloud RAN as the big data processing technology described above is an example of the convergence of 5G technology and IoT technology.

In the prior art, beamforming at the base station / terminal does not consider application of beamforming in the analog domain as a beamforming method in the digital domain. For analog beamforming, it is easy to apply in a high frequency band communication system in which the physical constraint of the antenna is small. In order to achieve a high data transmission rate, a 5G communication system is used in a microwave (mmWave) band , 60 GHz band). In this very high frequency band, the use of analog beamforming technology is discussed because the path loss reduction of the radio wave and the propagation distance of the radio wave are shortened. For beam operation through beamforming, a method for transmitting broadcast signals in the analog domain at the base station / terminal is required, but it has not been described in detail yet.

In the case of SIB information, which is system information in the LTE system, a specific PDSCH resource is allocated to the UE through the PDCCH, which is a DL control channel, and the SIB information is transmitted to the corresponding channel. However, in the mmWave beamforming system, in order to transmit the PDCCH to the UE in the initial access, the PDCCH must be transmitted in all directions, which means that a plurality of PDCCHs must be transmitted for one SIB information. As a result, it is impossible to send the DL control channel, which causes a limitation when transmitting SIB information by the conventional method. Unlike SIB, in case of MIB, information is broadcasted by PBCH in LTE, but there is no restriction on transmission of DL control information, but transmission scheme for MIB broadcasting is required. Therefore, we propose Beam reference signal transmission method, Broadcast signal transmission method and corresponding reference signal design method and device for mmWave beamforming communication system.

According to an aspect of the present invention, there is provided a method of processing a control signal in a wireless communication system, the method comprising: receiving a first control signal transmitted from a base station; Processing the received first control signal; And transmitting the second control signal generated based on the process to the base station.

According to one embodiment of the present invention, in order to achieve a high data rate, which is one of the requirements of the 5G communication system, an analog beam-based reference signal transmission method and a broadcast signal transmission method in a mmWave band It enables stable initial access.

1 is a diagram showing an embodiment of a BRS transmission period setting and a Beam Index setting.
2 is a diagram showing an embodiment of beam index mapping.
3 is a diagram illustrating a terminal operation procedure for initial access according to an indication of BRS setting.
4 is a diagram illustrating a PDSCH-based SIB transmission scheme.
5 is a diagram illustrating an ePBCH-based SIB transmission scheme.
6 is a diagram illustrating an example of a beam sweeping structure of one OFDM symbol unit.
7 is a diagram illustrating an example of a beam sweeping structure of two OFDM symbol units.
8 is a diagram illustrating a procedure of receiving a terminal in a beam sweeping structure of one OFDM symbol unit.
9 is a diagram illustrating a procedure of receiving a UE in a beam sweeping structure of two OFDM symbol units.
FIG. 10 is a diagram illustrating an example of setting a SIB transmission position through a 1-bit on / off indication within an MIB transmission period.
11 is a diagram illustrating an example of a location setting of a SIB to be transmitted through a 1-bit on / off indication within an MIB transmission period.
FIG. 12 is a diagram illustrating an example of location setting where SIB is distributed and transmitted through a 1 bit on / off indication within an MIB transmission period.
13 is a diagram illustrating a terminal operation procedure for acquiring SIB transmission information in the MIB.
14 is a diagram illustrating a paging terminal operation procedure according to acquisition of paging transmission information in the MIB.
15 is a diagram illustrating a paging terminal operation procedure according to acquisition of paging transmission information in the SIB.
16 is a diagram illustrating a paging terminal operation procedure according to acquisition of paging transmission information in the MIB / SIB.
FIG. 17 is a diagram illustrating a frequency domain DM-RS design in a beam sweeping structure of two OFDM symbol units. FIG.
18 is a diagram illustrating a time domain DM-RS design in a beam sweeping structure of two OFDM symbol units.
19 is a diagram illustrating an example of OCC mapping for each antenna port.
20 is a diagram illustrating a design example of a BRS for channel estimation using a dedicated broadcast channel and a FDM-based BRS.
21 is a diagram illustrating a design example of a BRS for channel estimation using a dedicated broadcast channel according to the number of antenna ports and a BRS having FDM.
22 is a diagram illustrating a BRS design method for channel estimation using a dedicated broadcast channel and a TDM BRS.
23 is a diagram illustrating an embodiment of a terminal operation procedure when setting an MIB transmission mode.
24 is a diagram illustrating an embodiment of a terminal operation procedure in SIB transmission mode setting.
FIG. 25 is a block diagram illustrating a terminal according to an embodiment of the present invention. Referring to FIG.
26 is a block diagram of a base station according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions of the present invention, and these may be changed according to the intention of the user, the operator, or the like. Therefore, the definition should be based on the contents throughout this specification.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

In the beam-based operating system, a reference signal is required to measure the selection of the terminal for the base station beam and the corresponding beam information. For generalized description, we define the beam reference signal (BRS) as the cell specific reference signal. The signal is periodic and assumes a mechanism operation in which the terminal measures and reports the BRS transmitted by the base station in order to acquire information about the beam. We propose BRS transmission method on the system.

The BRS is transmitted in a beam sweeping manner by analog beams operated by a base station. That is, the BRS is repeatedly transmitted to each analog beam, the corresponding signal is measured, the beam information is reported, and then the base station terminal beam is selected and transmitted / received by the corresponding beam. System information broadcasted at initial connection should be transmitted in beam sweeping mode like BRS. Broadcast information includes system information transmission such as LTE-based MIB and SIB. In the present invention, a method for SIB transmission will be described as an example for convenience of explanation. It is assumed that the MIB is transmitted through the PBCH and the SIB is transmitted through the ePBCH. The two channels are dedicated channels for each system information transmission. The contents of the present invention are applicable to transmission of all broadcast signals.

The present invention includes a BRS transmission method, a broadcast signal transmission method, an SIB transmission configuration indication method through an MIB, a signal transmission method using a dedicated broadcast channel, a reference signal transmission method, and a broadcast transmission mode setting method.

[BRS transmission method]

When one subframe is 0.2 ms and the radio frame is 10 ms, the BRS transmission period can be set as shown in FIG. In the embodiment of FIG. 1A, four configurations are defined, and the base station performs beam sweeping for a full BRS during one slot, one subframe, two subframes, and four subframes. In this embodiment, a frame structure in which one subframe is composed of 2 slots and one slot is composed of 7 OFDM symbols is assumed. If the beam sweeping is set to 1 slot and the base station has one antenna, the signal is transmitted in total 7 beams because the beam changes every 7 symbols corresponding to one slot. If the base station has P antennas and the corresponding P antennas are FDM in each OFDM symbol, it means sweeping 7 * P beams based on 1 slot. In FIG. 1A, the period of the BRS is indicated by 2 bits, and the corresponding signal is signaled to a higher layer. And the corresponding 2 bits are indicated in the MIB transmitted through the LTE reference PBCH. In FIG. 1, the BRS indication bit, the corresponding BRS transmission period, and the setting of the number of beams and the logical beam index that can be swept by the maximum BS corresponding to each transmission period are shown.

FIG. 2 shows an example in which a logical beam index is mapped by an OFDM symbol index and an antenna port index. It is assumed that the system allocates subframes that transmit BRS in 5ms increments. In this case, when the BRS transmission period is 1 slot, two beam sweeping is performed in one BRS subframe. When the BRS transmission period is 1 subframe, one beam sweeping is performed in one BRS subframe. When the BRS transmission period is 2 subframes, one beam sweeping is performed during 2 BRS subframes for 10 ms. When the BRS transmission period is 4 subframes, one beam sweeping is performed during 4 BRS subframes for 20 ms.

In FIG. 2, the meaning of the BRS transmission region means a BRS subframe in units of 5 ms, and is an example of a mapping expression of a logical beam index according to each OFDM symbol (i.e., index i) and an antenna port index (i.e., index p) in each subframe. N_symb ^ DL means the number of OFDM symbols in one slot, and the corresponding value for LTE is 7.

3 shows the terminal operation in the initial access procedure according to the indication bits of the BRS setting. After acquiring the synchronization based on the synchronization signal same as LTE, the system information is acquired through the broadcast channel. At this time, the BRS transmission antenna port number and BRS transmission related setting information in the system information are acquired. 2 bits indicating the transmission period of the BRS in the reference system information are obtained. Based on the information on the antenna port number and beam sweeping, information on the beam ID is derived according to the mapping method of FIG. 2, . Random access is performed based on effective beams among the measured beams, for example, beams having a large received signal magnitude. When reporting information about the beam in the random access process or a subsequent process, beam ID information is transmitted for distinguishing the effective beam.

[Broadcast signal transmission method]

4 is an illustration of a PDSCH based SIB transmission. In the existing LTE system, DCI is transmitted through the PDCCH and the terminal acquires PDSCH resource information for SIB transmission in the DCI, thereby receiving the SIB information transmitted by the base station.

When applying the method in the mmWave beamforming system, a plurality of subframes are required for beam sweeping as shown in FIG. In FIG. 4, whether or not the SIB is transmitted in the corresponding subframe and the SIB transmission location are indicated through the PDCCH of each subframe. It is difficult to perform beam sweeping by simultaneously using all the beams in one subframe because multiplexing of data with other users and the number of analog transmission beams that can be used by the base station itself are limited when the base station transmits SIBs in the PDSCH. Therefore, as shown in FIG. 4, up to 14 subframes can be used for SIB transmission, assuming that the base station operates 14 beams.

FIG. 5 shows a method of allocating a dedicated channel instead of the DCI-based PDSCH transmission for beam sweeping transmission, and broadcasting through beam sweeping in the corresponding channel, in contrast to the method of FIG. In the example of FIG. 5, it is assumed that the base station operates 14 beams, and it is assumed that one SIB information can be transmitted through one OFDM symbol as shown in the figure. In this case, since the SIB information is repeatedly transmitted 14 times through each beam, the SIB is broadcasted through beam sweeping through one subframe as shown in FIG.

We propose two schemes of beam sweeping in Dedicated channel based transmission as shown in Fig. 6 and Fig. In FIGS. 6 and 7, the base station operates 14 beams and repeats the broadcast information twice.

6 is an illustration of one OFDM symbol unit beam sweeping transmission. In the example, one SIB information is transmitted through one OFDM symbol, and the beam is repeatedly transmitted after beam sweeping using the entire beam. That is, the priority for beam sweeping is higher than the repetitive transmission. Rapid beam sweeping enables fast decoding if the channel environment is good, and efficient transmission when the number of total beams is large. FIG. 8 shows a terminal operation procedure when transmitting the SIB based on FIG. SIB is beam sweeping with different beams, and beam sweeping is transmitted again with same beams. Therefore, decoding is performed based on one OFDM symbol basis, and the corresponding decoding result is buffered when the decoding is unsuccessful. When the second beam sweeping is performed, a terminal operation that improves the probability of decoding success is performed by combining with the information transmitted in the same beam among the decoding results in the previous beam sweeping.

On the other hand, in FIG. 7, a beam sweeping-based broadcast channel is transmitted over the same beam with consecutive OFDM symbols with priority given to repetitive transmission rather than beam sweeping, and beam sweeping is performed per the number of OFDM symbols. Through repetitive transmission for each beam, it is possible to determine whether to perform combining according to the CRC check, thereby enabling efficient decoding and efficient transmission when the total number of beams is small. FIG. 9 shows a terminal operation procedure in the beam sweeping structure of FIG. Since it is a structure that transmits by the same beam through two consecutive OFDM symbols, the first OFDM symbol decoding is performed, and in case of failure, the second OFDM symbol decoding is attempted by combining with the decoding result of the first OFDM symbol, The height represents the terminal operation.

[SIB transmission configuration indication via MIB]

For convenience of explanation, it is assumed that the MIB is transmitted through the PBCH through the ePBCH, and each channel is a dedicated channel for broadcasting the corresponding information.

In case of MIB, the MIB location is transmitted through the fixed location in the existing LTE system since it is the system information that the terminal should acquire in the initial connection. If an indication of the information transmission setting of the corresponding MIB is required, an indication is possible through a reference signal / BRS for the synchronization signal / MIB transmission channel to be read in the initial connection process. However, in the present embodiments, the MIB is transmitted at a fixed position Assumes that the MIB contains at least one parameter associated with at least the SIB transmission and indicates the manner in which it is to be indicated.

Embodiment 1 is an example of setting a SIB transmission position through a 1 bit on / off indication within the MIB or PBCH transmission period as shown in FIG. In this example, when the MIB is repeatedly transmitted in units of 5 ms and the period is 40 ms, the MIB in the corresponding period transmits the same information. If the SIB transmission indication in the MIB is on, the corresponding information is transmitted through the MIB 8 times repeatedly. Therefore, if the MIB is repeated 8 times for 40 ms, the terminal can acquire information on the position to receive the SIB even if decoding is successful once. In this example, to provide the terminal with 8 MIB reception opportunities, the SIB transmission location is predefined after the last MIB transmission within 40 ms. The above embodiment is an example of transmitting to the last part of the corresponding radio frame after the last PBCH transmission, and is not limited to the specific SIB or ePBCH transmission position. The embodiment of the present invention is an embodiment for transmitting an ePBCH after completing all attempts of PBCH decoding, and it is possible to transmit SIB in a distributed manner. This is explained in the third embodiment.

Embodiment 2 is an embodiment of an SIB on / off indication in which an SIB transmission period in the MIB is considered, as shown in FIG. If the MIB is repeatedly transmitted in units of 5 ms and the period is 40 ms, the MIB in the corresponding period transmits the same information. If the SIB transmission indication in the MIB is on, it is assumed that the SIB transmission is performed at a specific fixed location. If the MIB is repeated 8 times for 40ms, the SIB transmission position is predefined and indicated after the last MIB transmission within the corresponding 40ms to receive the SIB even if decoding is successful only once. Assuming that the transmission period of the SIB is 80ms, since two cycles of the MIB are included in one cycle of the SIB, SIB transmission is performed in 40ms according to the indication bit in the MIB. In the above example, the SIB transmission period may be predefined in the system. The exemplary embodiment is for transmitting an ePBCH after completing all attempts of PBCH decoding.

Embodiment 3 is an embodiment of a distributed arrangement in SIB transmission as shown in FIG. The SIB is transmitted through the same beam, same beam sweeping sequence as the MIB. If there is an SIB transmission within the MIB period, the beams used for transmission within the MIB period are used for transmission of the corresponding SIB.

In the case of MIB or SIB, since the same information is repeatedly transmitted, the UE can perform decoding by combining the same MIB or SIB signal received through a plurality of OFDM symbols. The terminal can perform combining based on MIB decoding on the corresponding SIB symbols when decoding the SIB. If the MIB is repeatedly transmitted in units of 5 ms and the period is 40 ms, the MIB in the corresponding period transmits the same information. If the SIB transmission indication in the MIB is on, it is assumed that the SIB transmission is performed at a specific fixed location. If the MIB is repeated 8 times for 40ms, it is assumed that the SIB transmission position is set after the last MIB transmission within 40ms in order to enable reception of the SIB even if decoding is successful once.

If beam sweeping period is assumed to be 20ms, beam sweeping is performed twice within 40ms of PBCH. In this embodiment, ePBCH transmission is performed at a specific location after each 4 PBCH transmissions in which the second beam sweeping occurs. ePBCH is transmitted without being distributed. The embodiment of FIG. 12 is for transmitting an ePBCH after a decoding attempt through combining between PBCHs through a second beam sweeping based on 20 ms. That is, if there are 8 PBCH transmissions, decoding is enabled through the first and fifth PBCH combining, and the SIB on / off indication in the MIB delivered by the PBCH is checked. If on, the 5th radio frame EPBCH < / RTI > As shown in FIG. 12, there are four ePBCH transmission timings, which means that they are transmitted through one beam sweeping.

The entire terminal operation procedure for this embodiment is shown in FIG. Acquires MIB information through PBCH decoding, and acquires ePBCH indication information related to SIB transmission in the MIB information. SIB information is obtained through ePBCH Decoding.

[Configuration Indication Method for Paging Information Transmission via MIB]

In the conventional LTE system, PDCCH decoding based on P-RNTI is performed and paging information transmitted via the PDSCH is received. In the mmWave system, the user in Idle mode must select and receive the appropriate beam to receive the PDCCH from the base station. At this time, since the beam transmitted by the base station and the beam received by the mobile station are absent, the base station performs beam sweeping and transmits the PDCCH in order to apply the same operation scheme as LTE. After the mobile station receives the corresponding PDCCH, beam sweeping scheme. In this case, there is a problem of PDCCH capacity constraint and inefficiency in resource use. In addition to this method, paging information can be transmitted using a dedicated channel such as SIB. Paging information can be transmitted by designing a paging channel and broadcasting the channel based on beam sweeping.

In this case, the indication information such as the transmission period of the paging channel, the resource allocation, and the number of consecutive OFDM symbols to which the same beam is applied at the time of beam sweeping is required. In order to support this information, it is possible to transfer all or part of the information to the MIB transmitted through the PBCH. The information may also be transmitted in whole or in part to the SIB.

14, 15, and 16 show embodiments of a terminal operation procedure for obtaining paging information using the MIB and SIB. FIG. 14 illustrates a method for acquiring MIB information through PBCH decoding after the UE acquires synchronization. If all information related to paging is contained in the MIB, the paging transmission channel can be immediately decoded.

FIG. 15 shows a case where a UE obtains MIB information through PBCH decoding after acquiring synchronization. Acquires information related to the ePBCH transmission setup related to the SIB transmission in the MIB, and performs ePBCH decoding based on the information. acquires SIB through ePBCH decoding and obtains information related to paging transmission in SIB. Based on this, the mobile station decodes the paging channel to check paging information.

FIG. 16 shows a case where a UE acquires synchronization and acquires MIB information through PBCH decoding. Information related to the ePBCH transmission setup related to the SIB transmission and some information related to the paging transmission within the MIB and performs ePBCH decoding based on the information. acquires SIB through ePBCH decoding and acquires additional information related to paging transmission in SIB. Based on this, the mobile station decodes the paging channel to check paging information.

[Dedicated broadcast signal transmission method and corresponding reference signal transmission method]

FIGS. 17 and 18 show an example of a reference signal, i.e., a DM-RS design, during beam sweeping of two consecutive OFDM symbol units as shown in FIG. Figs. 17 and 18 show the same DM-RS design method and the design method in frequency domain and time domain.

As shown in this example, since it is two OFDM symbols transmitted in the same beam, OCC design and mapping are possible so that OCC processing can be performed on the frequency and time axis as shown in FIGS. 17 and 18. FIG. That is, the OCC corresponding to the second antenna port according to the even / odd OFDM symbol position is applied differently. 19 is an example of OCC mapping for this example.

In FIGS. 17 and 18, one square represents one RE. In the two figures, the vertical axis denotes a sub-carrier and the horizontal axis denotes an OFDM symbol. A specific color is the RE that is DM-RS transmitted. The frequency axis length 2-OCC processing can be performed as shown in FIG. In the example, four subcarriers are transmitted to the DM-RS on the vertical axis. In this case, length 2-OCC processing is performed in two subcarrier units, so it can be processed with at least 2 length 2-OCC DM-RSs and can be processed with up to 3 length 2-OCC DM-RSs. When processing with two length 2-OCC DM-RSs, the first DM-RS subcarrier is treated as one length 2-OCC from the top, and the third DM-RS subcarrier is treated as one length 2- OCC. When processing with three length 2-OCC DM-RSs, the second third subcarrier between the above two pairs can be processed as an additional length 2-OCC DM-RS.

In FIG. 18, in the case of length 2-OCC processing on the time axis, the DM-RS transmission subcarrier can process the continuous OFDM symbol as a time axis length 2-OCC DM-RS. Example Illustration The first RE pair from the top is Ant. Port 0 = [+1 +1], Ant. Port 0 = [+1 -1]. Example Illustration The second RE pair is Ant. Port 0 = [+1 +1], Ant. Port 0 = [-1 +1].

In a preferred embodiment of the present invention, when the broadcast transmission of the beam sweeping method is based on the 2-port SFBC, the channel estimation for the corresponding 2 ports can be performed in the same manner as the present embodiment. In the channel estimation, the reception algorithm can be estimated by considering the frequency / time domain processing selectively or in combination. The example is not limited to the ePBCH but can be applied / extended and modified in a manner that enables the time / frequency domain OCC in all PHY channels transmitting information in one beam in two adjacent OFDM symbols. The corresponding OCC values can be modified in any form if they are orthogonal to each other. It is possible to apply the OCC length extension according to the extension of the number of OFDM symbols sent through the same beam.

Unlike the example of the above-described invention, when transmitting a signal through a dedicated broadcast channel, it is possible to design a transmission scheme that can replace the DM-RS using a beam reference signal such as BRS without having an independent DM-RS. 20 is an example of a BRS design for use as an RS for channel estimation of a PBCH when the PBCH transmitting the BRS and the MIB is FDM in one OFDM symbol. In FIG. 10, one cell means one RE, and BRS and PBCH are FDM in 12 sub-carrier units. In this case, the number of antenna ports of the base station is eight. In this case, as shown in the example, it is proposed that the BRS signals transmitted through the eight antennas are grouped into two units so that they can be divided into length-2 OCCs. If beam-sweeping broadcast transmission is based on 2-port SFBC, the channel estimation for the 2 ports can be performed by decoding the OCC of 2 subcarrier units. For example, if PBCH is Ant. Port # 0, # 2, # 4 and # 6 are transmitted to one port or beam, and Ant. In case of 2 port SFBC that transmits the beam consisting of Port # 1, # 3, # 5 and # 7 to another port or beam, the channel estimation for each port of the PBCH is estimated can do.

FIG. 21 is an example for BRS transmission in the case of two or four BRS transmission antenna ports having a number smaller than eight. Since the number of antenna ports used for transmission of the BRS can not be known before the decoding of the PBCH, even if the number of BRS transmission antenna ports is not known by blind, the PBCH It is possible to estimate a channel value corresponding to one antenna port of the PBCH based on channel values in each of two subcarrier units in which one OCC is occupied.

20 and 21 can be applied to a beam sweeping structure of one OFDM symbol unit and a beam sweeping structure of a plurality of OFDM symbol units. In the case of FIG. 22, in a beam sweeping structure of two successive OFDM units, TDM is applied. The design method of the BRS is applicable in the same manner as in FIGS. 20 and 21. FIG. Since there is almost no channel change between consecutive OFDM symbols and the same beam is applied, the result of channel estimation through BRS can be utilized in PBCH decoding.

The example is not limited to the PBCH but can be extended and modified based on the OCC based channel estimation method using characteristics of beam sweeping in the same beam direction between FDM or TDM beam reference signal and dedicated broadcast channel. The corresponding OCC values can be modified in any form if they are orthogonal to each other. It is possible to apply the OCC length extension according to the extension of the number of OFDM symbols sent through the same beam. It is also possible to extend the OCC length according to the mapping of the dedicated reference broadcast channel and the beam reference signal for subcarriers in one OFDM symbol. For example, as shown in FIGS. 20, 21 and 22, when a dedicated broadcast channel is a 2-port diversity mode transmission (ie 2-port SFBC), two ports are classified using OCC in each frequency resource, Based on the estimated channel values, it is designed to estimate the channel for each port of the dedicated broadcast channel. However, when the dedicated broadcast channel is a 4-port diversity mode transmission (ie 4 port SFBC) It is also possible to design a scheme for estimating a channel for each port of a dedicated broadcast channel based on the same OCC-based estimated channel values in each frequency resource.

[Broadcast transmission mode setting method]

The transmission schemes of FIGS. 6 and 7 can operate more efficiently under certain circumstances. Therefore, it is possible to select the transmission mode through the mode setting for the two methods when transmitting with the beam sweeping based broadcast method. In this section, we propose a predefined example of transmission mode for each beam sweeping period and a transmission mode setting method by indication through signaling before MIB / SIB transmission time. The present invention is not limited to the values used as a reference in the present invention, for example, a specific periodic value, and the like.

It is possible to set the broadcast transmission mode according to the beam sweeping cycle. For example, if the beam sweeping periods are 2.5ms, 5ms, 10ms, and 20ms in the MIB or SIB transmission, transmission is possible in the case of 2.5ms and 5ms in FIG. 7, and in the case of 10ms and 20ms in FIG. . A broadcast transmission mode indication is required for this purpose. The MIB indication can be indicated via the RS for estimation of the SS signal or MIB transmission channel, that is, the PBCH, transmitted before the MIB transmission time. It is also possible to operate through SIB mode indication in MIB.

FIG. 23 is an embodiment of a terminal operation procedure in setting the MIB transmission mode. In this figure, MIB transmission mode indication information is obtained through the synchronization signal, and decoding is performed after channel estimation of the PBCH based on the transmission mode. FIG. 24 shows an embodiment of a terminal operation procedure when setting the SIB transmission mode. And obtains SIB transmission mode information in the MIB through PBCH decoding, and performs ePBCH channel estimation and decoding based on the SIB transmission mode information.

25 is an example of a block diagram of a device according to the embodiment of the present disclosure. Referring to FIG. 25, the terminal includes, for example, a control unit and a transmission / reception unit. A memory and a comparator. The configuration of such a terminal may be divided into a more detailed configuration or may be integrated into one configuration according to the embodiment or the operator's intention.

The memory stores information signaled by the base station or information buffered during decoding. In the embodiments of the above-described specification, the memory stores all information previously stored in the terminal. The transmission / reception unit receives the downlink signal of the above-described embodiments, performs beam measurement by applying terminal beamforming according to an instruction of the control unit, and stores the results in the memory unit. Further, beam information or the like to the base station is transmitted. The control unit controls the overall operation of the terminal in the above-described embodiments. Then, the comparing unit performs a comparing and checking operation performed by the device in the above-described embodiments in accordance with an instruction from the control unit. Detailed operation of each configuration is omitted.

26 is an example of a block diagram of a base station according to an embodiment of the present disclosure. Referring to FIG. 26, the base station includes, for example, a controller, a transceiver, a memory, a comparator, and a configuration information generator. The configuration of such a base station may be divided into more detailed configurations or integrated into one configuration depending on the embodiment or the operator's intention. The comparing unit compares and verifies information received from the terminal according to an instruction from the controller. The configuration information generation unit generates information to be provided to each terminal according to an instruction from the control unit. The memory stores the beam information reported by the terminal, the configuration information given to each terminal, and the like. In the embodiments of the above-described specification, the memory stores all information previously stored in the base station. The transceiver transmits downlink signals of the above-described embodiments. Particularly, in the present embodiment, signals based on beamforming are transmitted. The control unit controls the overall operation of the terminal in the above-described embodiments.

8 to 9 are described as an example only for convenience of explanation, and the device and the receiving end according to the embodiment of the present invention can be variously configured. Furthermore, embodiments of the present invention may exist independently or in part or in whole of at least one embodiment of the other embodiments.

Claims (1)

A method for processing a control signal in a wireless communication system,
Receiving a first control signal transmitted from a base station;
Processing the received first control signal; And
And transmitting the second control signal generated based on the process to the base station.

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