WO2022049733A1 - Terminal, base station, and communication method - Google Patents

Abstract

This terminal includes: a reception unit that receives a first signal from a base station by sequentially switching reception beamforming; and a control unit that determines the reception beamforming to be applied, on the basis of first signal measurement results. The reception unit applies the determined reception beamforming to receive a second signal from the base station. The control unit uses the second signal to execute synchronization and cell searching.

Description

Terminals, base stations and communication methods

The present invention relates to a terminal, a base station and a communication method in a wireless communication system.

In NR (New Radio) (also referred to as "5G"), which is the successor system to LTE (Long Term Evolution), the requirements are a large capacity system, high-speed data transmission speed, low delay, and simultaneous use of many terminals. Techniques that satisfy connection, low cost, power saving, etc. are being studied (for example, Non-Patent Document 1).

In NR release 17, it is considered to use a higher frequency band than the conventional release (for example, Non-Patent Document 2). For example, in the frequency band from 52.6 GHz to 71 GHz, applicable numerology including subcarrier spacing, channel bandwidth, etc., physical layer design, obstacles assumed in actual wireless communication, and the like are being studied.

In communication using a higher frequency band such as the millimeter wave band, the propagation loss becomes larger. Therefore, for example, it is necessary to reduce the loss by using a high-density beam (fine beam) using a multi-element antenna. On the other hand, when the beam density is increased, the area that can be covered becomes narrower, so that the higher the beam density, the larger the number of candidate beams. Therefore, it is expected that unacceptable overhead and delay will occur when determining the beam to be used according to the reception status while sequentially switching the beams in the initial access (beam sweeping).

The present invention has been made in view of the above points, and the initial access can be efficiently executed in the wireless communication system.

According to the disclosed technique, a receiving unit that sequentially switches received beamforming to receive a first signal from a base station, and a control unit that determines the received beamforming to be applied based on the measurement result of the first signal. The receiving unit applies the determined reception beamforming to receive a second signal from the base station, and the control unit uses the second signal for synchronization and cell. A terminal for performing a search is provided.

According to the disclosed technology, the initial access can be efficiently executed in the wireless communication system.

It is a figure which shows the structural example (1) of the wireless communication system in embodiment of this invention. It is a figure which shows the configuration example (2) of the wireless communication system in embodiment of this invention. It is a figure which shows the example of the hybrid beamforming. It is a sequence diagram for demonstrating an example of initial access. It is a figure which shows the example of SSB. It is a figure which shows the example of the SS burst set. It is a figure for demonstrating the example of the beam management in embodiment of this invention. It is a figure which shows the structural example (1) of the signal for beam management stage 1 in embodiment of this invention. It is a figure which shows the structural example (2) of the signal for beam management stage 1 in embodiment of this invention. It is a figure which shows the structural example (1) of the signal for beam management stage 2 in embodiment of this invention. It is a figure which shows the structural example (2) of the signal for beam management stage 2 in embodiment of this invention. It is a figure which shows the structural example (3) of the signal for beam management stage 2 in embodiment of this invention. It is a figure for demonstrating the example of the beam management stage 1 in embodiment of this invention. It is a figure for demonstrating the example of the beam management stage 2 in embodiment of this invention. It is a figure for demonstrating the example (1) of the beam management transmission mode 1 in embodiment of this invention. It is a figure for demonstrating the example (2) of the beam management transmission mode 1 in embodiment of this invention. It is a figure for demonstrating the example (3) of the beam management transmission mode 1 in embodiment of this invention. It is a figure for demonstrating the example (1) of the beam management transmission mode 2 in embodiment of this invention. It is a figure for demonstrating the example (2) of the beam management transmission mode 2 in embodiment of this invention. It is a figure for demonstrating the example (3) of the beam management transmission mode 2 in embodiment of this invention. It is a figure for demonstrating the example (1) of the beam management transmission mode 3 in embodiment of this invention. It is a figure for demonstrating the example (2) of the beam management transmission mode 3 in embodiment of this invention. It is a figure for demonstrating the example (3) of the beam management transmission mode 3 in embodiment of this invention. It is a figure for demonstrating the example (1) of the signal mapping for a beam management stage 1 in embodiment of this invention. It is a figure for demonstrating the example (2) of the signal mapping for a beam management stage 1 in embodiment of this invention. It is a figure for demonstrating the example (3) of the signal mapping for beam management stage 1 in embodiment of this invention. It is a figure for demonstrating the example (4) of the signal mapping for a beam management stage 1 in embodiment of this invention. It is a figure for demonstrating the example (5) of the signal mapping for a beam management stage 1 in embodiment of this invention. It is a figure for demonstrating the example (6) of the signal mapping for a beam management stage 1 in embodiment of this invention. It is a figure for demonstrating the example (7) of the signal mapping for beam management stage 1 in embodiment of this invention. It is a figure for demonstrating the example (1) of the mapping of the signal for beam management stage 2 in embodiment of this invention. It is a figure for demonstrating the example (2) of the signal mapping for a beam management stage 2 in embodiment of this invention. It is a figure for demonstrating the example (3) of the signal mapping for a beam management stage 2 in embodiment of this invention. It is a figure for demonstrating the example (4) of the signal mapping for a beam management stage 2 in embodiment of this invention. It is a figure for demonstrating the example (5) of the signal mapping for a beam management stage 2 in embodiment of this invention. It is a figure for demonstrating the example (6) of the signal mapping for a beam management stage 2 in embodiment of this invention. It is a figure for demonstrating the example (7) of the signal mapping for a beam management stage 2 in embodiment of this invention. It is a figure for demonstrating the example (8) of the signal mapping for a beam management stage 2 in embodiment of this invention. It is a figure for demonstrating the example (9) of the signal mapping for a beam management stage 2 in embodiment of this invention. It is a figure which shows an example of the functional structure of the base station 10 in embodiment of this invention. It is a figure which shows an example of the functional structure of the terminal 20 in embodiment of this invention. It is a figure which shows an example of the hardware composition of the base station 10 or the terminal 20 in embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments described below are examples, and the embodiments to which the present invention is applied are not limited to the following embodiments.

Existing technology is appropriately used in the operation of the wireless communication system according to the embodiment of the present invention. However, the existing technology is, for example, an existing LTE, but is not limited to the existing LTE. Further, the term "LTE" used in the present specification has a broad meaning including LTE-Advanced and LTE-Advanced and later methods (eg, NR) unless otherwise specified.

Further, in the embodiment of the present invention described below, SS (Synchronization signal), PSS (Primary SS), SSS (Secondary SS), PBCH (Physical broadcast channel), PRACH (Physical) used in the existing LTE. Random access channel), PDCCH (Physical Downlink Control Channel), PDSCH (Physical Downlink Shared Channel), PUCCH (Physical Uplink Control Channel), PUSCH (Physical Uplink Shared Channel), etc. are used. This is for convenience of description, and signals, functions, etc. similar to these may be referred to by other names. Further, the above-mentioned terms in NR correspond to NR-SS, NR-PSS, NR-SSS, NR-PBCH, NR-PRACH and the like. However, even if it is a signal used for NR, it is not always specified as "NR-".

Further, in the embodiment of the present invention, the duplex system may be a TDD (Time Division Duplex) system, an FDD (Frequency Division Duplex) system, or any other system (for example, Flexible Duplex, etc.). Method may be used.

Further, in the embodiment of the present invention, "configuring" the radio parameter or the like may mean that a predetermined value is set in advance (Pre-configure), or the base station 10 or The radio parameter notified from the terminal 20 may be set.

FIG. 1 is a diagram showing a configuration example (1) of a wireless communication system according to an embodiment of the present invention. The wireless communication system according to the embodiment of the present invention includes a base station 10 and a terminal 20 as shown in FIG. Although FIG. 1 shows one base station 10 and one terminal 20, this is an example, and each of them may be plural.

The base station 10 is a communication device that provides one or more cells and performs wireless communication with the terminal 20. The physical resources of the radio signal are defined in the time domain and the frequency domain, the time domain may be defined by the number of OFDM (Orthogonal Frequency Division Multiplexing) symbols, and the frequency domain is defined by the number of subcarriers or the number of resource blocks. May be good. The base station 10 transmits a synchronization signal and system information to the terminal 20. Synchronous signals are, for example, NR-PSS and NR-SSS. The system information is transmitted by, for example, NR-PBCH, and is also referred to as broadcast information. The synchronization signal and system information may be referred to as SSB (SS / PBCH block). As shown in FIG. 1, the base station 10 transmits a control signal or data to the terminal 20 by DL (Downlink), and receives the control signal or data from the terminal 20 by UL (Uplink). Both the base station 10 and the terminal 20 can perform beamforming to transmit and receive signals. Further, both the base station 10 and the terminal 20 can apply MIMO (Multiple Input Multiple Output) communication to DL or UL. Further, both the base station 10 and the terminal 20 may communicate via a secondary cell (SCell: Secondary Cell) and a primary cell (PCell: Primary Cell) by CA (Carrier Aggregation). Further, the terminal 20 may perform communication via a primary cell of the base station 10 by DC (Dual Connectivity) and a primary secondary cell group cell (PSCell: Primary SCG Cell) of another base station 10.

The terminal 20 is a communication device having a wireless communication function such as a smartphone, a mobile phone, a tablet, a wearable terminal, and a communication module for M2M (Machine-to-Machine). As shown in FIG. 1, the terminal 20 receives a control signal or data from the base station 10 by DL, and transmits the control signal or data to the base station 10 by UL, so that various types provided by the wireless communication system are provided. Use communication services. Further, the terminal 20 receives various reference signals transmitted from the base station 10, and measures the propagation path quality based on the reception result of the reference signals.

FIG. 2 is a diagram showing a configuration example (2) of the wireless communication system according to the embodiment of the present invention. The millimeter wave band can support higher data rates than, for example, frequency bands below 6 GHz, while large propagation losses and cutoffs may occur. As shown in FIG. 3, the link capacitance can be increased by using a large antenna array. In the example shown in FIG. 3, a data rate of 100 Gbps per cell is realized for a wireless LAN router, a dongle, or the like by a millimeter wave to which 3D beamforming is applied using a multi-element antenna. As an example, the millimeter wave is set to 10 GHz to 40 GHz, but other frequencies may be used.

However, in the above beamforming, since the electric power is concentrated on the narrow beam, it becomes difficult to adjust the beam direction at the time of initial access, and the beam switching is required when the terminal 20 moves.

FIG. 3 is a diagram showing an example of hybrid beamforming. As shown in FIG. 3, in hybrid beamforming, both digital beamforming and analog beamforming are applied. In the example shown in FIG. 3, the transmitting side digital beamforming is performed by the baseband precoder, and the transmitting side analog beamforming is performed by the phase shifter. Further, in the example shown in FIG. 3, the receiving side analog beamforming is performed by the phase shifter, and the transmitting side analog beamforming is performed by the baseband combiner. Hereinafter, beamforming may be referred to as a beam, and beamforming and beam may not be distinguished.

Since multiple RF chains and transceivers (TXRU) are used, it is necessary to control multiple beams at the same time. As the number of RF chains increases, the complexity of the beam search increases exponentially.

FIG. 4 is a sequence diagram for explaining an example of initial access. In 5G-NR, initial access based on beam management as shown in FIG. 4 is performed. The gNB 10 sequentially switches a plurality of spatial directions and transmits a synchronization signal and system information necessary for the UE 20 to access the network (Beam-Sweeping transmission). The UE 20 detects the strongest beam direction by continuing reception until the beam direction of the transmitter is matched (Beam-Sweeping reception). When the UE 20 grasps the beam to be used by the gNB 10 (UE individual beam selection), the UE 20 transmits the PRACH to the gNB 10. Subsequently, when the UE 20 and the gNB 10 establish communication with the optimum beam, the gNB 10 transmits the remaining system information necessary for setting the connection to the UE 20. The system can switch to UE-specific coverage using a narrower beam (UE individual beamforming) using beam reconfiguration procedures.

In step S1, the gNB 10 transmits a synchronization signal to the UE 20. Subsequently, the gNB 10 transmits the basic system information for all UEs to the UE 20 (S2). In steps S1 and S2, the Beam-Sweeping transmission, the Beam-Sweeping reception, and the UE individual beam selection may be executed. In step S3, the UE 20 transmits a random access channel to the gNB 10. Subsequently, the gNB 10 transmits a random access response and system information to the UE 20 (S4). In step S5, the gNB 10 transmits data and control channels to the UE 20. In step S5, the above UE individual beamforming may be applied.

For example, the initial access of communication using millimeter waves exceeding 52.6 GHz increases the complexity of beam management. Larger antenna arrays need to be used to compensate for large propagation losses. For example, by using a multi-element antenna array of more than 1000, a very dense and narrow beam and a very large number of candidate beams are expected.

Beam-Sweeping in the millimeter-wave band initial access as described above results in unacceptable overhead and delay, making it difficult to apply beam management in conventional 5G-NR. Therefore, in the above-mentioned initial access in the millimeter wave band, a method for realizing high-efficiency and high-speed initial access is required.

FIG. 5 is a diagram showing an example of SSB. The UE 20 executes a cell search procedure for beam management using SSB (SS / PBCH block) for Beam-Sweeping for the initial access in 5G-NR. The SSB is a signal for performing beam management at idle. As shown in FIG. 5, the time domain is composed of 4 OFDM symbols and the frequency domain is composed of 20 PRBs. Further, as shown in FIG. 5, the SSB is composed of a PSS and a synchronization signal including the SSS and a PBCH including at least a MIB (Master Information Block) message.

FIG. 6 is a diagram showing an example of an SS burst set. The SS burst set consists of a plurality of SSBs that support Beam-Sweeping. An SS burst set is a group of up to 64 consecutive L SSBs with different beam indexes. As shown in FIG. 6, one SS burst set is mapped to a slot in a 5 ms window (ie, half of the radio frame). The period _TB of the SS burst set is 5, 10, 20, 40, 80 or 160 ms, and the default value is 20 ms.

As mentioned above, the conventional SSB is composed of consecutive 4 OFDM symbols. Since the duration of one beam pair corresponds to at least one SSB in the initial access, Beam-Sweeping is inefficient because it takes a lot of time for more than hundreds of candidate beams, especially when the carrier is in the high frequency band. .. Also, if the transmit and receive beam pairs are not optimized, there is a lot of redundant information, which consumes time and frequency resources.

The overhead is calculated by (4 x _TS x L) / _TB . _TS is the period of one OFDM symbol. L is the number of SSBs included in the 1SS burst set. _TB is the period of the SS burst set. The delay is calculated by _TB x N _{SS burst set} . N _{SS burst set} is the number of SS burst sets required for Beam-Sweeping.

Table 1 shows the overhead and delay for completing Beam-Sweeping in 64 * 4 directions (L = 64, _TB = 20 ms) in one GSCN (Global Synchronization Channel Number).

As shown in Table 1, when the SCS is 120 KHz, the slot length is 0.125 ms, the overhead is 11.4%, and the delay is 80 ms. When the SCS is 240 KHz, the slot length is 0.0625 ms, the overhead is 5.7%, and the delay is 80 ms. Furthermore, assuming that the number of beams increases, it is necessary to shorten the period required for each beam pair in Beam-Sweeping.

Therefore, in beam management when using a higher frequency band than before, such as the millimeter wave band, a beam management mechanism for initial access based on the conventional SSB (SS / PBCH block) base in 5G-NR. Need to be strengthened.

First, BSB (Beam Sweeping Block), which is a new signal for Beam-Sweeping, is defined. Each BSB is composed of a plurality of SSs in the frequency domain or the time domain. Since the SS period is shorter than that of the SSB, the time required for the beam pairing process can be shortened. At the same time, a new signal, eSSB (enhanced SSB), is defined. There are multiple types of eSSB, and it is a signal for complementing BSB and completing the initial access. Details of the types will be described later.

Furthermore, a new cell search procedure will be designed. The new procedure includes two stages of Beam-Sweeping that are executed alternately, and a plurality of modes can be set. In the high-speed BSB sweep stage, which is the stage 1, the gNB 10 transmits the BSB by Beam-Sweeping, and the UE 20 can acquire the optimum beam direction. In the subsequent stage 2, the eSSBsweep stage, the gNB 10 transmits the eSSB by Beam-Sweeping, and the UE 20 executes synchronization and cell search in the reception beam direction determined in the stage 1. By repeating stage 1 and stage 2 several times, gNB10 and UE20 can obtain an optimum beam pair. The details of the mode will be described later.

With the enhanced beam management described above, signaling overhead and delay in initial access can be reduced.

As a basic configuration of the enhanced design, the BSB for high-speed Beam-Sweeping is composed only of PSS or new SS, and the eSSB is mainly composed of MIB messages. The gNB 10 alternately transmits BSBs and eSSBs to allow the UE 20 to identify the optimal beam pair and complete the initial access faster.

In the new beam management at the time of initial access, stage 1 and stage 2 are periodically repeated alternately. In stage 1, high-speed BSB sweep is executed. The gNB 10 transmits a BSB with Beam-Sweeping. The beam pair is sequentially switched between the gNB 10 and the UE 20, and the UE 20 identifies the optimum received beam in stage 1.

In stage 2, high-speed eSSB sweep is executed. gNB10 transmits eSSB by Beam-Sweeping. The UE 20 performs synchronization and cell search in the optimum reception beam direction determined in stage 1.

FIG. 7 is a diagram for explaining an example of beam management in the embodiment of the present invention. 1) shown in FIG. 7 is an example showing conventional beam management. 2) shown in FIG. 7 is a first example of beam management according to the embodiment of the present invention, in which stages 1 and 2 are alternately repeated with a period of 20 ms. 3) shown in FIG. 7 is a second example of beam management in the embodiment of the present invention, in which both stage 1 and stage 2 are executed within 5 ms and repeated with a period of 20 ms.

Here, 1BSB is composed of 4 beams, and 1 cycle (default 20 ms) is composed of 64BSB. For example, when Nt (number of SSBs) * Nr (number of received beams) = 64 * 4 and SCS is 120 KHz, it takes 80 ms to complete the Beam-Sweeping process in the conventional beam management. On the other hand, in the new beam management shown in 2) of FIG. 7, the Beam-Sweeping process can be completed in 40 ms. Further, in the new beam management shown in 3) of FIG. 7, the Beam-Sweeping process can be completed in 20 ms.

FIG. 8 is a diagram showing a configuration example (1) of a signal for beam management stage 1 according to an embodiment of the present invention. Two types may be specified as BSB. The signal shown in FIG. 8 is referred to as BSB type 1. As shown in FIG. ₈ , consecutive M1 OFDM symbols include SS in the common frequency domain. The direction of the beam may be different for each OFDM symbol. Hereinafter, the number of beams per BSB is referred to as M, and the number M of BSB type 1 beams is M ₁ .

FIG. 9 is a diagram showing a configuration example (2) of a signal for beam management stage 1 according to an embodiment of the present invention. The signal shown in FIG. 9 is referred to as BSB type 2. As shown in FIG. 9, each of the consecutive M ₁ OFDM symbols contains M ₂ SS and CP (Cyclic Prefix) in the time domain. As shown in FIG. 9, the direction of the beam of each of the M ₂ SSs may be different. The number M of the beams of BSB type 2 is M ₁ * M ₂ .

In the following explanation, BSB corresponds to BSB type 1 unless otherwise specified.

FIG. 10 is a diagram showing a configuration example (1) of a signal for beam management stage 2 according to the embodiment of the present invention. The eSSB type 1 shown in FIG. 10 is composed of consecutive 4 OFDM symbols. The eSSB type 1 has an SSB structure for compatibility with NR. As shown in FIG. 10, PSS is arranged in OFDM symbol # 0, PBCH is arranged in OFDM symbol # 1, SSS and PBCH are arranged in OFDM symbol # 2, and PBCH is arranged in OFDM symbol # 3. The PSS constituting the BSB is used only for Beam-Sweeping.

FIG. 11 is a diagram showing a configuration example (2) of a signal for beam management stage 2 according to the embodiment of the present invention. The eSSB type 2 shown in FIG. 11 is composed of consecutive 3 OFDM symbols omitting PSS in order to execute Beam-Sweeping at high speed. As shown in FIG. 11, PBCH is arranged in OFDM symbol # 0, SSS and PBCH are arranged in OFDM symbol # 1, and PBCH is arranged in OFDM symbol # 2. The PCI (Physical cell identifier) is identified by using the SSS included in the eSSB type 2 and the PSS constituting the BSB.

FIG. 12 is a diagram showing a configuration example (3) of a signal for beam management stage 2 according to the embodiment of the present invention. The eSSB type 3 shown in FIG. 12 is composed of consecutive 2 OFDM symbols containing only PBCH in order to realize a minimum delay. As shown in FIG. 11, PBCH is arranged in OFDM symbol # 0, and PBCH is arranged in OFDM symbol # 1. The SSs that make up the BSB are used to identify the PCI. In the eSSB type 3 PBCH, the resources in the frequency domain may be increased.

By combining the above-mentioned BSB type 1 and BSB type 2 with eSSB type 1, eSSB type 2 and eSSB type 3, six types of signal formats can be defined.

FIG. 13 is a diagram for explaining an example of the beam management stage 1 in the embodiment of the present invention. Hereinafter, the details of the above-mentioned stage 1 will be described. Stage 1 is a procedure for executing high-speed Beam-Sweeping, and realizes high-speed beam search. A group of L1 _BSBs that are continuous in less than 5 ms is defined as a BS burst set. In stage 1, the gNB 10 sequentially switches the candidate transmission beams to transmit a plurality of BSBs. Further, in stage 1, the UE 20 sequentially switches the candidate received beams to identify the optimum received beam based on, for example, the RSRP value.

Stage 1 may have periodicity. The periodic cycle may be determined by the UE 20 or may be predetermined. For example, the BSB index of the log ₂ (N ₂ L ₂ ) bits may be modulated into the BSB by cyclic shift. L ₂ is the number of eSSBs included in one cycle of the burst set of eSSBs, and N ₂ is the number of stages 2 executed. Further, the UE 20 may sequentially switch all received beams until it finds the optimum received beam.

Since only the optimum received beam is determined in stage 1, the transmitted beam in stage 1 may be coarser than the transmitted beam in stage 2 in order to reduce the number of beam pairs.

In the example of stage 1 shown in FIG. 13, each BSB of L ₁ is transmitted from gNB 10 with four transmission beams. For example, the odd-numbered BSB and the even-numbered BSB may have different beams, and eight transmission beams may be used in the BS burst set. On the other hand, the UE 20 may use all received beams.

FIG. 14 is a diagram for explaining an example of the beam management stage 2 in the embodiment of the present invention. Hereinafter, the details of the above-mentioned stage 2 will be described. Stage 2 is a procedure for executing a high-speed eSSB sweep, in which synchronization and cell search are executed. In stage 2, the gNB 10 sequentially switches the transmission beam to transmit the eSSB. On the other hand, in stage 2, the UE 20 is fixed to the optimum received beam determined in stage 1 and completes synchronization and cell search. A combination of BSB + eSSB type 1 (SSB similar to NR) can be assumed without losing generality. Here, N _t = N ₂ L ₂ so that synchronization and cell search are completed in N ₂ consecutive SS burst sets.

Since the UE 20 can identify the optimum reception beam in the stage 1, the UE 20 can perform reception using only the optimum reception beam in the stage 2. Therefore, the required number of eSSBs transmitted does not exceed N _t = N ₂ L ₂ .

In the example of stage 2 shown in FIG. 14, each of the _two L eSSBs sequentially switches the transmission beam and is transmitted from the gNB 10. On the other hand, the UE 20 fixedly uses the optimum received beam determined in stage 1 to perform synchronization and cell search. The UE 20 may report to the gNB 10 information indicating the best eSSB in the measurement result and specify the transmission beam to which the gNB 10 applies.

FIG. 15 is a diagram for explaining an example (1) of the beam management transmission mode 1 in the embodiment of the present invention. Beam management in embodiments of the present invention has three transmission modes based on stage 1 and stage 2 periodicity to accommodate different scenarios and system requirements. Hereinafter, the transmission mode 1 will be described. The feature of the transmission mode 1 is to minimize the average delay. FIG. 15 is an example in which the transmission mode 1 is applied to the BSB + eSSB type 1. As shown in FIG. 15, each stage occupies a fixed number of 5 ms long windows associated with the maximum number of beam pairs. In the example shown in FIG. 15, the number of windows having a length of 5 ms is 1. In stage 1, four transmit beams are used for each L ₁ BSB, and in stage 2, one transmit beam is used for every _two L eSSBs.

FIG. 16 is a diagram for explaining an example (2) of the beam management transmission mode 1 in the embodiment of the present invention. FIG. 16 is an example in which the transmission mode 1 is applied to the BSB + eSSB type 2. As shown in FIG. 16, each stage occupies a fixed number of 5 ms long windows associated with the maximum number of beam pairs. In the example shown in FIG. 16, the number of windows having a length of 5 ms is 1. In stage 1, four transmit beams are used for each L ₁ BSB, and in stage 2, one transmit beam is used for every _two L eSSBs.

FIG. 17 is a diagram for explaining an example (3) of the beam management transmission mode 1 in the embodiment of the present invention. FIG. 17 is an example in which the transmission mode 1 is applied to the BSB + eSSB type 3. As shown in FIG. 17, each stage occupies a fixed number of 5 ms long windows associated with the maximum number of beam pairs. In the example shown in FIG. 17, the number of windows having a length of 5 ms is 1. In stage 1, four transmit beams are used for each L ₁ BSB, and in stage 2, one transmit beam is used for every _two L eSSBs.

FIG. 18 is a diagram for explaining an example (1) of the beam management transmission mode 2 in the embodiment of the present invention. Hereinafter, the transmission mode 2 will be described. The feature of the transmission mode 2 is to more appropriately support the change of the number of beam pairs. FIG. 18 is an example in which the transmission mode 2 is applied to the BSB + eSSB type 1. As shown in FIG. 18, each stage occupies a single 5ms half frame, and stages 1 and 2 may be repeated. In stage 1, four transmit beams are used for each L ₁ BSB, and in stage 2, one transmit beam is used for every _two L eSSBs.

FIG. 19 is a diagram for explaining an example (2) of the beam management transmission mode 2 in the embodiment of the present invention. FIG. 19 is an example in which the transmission mode 2 is applied to the BSB + eSSB type 2. As shown in FIG. 19, each stage occupies a single 5ms half frame, and stages 1 and 2 may be repeated. In stage 1, four transmit beams are used for each L ₁ BSB, and in stage 2, one transmit beam is used for every _two L eSSBs.

FIG. 20 is a diagram for explaining an example (3) of the beam management transmission mode 2 in the embodiment of the present invention. FIG. 20 is an example in which the transmission mode 2 is applied to the BSB + eSSB type 3. As shown in FIG. 20, each stage occupies a single 5ms half frame, and stages 1 and 2 may be repeated. In stage 1, four transmit beams are used for each L ₁ BSB, and in stage 2, one transmit beam is used for every _two L eSSBs.

FIG. 21 is a diagram for explaining an example (1) of the beam management transmission mode 3 in the embodiment of the present invention. Hereinafter, the transmission mode 3 will be described. The feature of the transmission mode 3 is an integrated frame structure. FIG. 21 is an example in which the transmission mode 3 is applied to the BSB + eSSB type 1. As shown in FIG. 21, stage 1 and stage 2 may be integrated and placed in a single 5 ms half frame, with stage 1 and stage 2 being repeated. In stage 1, four transmit beams are used for each L ₁ BSB, and in stage 2, one transmit beam is used for every _two L eSSBs.

FIG. 22 is a diagram for explaining an example (2) of the beam management transmission mode 3 in the embodiment of the present invention. FIG. 22 is an example in which the transmission mode 3 is applied to the BSB + eSSB type 2. As shown in FIG. 22, stage 1 and stage 2 may be integrated and placed in a single 5 ms half frame, with stage 1 and stage 2 being repeated. In stage 1, four transmit beams are used for each L ₁ BSB, and in stage 2, one transmit beam is used for every _two L eSSBs.

FIG. 23 is a diagram for explaining an example (3) of the beam management transmission mode 3 in the embodiment of the present invention. FIG. 23 is an example in which the transmission mode 3 is applied to the BSB + eSSB type 3. As shown in FIG. 23, stage 1 and stage 2 may be integrated and placed in a single 5 ms half frame, with stage 1 and stage 2 being repeated. In stage 1, four transmit beams are used for each L ₁ BSB, and in stage 2, one transmit beam is used for every _two L eSSBs.

FIG. 24 is a diagram for explaining an example (1) of mapping a signal for the beam management stage 1 in the embodiment of the present invention. Hereinafter, a method of mapping BSB to a physical resource will be described for each case where SCS and M ₁ are different. FIG. 24 shows an example of BSB in which SCS is 120 KHz and M ₁ = 4 and L ₁ = 64. As shown in FIG. 24, transmission resources for PDCCH or PUCCH are guaranteed to be located in each slot. The index of the symbol at which the placement of the BSB is started is {2,8} + 14n. For the carrier frequency included in FR2, n = {0,1,2,3,4,5,6,7,10,11,12,13,14,15,16,17,20,21,22 , 23, 24, 25, 26, 27, 30, 31, 32, 33, 34, 35, 36, 37}. As shown in FIG. 24, in the first 10 slots in a 5 ms half frame, BSBs are arranged in all slots from slot 0 to slot 7. In the slot, the index of the symbol on which the BSB is placed is 2,3,4,5,8,9,10,11. Although the transmission mode 1 is shown in FIG. 24, the generality is not lost and it can be applied to other transmission modes.

FIG. 25 is a diagram for explaining an example (2) of signal mapping for the beam management stage 1 in the embodiment of the present invention. FIG. 25 shows an example of BSB in which SCS is 240 KHz and M ₁ = 4 and L ₁ = 64. As shown in FIG. 25, transmission resources for PDCCH or PUCCH are guaranteed to be located in each slot. The index of the symbol at which the placement of the BSB is started is {4,8,16,20} + 28n. For the carrier frequency included in FR2, n = {0,1,2,3,4,5,6,7,10,11,12,13,14,15,16,17}. As shown in FIG. 25, in the first 20 slots in the first 1/4 frame of 2.5 ms, BSBs are arranged in all slots from slot 0 to slot 15. In the slot, the index of the symbol of the first slot in which the BSB is placed is 4,5,6,7,8,9,10,11, and the index of the symbol of the second slot is 2,3,4,5. , 6, 7, 8 and 9. Although the transmission mode 1 is shown in FIG. 25, the generality is not lost and it can be applied to other transmission modes.

FIG. 26 is a diagram for explaining an example (3) of signal mapping for the beam management stage 1 in the embodiment of the present invention. FIG. 26 shows an example of BSB in which SCS is 120 KHz and M ₁ = 8 and L ₁ = 32. As shown in FIG. 26, the transmit resource for PDCCH or PUCCH is guaranteed to be located in each slot. The index of the symbol at which the placement of the BSB is started is {4,16} + 28n. For the carrier frequency included in FR2, n = {0,1,2,3,5,6,7,8,10,11,12,13,15,16,17,18}. As shown in FIG. 26, in the first 10 slots in a 5 ms half frame, BSBs are arranged in all slots from slot 0 to slot 7. In the slot, the index of the symbol of the first slot in which the BSB is placed is 4,5,6,7,8,9,10,11, and the index of the symbol of the second slot is 2,3,4,5. , 6, 7, 8 and 9. Although the transmission mode 1 is shown in FIG. 26, the generality is not lost and it can be applied to other transmission modes.

FIG. 27 is a diagram for explaining an example (4) of signal mapping for the beam management stage 1 in the embodiment of the present invention. FIG. 27 shows an example of BSB in which SCS is 240 KHz and M ₁ = 8 and L ₁ = 32. As shown in FIG. 27, the transmit resource for PDCCH or PUCCH is guaranteed to be located every two slots. The index of the symbol at which the placement of the BSB is started is {8,16,32,40} + 56n. For the carrier frequency included in FR2, n = {0,1,2,3,5,6,7,8}. As shown in FIG. 27, in the first 20 slots in the first 1/4 frame of 2.5 ms, BSBs are arranged in all slots from slot 0 to slot 15. In the slot, the index of the symbol of the first slot in which the BSB is placed is 8, 9, 10, 11, 12, 13, and the index of the symbol of the second slot is 0, 1, 2, 3, 4, 5. , 6,7,8,9, the index of the symbol in the third slot is 4,5,6,7,8,9,10,11,12,13, and the index of the symbol in the fourth slot is 0. , 1, 2, 3, 4, 5. Although the transmission mode 1 is shown in FIG. 27, the generality is not lost and it can be applied to other transmission modes.

FIG. 28 is a diagram for explaining an example (5) of signal mapping for the beam management stage 1 in the embodiment of the present invention. FIG. 28 shows an example of BSB in which SCS is 120 KHz and M ₁ = 10 and L ₁ = 32. As shown in FIG. 28, transmission resources for PDCCH or PUCCH are guaranteed to be located in each slot. The index of the symbol at which the placement of the BSB is started is {2} + 14n. For the carrier frequency included in FR2, n = {0,1,2,3,4,5,6,7,10,11,12,13,14,15,16,17,20,21,22 , 23, 24, 25, 26, 27, 30, 31, 32, 33, 34, 35, 36, 37}. As shown in FIG. 28, in the first 10 slots in a 5 ms half frame, BSBs are arranged in all slots from slot 0 to slot 7. In the slot, the index of the symbol on which the BSB is placed is 2,3,4,5,6,7,8,9,10,11. Although the transmission mode 1 is shown in FIG. 28, the generality is not lost and it can be applied to other transmission modes.

FIG. 29 is a diagram for explaining an example (6) of signal mapping for the beam management stage 1 in the embodiment of the present invention. FIG. 29 shows an example of BSB in which SCS is 240 KHz and M ₁ = 10 and L ₁ = 32. As shown in FIG. 29, the transmit resource for PDCCH or PUCCH is guaranteed to be located every two slots. The index of the symbol at which the placement of the BSB is started is {4,14} + 28n. For the carrier frequency included in FR2, n = {0,1,2,3,4,5,6,7,10,11,12,13,14,15,16,17}. As shown in FIG. 29, in the first 20 slots in the first 1/4 frame of 2.5 ms, BSBs are arranged in all slots from slot 0 to slot 15. In the slot, the index of the symbol of the first slot in which the BSB is placed is 4,5,6,7,8,9,10,11,12,13, and the index of the symbol of the second slot is 0,1. , 2,3,4,5,6,7,8,9. Although the transmission mode 1 is shown in FIG. 27, the generality is not lost and it can be applied to other transmission modes.

FIG. 30 is a diagram for explaining an example (7) of signal mapping for beam management stage 1 in the embodiment of the present invention. For larger SCSs used in the high frequency band, such as 480 KHz or 960 KHz, it is assumed that the period required for beam switching cannot be ignored. Therefore, for example, when the SCS is 480 KHz, the BSB frame structure as shown in FIG. 30 may be used. As shown in FIG. 30, transmission resources for PDCCH or PUCCH are guaranteed to be placed every two slots. The index of the symbol at which the placement of the BSB is started is {2,15} + 28n. For the carrier frequency included in FR2, n = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14, every 1.25 ms interval. 15, 16, 17}. As shown in FIG. 30, in the first 40 slots in a 5 ms half frame, BSBs are arranged in all slots from slot 0 to slot 35. In the slot, the index of the symbol of the first slot in which the BSB is placed is 2,4,6,8,10,12, and the index of the symbol of the second slot is 1,3,5,7,9,11. Is. That is, the time required for beam switching is secured for at least one symbol. Although the transmission mode 1 is shown in FIG. 30, the generality is not lost and it can be applied to other transmission modes.

FIG. 31 is a diagram for explaining an example (1) of mapping a signal for the beam management stage 2 in the embodiment of the present invention. Hereinafter, a method of mapping the eSSB to a physical resource will be described for each case where the SCS is different. FIG. 31 shows an example of eSSB type 1 in which SCS is 120 KHz and L ₂ = 64. The index of the symbol at which the placement of the eSSB type 1 is started is {4,8,16,20} + 28n. For the carrier frequency included in FR2, n = {0,1,2,3,5,6,7,8,10,11,12,13,15,16,17,18}. As shown in FIG. 31, in the first 10 slots in the 5 ms half frame, the eSSB type 1 is arranged in all the slots from slot 0 to slot 7. In the slot, the index of the symbol of the first slot in which the eSSB type 1 is arranged is 4,5,6,7,8,9,10,11, and the index of the symbol of the second slot is 2,3,4. , 5, 6, 7, 8, 9. Although the transmission mode 1 is shown in FIG. 31, the generality is not lost and it can be applied to other transmission modes.

FIG. 32 is a diagram for explaining an example (2) of signal mapping for the beam management stage 2 in the embodiment of the present invention. FIG. 32 shows an example of eSSB type 1 in which SCS is 240 KHz and L ₂ = 64. The index of the symbol at which the placement of the eSSB type 1 is started is {8,12,16,20,32,36,40,44} + 56n. For the carrier frequency included in FR2, n = {0,1,2,3,5,6,7,8}. As shown in FIG. 32, in the first 20 slots in the first 1/4 frame of 2.5 ms, the eSSB type 1 is arranged in all the slots from slot 0 to slot 15. In the slot, the index of the symbol of the first slot in which the eSSB type 1 is arranged is 8, 9, 10, 11, 12, 13, and the index of the symbol of the second slot is 0, 1, 2, 3, 4. , 5, 6, 7, 8, 9, and the index of the symbol in the third slot is 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, and the index of the symbol in the fourth slot. Is 0,1,2,3,4,5. Although the transmission mode 1 is shown in FIG. 32, the generality is not lost and it can be applied to other transmission modes.

FIG. 33 is a diagram for explaining an example (3) of signal mapping for the beam management stage 2 in the embodiment of the present invention. For larger SCSs used in the high frequency band, such as 480 KHz or 960 KHz, it is assumed that the period required for beam switching cannot be ignored. Therefore, for example, when the SCS is 480 KHz, the eSSB type 1 frame structure as shown in FIG. 33 may be used. The index of the symbol at which the placement of the eSSB type 1 is started is {3,8,16,21} + 28n. For the carrier frequency included in FR2, n = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14, every 1.25 ms interval. 15, 16, 17}. As shown in FIG. 33, in the first 40 slots in the 5 ms half frame, the eSSB type 1 is arranged in all the slots from slot 0 to slot 35. In the slot, the index of the symbol of the first slot in which the eSSB type 1 is arranged is 3,4,5,6,8,9,10,11, and the index of the symbol of the second slot is 2,3,4. , 5, 7, 8, 9, 10. That is, the time required for beam switching is secured for at least one symbol. Although the transmission mode 1 is shown in FIG. 33, the generality is not lost and it can be applied to other transmission modes.

FIG. 34 is a diagram for explaining an example (4) of signal mapping for the beam management stage 2 in the embodiment of the present invention. FIG. 34 shows an example of eSSB type 2 in which SCS is 120 KHz and L ₂ = 64. The index of the symbol at which the placement of eSSB type 2 is started is {3,6,9,16,19,22} + 28n. For the carrier frequency included in FR2, n = {0,1,2,3,5,6,7,8,10,11,12,13,15,16,17,18}. As shown in FIG. 34, in the first 10 slots in the 5 ms half frame, the eSSB type 2 is arranged in all the slots from slot 0 to slot 7. In the slot, the index of the symbol of the first slot in which the eSSB type 2 is arranged is 3,4,5,6,7,8,9,10,11, and the index of the symbol of the second slot is 2,3. , 4, 5, 6, 7, 8, 9, 10. Although the transmission mode 1 is shown in FIG. 34, the generality is not lost and it can be applied to other transmission modes.

FIG. 35 is a diagram for explaining an example (5) of signal mapping for the beam management stage 2 in the embodiment of the present invention. FIG. 35 shows an example of eSSB type 2 in which SCS is 240 KHz and L ₂ = 64. The index of the symbol at which the placement of eSSB type 2 is started is {6,9,12,15,18,21,32,35,38,41,44,47} + 56n. For the carrier frequency included in FR2, n = {0,1,2,3,5,6,7,8}. As shown in FIG. 35, in the first 20 slots in the first 1/4 frame of 2.5 ms, the eSSB type 2 is arranged in all the slots from slot 0 to slot 15. In the slot, the index of the symbol of the first slot in which the eSSB type 2 is arranged is 6,7,8,9,10,11,12,13, and the index of the symbol of the second slot is 0,1,2. , 3, 4, 5, 6, 7, 8, 9, and the index of the symbol in the third slot is 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, and the fourth slot. The index of the symbol of is 0,1,2,3,4,5,6,7. Although the transmission mode 1 is shown in FIG. 35, the generality is not lost and it can be applied to other transmission modes.

FIG. 36 is a diagram for explaining an example (6) of signal mapping for the beam management stage 2 in the embodiment of the present invention. For larger SCSs used in the high frequency band, such as 480 KHz or 960 KHz, it is assumed that the period required for beam switching cannot be ignored. Therefore, for example, when the SCS is 480 KHz, the eSSB type 2 frame structure as shown in FIG. 36 may be used. The index of the symbol at which the placement of eSSB type 2 is started is {2,6,10,15,19,23} + 28n. For the carrier frequency included in FR2, n = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14, every 1.25 ms interval. 15, 16, 17}. As shown in FIG. 36, in the first 40 slots in the 5 ms half frame, the eSSB type 2 is arranged in all the slots from slot 0 to slot 35. In the slot, the index of the symbol of the first slot in which the eSSB type 2 is arranged is 2,3,4,6,7,8,10,11,12, and the index of the symbol of the second slot is 1,2. , 3, 5, 6, 7, 9, 10, 11. That is, the time required for beam switching is secured for at least one symbol. Although FIG. 36 shows the transmission mode 1, the generality is not lost and the transmission mode can be applied to other transmission modes.

FIG. 37 is a diagram for explaining an example (7) of signal mapping for the beam management stage 2 in the embodiment of the present invention. FIG. 37 shows an example of eSSB type 3 in which SCS is 120 KHz and L ₂ = 64. The index of the symbol at which the placement of the eSSB type 3 is started is {4,6,8,10,16,18,20,22} + 28n. For the carrier frequency included in FR2, n = {0,1,2,3,5,6,7,8,10,11,12,13,15,16,17,18}. As shown in FIG. 34, in the first 10 slots in the 5 ms half frame, the eSSB type 3 is arranged in all the slots from slot 0 to slot 7. In the slot, the index of the symbol of the first slot in which the eSSB type 3 is arranged is 4,5,6,7,8,9,10,11, and the index of the symbol of the second slot is 2,3,4. , 5, 6, 7, 8, 9. Although the transmission mode 1 is shown in FIG. 37, the generality is not lost and it can be applied to other transmission modes.

FIG. 38 is a diagram for explaining an example (8) of signal mapping for the beam management stage 2 in the embodiment of the present invention. FIG. 38 shows an example of eSSB type 3 in which SCS is 240 KHz and L ₂ = 64. The index of the symbol at which the placement of eSSB type 3 is started is {8,10,12,14,16,18,20,22,32,34,36,38,40,42,44,46} + 56n. .. For the carrier frequency included in FR2, n = {0,1,2,3,5,6,7,8}. As shown in FIG. 38, in the first 20 slots in the first 1/4 frame of 2.5 ms, the eSSB type 3 is arranged in all the slots from slot 0 to slot 15. In the slot, the index of the symbol of the first slot in which the eSSB type 3 is arranged is 8, 9, 10, 11, 12, 13, and the index of the symbol of the second slot is 0, 1, 2, 3, 4. , 5, 6, 7, 8, 9, and the index of the symbol in the third slot is 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, and the index of the symbol in the fourth slot. Is 0,1,2,3,4,5. Although the transmission mode 1 is shown in FIG. 38, the generality is not lost and it can be applied to other transmission modes.

FIG. 39 is a diagram for explaining an example (9) of signal mapping for the beam management stage 2 in the embodiment of the present invention. For larger SCSs used in the high frequency band, such as 480 KHz or 960 KHz, it is assumed that the period required for beam switching cannot be ignored. Therefore, for example, when the SCS is 480 KHz, the eSSB type 3 frame structure as shown in FIG. 39 may be used. The index of the symbol at which the placement of the eSSB type 3 is started is {2,5,8,11,15,18,21,24} + 28n. For the carrier frequency included in FR2, n = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14, every 1.25 ms interval. 15, 16, 17}. As shown in FIG. 39, in the first 40 slots in the 5 ms half frame, the eSSB type 3 is arranged in all the slots from slot 0 to slot 35. In the slot, the index of the symbol of the first slot in which the eSSB type 3 is arranged is 2,3,5,6,8,9,11,12, and the index of the symbol of the second slot is 1,2,4. , 5, 7, 8, 10, 11. That is, the time required for beam switching is secured for at least one symbol. Although FIG. 39 shows the transmission mode 1, the generality is not lost and the transmission mode can be applied to other transmission modes.

According to the above embodiment, the base station 10 and the terminal 20 can reduce the overhead and delay related to the initial access by executing the beam management that enables high-speed Beam-Sweeping.

That is, the initial access can be efficiently executed in the wireless communication system.

(Device configuration)
Next, a functional configuration example of the base station 10 and the terminal 20 that execute the processes and operations described so far will be described. The base station 10 and the terminal 20 include a function for carrying out the above-described embodiment. However, the base station 10 and the terminal 20 may each have only a part of the functions in the embodiment.

<Base station 10>
FIG. 40 is a diagram showing an example of the functional configuration of the base station 10 according to the embodiment of the present invention. As shown in FIG. 40, the base station 10 has a transmission unit 110, a reception unit 120, a setting unit 130, and a control unit 140. The functional configuration shown in FIG. 40 is only an example. Any function classification and name of the functional unit may be used as long as the operation according to the embodiment of the present invention can be performed.

The transmission unit 110 includes a function of generating a signal to be transmitted to the terminal 20 side and transmitting the signal wirelessly. Further, the transmission unit 110 transmits a message between network nodes to another network node. The receiving unit 120 includes a function of receiving various signals transmitted from the terminal 20 and acquiring information of, for example, a higher layer from the received signals. Further, the transmission unit 110 has a function of transmitting NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals and the like to the terminal 20. Further, the receiving unit 120 receives a message between network nodes from another network node.

The setting unit 130 stores preset setting information and various setting information to be transmitted to the terminal 20. The content of the setting information is, for example, information related to the initial access setting.

The control unit 140 controls the setting of the initial access as described in the embodiment. Further, the control unit 140 controls the transmission beamforming. The function unit related to signal transmission in the control unit 140 may be included in the transmission unit 110, and the function unit related to signal reception in the control unit 140 may be included in the reception unit 120.

<Terminal 20>
FIG. 41 is a diagram showing an example of the functional configuration of the terminal 20 according to the embodiment of the present invention. As shown in FIG. 41, the terminal 20 has a transmission unit 210, a reception unit 220, a setting unit 230, and a control unit 240. The functional configuration shown in FIG. 41 is only an example. Any function classification and name of the functional unit may be used as long as the operation according to the embodiment of the present invention can be performed.

The transmission unit 210 creates a transmission signal from the transmission data and wirelessly transmits the transmission signal. The receiving unit 220 wirelessly receives various signals and acquires a signal of a higher layer from the received signal of the physical layer. Further, the receiving unit 220 has a function of receiving NR-PSS, NR-SSS, NR-PBCH, DL / UL / SL control signals and the like transmitted from the base station 10. Further, for example, the transmission unit 210 may use PSCCH (Physical Sidelink Control Channel), PSSCH (Physical Sidelink Shared Channel), PSDCH (Physical Sidelink Discovery Channel), PSBCH (Physical Sidelink Broadcast Channel) on another terminal 20 as D2D communication. Etc. are transmitted, and the receiving unit 220 receives PSCCH, PSCH, PSDCH, PSBCH, etc. from the other terminal 20.

The setting unit 230 stores various setting information received from the base station 10 by the receiving unit 220. The setting unit 230 also stores preset setting information. The content of the setting information is, for example, information related to the initial access setting.

The control unit 240 controls the setting of the initial access as described in the embodiment. Further, the control unit 240 controls the received beamforming. The function unit related to signal transmission in the control unit 240 may be included in the transmission unit 210, and the function unit related to signal reception in the control unit 240 may be included in the reception unit 220.

(Hardware configuration)
The block diagram (FIGS. 40 and 41) used in the description of the above embodiment shows a block of functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Further, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one physically or logically coupled device, or two or more physically or logically separated devices can be directly or indirectly (eg, for example). , Wired, wireless, etc.) and may be realized using these plurality of devices. The functional block may be realized by combining the software with the one device or the plurality of devices.

Functions include judgment, decision, judgment, calculation, calculation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, solution, selection, selection, establishment, comparison, assumption, expectation, and assumption. Broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, assigning, etc., but limited to these I can't. For example, a functional block (configuration unit) that makes transmission function is called a transmitting unit (transmitting unit) or a transmitter (transmitter). In each case, as described above, the realization method is not particularly limited.

For example, the base station 10, the terminal 20, and the like in one embodiment of the present disclosure may function as a computer that processes the wireless communication method of the present disclosure. FIG. 42 is a diagram showing an example of the hardware configuration of the base station 10 and the terminal 20 according to the embodiment of the present disclosure. The above-mentioned base station 10 and terminal 20 are physically configured as a computer device including a processor 1001, a storage device 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like. May be good.

In the following explanation, the word "device" can be read as a circuit, device, unit, etc. The hardware configuration of the base station 10 and the terminal 20 may be configured to include one or more of the devices shown in the figure, or may be configured not to include some of the devices.

For each function in the base station 10 and the terminal 20, by loading predetermined software (program) on the hardware such as the processor 1001 and the storage device 1002, the processor 1001 performs an calculation and controls the communication by the communication device 1004. It is realized by controlling at least one of reading and writing of data in the storage device 1002 and the auxiliary storage device 1003.

The processor 1001 operates, for example, an operating system to control the entire computer. The processor 1001 may be configured by a central processing unit (CPU: Central Processing Unit) including an interface with a peripheral device, a control device, an arithmetic unit, a register, and the like. For example, the above-mentioned control unit 140, control unit 240, and the like may be realized by the processor 1001.

Further, the processor 1001 reads a program (program code), a software module, data, or the like from at least one of the auxiliary storage device 1003 and the communication device 1004 into the storage device 1002, and executes various processes according to these. As the program, a program that causes a computer to execute at least a part of the operations described in the above-described embodiment is used. For example, the control unit 140 of the base station 10 shown in FIG. 40 may be realized by a control program stored in the storage device 1002 and operated by the processor 1001. Further, for example, the control unit 240 of the terminal 20 shown in FIG. 41 may be realized by a control program stored in the storage device 1002 and operated by the processor 1001. Although it has been described that the various processes described above are executed by one processor 1001, they may be executed simultaneously or sequentially by two or more processors 1001. Processor 1001 may be mounted by one or more chips. The program may be transmitted from the network via a telecommunication line.

The storage device 1002 is a computer-readable recording medium, and is, for example, by at least one of ROM (ReadOnlyMemory), EPROM (ErasableProgrammableROM), EEPROM (ElectricallyErasableProgrammableROM), RAM (RandomAccessMemory), and the like. It may be configured. The storage device 1002 may be referred to as a register, a cache, a main memory (main storage device), or the like. The storage device 1002 can store a program (program code), a software module, or the like that can be executed to implement the communication method according to the embodiment of the present disclosure.

The auxiliary storage device 1003 is a computer-readable recording medium, and is, for example, an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, an optical magnetic disk (for example, a compact disk, a digital versatile disk, Blu). -It may be composed of at least one of a ray (registered trademark) disk), a smart card, a flash memory (for example, a card, a stick, a key drive), a floppy (registered trademark) disk, a magnetic strip, and the like. The storage medium described above may be, for example, a database, server or other suitable medium containing at least one of the storage device 1002 and the auxiliary storage device 1003.

The communication device 1004 is hardware (transmission / reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, a communication module, or the like. The communication device 1004 includes, for example, a high frequency switch, a duplexer, a filter, a frequency synthesizer, and the like in order to realize at least one of frequency division duplex (FDD: Frequency Division Duplex) and time division duplex (TDD: Time Division Duplex). It may be composed of. For example, the transmission / reception antenna, the amplifier unit, the transmission / reception unit, the transmission line interface, and the like may be realized by the communication device 1004. The transmission / reception unit may be physically or logically separated from each other in the transmission unit and the reception unit.

The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that accepts an input from the outside. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, etc.) that outputs to the outside. The input device 1005 and the output device 1006 may have an integrated configuration (for example, a touch panel).

Further, each device such as the processor 1001 and the storage device 1002 is connected by the bus 1007 for communicating information. The bus 1007 may be configured by using a single bus, or may be configured by using a different bus for each device.

Further, the base station 10 and the terminal 20 are hardware such as a microprocessor, a digital signal processor (DSP: Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), and an FPGA (Field Programmable Gate Array). It may be configured to include, and a part or all of each functional block may be realized by the hardware. For example, processor 1001 may be implemented using at least one of these hardware.

(Summary of embodiments)
As described above, according to the embodiment of the present invention, the receiving unit that sequentially switches the received beamforming to receive the first signal from the base station and the measurement result of the first signal are used. It has a control unit that determines the received beamforming to be applied, the receiving unit applies the determined receiving beamforming, receives a second signal from the base station, and the control unit receives the second signal from the base station. A terminal is provided that performs synchronization and cell search using the second signal.

With the above configuration, the base station 10 and the terminal 20 can reduce the overhead and delay related to the initial access by executing the beam management that enables high-speed Beam-Sweeping. That is, in the wireless communication system, the initial access can be efficiently executed.

The first signal may be composed of only a synchronization signal. With this configuration, the terminal 20 can execute beam management that enables high-speed Beam-Sweeping.

The first signal may be subjected to different transmission beamforming for each symbol. With this configuration, the terminal 20 can execute beam management that enables high-speed Beam-Sweeping.

The second signal may be configured only from PBCH (Physical broadcast channel). With this configuration, the terminal 20 can execute beam management that enables high-speed Beam-Sweeping.

Further, according to the embodiment of the present invention, different transmission beamforming is applied to each symbol to transmit the first signal to the terminal, and the transmission beamforming is sequentially switched to transmit the second signal to the terminal. A base station having a transmission unit, a reception unit that receives information indicating the measurement result of the second signal from the terminal, and a control unit that determines the transmission beamforming to be applied based on the information indicating the measurement result. Is provided.

With the above configuration, the base station 10 and the terminal 20 can reduce the overhead and delay related to the initial access by executing the beam management that enables high-speed Beam-Sweeping. That is, in the wireless communication system, the initial access can be efficiently executed.

Further, according to the embodiment of the present invention, the received beamforming to be applied is applied based on the receiving procedure of sequentially switching the received beamforming to receive the first signal from the base station and the measurement result of the first signal. The terminal executes the control procedure for determining the above, applies the determined received beamforming, receives the second signal from the base station, and executes synchronization and cell search using the second signal. Communication method is provided.

With the above configuration, the base station 10 and the terminal 20 can reduce the overhead and delay related to the initial access by executing the beam management that enables high-speed Beam-Sweeping. That is, in the wireless communication system, the initial access can be efficiently executed.

(Supplement to the embodiment)
Although the embodiments of the present invention have been described above, the disclosed inventions are not limited to such embodiments, and those skilled in the art will understand various modifications, modifications, alternatives, substitutions, and the like. There will be. Although explanations have been given using specific numerical examples in order to promote understanding of the invention, these numerical values are merely examples and any appropriate value may be used unless otherwise specified. The classification of items in the above description is not essential to the present invention, and the items described in two or more items may be used in combination as necessary, and the items described in one item may be used in another item. May apply (as long as there is no conflict) to the matters described in. The boundary of the functional part or the processing part in the functional block diagram does not always correspond to the boundary of the physical component. The operation of the plurality of functional units may be physically performed by one component, or the operation of one functional unit may be physically performed by a plurality of components. Regarding the processing procedure described in the embodiment, the processing order may be changed as long as there is no contradiction. For convenience of processing, the base station 10 and the terminal 20 have been described with reference to functional block diagrams, but such devices may be implemented in hardware, software, or a combination thereof. The software operated by the processor of the base station 10 according to the embodiment of the present invention and the software operated by the processor of the terminal 20 according to the embodiment of the present invention are random access memory (RAM), flash memory, and read-only memory, respectively. It may be stored in (ROM), EPROM, EPROM, registers, hard disk (HDD), removable disk, CD-ROM, database, server or any other suitable storage medium.

Further, the notification of information is not limited to the embodiment / embodiment described in the present disclosure, and may be performed by using another method. For example, information notification includes physical layer signaling (for example, DCI (Downlink Control Information), UCI (Uplink Control Information)), higher layer signaling (for example, RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, etc. It may be carried out by broadcast information (MIB (Master Information Block), SIB (System Information Block)), other signals, or a combination thereof. RRC signaling may be referred to as an RRC message, for example, RRC. It may be a connection setup (RRCConnectionSetup) message, an RRC connection reconfiguration (RRCConnectionReconfiguration) message, or the like.

Each aspect / embodiment described in the present disclosure includes LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), and 5G (5th generation mobile communication). system), FRA (Future Radio Access), NR (new Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)) )), LTE 802.16 (WiMAX®), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth®, and other systems that utilize appropriate systems and have been extended based on these. It may be applied to at least one of the next generation systems. Further, a plurality of systems may be applied in combination (for example, a combination of at least one of LTE and LTE-A and 5G).

The order of the processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in the present specification may be changed as long as there is no contradiction. For example, the methods described in the present disclosure present elements of various steps using exemplary order, and are not limited to the particular order presented.

In some cases, the specific operation performed by the base station 10 in the present specification may be performed by its upper node (upper node). In a network consisting of one or more network nodes having a base station 10, various operations performed for communication with the terminal 20 are performed by the base station 10 and other network nodes other than the base station 10 ( For example, MME, S-GW, etc. are conceivable, but it is clear that it can be done by at least one of these). In the above example, the case where there is one network node other than the base station 10 is illustrated, but the other network node may be a combination of a plurality of other network nodes (for example, MME and S-GW). ..

The information, signals, etc. described in the present disclosure can be output from the upper layer (or lower layer) to the lower layer (or upper layer). Input / output may be performed via a plurality of network nodes.

The input / output information and the like may be stored in a specific location (for example, a memory) or may be managed using a management table. Information to be input / output may be overwritten, updated, or added. The output information and the like may be deleted. The input information or the like may be transmitted to another device.

The determination in the present disclosure may be made by a value represented by 1 bit (0 or 1), by a boolean value (Boolean: true or false), or by comparison of numerical values (for example). , Comparison with a predetermined value).

Software, whether referred to as software, firmware, middleware, microcode, hardware description language, or other names, is an instruction, instruction set, code, code segment, program code, program, subprogram, software module. , Applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, features, etc. should be broadly interpreted.

Further, software, instructions, information, etc. may be transmitted and received via a transmission medium. For example, the software may use at least one of wired technology (coaxial cable, optical fiber cable, twisted pair, digital subscriber line (DSL: Digital Subscriber Line), etc.) and wireless technology (infrared, microwave, etc.) to create a website. When transmitted from a server or other remote source, at least one of these wired and wireless technologies is included within the definition of transmission medium.

The information, signals, etc. described in this disclosure may be represented using any of a variety of different techniques. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description are voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any of these. It may be represented by a combination of.

The terms described in the present disclosure and the terms necessary for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may be a signal (signaling). Also, the signal may be a message. Further, the component carrier (CC: Component Carrier) may be referred to as a carrier frequency, a cell, a frequency carrier, or the like.

The terms "system" and "network" used in this disclosure are used interchangeably.

Further, the information, parameters, etc. described in the present disclosure may be expressed using an absolute value, a relative value from a predetermined value, or another corresponding information. It may be represented. For example, the radio resource may be one indicated by an index.

The names used for the above parameters are not limited in any respect. Further, mathematical formulas and the like using these parameters may differ from those expressly disclosed in this disclosure. Since the various channels (eg, PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, the various names assigned to these various channels and information elements are in any respect limited names. is not it.

In this disclosure, "base station (BS: Base Station)", "wireless base station", "base station device", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB" (GNB) ”,“ access point ”,“ transmission point ”,“ reception point ”,“ transmission / reception point ”,“ cell ”,“ sector ”, Terms such as "cell group," "carrier," and "component carrier" may be used interchangeably. Base stations are sometimes referred to by terms such as macrocells, small cells, femtocells, and picocells.

The base station can accommodate one or more (eg, 3) cells. When a base station accommodates multiple cells, the entire base station coverage area can be divided into multiple smaller areas, each smaller area being a base station subsystem (eg, a small indoor base station (RRH:)). Communication services can also be provided by (Remote Radio Head). The term "cell" or "sector" is a part or all of the coverage area of at least one of the base stations and base station subsystems that provide communication services in this coverage. Point to.

In the present disclosure, terms such as "mobile station (MS: Mobile Station)", "user terminal", "user device (UE: User Equipment)", and "terminal" may be used interchangeably. ..

Mobile stations can be used by those skilled in the art as subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobile terminals, wireless. It may also be referred to as a terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable term.

At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, or the like. At least one of the base station and the mobile station may be a device mounted on the mobile body, a mobile body itself, or the like. The moving body may be a vehicle (eg, car, airplane, etc.), an unmanned moving body (eg, drone, self-driving car, etc.), or a robot (manned or unmanned). ) May be. It should be noted that at least one of the base station and the mobile station includes a device that does not necessarily move during communication operation. For example, at least one of a base station and a mobile station may be an IoT (Internet of Things) device such as a sensor.

Further, the base station in the present disclosure may be read by the user terminal. For example, the communication between the base station and the user terminal is replaced with the communication between a plurality of terminals 20 (for example, it may be referred to as D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.). Each aspect / embodiment of the present disclosure may be applied to the configuration. In this case, the terminal 20 may have the functions of the base station 10 described above. Further, words such as "up" and "down" may be read as words corresponding to communication between terminals (for example, "side"). For example, the upstream channel, the downstream channel, and the like may be read as a side channel.

Similarly, the user terminal in the present disclosure may be read as a base station. In this case, the base station may have the functions of the above-mentioned user terminal.

The terms "determining" and "determining" used in this disclosure may include a wide variety of actions. "Judgment" and "decision" are, for example, judgment (judging), calculation (calculating), calculation (computing), processing (processing), derivation (deriving), investigation (investigating), search (looking up, search, inquiry). It may include (eg, searching in a table, database or another data structure), ascertaining as "judgment" or "decision". Also, "judgment" and "decision" are receiving (for example, receiving information), transmitting (for example, transmitting information), input (input), output (output), and access. It may include (for example, accessing data in memory) to be regarded as "judgment" or "decision". In addition, "judgment" and "decision" are considered to be "judgment" and "decision" when the things such as solving, selecting, choosing, establishing, and comparing are regarded as "judgment" and "decision". Can include. That is, "judgment" and "decision" may include considering some action as "judgment" and "decision". Further, "judgment (decision)" may be read as "assuming", "expecting", "considering" and the like.

The terms "connected", "coupled", or any variation thereof, mean any direct or indirect connection or connection between two or more elements and each other. It can include the presence of one or more intermediate elements between two "connected" or "combined" elements. The connection or connection between the elements may be physical, logical, or a combination thereof. For example, "connection" may be read as "access". As used in the present disclosure, the two elements use at least one of one or more wires, cables and printed electrical connections, and as some non-limiting and non-comprehensive examples, the radio frequency domain. Can be considered to be "connected" or "coupled" to each other using electromagnetic energy having wavelengths in the microwave and light (both visible and invisible) regions.

The reference signal can also be abbreviated as RS (Reference Signal), and may be called a pilot (Pilot) depending on the applied standard.

The statement "based on" used in this disclosure does not mean "based on" unless otherwise stated. In other words, the statement "based on" means both "based only" and "at least based on".

Any reference to elements using designations such as "first" and "second" as used in this disclosure does not generally limit the quantity or order of those elements. These designations can be used in the present disclosure as a convenient way to distinguish between two or more elements. Therefore, references to the first and second elements do not mean that only two elements can be adopted, or that the first element must somehow precede the second element.

The "means" in the configuration of each of the above devices may be replaced with a "part", a "circuit", a "device", or the like.

When "include", "including" and variations thereof are used in the present disclosure, these terms are as inclusive as the term "comprising". Is intended. Moreover, the term "or" used in the present disclosure is intended not to be an exclusive OR.

The wireless frame may be composed of one or more frames in the time domain. Each one or more frames in the time domain may be referred to as a subframe. The subframe may further be composed of one or more slots in the time domain. The subframe may have a fixed time length (eg, 1 ms) that does not depend on numerology.

The numerology may be a communication parameter applied to at least one of transmission and reception of a signal or channel. Numerology includes, for example, subcarrier interval (SCS: SubCarrier Spacing), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI: Transmission Time Interval), number of symbols per TTI, wireless frame configuration, and transmitter / receiver. It may indicate at least one of a specific filtering process performed in the frequency domain, a specific windowing process performed by the transmitter / receiver in the time domain, and the like.

The slot may be composed of one or more symbols (OFDM (Orthogonal Frequency Division Multiplexing) symbol, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbol, etc.) in the time domain. Slots may be time units based on numerology.

The slot may include a plurality of mini slots. Each minislot may be composed of one or more symbols in the time domain. Further, the mini slot may be referred to as a sub slot. The minislot may consist of a smaller number of symbols than the slot. A PDSCH (or PUSCH) transmitted in time units larger than the minislot may be referred to as a PDSCH (or PUSCH) mapping type A. The PDSCH (or PUSCH) transmitted using the minislot may be referred to as PDSCH (or PUSCH) mapping type B.

The wireless frame, subframe, slot, minislot and symbol all represent the time unit when transmitting a signal. The radio frame, subframe, slot, minislot and symbol may use different names corresponding to each.

For example, one subframe may be called a transmission time interval (TTI), a plurality of consecutive subframes may be called TTI, and one slot or one minislot may be called TTI. You may. That is, at least one of the subframe and TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (eg, 1-13 symbols), or a period longer than 1 ms. May be. The unit representing TTI may be called a slot, a mini slot, or the like instead of a subframe.

Here, TTI refers to, for example, the minimum time unit of scheduling in wireless communication. For example, in the LTE system, the base station schedules each terminal 20 to allocate radio resources (frequency bandwidth that can be used in each terminal 20, transmission power, etc.) in TTI units. The definition of TTI is not limited to this.

TTI may be a transmission time unit such as a channel-encoded data packet (transport block), a code block, or a code word, or may be a processing unit such as scheduling or link adaptation. When a TTI is given, the time interval (for example, the number of symbols) to which the transport block, code block, code word, etc. are actually mapped may be shorter than the TTI.

When one slot or one mini slot is called TTI, one or more TTIs (that is, one or more slots or one or more mini slots) may be the minimum time unit for scheduling. Further, the number of slots (number of mini-slots) constituting the minimum time unit of the scheduling may be controlled.

A TTI having a time length of 1 ms may be referred to as a normal TTI (TTI in LTE Rel. 8-12), a normal TTI, a long TTI, a normal subframe, a normal subframe, a long subframe, a slot, or the like. TTI shorter than normal TTI may be referred to as shortened TTI, short TTI, partial TTI (partial or fractional TTI), shortened subframe, short subframe, minislot, subslot, slot and the like.

The long TTI (eg, normal TTI, subframe, etc.) may be read as a TTI having a time length of more than 1 ms, and the short TTI (eg, shortened TTI, etc.) may be read as a TTI less than the TTI length of the long TTI and 1 ms. It may be read as TTI having the above TTI length.

The resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and may include one or a plurality of continuous subcarriers in the frequency domain. The number of subcarriers contained in the RB may be the same regardless of the numerology, and may be, for example, 12. The number of subcarriers contained in the RB may be determined based on numerology.

Further, the time domain of the RB may include one or more symbols, and may have a length of 1 slot, 1 mini slot, 1 subframe, or 1 TTI. Each 1TTI, 1 subframe, etc. may be composed of one or a plurality of resource blocks.

One or more RBs include a physical resource block (PRB: Physical RB), a sub-carrier group (SCG: Sub-Carrier Group), a resource element group (REG: Resource Element Group), a PRB pair, an RB pair, and the like. May be called.

Further, the resource block may be composed of one or a plurality of resource elements (RE: Resource Element). For example, 1RE may be a radio resource area of 1 subcarrier and 1 symbol.

The bandwidth part (BWP: Bandwidth Part) (which may also be called partial bandwidth) may represent a subset of consecutive common resource blocks (RBs) for a certain neurology in a carrier. Here, the common RB may be specified by the index of the RB with respect to the common reference point of the carrier. PRBs may be defined in a BWP and numbered within that BWP.

The BWP may include a BWP for UL (UL BWP) and a BWP for DL (DL BWP). One or more BWPs may be set in one carrier for the UE.

At least one of the configured BWPs may be active and the UE may not expect to send or receive a given signal / channel outside the active BWP. In addition, "cell", "carrier" and the like in this disclosure may be read as "BWP".

The above-mentioned structures such as wireless frames, subframes, slots, mini-slots and symbols are merely examples. For example, the number of subframes contained in a radio frame, the number of slots per subframe or radioframe, the number of minislots contained within a slot, the number of symbols and RBs contained in a slot or minislot, included in the RB. The number of subcarriers, the number of symbols in TTI, the symbol length, the cyclic prefix (CP: Cyclic Prefix) length, and other configurations can be changed in various ways.

In the present disclosure, if articles are added by translation, for example, a, an and the in English, the disclosure may include the plural nouns following these articles.

In the present disclosure, the term "A and B are different" may mean "A and B are different from each other". The term may mean that "A and B are different from C". Terms such as "separate" and "combined" may be interpreted in the same way as "different".

Each aspect / embodiment described in the present disclosure may be used alone, in combination, or may be switched and used according to the execution. Further, the notification of predetermined information (for example, the notification of "being X") is not limited to the explicit one, but is performed implicitly (for example, the notification of the predetermined information is not performed). May be good.

The BSB in the present disclosure is an example of the first signal. The eSSB is an example of a second signal.

Although the present disclosure has been described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure may be implemented as amendments and modifications without departing from the spirit and scope of the present disclosure as determined by the description of the scope of claims. Therefore, the description of this disclosure is for purposes of illustration and does not have any limiting meaning to this disclosure.

10 base station or gNB
110 Transmitter 120 Receiver 130 Setting 140 Control 20 Terminal or UE
210 Transmitter 220 Receiver 230 Setting 240 Control 1001 Processor 1002 Storage device 1003 Auxiliary storage device 1004 Communication device 1005 Input device 1006 Output device

Claims (6)

1. A receiver that sequentially switches receive beamforming to receive the first signal from the base station,
   It has a control unit that determines the received beamforming to be applied based on the measurement result of the first signal.
   The receiver applies the determined receive beamforming to receive a second signal from the base station.
   The control unit is a terminal that executes synchronization and cell search using the second signal.
2. The terminal according to claim 1, wherein the first signal is composed only of a synchronization signal.
3. The terminal according to claim 2, wherein the first signal is to which transmission beamforming different for each symbol is applied.
4. The terminal according to claim 2, wherein the second signal is composed only of a PBCH (Physical broadcast channel).
5. A transmission unit that applies different transmission beamforming for each symbol to transmit the first signal to the terminal, and sequentially switches the transmission beamforming to transmit the second signal to the terminal.
   A receiving unit that receives information indicating the measurement result of the second signal from the terminal, and
   A base station having a control unit that determines the transmitted beamforming to be applied based on the information indicating the measurement result.
6. The reception procedure of sequentially switching the receive beamforming and receiving the first signal from the base station,
   The terminal executes a control procedure for determining the received beamforming to be applied based on the measurement result of the first signal.
   Applying the determined receive beamforming, a second signal is received from the base station.
   A communication method for executing synchronization and cell search using the second signal.

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