Base station, terminal equipment, control method, and program for high-speed beam selection

Abstract

In mobile communication systems, performing beam selection in a short time. [Solution] A base station that performs wireless communication with a terminal device based on the cellular communication standard of the 3rd Generation Partnership Project transmits synchronization signal (SS) / physical broadcast channel (PBCH) blocks (SSB) associated with each of the multiple beams in a common time resource, using multiple beams with different directional patterns in a single cell provided by the base station, in each of the multiple non-overlapping frequency resources associated with each of the multiple beams, obtains a report on the measurement of the terminal device, which includes frequency information that identifies the frequency resource from which the SSB was received by the terminal device, identifies the beam with the directional pattern associated with the frequency resource identified based on the report as the beam to be used for communication with the terminal device, and performs communication with the terminal device using the identified beam.

Description

Technical Field

[0004] , , ,

[0001] The present invention relates to a technique for beam selection in a mobile communication system.

Background Art

[0002] In a mobile communication system compliant with the cellular communication standard of the 3rd Generation Partnership Project (3GPP (registered trademark)), a base station forms a plurality of beams having different directivity patterns and communicates with a terminal. Among the beams formed by the base station, a beam with good radio quality is selected from the beams received by the terminal and used for communication between the base station and the terminal. As configurations of antennas for the base station to form a plurality of beams, there are configurations using a phased array antenna and configurations using a real-time delay array antenna. Non-Patent Document 1 describes a configuration combining a phased array antenna and a real-time delay array antenna.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The selection of beams used between a base station and a terminal can be performed using an SS / PBCH Block signal transmitted by the base station. SS / PBCH is an abbreviation for Synchronization Signal / Physical Broadcast Channel. The SS / PBCH Block may be called SSB. The base station can transmit SSB by sequentially using each beam, changing the beam used for transmission. The terminal measures the radio quality of the received SSB from among the SSBs transmitted using each beam. For example, the terminal selects the beam to be used between the base station and the terminal by comparing the measured radio quality. In this case, the time required to select a beam increases as the number of beams increases. This invention provides a technique for performing beam selection in a mobile communication system in a short time. [Means for solving the problem]

[0005] A terminal device according to one aspect of the present invention is a base station that performs wireless communication with a terminal device based on the cellular communication standard of the Third Generation Partnership Project (3GPP), and comprises: a transmission means that, in a single cell provided by the base station, transmits synchronization signal (SS) / physical broadcast channel (PBCH) blocks (SSB) associated with each of the plurality of beams in a common time resource, using a plurality of beams having different directional patterns, in each of a plurality of non-overlapping frequency resources associated with each of the plurality of beams; an acquisition means that acquires a report relating to measurements of the terminal device, the report including frequency information that identifies the frequency resource from which the SSB was received by the terminal device; an identification means that identifies a beam with a directional pattern associated with the frequency resource identified based on the report as a beam to be used for communication with the terminal device; and a communication means that performs communication with the terminal device using the identified beam.

[0006] A terminal device that communicates with a base station based on the cellular communication standard of the Third Generation Partnership Project (3GPP), comprising: receiving means for receiving synchronization signal (SS) / physical broadcast channel (PBCH) blocks (SSB) associated with each of a plurality of beams that the base station transmits using a common time resource in each of a plurality of non-overlapping frequency resources associated with each of the plurality of beams, each of which has a plurality of beams having, each of which has a plurality of beams that do not overlap with each other, in a cell provided by the base station; reporting means for reporting to the base station a report relating to the measurement of the terminal device, the report including frequency information that identifies the frequency resource in which the SSB was received by the terminal device; and communication means for communicating with the base station using beams set by the base station based on the report. [Effects of the Invention]

[0007] According to the present invention, beam selection can be performed in a mobile communication system in a short amount of time. [Brief explanation of the drawing]

[0008] [Figure 1] This is a diagram showing an example configuration of a mobile communication system. [Figure 2] This figure shows an example of SSB transmission. [Figure 3] This figure shows an example of SSB transmission using multiple beams at a base station. [Figure 4] This figure shows an example of SSB transmission using multiple beams at a base station. [Figure 5] This figure shows an example of SSB transmission. [Figure 6] This figure shows an example of the configuration of an antenna control circuit. [Figure 7] This diagram shows an example of the processing flow at a base station. [Figure 8] This diagram shows an example of the terminal's processing flow. [Figure 9] This diagram shows an example of the hardware configuration of a base station and a terminal. [Figure 10]This figure shows an example of the functional configuration of a base station. [Figure 11] This figure shows an example of the device's functional configuration. [Modes for carrying out the invention]

[0009] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more of the features described in the embodiments may be combined in any way. Furthermore, identical or similar configurations will be given the same reference numeral, and redundant descriptions will be omitted.

[0010] (System Configuration) Figure 1 shows an example configuration of a mobile communication system according to this embodiment. The mobile communication system of this embodiment is, for example, a cellular communication system compliant with the cellular communication standard of the Third Generation Partnership Project (3GPP®). However, it is not limited to this, and the following discussion can be applied to a mobile communication system compliant with any wireless communication standard. This mobile communication system is composed of, for example, a base station 101 and a terminal 111. The base station 101 exchanges radio signals with the terminal 111 via a wireless medium. The base station 101 includes, for example, a gNB (next Generation Node B), an eNB (evolved Node B), etc. The base station 101 is connected to a core network (not shown). The core network may be, for example, an Evolved Packet System (EPS) or a 5G Core Network (5GC). The terminal 111 is a terminal used by a user and exchanges radio signals with the base station 101 via a wireless medium. The terminal 111 may be called User Equipment (UE). The terminal 111 may be called by other names such as wireless terminal. Terminal 111 includes, for example, smartphones, mobile phones, personal computers, tablet devices, wearable devices, IoT (Internet of Things) devices, etc. Figure 1 shows an example where there is one base station 101 and one terminal 111, but in a mobile communication system, there may be two or more base stations 101 and two or more terminals 111. In this case, multiple terminals 111 may be connected to one base station 101, and one terminal 111 may be connected to multiple base stations 101.

[0011] Base station 101 constitutes a cell. A cell is, for example, a geographical area from which communication with base station 101 providing this cell is possible. If base station 101 has multiple antennas, multiple beams with different directional patterns can be formed using these antennas. Base station 101 can constitute a cell using multiple beams. Base station 101 may constitute multiple different cells using each beam, or it may constitute a single cell formed by multiple beams. In Figure 1, base station 101 forms beams 121_0 to 121_(k-1). Base station 101 can form any number (K) beams. The maximum number of beams formed by base station 101 may vary depending on the frequency band. For example, base station 101 can form up to 8 beams in the 3.7 GHz and 4.5 GHz bands. Also, base station 101 can form up to 64 beams in the 28 GHz band.

[0012] Base station 101 communicates with terminal 111 using a selected beam. The beam used for communication with terminal 111 may be selected from among multiple beams formed by base station 101, based on the beam with the best radio quality received by terminal 111. Beam selection may be performed using an SS / PBCH Block transmitted by base station 101. SS / PBCH is an abbreviation for Synchronization Signal / Physical Broadcast Channel. An SS / PBCH Block may be called SSB. Base station 101 may transmit SSB by sequentially using each beam while changing the beam used for transmission of the SSB. Terminal 111 evaluates the radio quality of the received SSB from among the SSBs transmitted using each beam. To evaluate the radio quality of the received SSB, terminal 111 may measure RSSI, RSRP, RSRQ, SINR, etc. RSSI is an abbreviation for Received Signal Strength Indicator. RSRP is an abbreviation for Reference Signal Received Power. RSRQ is an abbreviation for Reference Signal Received Quality. SINR is an abbreviation for Signal to Interference and Noise Ratio. Terminal 111 notifies base station 101 of information indicating the measurement results and information that allows identification of the beam selected based on the measurement results. Base station 101 identifies the beam to be used for communication based on the information notified by terminal 111. In this way, the beam to be used for communication can be identified between base station 101 and terminal 111.

[0013] Figure 2 shows an example of the operation of base station 101 when transmitting SSB. Base station 101 transmits SSB at a predetermined period. The period during which base station 101 transmits SSB may be called the SSB transmission period. Base station 101 may transmit an SS burst set consisting of multiple SSBs for each SSB transmission period. For example, an SS burst set may consist of 64 SSBs. An SS burst set may contain more or fewer SSBs. Each SSB may contain index information that identifies the time axis position of each SSB within the SS burst. This index information may be called the SSB index or SS-block time index. For example, if one SS burst contains 64 SSBs, SSB index 0 (SSB#0) to SSB index 63 (SSB#63) are assigned to identify SSBs 0 to 63, respectively. The slot in a radio frame in which SSB is transmitted is called the SSB transmission slot. One slot can consist of 14 OFDM symbols. OFDM is an abbreviation for Orthogonal frequency-division multiplexing. In one slot, for example, two SSBs may be transmitted. For example, if one slot is 0.125 ms (milliseconds) long, it takes 4 ms to transmit an SS burst with 64 SSBs. Each SSB constituting an SS burst may be transmitted using beams with different directional patterns. For example, if base station 101 forms 64 beams, each of the 64 SSBs constituting the SS burst may be transmitted using a different beam. In this case, base station 101 can store the SSB index of each SSB in association with the beam from which each SSB is transmitted. Figure 3 shows an example of operation when base station 101 transmits by associating each beam with the SSB index of the SSB transmitted using that beam. For example, base station 101 associates beam 121_0 with SSB index 0 and then transmits the SSB with SSB index 0 set using beam 121_0.Similarly, base station 101 associates SSB index 1, SSB index 2, ..., SSB index (n-1) with each of beams 121_1, beam 121_2, ..., beam 121_(k-1), and then transmits SSB with the corresponding SSB index set using each beam. In this way, base station 101 can transmit SS bursts while associating each beam with the SSB index of the SSB transmitted by that beam.

[0014] Furthermore, base station 101 notifies terminal 111 of the timing for transmitting SS bursts. For example, base station 101 may notify terminal 111 of SMTC window information as configuration information for measuring the radio quality of SSB. SMTC is an abbreviation for SS / PBCH block Measurement Timing Configuration. The SMTC window may include information such as the measurement period, timing offset, measurement period, identifier of the cell to be measured, and the SSB to be measured. The SMTC window may indicate the period during which terminal 111 should measure the signal.

[0015] The terminal 111 can measure the radio quality of each SSB in the SMTC window. For example, the terminal 111 can associate and store the SSB index included in the SSB received in the SMTC window with the radio quality measured using that SSB. The terminal 111 determines the SSB with the highest radio quality among the measured SSBs. The terminal 111 notifies the base station 101 of the SSB index associated with the SSB having the highest radio quality. Note that the terminal 111 may notify the base station 101 of the SSB index associated with the SSB whose measurement value (RSSI, RSRP, RSRQ, SINR, etc.) indicating the radio quality exceeds a predetermined threshold. Also, the terminal 111 may notify the base station 101 of the SSB indexes associated with a predetermined number of SSBs in order from the highest measurement value indicating the radio quality. When the base station 101 receives the SSB index from the terminal 111, it specifies the beam associated with the notified SSB index as the beam to be used in communication with the terminal 111. Note that when the base station 101 is notified of a plurality of SSB indexes by the terminal 111, it can select one beam from them. Also, the base station 101 may execute a procedure for forming a beam with higher accuracy based on the SSB index notified from the terminal 111. For example, the base station 101 can execute beam selection again with the terminal 111 using a plurality of beams having a directivity pattern close to the directivity pattern of the beam corresponding to the SSB index notified from the terminal 111. In this way, the base station 101 can determine the beam to be used in communication with the terminal 111.

[0016] As described above, the base station 101 and the terminal 111 can determine which beam to use for communication based on the SSB that base station 101 transmits using each beam. In this case, the more beams there are, the longer it takes to determine which beam to use. For example, if base station 101 forms 64 beams, it is necessary to transmit 64 SSBs. If two SSBs are transmitted in one slot, 32 slots are required to transmit an SS burst containing 64 SSBs. In this case, if the time length of one slot is 0.125 ms, then, for example, 4 ms is required. For example, if the SSB transmission period is 20 ms, the SS burst will be transmitted for 1 / 5 of this period, and during that period terminal 111 will perform radio quality measurements. If terminal 111 is unable to communicate with base station 111 during that period, terminal 111's throughput may decrease, or delays may occur in data transmission.

[0017] In view of such circumstances, in this embodiment, the base station 101 uses a plurality of beams with different directivity patterns in one cell provided by the self-device, and in each of a plurality of non-overlapping frequency resources associated with each beam, transmits the SSB associated with each beam in a common time resource. The terminal 111 receives the SSB transmitted by the base station in each frequency resource, performs measurements using each of the received SSBs, and reports to the base station 101 a report including frequency information for identifying the frequency resource in which the SSB was received. When the base station 101 acquires a report including frequency information for identifying the frequency resource in which the SSB was received at the terminal 111, the base station 101 identifies the beam associated with the frequency resource specified based on this report as the beam to be used for communication with the terminal device. Then, the base station 101 and the terminal device 111 perform communication using the set beam. With such a configuration, the base station 101 can execute the transmission of the SSB using a plurality of beams having different directivity patterns in parallel using different frequency resources. As a result, the transmission of the SS burst can be completed in a short time, so that the time required for beam selection is shortened.

[0018] Base station 101 may include information for beam identification within the SSB. For example, base station 101 may transmit an SSB including a frequency index indicating the frequency resource used for transmitting the SSB. For example, as shown in the example of SSB transmission in Figure 2, the SSB index is information indicating the temporal arrangement of SSBs within an SS burst, so if multiple SSBs are transmitted using the same time resource, they cannot be identified. Therefore, the current SSB index cannot be used as is to identify the beam. In contrast, by setting a frequency index in the SSB as identification information indicating the frequency resource used for the SSB frequency, it becomes possible to identify the SSB on the frequency axis. This makes it possible to identify each SSB even if multiple SSBs are transmitted using different frequency resources using the same time resource, thus enabling beam selection based on SSB measurements. Terminal 111 may identify the frequency on which the SSB was received and notify the base station of the information indicating the identified frequency. With this configuration, it becomes unnecessary to set a frequency index in the SSB. This reduces the amount of information that needs to be transmitted in the SSB. The following describes the information exchanged between terminal 101 and base station 110 operating as described above, as well as examples of the configuration of each device.

[0019] (SSB transmission method) First, an example of operation when base station 101 transmits SSB will be described. Figure 4 is a diagram showing an example of the relationship between the beams used to transmit the SSB included in the SS burst when base station 101 transmits an SS burst and the frequency resources. Base station 101 forms K beams: beam 121_0, beam 121_1, beam 121_2, ..., beam 121_(k-1). The directivity patterns of each beam are different from each other, and there may or may not be partial overlap in spatially adjacent beams. In addition, base station 101 sets up multiple (M) frequency resources for transmitting SSB in the frequency band used by its device for communication. The number M of frequency resources may be K ≥ M when the number of beams formed by base station 101 is K. Note that each of the frequency resources is set up so as not to overlap with each other. The bandwidths of each of the multiple frequency resources may be different, or the bandwidths of all or some of the frequency resources may be the same. Each frequency resource for transmitting SSB may be formed by dividing the frequency band used in a single cell configured by the base station 101 into multiple frequency bands. For example, a frequency resource for transmitting SSB may be formed based on the arrangement of Resource Blocks (RBs) configured on the frequency axis of the radio frame. For example, a frequency resource for transmitting SSB may be associated with one or more RBs. Alternatively, a frequency resource for transmitting SSB may be formed independently of the RBs. For example, a frequency resource for transmitting SSB may be formed, regardless of the arrangement of RBs, by dividing the frequency band used in a cell configured by the base station based on the number of beams formed by the base station 101.

[0020] The base station 101 associates each of the K beams formed by its device with each of the M frequency resources for transmitting SSB. For example, in Figure 4, the base station 101 can associate beam 121_0 with frequency resource f_0. Similarly, the base station 101 can associate beam 121_1 with frequency resource f_1, beam 121_2 with frequency resource f_2, and beam 121_(k-1) with frequency resource f_(m-1). If the number of beams (K) is greater than the number of frequency resources (M) (K > M), multiple beams with different directional patterns can be associated with the same frequency resource. In this case, beams with different directional patterns can be formed at different timings (time resources) within the same frequency resource. The base station 101 stores the association between each beam and its respective frequency resource. For example, the base station 101 can assign unique identification information to each of the multiple beams formed by its device. Furthermore, the base station 101 can assign unique identification information to each of the multiple frequency resources for transmitting SSB. The base station 101 can store the identification information assigned to each beam in association with the identification information assigned to each frequency resource.

[0021] The base station 101 associates each beam formed by its device with an SSB transmitted using that beam. For example, the base station 101 manages the identification information of each beam in association with the identification information of the SSB. The identification information of the SSB associated with each beam may be an SSB index or other identification information. For example, if the number of beams K formed by its device is the same as the number of SSBs N included in the SS burst (for example, K=N=64), the base station 101 can store the identification information of each beam in association with the identification information of the SSB transmitted using that beam. Also, if the number of beams K formed by its device is less than the number of SSBs N included in the SS burst (for example, K=8, N=64), the base station 101 may associate multiple SSBs with beams of the same directional pattern. In this case, multiple SSBs associated with the same beam may be transmitted at different timings (time resources). The base station 101 may associate identification information for SSB to be transmitted using a given combination of beams and frequency resources with each other.

[0022] An example of operation when base station 101 transmits SSB using a combination of frequency resources and beams associated with each other will be explained using Figures 5(A) to 5(C). Figure 5(A) shows an example in which base station 101 transmits an SS burst consisting of 64 SSBs when the number of frequency resources equals the number of beams K formed by base station 101 (M=K=64). In Figure 5(A), the vertical axis represents frequency and the horizontal axis represents time. For example, in the example of Figure 5(A), 64 frequency resources f_0 to f_63 are set in the frequency band used by base station 101. In this case, base station 101 can transmit 64 SSBs in a common time resource t_0. For example, for each of the frequency resources f_0 to f_63, base station 101 can transmit the SSB associated with that beam from SSB#0 to SSB#63 using the beam associated with that frequency resource from among 64 beams having different directivity. As shown in the example in Figure 5(A), base station 101 transmits 64 SSBs in parallel within one slot (the 0th slot). Terminal 111 can receive SSB#0 to SSB#63 in each of the frequency resources f_0 to f_63. Terminal 111 measures the radio quality of each received SSB. In this case, the transmission of SS bursts included in an SS burst is performed in parallel within one slot, and the measurement of the radio quality of each SSB is also performed in parallel within one slot. Thus, in this example, the operation for beam selection can be completed with just one slot.

[0023] Figure 5(B) shows an example where base station 101 transmits an SS burst consisting of 64 SSBs when fewer frequency resources are set than the number of beams K formed by base station 101 (M=2, K=64). For example, in the example in Figure 5(B), two frequency resources f_0 and f_1 for transmitting SSBs are set in the frequency band used by base station 101. In this case, base station 101 can transmit two SSBs in parallel in each of the common time resources t_0, t_1, ..., t_31. For example, base station 101 can transmit in order from the SSB with the smallest SSB index, using the beam associated with that SSB and the frequency resource associated with that beam. Base station 101 can continue transmitting SSBs in order until all SSBs included in the SS burst have been transmitted. For example, if an SS burst contains 64 SSBs, 16 slots (slots 0 through 15) will be needed for all SSBs in the SS burst to be transmitted. Even in this case, each SSB is transmitted using a different beam. Terminal 111 measures the radio quality using one or more SSBs received in each frequency resource. In Figure 5(B), terminal 111 performs SSB reception and radio quality measurement across 16 slots. Thus, in this example, the beam selection operation can be completed using 16 slots.

[0024] Figure 5(C) shows another example where fewer frequency resources are configured than the number of beams K formed by the base station 101 (M=8, K=64). For example, in the example in Figure 5(C), eight frequency resources f_0, f_1, ..., f_7 are configured in the frequency band used by the base station 101. In this case, the base station 101 can transmit eight SSBs in parallel on each of the common time resources t_0, t_1, ..., t_7. For example, the base station 101 may transmit the SSB associated with a beam using the frequency resource associated with that beam, starting with the beam with the smallest assigned identification information value. The base station 101 may continue transmitting SSBs sequentially until all SSBs included in the SS burst have been transmitted. For example, if the SS burst contains 64 SSBs, four slots (slots 0 to 3) will be required to transmit all SSBs included in the SS burst. Note that even in this case, each SSB is transmitted using a different beam. Terminal 111 performs radio quality measurements using one or more SSBs received in each frequency resource. In Figure 5(C), terminal 111 performs SSB reception and radio quality measurements across four slots. Thus, in this example, the beam selection operation can be completed using four slots.

[0025] The methods by which base station 101 transmits SSBs using each beam are not limited to these. For example, in the examples in Figures 5(A) to 5(C), base station 101 transmits the same number of SSBs in parallel for each time resource, but the number of SSBs that base station 101 transmits in parallel may differ for each slot or for each transmission. In each of the multiple frequency resources set by base station 101, multiple SSBs should be transmitted in parallel using multiple beams with different directivity so that the time required to complete the transmission of the SS burst is shortened. Note that if the number of beams K formed by base station 101 is less than the number of SSBs N, some SSBs may be transmitted using the same beam as other SSBs. For example, in the example in Figure 5(C), if the number of beams K formed by base station 101 is 16, then each of the 16 SSBs in the 0th slot is transmitted using a different beam, thereby performing SSB transmission using all of the beams formed by base station 101. In this case, the first to third slots can also transmit SSB signals using the same beam as the zeroth slot.

[0026] (Measurement report and beam identification method) Base station 101 may set specific information for each SSB included in the SS burst to identify the beam used for transmitting that SSB. Terminal 111 may measure the radio quality using the received SSB and report the measurement results to base station 101 using the specific information obtained from that SSB. For example, terminal 111 may report the radio quality of each received SSB to base station 101 as a measurement result. Terminal 111 may also report to base station 101 only those SSBs whose radio quality values ​​exceed a predetermined threshold as a measurement result. This reduces the amount of information that terminal 111 needs to report to base station 101. Alternatively, terminal 111 may report a predetermined number of SSBs to base station 101 in order of highest radio quality values. The predetermined number may be one or more. In these cases, terminal 111 may report to base station 101 the measured radio quality value and the specific information for identifying the beam corresponding to that measurement value, in association with each other. Alternatively, terminal 111 may report the specific information for identifying the beam without reporting the measured radio quality value.

[0027] Base station 101 may use beam identification information assigned to each beam as identification information to identify each beam. For example, if base station 101 forms 64 beams, it may assign an identifier from 0 to 63 to each beam to uniquely identify each beam. Base station 101 may set the beam identification information used for transmitting the SSB to the SSB transmitted using each beam. Terminal 111 may use the beam identification information set in the received SSB as identification information to identify the beam and report to base station 101.

[0028] Base station 101 may use the SSB index of the SSB as identifying information to identify each beam. For example, as shown in the example in Figure 5(B), base station 101 may assign a smaller SSB number to an SSB that is transmitted earlier. Also, as shown in the example in Figure 5(C), base station 101 may assign a smaller SSB number to an SSB that is transmitted at a lower frequency. When the SSB index is used as identifying information to identify a beam, base station 101 does not need to add new information to the SSB. This reduces the amount of information that needs to be transmitted in SSB, where the amount of information that can be transmitted is limited. Terminal 111 may use the SSB index set in the received SSB as identifying information to identify the beam and report it to base station 101. Base station 101 may identify the beam associated with the SSB index included in the report from terminal 111 as the beam to be used for communication with terminal 111.

[0029] Base station 101 may use identification information (frequency index) assigned to the frequency resource associated with a beam as identification information to identify that beam. The identification information of the frequency resource used as identification information to identify a beam may be called the SS-block frequency index. The identification information of the frequency resource may be called by other names. For example, as shown in the example in Figure 5(A), if the number M of frequency resources that base station 101 sets up for transmitting SSB is the same as the number K of beams, each beam can be uniquely identified by the frequency index. For example, base station 101 may set the frequency index used for transmitting the SSB for each SSB transmitted using each frequency resource. Terminal 111 may use the frequency index (frequency information) set in the received SSB as identification information to identify the beam and report it to base station 101. Base station 101 may identify the beam associated with the frequency index included in the report from terminal 111 as the beam to be used for communication with terminal 111.

[0030] Furthermore, if terminal 111 can identify the frequency on which the SSB was received and manage it in association with the radio quality measured using that SSB, base station 101 does not need to set identification information for beam identification in the SSB. In this case, terminal 111 notifies base station 101 of frequency information that identifies the frequency on which the SSB was received. Base station 101 can identify the beam to be used between terminal 111 and terminal 111 by identifying the beam corresponding to the frequency notified by terminal 111. The frequency information indicating the frequency on which the SSB was received may be, for example, the center frequency of the frequency band on which the SSB was received, or the frequencies indicating the upper or lower end of that frequency band. Alternatively, the frequency information indicating the frequency on which the SSB was received may be an offset value based on the lower end or center frequency of the frequency band used by base station 101. Alternatively, the frequency information indicating the frequency on which the SSB was received may be the number of the RB located in the frequency band used by base station 101. If identification information is assigned to the frequencies on which SSB can be transmitted between base station 101 and terminal 111, terminal 111 may use that identification information as frequency information indicating the frequency on which the SSB was received.

[0031] The base station 101 may use a combination of identification information for each beam, namely, identification information for the frequency resource used to transmit the SSB associated with that beam (frequency index) and identification information for the time resource used to transmit that SSB (time index). The information used to identify the time resource (the transmission timing of a predetermined SSB in an SS burst) used as identification information for identifying a beam may be called the SS-block timing index. The information used to identify the time resource for transmitting a predetermined SSB in an SS burst may be called by another name. In this case, the base station 101 may manage the frequency index and time index in advance for each beam formed by its device. As shown in the example in Figure 5(C), a combination of time resources t_0 to t_7 in the time axis direction and frequency resources f_0 to f_7 in the frequency axis direction may be associated with each beam. For example, base station 101 can set a combination of time indices corresponding to time resources t_0 to t_7 used for SSB transmission and frequency indices corresponding to frequency resources f_0 to f_7 for each SSB. Terminal 111 can use the frequency index and time index set for the received SSB as identifying information to report to base station 101. Base station 101 can identify the beam associated with the frequency index and time index included in the report from terminal 111 as the beam to be used for communication with terminal 111. The identifying information that base station 101 can use to identify each beam is not limited to the above, and is sufficient if it is information that allows terminal 110 to identify the beam used for transmitting the SSB based on the SSB received by that SSB.

[0032] (Method of beam configuration) An example of how a base station 101 uses multiple antennas to form multiple beams having different directivity in each of the frequency resources for transmitting SSB is described. Figure 6(A) shows a first configuration example of an antenna control circuit for forming beams using multiple antennas. The first configuration example may be called a phased array. The antenna control circuit according to the first configuration example consists of one RF chain 601, multiple phase shifters 611-613, and multiple antennas 621-623. The RF chain 601 outputs a transmit signal to each antenna. The RF chain 601 can generate duplicates corresponding to the number of antennas from a single transmit signal input from a circuit (not shown) that generates a transmit signal, and output them to each antenna. The transmit signals output by the RF chain 601 undergo signal processing by the phase shifters 611-613 before being input to each of the antennas 621-623. Each of the phase shifters 611-613 controls the phase of the input transmit signal. The amount of phase control for the transmitted signal in each of the phase shifters 611 to 613 can be determined by the directional pattern of the beam formed by the antennas 621 to 623. For example, the amount of phase control to be set in each of the phase shifters 611 to 613 in order to direct the beam's directional pattern in a predetermined direction can be determined in advance by taking measurements. The base station 101 can maintain a table that associates each directional pattern of the beam formed by its device with the corresponding phase control amount of the phase shifters 611 to 613. At the timing of transmitting SSB, the base station 101 can control the beam's directional pattern by switching the phase control amount of each of the phase shifters 611 to 613 to the desired value based on the table. In this first configuration example, the directional pattern of the beam formed by the antennas 621 to 623 can be uniform on the frequency axis. In this case, the base station 101 cannot form beams with different directional patterns for each frequency resource.

[0033] In contrast, by further including time delays in the first configuration example, beams with different directional patterns can be formed for each frequency resource. Figure 6(B) shows a second configuration example of an antenna control circuit for forming a beam using multiple antennas. The second configuration example may be called a real-time delay phased array. The real-time delay may be called a true-time delay. The antenna control circuit according to the second configuration example consists of one RF chain 601, multiple phase shifters 611-613, time delays 631-633, and multiple antennas 621-623. In Figure 6(B), the same reference numerals are used for configurations similar to those in Figure 6(A), and their explanations are omitted. That is, in Figure 6(B), the transmit signal output by the RF chain 601 is input to each of the time delays 631-633. Each of the time delays 631-633 generates a delay in the input transmit signal. The amount of delay added to the transmitted signal in each of the time delay units 631 to 633 can be determined by the directional pattern of the beam formed by the antennas 621 to 623 and the frequency resources that form each beam. The directional pattern of the beam formed by the antennas 621 to 623 and the frequency resources that form each beam can be determined by the amount of delay added in each of the time delay units 631 to 633 and the phase control amount in each of the phase shifters 611 to 613. For example, the phase control amount to be set in each of the phase shifters 611 to 613 to direct the beam directional pattern in a predetermined direction at a given frequency resource, and the amount of delay added in each of the time delay units 631 to 633, can be determined in advance by measurement or other means. The base station 101 can maintain a table that associates the directional patterns of the beams formed by its device at each frequency resource with the corresponding phase control amounts of the phase shifters 611 to 613 and the amount of delay added in the time delay units 631 to 633.Base station 101 can control the beam directivity pattern formed for each frequency resource by switching the delay amount added in each time delayer 631-633 and the phase control amount of each phase shifter 611-613 to a set value based on a table for the time resource on which SSB is transmitted. Note that the method by which base station 101 forms a beam in a desired direction for each frequency resource is not limited to this, and any method can be used. For example, base station 101 may prepare multiple antennas for each frequency resource that are set to form a beam in a desired direction, and transmit SSB using each beam by filtering so that the SSB transmitted does not interfere with each other.

[0034] (Processing at the base station) The process performed by base station 101 when transmitting SSB is described below. Figure 7 shows an example of the processing flow when base station 101 transmits SSB. This process may be performed for each SSB transmission period set in base station 101. Base station 101 transmits SSB using the time resource t_0 of the 0th slot of the SSB transmission slots (S701). For example, base station 101 may transmit the same number of SSBs as the number of frequency resources M set for SSB transmission, in order from the SSB with the smallest SSB index value to the SSB in each frequency resource. Base station 101 controls the antenna so that the beam associated with each SSB index of the SSB to be transmitted is formed in the frequency resource associated with each beam, and transmits each SSB in time resource t_0. When base station 101 has transmitted all SSBs included in the SS burst with this transmission (YES in S702), it terminates the SSB transmission process. For example, if the same number of frequency resources as the number of SSBs included in the SS burst are set up as shown in Figure 5(A) (M=N=64), base station 101 can complete the transmission of all SSBs included in the SS burst in a single transmission. If base station 101 has not completed the transmission of all SSBs included in the SS burst (NO in S702), it switches the beam directivity pattern for each frequency resource (S703) and transmits the SSBs that have not been transmitted (S704). For example, base station 101 controls its antenna so that the beam associated with each SSB is formed in the frequency resource associated with each beam, starting with the SSB with the smallest SSB index value among the SSBs that have not been transmitted, and transmits each SSB in time resource t_1. Base station 101 repeats the process from S702 to S704 until the transmission of all SSBs included in the SS burst is completed.

[0035] Base station 101 may notify terminal 111 in advance of configuration information that identifies the frequency and time resources for transmitting each SSB. For example, base station 101 may notify terminal 111 of information indicating each of the frequency resources for transmitting SSB. Base station 101 may also notify terminal 111 of the number of frequency resources configured for transmitting SSB. In this case, terminal 111 may perform SSB reception processing at each frequency resource, assuming that the frequency band used by base station 101 for communication is equally divided by the number of notified frequency resources. Base station 101 may also notify information indicating the SMTC window to indicate the time resource on which SSB is transmitted. Base station 101 may use the MIB included in the SSB's PBCH, the SIB received based on the MIB, or the RRC message exchanged after the connection with terminal 111 is established to transmit the frequency and time resources for transmitting SSB. MIB is an abbreviation for Master Information Block, SIB is an abbreviation for System Information Block, and RRC is an abbreviation for Radio Resource Control. The base station 101 can widely notify an unspecified number of terminals 111 of the frequency and time resources for transmitting SSB by using MIB or SIB notifications. Furthermore, the base station 101 can individually notify terminals 111 that support this technology of the frequency and time resources for transmitting SSB by using RRC messages. Note that the frequency resources set for SSB transmission may be shared in advance between the base station 101 and the terminals 111. For example, the frequency resources set for SSB transmission may be configured as device settings on both the base station 101 and the terminals 111, or they may be configured on each device by the user through an application, etc. In this case, the base station 101 does not need to notify the terminals 111 of the configuration information that identifies the frequency and time resources for transmitting SSB. Alternatively, the base station 101 may notify the terminals 111 of the configuration information via other base stations.For example, if terminal 111 detects a base station with better wireless quality than the base station (serving base station) 101 to which it is currently connected, it may perform a handover to that base station. As preparation for the handover, terminal 111 measures the wireless quality of surrounding base stations. In this case, terminal 111 may obtain configuration information of surrounding base stations via serving base station 101. For example, base station 101 may obtain configuration information from base stations located around its own device and notify terminal 111 of that configuration information.

[0036] Once the transmission of the SS burst is complete, base station 101 may receive a report of the SSB measurement results from terminal 111. For example, when terminal 111 makes an initial connection to base station 101, it may send a random access preamble signal to the radio resource (PRACH) indicated by the SSB with the highest measured radio quality value. PRACH is an abbreviation for Physical Random Access Channel. Based on the PRACH received from terminal 111, base station 101 may identify the SSB selected by terminal 111 and identify the beam associated with the identified SSB as the beam to be used for communication with terminal 111. Terminal 111 may also notify base station 101 of the SSB measurement results using the MeasResults IE of the RRC Measurement Report message, etc. The measurement results may include information that allows the base station 101 to identify the beam to be used for communication with the terminal 111, such as beam identification information, SSB index, frequency index, time index, and frequency information of the SSB received by the terminal 111. Based on the information included in the acquired measurement results, the base station 111 identifies the beam to be used for communication with the terminal 111. The base station 101 then uses the identified beam to communicate with the terminal 111. At this time, the base station 101 uses the beam identified as the beam to be used for communication with the terminal 111 within the frequency resources allocated for communicating data, etc., to the terminal 111. In other words, the antenna control method used by the base station 101 when communicating data, etc., with the terminal 111 may differ from the antenna control method used to form beams in each frequency resource for transmitting SSB.

[0037] (Processing at the terminal) The process performed by terminal 111 when receiving SSB is described below. Figure 8 shows an example of the processing flow when terminal 111 receives SSB. This process may be performed for each SSB transmission cycle notified by base station 101. Terminal 111 receives SSB using the time resource t_0 of the 0th slot of the SSB transmission slots (S801). For example, terminal 111 can receive SSB in each of the frequency resources set for SSB transmission. Terminal 111 may acquire in advance setting information that identifies the frequency and time resources set for SSB transmission. Terminal 111 performs a radio quality measurement for each received SSB (S802). Terminal 111 may store identification information for identifying the beam acquired from the received SSB and information indicating the radio quality of the measured SSB in association with each other. For example, terminal 111 may acquire beam identification information, SSB index, frequency index, time index, etc. from the received SSB. If the SSB transmission slot has not finished (NO in S803), terminal 111 receives SSB using the next time resource t_1 (S804). In this case as well, terminal 111 can receive SSB on each of the frequency resources set for SSB transmission. If the SSB transmission slot has finished (YES in S803), terminal 111 reports to base station 101 and performs random access based on the measured radio quality (S805). For example, terminal 111 determines that the beam corresponding to the SSB with the highest radio quality value should be used for communication. Terminal 111 accesses base station 101 by transmitting a random access preamble in the PRACH included in the SSB corresponding to the determined beam. Terminal 111 also reports to base station 101 the measured radio quality and the identification information obtained from the SSB used for the measurement, associating them. Terminal 111 may also report to base station 101 the identification information obtained from the SSB used for the measurement without reporting the measured radio quality. Terminal 111 can report to base station 101 using the MeasResults IE of the RRC Measurement Report message, etc.

[0038] (Circuit configuration) An example configuration of the base station 101 and terminal 111 described above will now be explained. Figure 9 shows the hardware configuration of the base station 101 and terminal 111. In one example, the base station 101 and terminal 111 are configured to include a processor 901, ROM 902, RAM 903, storage device 904, and communication circuit 905. The processor 901 is a computer configured to include one or more processing circuits, such as a general-purpose CPU (Central Processing Unit) or ASIC (Application-Specific Integrated Circuit). The processor 901 performs the overall processing of the device and the above-mentioned processing by reading and executing programs stored in the ROM 902 and storage device 904. The ROM 902 is a read-only memory in which information such as programs and various parameters related to the processing performed by the base station 101 and terminal 111 is recorded. The RAM 903 functions as a workspace when the processor 901 executes programs and is a random access memory in which temporary information is recorded. The storage device 904 is configured, for example, by a removable external storage device. The communication circuit 905 is configured to include, for example, circuits for wired or wireless communication between the base station 101 and the terminal 111. For example, the base station 101 and the terminal 111 can communicate with each other using the communication circuit 905 for LTE or 5G.

[0039] (Functional Configuration) Figure 10 shows an example of the functional configuration of a base station 101. The base station 101 is configured to include, for example, an SSB transmission control unit 1001, a report acquisition unit 1002, a beam identification unit 1003, a data communication unit 1004, and an antenna control unit 1005. Figure 10 shows the functional configuration of the base station 101 in this embodiment, and omits, for example, the general configuration of the base station 101. These functional units can be realized, for example, by the processor 901 executing a program stored in the ROM 902 or storage device 904 and controlling the communication circuit 905 as needed. However, it is not limited to this, and for example, dedicated hardware for realizing each function may be provided.

[0040] The SSB transmission control unit 1001 controls the transmission of SSB signals. For example, the SSB transmission control unit 1001 determines the beam, frequency resource, and time resource to be used for each SSB transmission and executes the SSB transmission. The SSB transmission control unit 1001 can associate each SSB signal with the beam used for its transmission. The SSB transmission control unit 1001 can also associate each beam used for SSB transmission with the frequency resource that forms that beam. Furthermore, the SSB transmission control unit 1001 can associate each beam used for SSB transmission with the time resource that forms that beam. The SSB transmission control unit 1001 maintains these associations and, when transmitting each SSB signal, can notify the antenna control unit 1005 of the beam directivity pattern that should be formed in each frequency resource and time resource for transmitting each SSB signal. The SSB transmission control unit 1001 can also set information that identifies the beam used for the transmission of each SSB signal when generating each SSB signal. Furthermore, the SSB transmission control unit 1001 can notify the terminal 111 of configuration information for identifying the frequency and time resources for transmitting SSB.

[0041] The report acquisition unit 1002 acquires measurement reports using SSB from the terminal 111. For example, the report acquisition unit 1002 may acquire the measurement report from the MeasResult IE in the RRC Measurement Report message transmitted by the terminal 111. The report acquisition unit 1002 may notify the beam identification unit 1003 of the measurement results of the radio quality and information for identifying the beam included in the acquired report. The beam identification unit 1003 identifies the beam that should be used for communication with the terminal 111. For example, the beam identification unit 1003 may identify the beam that should be used for communication with the terminal 111 based on the measurement results of the radio quality and information for identifying the beam notified by the report acquisition unit 1002. For example, if measurement results of the radio quality are acquired, the beam identification unit 1003 may identify the beam with the highest value indicating radio quality as the beam that should be used for communication with the terminal 111. In this case, the beam identification unit 1003 may identify the beam based on the information for identifying the beam acquired in association with the highest value indicating radio quality. For example, the beam identification unit 1003 may acquire information for identifying a beam, such as beam identification information, an SSB index, a frequency index, a time index, and frequency information indicating the frequency at which the SSB was received. The beam identification unit 1003 may also identify a beam to be used for communication with the terminal 111 using random numbers or the like from among one or more beams whose wireless quality value exceeds a threshold, or a predetermined number of beams selected in order from those with high wireless quality. Alternatively, the beam identification unit 1003 may identify multiple candidates and select one beam from these multiple candidates using another method. Furthermore, if the beam identification unit 1003 acquires information for identifying a beam without acquiring wireless quality information from the terminal 111, it may identify one beam from among them as the beam to be used for communication with the terminal 111. In this case, the beam identification unit 1003 may select one beam from the identified beams using random numbers or the like. In this case as well, the beam identification unit 1003 may identify multiple candidates and select one beam from these multiple candidates using another method. The beam identification unit 1003 can notify the antenna control unit 1005 of the beam it has identified as the beam to be used for communication with the terminal 111.The data communication unit 1004 communicates data with the terminal 111. For example, the data communication unit 1004 allocates radio resources (frequency resources and time resources) to be used for data communication to the terminal 111, and uses the allocated radio resources to exchange data. The data communication unit 1004 can perform data communication with the terminal 111 using the beam identified by the beam identification unit 1003 as the beam to be used for communication with the terminal 111. In this case, the data communication unit 1004 can notify the antenna control unit of the radio resources allocated for data communication with the terminal 111. The antenna control unit 1005 controls the directional pattern of the antenna. For example, the antenna control unit 1005 can control the phase and delay time of the transmission signal so that a beam with the directional pattern notified by the frequency resources and time resources notified by the SSB transmission control unit 1001 is formed. The antenna control unit 1005 can also control the phase and delay time of the transmission signal so that a beam notified by the beam identification unit 1003 is formed in the radio resources notified by the data communication unit 1004.

[0042] Figure 11 shows an example of the functional configuration of terminal 111. Terminal 111 includes, for example, an SSB receiving unit 1101, a wireless quality measurement unit 1102, an SSB analysis unit 1103, a frequency identification unit 1104, a report notification unit 1105, and a data communication unit 1106. Figure 11 shows the functional configuration of terminal 111 in this embodiment, and omits, for example, the general configuration of terminal 111. These functional units can be realized, for example, by the processor 901 executing a program stored in the ROM 902 or storage device 904 and controlling the communication circuit 905 as needed. However, it is not limited to this, and for example, dedicated hardware may be provided to realize each function.

[0043] The SSB receiver 1101 receives SSB transmitted from the base station 101. For example, the SSB receiver 1101 can receive each SSB transmitted using the respective time resources in each frequency resource set in the frequency band used by the base station 101 for communication. The radio quality measurement unit 1102 performs radio quality measurement using the SSB received by the SSB receiver 1101. For example, the radio quality measurement unit 1102 can measure the RSSI, RSRQ, RSRP, SINR, etc. of the received SSB. The radio quality measurement unit 1102 can also perform analysis of the measurement results. For example, the radio quality measurement unit 1102 can notify the reporting / notification unit 1105 of radio quality values ​​that exceed a predetermined threshold. The radio quality measurement unit 1102 can also notify the reporting / notification unit 1105 of a predetermined number of radio quality values, starting with the highest values. The predetermined number may be 1 or more. The SSB analysis unit 1103 analyzes the information contained in the SSB received by the SSB receiver 1101. For example, the SSB analysis unit 1103 can acquire identification information, etc., contained in the SSB. Identification information contained in the SSB may include a beam identifier, SSB index, frequency index, time index, etc. Based on the analysis of the measurement results in the radio quality measurement unit 1102, the SSB analysis unit may analyze only the SSB information related to the measurement results notified to the reporting and notification unit 1105. The SSB analysis unit 1103 can notify the reporting and notification unit 1105 of the acquired identification information, etc. The frequency identification unit 1104 identifies the frequency at which the SSB receiving unit 1101 received the SSB. The frequency identification unit 1104 can also generate frequency information indicating the frequency at which each SSB was received and notify the reporting and notification unit 1105. The reporting and notification unit 1105 reports the measurement results to the base station 101. For example, the reporting and notification unit 1105 can report each of the radio quality values ​​notified by the radio quality measurement unit 1102 to the base station 101. Furthermore, the reporting and notification unit 1105 may report to the base station 101 the beam identification information notified by the SSB analysis unit 1103 and the frequency identification information notified by the frequency identification unit 1104, in association with a value indicating radio quality. The radio quality measurement unit 1102 may report the beam identification information and frequency information to the base station 101 without reporting a value indicating radio quality.Furthermore, the reporting and notification unit 1105 may perform random access to the base station 101 based on the measurement results. In this case, the reporting and notification unit 1105 may transmit a random access preamble signal to PRACH acquired by the SSB analysis unit 1103. The data communication unit 1106 performs data communication with the base station 101. For example, when the data communication unit 1106 performs data communication with the base station 101, the beam set by the base station 101 may be used.

[0044] As described above, according to this embodiment, the base station 101 transmits SSB associated with each beam using multiple beams with different directional patterns in a single cell provided by its device, using multiple non-overlapping frequency resources associated with each beam, within a common time resource. The terminal device 111 receives the SSB transmitted by the base station in each frequency resource, performs measurements using each of the received SSBs, and reports to the base station 101 a report containing frequency information that identifies the frequency resource where the SSB was received. Based on this report, the base station 101 identifies the beam with the directional pattern associated with the identified frequency resource as the beam to be used for communication with the terminal device. With this configuration, the base station 101 can perform SSB transmission using multiple beams with different directional patterns in parallel using different frequency resources, thereby enabling the measurement of SSB at the terminal 111 to be completed in a short time and reducing the time required for beam selection. As a result, the time available for data communication between the base station 101 and the terminal 111 increases, increasing throughput and suppressing transmission delays. Therefore, it becomes possible to contribute to Goal 9 of the United Nations-led Sustainable Development Goals (SDGs): "Build resilient infrastructure, promote sustainable industrialization and foster innovation."

[0045] The invention is not limited to the embodiments described above, and various modifications and changes are possible within the scope of the invention's essence. [Explanation of Symbols]

[0046] 101: Base station, 111: Terminal

Claims

1. A base station that performs wireless communication with terminal devices based on the cellular communication standard of the Third Generation Partnership Project (3GPP), A transmission means that, in a single cell provided by the base station, transmits a synchronization signal (SS) / physical broadcast channel (PBCH) block (SSB) associated with each of the multiple beams in a common time resource, using multiple beams with different directional patterns, and in each of the multiple non-overlapping frequency resources associated with each of the multiple beams. A means for obtaining a report relating to the measurement of the terminal device, the report including frequency information that identifies the frequency resource from which SSB was received by the terminal device, Identification means for identifying a beam of a directional pattern associated with a frequency resource identified based on the above report as a beam to be used for communication with the terminal device, It includes a communication means that communicates with the terminal device using a specified beam. A base station characterized by the following features.

2. The transmitting means transmits within the SSB a frequency index indicating the frequency resources used for transmitting the SSB, The terminal device includes the frequency index obtained from the SSB related to the report as frequency information in the report and transmits it. The identification means identifies a beam of a directional pattern associated with a frequency resource identified based on the frequency index obtained from the report as a beam to be used for communication with the terminal device. The base station according to feature 1.

3. The terminal device identifies the frequency on which the SSB related to the report was received, and transmits the report including information indicating the identified frequency as the frequency information. The identification means identifies a beam of a directional pattern associated with a frequency resource identified based on information indicating the frequency identified by the terminal device as a beam to be used for communication with the terminal device. The base station according to feature 1.

4. The transmitting means controls the phase and transmission timing of the signal transmitted via the antenna to form a plurality of beams with different directional patterns in each of a plurality of non-overlapping frequency resources associated with each of the plurality of beams. A base station according to any one of claims 1 to 3, characterized by the features described herein.

5. A terminal device that communicates with a base station based on the cellular communication standard of the Third Generation Partnership Project (3GPP), In a cell provided by the base station, the base station has receiving means for receiving synchronization signal (SS) / physical broadcast channel (PBCH) blocks (SSB) associated with each of the multiple beams, which are transmitted using a common time resource in each of the multiple non-overlapping frequency resources associated with each of the multiple beams, each of which has a different directional pattern. A reporting means for reporting to the base station a report relating to measurements of the terminal device, the report including frequency information that identifies the frequency resource from which SSB was received by the terminal device, A communication means that communicates with the base station using a beam set by the base station based on the above report. A terminal device characterized by the following features.

6. The SSB includes a frequency index that identifies the frequency resources used for transmitting the SSB, The terminal device further includes acquisition means for acquiring the frequency index from the SSB related to the report, The reporting means includes the frequency index obtained by the acquisition means as frequency information in the report and reports it. The terminal device according to feature 5.

7. The system further includes a means for identifying the frequency at which the SSB related to the aforementioned report was received, The reporting means includes information indicating the frequency identified by the identification means as the frequency information in the report. The terminal device according to feature 5.

8. A control method performed by a base station that performs wireless communication with terminal devices based on the cellular communication standard of the Third Generation Partnership Project (3GPP), A transmission step in which, in a single cell provided by the base station, a plurality of beams having different directional patterns are used to transmit a synchronization signal (SS) / physical broadcast channel (PBCH) block (SSB) associated with each of the plurality of beams in a common time resource, in each of the plurality of non-overlapping frequency resources associated with each of the plurality of beams, A step of obtaining a report relating to the measurement of the terminal device, the report including frequency information that identifies the frequency resource from which SSB was received by the terminal device, Identification step of identifying the beam of the directional pattern associated with the frequency resource identified based on the above report as the beam to be used for communication with the terminal device, A communication step which involves communicating with the terminal device using a specified beam. A control method characterized by the following:

9. A control method performed by a terminal device that communicates with a base station based on the cellular communication standard of the Third Generation Partnership Project (3GPP), A receiving step in which, in one cell provided by the base station, the base station receives synchronization signal (SS) / physical broadcast channel (PBCH) block (SSB) associated with each of the multiple beams transmitted using a common time resource in each of the multiple non-overlapping frequency resources associated with each of the multiple beams, each of which has a different directional pattern; A reporting step of reporting to the base station a report relating to the measurement of the terminal device, the report including frequency information that identifies the frequency resource from which SSB was received by the terminal device, The process includes a communication step of communicating with the base station using a beam set by the base station based on the aforementioned report. A control method characterized by the following:

10. A program for causing a computer to function as one of the means of the base station described in claim 1.

11. A program for causing a computer to function as each of the means of the terminal device described in claim 5.

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