Wireless terminal, base station, and methods thereof

Abstract

This wireless terminal attempts to receive a plurality of downlink signal block bursts that are repeatedly transmitted in the time domain. Each downlink signal block burst includes one or more downlink signal blocks within a predetermined time window. Each downlink signal block includes at least one or more synchronization signals used for downlink synchronization. One or more signals, one or more physical channels, or a combination thereof included in each downlink signal block included in at least one of the plurality of downlink signal block bursts indicate transmission pattern information of the plurality of downlink signal block bursts. For example, this contributes to mitigating the impact of adaptive transmission of a downlink synchronization signal on an operation for downlink synchronization of the wireless terminal.

Description

Wireless terminals, base stations, and methods thereof

[0001] This disclosure relates to wireless communication systems, and more particularly to the transmission of downlink synchronization signals by base stations.

[0002] The 3rd Generation Partnership Project (3GPP®) Fifth Generation (5G) systems use beam sweeping to enable User Equipment (UE) to select the best beam during initial access. Specifically, the gNB transmits multiple Synchronization Signal (SS) / Physical Broadcast Channel (PBCH) blocks (SSBs) as bursts at a periodicity, changing the beam direction with each SSB transmission. A single SSB includes the Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS), PBCH, and PBCH Demodulation Reference Signal (DMRS).

[0003] One SSB spans four consecutive Orthogonal Frequency Division Multiplexing (OFDM) symbols in the time domain and 240 consecutive subcarriers (i.e., 20 resource blocks) in the frequency domain. Each SSB within one burst corresponds to an individual beam and is beamformed in different directions. A set of SSBs within one burst is called an SSB burst or SSB burst set and is transmitted within a half radio frame, i.e., a time window of 5 milliseconds (ms). The SSB burst is typically repeated with a period of two radio frames, i.e., 20 ms. The maximum number of SSBs within an SSB burst (i.e., 5 ms duration) is defined as 4 in the frequency band up to 3 GHz, 8 in the range of 3 - 6 GHz, and 64 in the range of 6 - 52.6 GHz in order to achieve a trade-off between coverage and resource overhead. Note that the number of SSBs within one SSB burst actually transmitted within a cell is configurable and may be less than the maximum number.

[0004] Each SSB within one SSB burst is assigned an SSB index which is a unique number starting from 0 and incrementing by 1. When the maximum number of candidate SSBs that can be transmitted within an SSB burst set is 64, the SSB index is notified to the UE via two parts within the SSB. The SSB index is split into two fields, the first field is carried as part of the PBCH payload, and the second part of the SSB index is carried as part of the sequence of PBCH DMRS.

[0005] When synchronizing to the radio access network, the UE needs to receive SSBs. Specifically, if a UE in the Radio Resource Control (RRC)_IDLE or RRC_INACTIVE state is not synchronized with the radio access network, the UE attempts to receive multiple SSB bursts to establish downlink synchronization. Based on the reception of SSB bursts, the UE establishes downlink synchronization and selects the SSB with the best reception quality, i.e., the best beam.

[0006] For Release 19 and subsequent releases, 3GPP is discussing “adaptation of SSB in time domain” as one of the network energy saving (NES) techniques (see, for example, Non-Patent Documents 1 and 2). Specifically, the adaptation of the SSB burst period is discussed. In addition, the skipping or non-uniform transmission of some SSB bursts instead of the uniform and periodic transmission of consecutive SSB bursts is also discussed. Skipping the transmission of some SSB bursts can be done by setting, changing, or activating the SSB burst transmission pattern (see, for example, Non-Patent Document 1). In some implementations, a gNB in ​​NES mode can change the SSB burst period to transmit SSB bursts with periods longer than 20 ms. In some implementations, a gNB in ​​NES mode sets or activates the SSB burst transmission pattern. When an SSB burst transmission pattern is set or activated, for example, a gNB can transmit a predetermined number of SSB bursts at a 20ms period at the beginning of a (long) cycle of the SSB burst transmission pattern, and then stop transmitting SSB bursts for the remainder of the cycle.

[0007] CATT, "Discussion on adaptation of common signal / channel transmissions", R1-2404409, 3GPP TSG-RAN WG1 Meeting #117, Fukuoka, Japan, May 20-24, 2024Moderator (Ericsson), "Final summary of AI 9.5.3 for R19 NES", R1-2407552, 3GPP TSG-RAN WG1 Meeting #118, Maastricht, Nederland, August 19-23, 2024

[0008] Current discussions regarding SSB adaptation in the time domain suggest that SSB burst periods may be dynamically altered, or that some transmissions of periodic SSB bursts may be skipped. UEs in the RRC_IDLE or RRC_INACTIVE state and not synchronized with the radio access network may not be aware that such SSB adaptation is occurring or planned by a gNB in ​​NES mode. This could cause these UEs to fail to perform downlink synchronization based on SSB reception. Alternatively, this could lead to an increase in the time required for these UEs to perform downlink synchronization (in other words, a decrease in their power saving time). Similar problems can occur in other radio systems different from 5G systems, specifically in radio systems employing mechanisms similar to downlink synchronization based on SSB burst reception in 5G systems.

[0009] One of the objectives that the embodiments disclosed herein seek to achieve is to provide apparatus, methods, and programs that contribute to solving at least one of several problems related to the adaptive transmission of signals used for downlink synchronization, including the problems described above. It should be noted that this objective is only one of several objectives that the embodiments disclosed herein seek to achieve. Other objectives or problems and novel features will be revealed by the description herein or by the accompanying drawings.

[0010] In a first embodiment, a wireless terminal is configured to attempt to receive a plurality of downlink signal block bursts transmitted repeatedly in a time domain. Each downlink signal block burst includes one or more downlink signal blocks within a predetermined time window. Each downlink signal block includes at least one synchronization signal used for downlink synchronization. One or more signals, one or more physical channels, or a combination thereof, contained within each downlink signal block contained within at least one of the plurality of downlink signal block bursts represent the transmission pattern information of the plurality of downlink signal block bursts.

[0011] In a second embodiment, the method performed by the wireless terminal includes attempting to receive a plurality of downlink signal block bursts transmitted repeatedly in a time domain. Each downlink signal block burst includes one or more downlink signal blocks within a predetermined time window. Each downlink signal block includes at least one or more synchronization signals used for downlink synchronization. One or more signals, one or more physical channels, or a combination thereof, contained within each downlink signal block contained within at least one of the plurality of downlink signal block bursts represent the transmission pattern information of the plurality of downlink signal block bursts.

[0012] In a third embodiment, the base station is configured to repeatedly transmit a plurality of downlink signal block bursts in a time domain. Each downlink signal block burst includes one or more downlink signal blocks within a predetermined time window. Each downlink signal block includes at least one or more synchronization signals used for downlink synchronization. One or more signals, one or more physical channels, or a combination thereof, included in each downlink signal block included in at least one of the plurality of downlink signal block bursts represent the transmission pattern information of the plurality of downlink signal block bursts.

[0013] In a fourth aspect, the method performed by the base station includes repeatedly transmitting a plurality of downlink signal block bursts in a time domain. Each downlink signal block burst includes one or more downlink signal blocks within a predetermined time window. Each downlink signal block includes at least one or more synchronization signals used for downlink synchronization. One or more signals, one or more physical channels, or a combination thereof, included in each downlink signal block included in at least one of the plurality of downlink signal block bursts represent the transmission pattern information of the plurality of downlink signal block bursts.

[0014] In the fifth aspect, the program includes a set of instructions (software code) that, when loaded into a computer, cause the computer to perform the method according to the second or fourth aspect described above.

[0015] According to the above-described embodiment, it is possible to provide an apparatus, method, and program that contribute to solving at least one of several problems related to the adaptive transmission of signals used for downlink synchronization, including the problems described above.

[0016] This figure shows an example configuration of a wireless communication system relating to one or more embodiments. This figure shows an example of the SSB format. This figure shows an example of an SSB burst transmission pattern. This figure shows an example of changing the SSB burst transmission pattern. This figure shows an example of changing the SSB burst transmission pattern. This figure shows an example of changing the SSB burst transmission pattern. This figure shows an example of changing the SSB burst transmission pattern. This figure shows an example of changing the SSB burst transmission pattern. This is a sequence diagram showing an example of the operation of a UE and gNB relating to one or more embodiments. This is a flowchart showing an example of the operation of a UE relating to one or more embodiments. This figure shows an example of mapping between the value of SSB transmission pattern information and the change of the SSB burst period or the remaining number of transmissions until SSB burst transmission is stopped relating to one or more embodiments. This figure shows an example of mapping between the value of SSB transmission pattern information and the change of the SSB burst period or the remaining number of transmissions until SSB burst transmission is stopped relating to one or more embodiments. This figure shows an example of mapping between the value of SSB transmission pattern information and the SSB burst period relating to one or more embodiments. This figure shows an example of mapping between the value of SSB transmission pattern information and the SSB burst period relating to one or more embodiments. This figure shows an example of the configuration of a UE relating to one or more embodiments. This figure shows an example of the configuration of a gNB relating to one or more embodiments.

[0017] The following describes specific embodiments in detail with reference to the drawings. In each drawing, the same or corresponding elements are denoted by the same reference numerals, and redundant explanations are omitted where necessary for clarity.

[0018] The multiple embodiments described below may be used individually or two or more embodiments may be combined as appropriate. These multiple embodiments may have novel features that differ from each other. Therefore, these multiple embodiments may contribute to achieving different objectives or solving different problems, and may contribute to producing different effects.

[0019] Each drawing is merely illustrative to illustrate one or more embodiments. Each drawing may be associated with one or more other embodiments, rather than being associated with only one specific embodiment. As those skilled in the art will understand, various features or steps described with reference to any one drawing can be combined with features or steps shown in one or more other drawings, for example, to create embodiments not explicitly shown or described. Not all features or steps shown in any one drawing to illustrate an exemplary embodiment are necessarily required, and some features or steps may be omitted. The order of steps described in any of the drawings may be changed as appropriate.

[0020] The following embodiments are described primarily with reference to 3GPP fifth-generation mobile communication systems (5G systems). However, these embodiments may also be applied to other radio systems employing downlink synchronization based on SSB burst reception in 5G systems and similar mechanisms.

[0021] As used herein, depending on the context, “if” may be interpreted as meaning “when,” “while,” “at or around the time,” “after,” “upon,” “in response to determining,” “in accordance with a determination,” or “in response to detecting.” These expressions may be interpreted as having the same meaning depending on the context. As used herein, depending on the context, “in response to” may be rephrased as “based on.”

[0022] First, the configuration and operation of several network elements common to multiple embodiments will be described. Figure 1 shows an example configuration of a wireless communication system related to multiple embodiments. Each element (network function) shown in Figure 1 can be implemented, for example, as a network element on dedicated hardware, as a running software instance on dedicated hardware, or as an instantiated virtualization function on an application platform.

[0023] In the example in Figure 1, the wireless communication system includes multiple UEs 1 and gNB 2. Hereafter, when describing matters common to multiple UEs 1, the term UE 1 will be used unless otherwise specified. UE 1 may also be referred to by other terms such as wireless terminal, mobile terminal, mobile station, or wireless transmit-receive unit (WTRU). gNB 2 may also be referred to by other terms such as base station, radio access network (RAN) node, radio station, RAN, or network. UE 1 has at least one wireless transceiver and communicates with gNB 2. gNB 2 manages, operates, or provides cell 21 and communicates with multiple UEs 1 within cell 21 using cellular communication technology (ie., NR Radio Access Technology). These communications include downlink and uplink transmissions. Downlink transmissions include transmission of cell-specific synchronization signals, cell-specific and UE-specific reference signals, broadcast channel transmissions (e.g., Physical Broadcast Channel (PBCH)), control channel transmissions (e.g., Physical Downlink Control Channel (PDCCH)), and data transmission channels (e.g., Physical Downlink Shared Channel (PDSCH)). Uplink transmissions include transmission of reference signals, random access channels (e.g., Physical RACH (PRACH)), control channel transmissions (e.g., Physical Uplink Control Channel (PUCCH)), and data transmission channels (e.g., Physical Uplink Shared Channel (PUSCH)).

[0024] gNB2 may provide multiple cells, including cell 21, and UE1 may be simultaneously connected to multiple cells provided by gNB2. In other words, UE1 may perform carrier aggregation (CA) between multiple cells provided by gNB2. In addition, UE1 may be simultaneously connected to gNB2 and other RAN nodes (e.g., gNB or eNB) for dual connectivity (DC).

[0025] gNB2 may be a combination of a gNB Central Unit (CU) and one or more gNB Distributed Units (DUs) in a centralized or cloud RAN (C-RAN) deployment. gNB-CU may be a logical node hosting the gNB's Radio Resource Control (RRC), Service Data Adaptation Protocol (SDAP), and Packet Data Convergence Protocol (PDCP) protocols. gNB-DU may be a logical node hosting the gNB's Radio Link Control (RLC), Medium Access Control (MAC), and Physical (PHY) layers.

[0026] gNB2 performs SSB transmission. SSB is transmitted as an SSB burst. Therefore, SSB transmission may also be called SSB burst transmission. SSB includes at least one or more synchronization signals used for downlink synchronization. Figure 2 shows an example of SSB format. As mentioned above, according to the current 3GPP specification, one SSB includes PSS, SSS, PBCH, and PBCH DMRS. One SSB spans four consecutive OFDM symbols in the time domain and 240 consecutive subcarriers (i.e., 20 resource blocks) in the frequency domain.

[0027] PSS and SSS are specific physical layer signals used by UE1 for downlink synchronization (or radio frame synchronization). If a UE is not synchronized with the radio access network and is in the Radio Resource Control (RRC)_IDLE or RRC_INACTIVE state, the UE first attempts to detect the PSS, and if successful, begins decoding the entire SSB. The UE can obtain the Physical Cell ID (PCI) from the PSS and SSS sequences.

[0028] The PBCH DMRS is used by UE1 to demodulate the PBCH. The position of the PBCH DMRS depends on the PCI. Based on the PCI obtained from the PSS and SSS sequences, UE1 can determine the position of the PBCH DMRS within the SSB. Based on the received PBCH DMRS, UE1 performs channel estimation and uses the estimated channel matrix to demodulate and decode the PBCH.

[0029] The PBCH is a downlink physical channel. The PBCH payload contains essential system information, namely the Master Information Block (MIB), along with other information (e.g., part of the SSB index). The SSB index is divided into two fields: the first field is carried as part of the PBCH payload, and the second field of the SSB index is carried as part of the PBCH DMRS sequence.

[0030] gNB2 transmits SSB bursts repeatedly in the time domain. Figure 3 shows an example of repeated transmission of SSB bursts by gNB2. As already explained, gNB2 transmits multiple SSBs as bursts at a fixed periodicity, changing the beam direction with each SSB transmission. Each SSB within an SSB burst corresponds to an individual beam and is beamformed in a different direction. The set of SSBs within an SSB burst is transmitted within a predetermined time window, i.e., a 5 ms time window. According to the current 3GPP specification, the maximum number of SSBs in an SSB burst (i.e., 5 ms duration) is specified as 4 for frequency bands up to 3 GHz, 8 for 3-6 GHz, and 64 for 6-52.6 GHz. Note that the actual number of SSBs in an SSB burst transmitted within cell 21 is configurable and may be less than the maximum number.

[0031] According to the current 3GPP specification, the SSB burst period (i.e., the transmission period or cycle of an SSB burst) can be 5 ms, 20 ms, 40 ms, 80 ms, or 160 ms. However, a typical value for the SSB burst period is 20 ms. If not specified, UE1 defaults to assuming an SSB period of 20 milliseconds when searching for an SSB. The transmission cycle of a specific SSB (i.e., an SSB or SSB beam at a specific SSB index) within an SSB burst is the same as the transmission cycle of the SSB burst. Therefore, the SSB burst period can also be called the SSB period.

[0032] gNB2 can transmit multiple SSBs within the carrier frequency band of cell 21. In other words, gNB2 can perform multiple SSB transmissions (or SSB transmissions) on different frequency resources. These multiple SSB transmissions may occur within a single Bandwidth Part (BWP) or across multiple BWPs. These multiple SSB transmissions may include Cell Defining SSB (CD-SSB) transmissions and one or more Non-Cell Defining SSBs (SSBs). According to the current 3GPP specification, CD-SSB is an SSB associated with Remaining Minimum System Information (RMSI), i.e., System Information Block Type 1 (SIB1). CD-SSB is transmitted within a synchronous raster. The synchronous raster occupies a predetermined (or fixed) range of frequencies within the NR channel bandwidth. NCD-SSB is an SSB not associated with RMSI (i.e., SIB1). NCD-SSB can be transmitted on or off the synchronous raster of cell 21. However, the definitions of SSB types herein are not limited to these and may be defined to cover future 3GPP specifications. For example, CD-SSB may be transmitted at a frequency off the synchronous raster of cell 21.

[0033] gNB2 supports SSB adaptation in the time domain. This includes changing the SSB burst period, temporarily suspending SSB burst transmission, or both. SSB adaptation may be implemented as an extension of discontinuous transmission (DTX). Cell DTX is one of the NES technologies newly introduced in 3GPP Release 18. During cell DTX, i.e., while cell 21 is inactive or in NES mode, cell 21 maintains only limited downlink transmission.

[0034] gNB2 may apply time-domain adaptation to only some of the multiple SSBs transmitted within the carrier frequency band of cell 21. For example, gNB2 may perform time-domain adaptation to one or more NCD-SSBs, but not to the CD-SSB and one or more other NCD-SSBs.

[0035] Figures 4 to 7 show examples of SSB adaptation in the time domain. In the example in Figure 4, gNB2 dynamically changes the SSB burst period. When gNB2 or cell 21 is in non-NES mode (or normal mode), gNB2 repeatedly transmits SSB bursts with a first period T1 (e.g., 20 ms). In contrast, when gNB2 or cell 21 is in NES mode, gNB2 repeatedly transmits SSB bursts with a second period T2 (e.g., 80 ms), which is longer than the first period T1. gNB2 may also notify UEs1 in the RRC_CONNECTED state in cell 21 of the change in the SSB burst period via Layer 1 signaling (e.g., Downlink Control Information (DCI)) or Layer 2 signaling (e.g., MAC Control Element (CE)).

[0036] In the example in Figure 5, gNB2 temporarily stops transmitting SSB bursts. When gNB2 or cell 21 is in non-NES mode (or normal mode), gNB2 repeatedly transmits SSB bursts at a first period T1 (e.g., 20 ms). Conversely, when gNB2 or cell 21 is in NES mode, gNB2 does not transmit SSB bursts. gNB2 may also notify UEs1, which are in the RRC_CONNECTED state in cell 21, of the temporary suspension of SSB burst transmission via Layer 1 signaling (e.g., DCI) or Layer 2 signaling (e.g., MAC CE).

[0037] In the example in Figure 6, gNB2 alternates between two SSB burst periods. This may be implemented as an extension of the cell DTX. Specifically, during the active period or time within the cell DTX cycle, gNB2 repeatedly transmits SSB bursts with a first period T1 (e.g., 20 ms). Conversely, during the inactive period or time within the cell DTX cycle, gNB2 repeatedly transmits SSB bursts with a second period T2 (e.g., 80 ms), which is longer than the first period T1.

[0038] In the example shown in Figure 7, gNB2 alternates between periods of SSB burst transmission and periods of suspension of SSB burst transmission. This may be implemented as an extension of the cell DTX. Specifically, during the active period or time within the cell DTX cycle, gNB2 repeatedly transmits SSB bursts at a first period T1 (e.g., 20 ms). Conversely, during the inactive period or time within the cell DTX cycle, gNB2 stops transmitting SSB bursts.

[0039] <First Embodiment> The configuration example of the wireless communication system according to this embodiment is the same as the configuration example described with reference to Figure 1. Figure 8 shows an example of the operation of UE1 and gNB2. In step 801, gNB2 transmits SSB transmission pattern information relating to a specific SSB or SSB burst using one or more signals (i.e., physical layer signals), one or more physical channels, or a combination thereof, which are included in the SSB. In other words, one or more signals, one or more physical channels, or a combination thereof, which are included in each SSB that is included in at least one of a plurality of SSB bursts that are repeatedly transmitted in the time domain, represent SSB transmission pattern information relating to these SSB bursts. UE1 obtains the SSB transmission pattern information from the SSB itself. Based on the SSB transmission pattern information, UE1 may decide whether or not to perform downlink synchronization, or whether or not to continue downlink synchronization.

[0040] Figure 9 shows an example of the operation of UE1. In step 901, UE1 attempts to receive multiple SSB bursts that are transmitted repeatedly in the time domain. UE1 may attempt to receive SSB bursts if UE1 is in the RRC_IDLE or RRC_INACTIVE state and is not synchronized with the radio access network (e.g., cell 21). In step 902, UE1 obtains SSB transmission pattern information for these SSB bursts from one or more signals, one or more physical channels, or a combination thereof, that are included in the successfully received SSBs. In step 903, UE1 determines whether to continue downlink synchronization based on the transmission pattern information.

[0041] SSB transmission pattern information may be transmitted using at least a sequence of one or more synchronization signals within the SSB, i.e., at least one of PSS and SSS. Alternatively, SSB transmission pattern information may be transmitted using at least a payload of a physical channel within the SSB, i.e., PBCH. SSB transmission pattern information may be contained in an MIB carried by the PBCH. Alternatively, SSB transmission pattern information may be transmitted using at least a sequence of other physical layer signals within the SSB, i.e., DMRS. Two or more of these transmission methods may be used in combination. For example, a first part of the SSB transmission pattern information may be carried as part of the PBCH payload, and a second part of the SSB transmission pattern information may be carried as part of a sequence of PBCH DMRS.

[0042] In some implementations, the SSB transmission pattern information in step 801 provides information related to the transmission period or cycle (i.e., SSB burst period) of the SSB burst. In one example, the SSB transmission pattern information may indicate that the SSB burst transmission period is scheduled to be changed. The change in the SSB burst period may be a change from a first period (T1) to a second period (T2) that is longer than the first period, as shown in Figure 4 or Figure 6. Alternatively, the SSB transmission pattern information may indicate that the SSB burst transmission is scheduled to be stopped. A temporary stop in SSB burst transmission may be indicated by changing the SSB burst period to infinity or an invalid value (e.g., 0).

[0043] SSB transmission pattern information may provide information related to the remaining number of SSB burst transmissions until the SSB burst period is changed or SSB burst transmission is temporarily stopped. For example, SSB transmission pattern information may indicate the remaining number of SSB burst transmissions until the SSB burst period is changed or SSB burst transmission is stopped. SSB transmission pattern information may indicate whether the remaining number of SSB burst transmissions until the SSB burst period is changed or SSB burst transmission is stopped is greater than a predetermined value. SSB transmission pattern information may indicate the range of the remaining number of SSB burst transmissions until the SSB burst period is changed or SSB burst transmission is stopped.

[0044] The SSB transmission pattern information may indicate whether the remaining number of SSB burst transmissions is sufficient to establish downlink synchronization. For example, if UE1 needs to receive three SSB bursts to establish synchronization, UE1 needs to receive two more SSB bursts in addition to the first SSB burst it detected. In this case, if the remaining number of SSB burst transmissions is one or less, the SSB transmission pattern information may indicate that the remaining number of SSB burst transmissions is not sufficient to establish downlink synchronization. Conversely, if the remaining number of SSB burst transmissions is two or more, the SSB transmission pattern information may indicate that the remaining number of SSB burst transmissions is sufficient to establish downlink synchronization.

[0045] In some implementations, for example, with an adaptive extension of the active period of cell DTX, there may be a case where the period during which SSB burst transmission is performed at the first period (T1) is extended. In this case, gNB 2 may adaptively update the value of the SSB pattern information indicated by each SSB.

[0046] According to several specific examples of the SSB pattern information described above, UE 1 can know from the successfully detected SSB itself that the SSB burst transmission period is scheduled to change (or the SSB burst transmission is temporarily stopped). In some specific examples, UE 1 can know from the successfully detected SSB itself the remaining number of SSB burst transmissions until the SSB burst period changes (or until the SSB burst transmission is temporarily stopped). In some specific examples, UE 1 can know from the successfully detected SSB itself whether the remaining number of SSB burst transmissions until the SSB burst period changes (or until the SSB burst transmission is temporarily stopped) is sufficient to establish downlink synchronization. This may contribute to mitigating the impact of the adaptive transmission of downlink synchronization signals (e.g., PSS and SSS) on the operation for UE 1's downlink synchronization.

[0047] For example, if UE1 knows from the received SSB that the SSB burst transmission period is to be changed (or the SSB burst transmission is to be temporarily stopped), UE1 may abort the operations for downlink synchronization establishment and wait until the repeated transmission of the SSB burst according to the first period (T1) is next started. If UE1 knows from the received SSB that the remaining number of transmissions of the SSB burst until the SSB burst period is changed (or until the SSB burst transmission is temporarily stopped) is not sufficient to establish downlink synchronization, UE1 may abort the operations for downlink synchronization establishment and wait until the repeated transmission of the SSB burst according to the first period (T1) is next started. This enables UE1 to avoid, for example, a failure in downlink synchronization. Further or alternatively, this enables UE1 to avoid, for example, an increase in the time required for UE1 to perform downlink synchronization.

[0048] Figures 10 and 11 show examples of the mapping between the value of the SSB transmission pattern information and the remaining number of transmissions until the change in the SSB burst period or the stop of the SSB burst transmission. In the example of Figure 10, the length of the SSB transmission pattern information is 2 bits. In the example of Figure 10, when the value of the SSB transmission pattern information is "00", "01", "10", or "11", it means that the remaining number of transmissions of the SSB burst is "0", "1", "2", or "3 or more", respectively. In the example of Figure 11, the length of the SSB transmission pattern information is 1 bit. In the example of Figure 1, when the value of the SSB transmission pattern information is "0" or "1", it means that the remaining number of transmissions of the SSB burst is "1 or less" or "2 or more", respectively.

[0049] The mappings shown in Figures 10 and 11 can be changed as appropriate. For example, the length of the SSB transmission pattern information may be 3 bits or more. Each value of the SSB transmission pattern information may be associated with other values of the remaining number of transmissions or may be associated with other ranges of the remaining number of transmissions.

[0050] Furthermore, or alternatively, the SSB transmission pattern information may indicate the length of the SSB burst period. The SSB transmission pattern information may indicate whether the length of the SSB burst period is longer than a predetermined value. The SSB transmission pattern information may indicate a range of lengths for the SSB burst period. This may help mitigate the effect of adaptive transmission of downlink synchronization signals (e.g., PSS and SSS) on the operation of UE1 for downlink synchronization.

[0051] For example, if UE1 learns from the received SSB that the SSB burst transmission period is a second period (T2) that is longer than the first period (T1), UE1 may abort the operation to establish downlink synchronization and wait until the next repeated transmission of SSB bursts following the first period (T1) begins. This allows UE1 to avoid, for example, a failure of downlink synchronization. Furthermore, or alternatively, this allows UE1 to avoid an increase in the time required for UE1 to perform downlink synchronization.

[0052] Figures 12 and 13 show examples of mappings between SSB transmission pattern information values ​​and SSB burst periods. In the example in Figure 12, the length of the SSB transmission pattern information is 2 bits. In the example in Figure 12, when the value of the SSB transmission pattern information is "00", "01", "10", or "11", it means that the SSB burst period is "20 ms (or less)", "greater than 20 ms and 100 ms or less", "greater than 100 ms and 200 ms or less", or "greater than 200 ms", respectively. In the example in Figure 13, the length of the SSB transmission pattern information is 1 bit. In the example in Figure 13, when the value of the SSB transmission pattern information is "0" or "1", it means that the SSB burst period is "20 ms (or less)" or "greater than 20 ms", respectively.

[0053] The mappings shown in Figures 12 and 13 can be modified as appropriate. For example, the length of the SSB transmission pattern information may be 3 bits or more. Each value of the SSB transmission pattern information may be associated with another value of the SSB burst period, or with another range of the SSB burst period.

[0054] Next, configuration examples of UE1 and gNB2 related to the above-described embodiments will be explained. Figure 14 is a block diagram showing a configuration example of UE1. The RF transceiver 1401 performs analog RF signal processing to communicate with gNB2. The RF transceiver 1401 may include multiple transceivers. The analog RF signal processing performed by the RF transceiver 1401 includes frequency upconversion, frequency downconversion, and amplification. The RF transceiver 1401 is coupled with the antenna array 1402 and the baseband processor 1403. The RF transceiver 1401 receives modulation symbol data (or orthogonal frequency-division multiplexing (OFDM) symbol data) from the baseband processor 1403, generates a transmit RF signal, and supplies the transmit RF signal to the antenna array 1402. The RF transceiver 1401 also generates a baseband receive signal based on the received RF signal received by the antenna array 1402 and supplies this to the baseband processor 1403. The RF transceiver 1401 may include an analog beamformer circuit for beamforming. The analog beamformer circuit may include, for example, multiple phase shifters and multiple power amplifiers.

[0055] The baseband processor 1403 performs digital baseband signal processing (data plane processing) and control plane processing for wireless communication. Digital baseband signal processing may include (a) data compression / decompression, (b) data segmentation / concatenation, (c) generation / decomposition of transmission format (transmission frame), (d) transmission path coding / decoding, (e) modulation (symbol mapping) / demodulation, and (f) generation of OFDM symbol data (baseband OFDM signal) by Inverse Fast Fourier Transform (IFFT). On the other hand, control plane processing may include communication management at Layer 1 (e.g., transmit power control), Layer 2 (e.g., radio resource management and hybrid automatic repeat request (HARQ) processing), and Layer 3 (e.g., signaling related to attach, mobility, and call management).

[0056] For example, the digital baseband signal processing by the baseband processor 1403 may include signal processing for the PDCP layer, RLC layer, MAC layer, and PHY layer. Furthermore, the control plane processing by the baseband processor 1403 may include processing for the Non-Access Stratum (NAS) protocol, RRC protocol, MAC CEs, and DCIs.

[0057] The baseband processor 1403 may perform multiple-input and multiple-output (MIMO) encoding and precoding for beamforming.

[0058] The baseband processor 1403 may include a modem processor (e.g., Digital Signal Processor (DSP)) for performing digital baseband signal processing and a protocol stack processor (e.g., Central Processing Unit (CPU) or Micro Processing Unit (MPU)) for performing control plane processing. In this case, the protocol stack processor for performing control plane processing may be shared with the application processor 1404 described later.

[0059] The application processor 1404 is also called a CPU, MPU, microprocessor, or processor core. The application processor 1404 may include multiple processors (multiple processor cores). The application processor 1404 implements various functions of the UE 1 by executing system software programs (Operating System (OS)) and various application programs (e.g., calling applications, web browsers, mail clients, camera operation applications, music playback applications) read from memory 1406 or other memory.

[0060] In some implementations, the baseband processor 1403 and the application processor 1404 may be integrated on a single chip, as shown by the dashed line (1405) in Figure 14. In other words, the baseband processor 1403 and the application processor 1404 may be implemented as a single System on Chip (SoC) device 1405. An SoC device is sometimes called a System Large Scale Integration (LSI) or chipset.

[0061] Memory 1406 is volatile memory, non-volatile memory, or a combination thereof. Memory 1406 may include multiple physically independent memory devices. Volatile memory is, for example, Static Random Access Memory (SRAM) or Dynamic RAM (DRAM), or a combination thereof. Non-volatile memory is Mask Read Only Memory (MROM), Electrically Erasable Programmable ROM (EEPROM), flash memory, or hard disk drive, or any combination thereof. For example, memory 1406 may include an external memory device accessible from the baseband processor 1403, the application processor 1404, and the SoC 1405. Memory 1406 may also include an internal memory device integrated within the baseband processor 1403, the application processor 1404, or the SoC 1405. Furthermore, memory 1406 may include memory within a Universal Integrated Circuit Card (UICC).

[0062] The memory 1406 may store one or more software modules (computer programs) 1407 containing instruction sets and data for processing by the UE 1. In some implementations, the baseband processor 1403 or application processor 1404 may be configured to read and execute the software modules 1407 from the memory 1406 to perform the processing of the UE 1 as described in one or more of the multiple embodiments.

[0063] Furthermore, the control plane processing and operations performed by the UE1 described in the above embodiment can be realized by other elements other than the RF transceiver 1401 and antenna array 1402, namely at least one of the baseband processor 1403 and application processor 1404 and the memory 1406 storing the software module 1407.

[0064] Figure 15 is a block diagram showing an example configuration of gNB2. Referring to Figure 15, gNB2 includes an RF transceiver 1501, a network interface 1503, a processor 1504, and a memory 1505. The RF transceiver 1501 performs analog RF signal processing to communicate with UEs 1. The RF transceiver 1501 may include multiple transceivers. The RF transceiver 1501 is coupled with an antenna array 1502 and a processor 1504. The RF transceiver 1501 receives modulation symbol data from the processor 1504, generates a transmit RF signal, and supplies the transmit RF signal to the antenna array 1502. The RF transceiver 1501 also generates a baseband receive signal based on the received RF signal received by the antenna array 1502 and supplies this to the processor 1504. The RF transceiver 1501 may include an analog beamformer circuit for beamforming. The analog beamformer circuit includes, for example, multiple phase shifters and multiple power amplifiers.

[0065] The network interface 1503 is used to communicate with network nodes (e.g., other RAN nodes, as well as control and forwarding nodes of the core network). The network interface 1503 may include, for example, a network interface card compliant with the IEEE 802.3 series.

[0066] Processor 1504 performs digital baseband signal processing (data plane processing) and control plane processing for wireless communication. Processor 1504 may include multiple processors. For example, processor 1504 may include a modem processor (e.g., Digital Signal Processor (DSP)) for digital baseband signal processing and a protocol stack processor (e.g., CPU or MPU) for control plane processing. Processor 1504 may also include a digital beamformer module for beamforming. The digital beamformer module may include a MIMO encoder and a precoder.

[0067] Memory 1505 is composed of a combination of volatile memory and non-volatile memory. The volatile memory is, for example, SRAM or DRAM or a combination thereof. The non-volatile memory is MROM, EEPROM, flash memory, or a hard disk drive or any combination thereof. Memory 1505 may include storage located away from the processor 1504. In this case, the processor 1504 may access memory 1505 via the network interface 1503 or other I / O interfaces.

[0068] The memory 1505 may store one or more software modules (computer programs) 1506 containing instruction sets and data for processing by the gNB2. In some implementations, the processor 1504 may be configured to read the software modules 1506 from the memory 1505 and execute them to perform the gNB2 processing described in one or more of the multiple embodiments.

[0069] Furthermore, the control plane processing and operation performed by the gNB2 described in the above embodiment can be realized by elements other than the RF transceiver 1501 and antenna array 1502, namely the processor 1504 and the memory 1505 storing the software module 1506.

[0070] The embodiments described above are merely examples of how the technical concept obtained by the present inventor can be applied. In other words, the technical concept is not limited to the embodiments described above, and various modifications are certainly possible.

[0071] For example, some or all of the embodiments described above may also be described as follows, but are not limited to: Some or all of the elements (e.g., configuration and function) described in the notes directed to devices (e.g., wireless terminals, base stations) may also be described as notes directed to methods and programs. For example, some or all of the elements described in Notes 2-20, which are dependent on Note 1, may also be described as notes dependent on Notes 21 and 22, in a similar dependency relationship to Notes 2-20. Similarly, some or all of the elements described in Notes 24-42, which are dependent on Note 23, may also be described as notes dependent on Notes 43 and 44, in a similar dependency relationship to Notes 24-42. Some or all of the elements described in any note may be applied to various hardware, software, recording means for recording software, systems, and methods.

[0072] (Note 1) A wireless terminal comprising means for attempting to receive a plurality of downlink signal block bursts transmitted repeatedly in a time domain, each downlink signal block burst comprising one or more downlink signal blocks within a predetermined time window, each downlink signal block comprising at least one synchronization signal used for downlink synchronization, and one or more signals, one or more physical channels, or a combination thereof, contained in each downlink signal block contained in at least one of the plurality of downlink signal block bursts, which indicates transmission pattern information for the plurality of downlink signal block bursts. (Note 2) The wireless terminal according to Note 1, wherein the transmission pattern information provides information relating to the transmission period of the plurality of downlink signal block bursts. (Note 3) The wireless terminal according to Note 2, wherein the transmission pattern information indicates that the transmission period is scheduled to be changed, or that the transmission of the plurality of downlink signal block bursts is scheduled to be temporarily suspended. (Note 4) The wireless terminal according to Note 2, wherein the information indicates the length of the transmission period. (Note 5) The wireless terminal as described in Note 2, wherein the information indicates whether the length of the transmission cycle is longer than a predetermined value. (Note 6) The wireless terminal as described in Note 2, wherein the information indicates a range of the length of the transmission cycle. (Note 7) The wireless terminal as described in any one of Notes 1 to 3, wherein the transmission pattern information provides information relating to the remaining number of transmissions of the downlink signal block burst until the transmission cycle of the plurality of downlink signal block bursts is changed or until the transmission of the plurality of downlink signal block bursts is temporarily stopped. (Note 8) The wireless terminal as described in Note 7, wherein the transmission pattern information indicates the remaining number of transmissions. (Note 9) The wireless terminal as described in Note 7, wherein the transmission pattern information indicates whether the remaining number of transmissions is greater than a predetermined value. (Note 10) The wireless terminal as described in Note 7, wherein the transmission pattern information indicates whether the remaining number of transmissions is sufficient to establish downlink synchronization.(Note 11) The remaining number of transmissions is the remaining number of transmissions until the transmission cycle is changed from a first cycle to a second cycle that is longer than the first cycle, as described in any one of Notes 7 to 10. (Note 12) The remaining number of transmissions is the remaining number of transmissions until the transmission of the plurality of downlink signal block bursts is temporarily stopped, as described in any one of Notes 7 to 10. (Note 13) The wireless terminal according to any one of Notes 1 to 12, further comprising means for determining whether or not to perform downlink synchronization or whether or not to continue downlink synchronization based on the transmission pattern information. (Note 14) The wireless terminal according to any one of Notes 1 to 13, where each downlink signal block is a Synchronization Signal (SS) / Physical Broadcast Channel (PBCH) block (SSB), and each downlink signal block burst is an SSB burst. (Note 15) The wireless terminal according to any one of Notes 1 to 14, wherein the transmission pattern information is transmitted using at least one sequence of the one or more synchronization signals. (Note 16) The wireless terminal according to Note 15, wherein the synchronization signal is a Primary Synchronization Signal (PSS) or a Secondary Synchronization Signal (SSS). (Note 17) The wireless terminal according to any one of Notes 1 to 14, wherein the transmission pattern information is transmitted using at least a physical channel payload. (Note 18) The wireless terminal according to Note 17, wherein the payload is a Physical Broadcast Channel (PBCH) payload. (Note 19) The wireless terminal according to any one of Notes 1 to 14, wherein the transmission pattern information is transmitted using at least a sequence of demodulation reference signals used to demodulate modulation symbols generated from the physical channel payload.(Note 20) The wireless terminal as described in Note 19, wherein the demodulation reference signal is a Physical Broadcast Channel (PBCH) Demodulation Reference Signal (DMRS). (Note 21) A method performed by a wireless terminal, comprising attempting to receive a plurality of downlink signal block bursts transmitted repeatedly in a time domain, each downlink signal block burst comprising one or more downlink signal blocks within a predetermined time window, each downlink signal block comprising at least one synchronization signal used for downlink synchronization, and one or more signals, one or more physical channels, or a combination thereof, contained in each downlink signal block contained in at least one of the plurality of downlink signal block bursts indicating transmission pattern information of the plurality of downlink signal block bursts. (Note 22) A program for a wireless terminal comprising causing a computer to perform a method for attempting to receive a plurality of downlink signal block bursts transmitted repeatedly in a time domain, wherein each downlink signal block burst comprises one or more downlink signal blocks within a predetermined time window, each downlink signal block comprises at least one or more synchronization signals used for downlink synchronization, and one or more signals, one or more physical channels, or a combination thereof, contained within each downlink signal block contained within at least one of the plurality of downlink signal block bursts, indicating transmission pattern information for the plurality of downlink signal block bursts.(Note 23) A base station comprising means for repeatedly transmitting a plurality of downlink signal block bursts in a time domain, each downlink signal block burst comprising one or more downlink signal blocks within a predetermined time window, each downlink signal block comprising at least one synchronization signal used for downlink synchronization, and one or more signals, one or more physical channels, or a combination thereof, contained in each downlink signal block contained in at least one of the plurality of downlink signal block bursts, which indicates transmission pattern information for the plurality of downlink signal block bursts. (Note 24) The base station according to Note 23, wherein the transmission pattern information provides information relating to the transmission period of the plurality of downlink signal block bursts. (Note 25) The base station according to Note 24, wherein the transmission pattern information indicates that the transmission period is scheduled to be changed or that the transmission of the plurality of downlink signal block bursts is scheduled to be temporarily suspended. (Note 26) The base station according to Note 24, wherein the information indicates the length of the transmission period. (Note 27) The base station according to Note 24, wherein the information indicates whether the length of the transmission period is longer than a predetermined value. (Note 28) The base station according to Note 24, wherein the information indicates a range of the length of the transmission period. (Note 29) The base station according to any one of Notes 23 to 25, wherein the transmission pattern information provides information relating to the remaining number of transmissions of the downlink signal block burst until the transmission period of the plurality of downlink signal block bursts is changed or until the transmission of the plurality of downlink signal block bursts is temporarily stopped. (Note 30) The base station according to Note 29, wherein the transmission pattern information indicates the remaining number of transmissions. (Note 31) The base station according to Note 29, wherein the transmission pattern information indicates whether the remaining number of transmissions is greater than a predetermined value. (Note 32) The base station according to Note 29, wherein the transmission pattern information indicates whether the remaining number of transmissions is sufficient to establish downlink synchronization.(Note 33) The remaining number of transmissions is the remaining number of transmissions until the transmission cycle is changed from a first cycle to a second cycle that is longer than the first cycle, as described in any one of Notes 29 to 32. (Note 34) The remaining number of transmissions is the remaining number of transmissions until the transmission of the plurality of downlink signal block bursts is temporarily stopped, as described in any one of Notes 29 to 32. (Note 35) The transmission pattern information is used by a wireless terminal to determine whether or not to perform downlink synchronization or whether or not to continue downlink synchronization, as described in any one of Notes 23 to 34. (Note 36) Each downlink signal block is a Synchronization Signal (SS) / Physical Broadcast Channel (PBCH) block (SSB), and each downlink signal block burst is an SSB burst, as described in any one of Notes 23 to 35. (Note 37) The base station according to any one of Notes 23 to 36, wherein the transmission pattern information is transmitted using at least a sequence of one or more synchronization signals. (Note 38) The base station according to Note 37, wherein the synchronization signal is a Primary Synchronization Signal (PSS) or a Secondary Synchronization Signal (SSS). (Note 39) The base station according to any one of Notes 23 to 36, wherein the transmission pattern information is transmitted using at least a physical channel payload. (Note 40) The base station according to Note 39, wherein the payload is a Physical Broadcast Channel (PBCH) payload. (Note 41) The base station according to any one of Notes 23 to 36, wherein the transmission pattern information is transmitted using at least a sequence of demodulation reference signals used to demodulate modulation symbols generated from the physical channel payload.(Note 42) The base station as described in Note 41, wherein the demodulation reference signal is a Physical Broadcast Channel (PBCH) Demodulation Reference Signal (DMRS). (Note 43) A method performed by a base station, comprising repeatedly transmitting a plurality of downlink signal block bursts in a time domain, each downlink signal block burst comprising one or more downlink signal blocks within a predetermined time window, each downlink signal block comprising at least one synchronization signal used for downlink synchronization, and one or more signals, one or more physical channels, or a combination thereof, contained in each downlink signal block contained in at least one of the plurality of downlink signal block bursts, indicating transmission pattern information of the plurality of downlink signal block bursts. (Note 44) A program for causing a computer to perform a method for a base station comprising repeatedly transmitting a plurality of downlink signal block bursts in a time domain, wherein each downlink signal block burst comprises one or more downlink signal blocks within a predetermined time window, each downlink signal block comprises at least one or more synchronization signals used for downlink synchronization, and one or more signals, one or more physical channels, or a combination thereof, contained within each downlink signal block contained within at least one of the plurality of downlink signal block bursts represent the transmission pattern information of the plurality of downlink signal block bursts.

[0073] This application claims priority based on Japanese Patent Application No. 2024-173047, filed on 2 October 2024, and incorporates all of its disclosures herein.

[0074] 1 UE 2 gNB 21 Cells 1403 Baseband Processor 1404 Application Processor 1406 Memory 1407 Modules 1504 Processor 1505 Memory 1506 Modules

Claims

1. A wireless terminal comprising means for attempting to receive a plurality of downlink signal block bursts transmitted repeatedly in a time domain, each downlink signal block burst comprising one or more downlink signal blocks within a predetermined time window, each downlink signal block comprising at least one synchronization signal used for downlink synchronization, and one or more signals, one or more physical channels, or a combination thereof, comprising each downlink signal block comprising at least one of the plurality of downlink signal block bursts, indicating transmission pattern information of the plurality of downlink signal block bursts.

2. The wireless terminal according to claim 1, wherein the transmission pattern information provides information related to the transmission period of the plurality of downlink signal block bursts.

3. The wireless terminal according to claim 2, wherein the transmission pattern information indicates that the transmission cycle is scheduled to be changed, or that the transmission of the plurality of downlink signal block bursts is scheduled to be temporarily suspended.

4. The wireless terminal according to claim 2, wherein the information indicates the length of the transmission cycle.

5. The wireless terminal according to claim 2, wherein the information indicates whether the length of the transmission cycle is longer than a predetermined value.

6. The wireless terminal according to claim 2, wherein the information indicates a range of the length of the transmission cycle.

7. The wireless terminal according to any one of claims 1 to 3, wherein the transmission pattern information provides information relating to the remaining number of transmissions of the downlink signal block bursts until the transmission cycle of the plurality of downlink signal block bursts is changed or until the transmission of the plurality of downlink signal block bursts is temporarily suspended.

8. The wireless terminal according to claim 7, wherein the transmission pattern information indicates the remaining number of transmissions.

9. The wireless terminal according to claim 7, wherein the transmission pattern information indicates whether the remaining number of transmissions is greater than a predetermined value.

10. The wireless terminal according to claim 7, wherein the transmission pattern information indicates whether the remaining number of transmissions is sufficient to establish the downlink synchronization.

11. The remaining number of transmissions is the remaining number of transmissions until the transmission cycle is changed from a first cycle to a second cycle which is longer than the first cycle, according to any one of claims 7 to 10.

12. The remaining number of transmissions is the number of transmissions remaining until the transmission of the plurality of downlink signal block bursts is temporarily stopped, according to any one of claims 7 to 10.

13. The wireless terminal according to any one of claims 1 to 12, further comprising means for determining whether or not to perform downlink synchronization or whether or not to continue downlink synchronization based on the transmission pattern information.

14. The wireless terminal according to any one of claims 1 to 13, wherein each downlink signal block is a Synchronization Signal (SS) / Physical Broadcast Channel (PBCH) block (SSB), and each downlink signal block burst is an SSB burst.

15. The wireless terminal according to any one of claims 1 to 14, wherein the transmission pattern information is transmitted using at least one sequence of the one or more synchronization signals.

16. The wireless terminal according to claim 15, wherein either of the synchronization signals is a Primary Synchronization Signal (PSS) or a Secondary Synchronization Signal (SSS).

17. The wireless terminal according to any one of claims 1 to 14, wherein the transmission pattern information is transmitted using at least the payload of a physical channel.

18. The wireless terminal according to claim 17, wherein the payload is a Physical Broadcast Channel (PBCH) payload.

19. The wireless terminal according to any one of claims 1 to 14, wherein the transmission pattern information is transmitted using at least a sequence of demodulation reference signals used to demodulate modulation symbols generated from the payload of the physical channel.

20. The wireless terminal according to claim 19, wherein the demodulation reference signal is a Physical Broadcast Channel (PBCH) Demodulation Reference Signal (DMRS).

21. A method performed by a wireless terminal, comprising attempting to receive a plurality of downlink signal block bursts transmitted repeatedly in a time domain, each downlink signal block burst comprising one or more downlink signal blocks within a predetermined time window, each downlink signal block comprising at least one synchronization signal used for downlink synchronization, and one or more signals, one or more physical channels, or a combination thereof, comprising each downlink signal block comprising at least one of the plurality of downlink signal block bursts, indicating transmission pattern information of the plurality of downlink signal block bursts.

22. A program for a wireless terminal comprising causing a computer to perform a method for attempting to receive a plurality of downlink signal block bursts transmitted repeatedly in a time domain, each downlink signal block burst comprising one or more downlink signal blocks within a predetermined time window, each downlink signal block comprising at least one synchronization signal used for downlink synchronization, and one or more signals, one or more physical channels, or a combination thereof, contained within each downlink signal block contained within at least one of the plurality of downlink signal block bursts, indicating transmission pattern information for the plurality of downlink signal block bursts.

23. A base station comprising means for repeatedly transmitting a plurality of downlink signal block bursts in a time domain, each downlink signal block burst comprising one or more downlink signal blocks within a predetermined time window, each downlink signal block comprising at least one synchronization signal used for downlink synchronization, and one or more signals, one or more physical channels, or a combination thereof, comprising each downlink signal block comprising at least one of the plurality of downlink signal block bursts, representing the transmission pattern information of the plurality of downlink signal block bursts.

24. The base station according to claim 23, wherein the transmission pattern information provides information relating to the transmission periods of the plurality of downlink signal block bursts.

25. The base station according to claim 24, wherein the transmission pattern information indicates that the transmission period is scheduled to be changed, or that the transmission of the plurality of downlink signal block bursts is scheduled to be temporarily suspended.

26. The base station according to claim 24, wherein the information indicates the length of the transmission period.

27. The base station according to claim 24, wherein the information indicates whether the length of the transmission period is longer than a predetermined value.

28. The base station according to claim 24, wherein the information indicates a range of the length of the transmission period.

29. The base station according to any one of claims 23 to 25, wherein the transmission pattern information provides information relating to the remaining number of transmissions of the downlink signal block bursts until the transmission cycle of the plurality of downlink signal block bursts is changed or until the transmission of the plurality of downlink signal block bursts is temporarily suspended.

30. The base station according to claim 29, wherein the transmission pattern information indicates the remaining number of transmissions.

31. The base station according to claim 29, wherein the transmission pattern information indicates whether the remaining number of transmissions is greater than a predetermined value.

32. The base station according to claim 29, wherein the transmission pattern information indicates whether the remaining number of transmissions is sufficient to establish downlink synchronization.

33. The base station according to any one of claims 29 to 32, wherein the remaining number of transmissions is the remaining number of transmissions until the transmission cycle is changed from a first cycle to a second cycle which is longer than the first cycle.

34. The base station according to any one of claims 29 to 32, wherein the remaining number of transmissions is the number of transmissions remaining until the transmission of the plurality of downlink signal block bursts is temporarily stopped.

35. The base station according to any one of claims 23 to 34, wherein the transmission pattern information is used by a wireless terminal to determine whether or not to perform downlink synchronization or whether or not to continue downlink synchronization.

36. The base station according to any one of claims 23 to 35, wherein each downlink signal block is a Synchronization Signal (SS) / Physical Broadcast Channel (PBCH) block (SSB), and each downlink signal block burst is an SSB burst.

37. The base station according to any one of claims 23 to 36, wherein the transmission pattern information is transmitted using at least one sequence of the one or more synchronization signals.

38. The base station according to claim 37, wherein either of the synchronization signals is a Primary Synchronization Signal (PSS) or a Secondary Synchronization Signal (SSS).

39. The base station according to any one of claims 23 to 36, wherein the transmission pattern information is transmitted using at least the payload of a physical channel.

40. The base station according to claim 39, wherein the payload is a Physical Broadcast Channel (PBCH) payload.

41. The base station according to any one of claims 23 to 36, wherein the transmission pattern information is transmitted using at least a sequence of demodulation reference signals used to demodulate modulation symbols generated from the payload of the physical channel.

42. The base station according to claim 41, wherein the demodulation reference signal is a Physical Broadcast Channel (PBCH) Demodulation Reference Signal (DMRS).

43. A method performed by a base station, comprising repeatedly transmitting a plurality of downlink signal block bursts in a time domain, each downlink signal block burst comprising one or more downlink signal blocks within a predetermined time window, each downlink signal block comprising at least one synchronization signal used for downlink synchronization, and one or more signals, one or more physical channels, or a combination thereof, comprising each downlink signal block comprising at least one of the plurality of downlink signal block bursts, which indicates the transmission pattern information of the plurality of downlink signal block bursts.

44. A program for causing a computer to perform a method for a base station comprising repeatedly transmitting a plurality of downlink signal block bursts in a time domain, each downlink signal block burst comprising one or more downlink signal blocks within a predetermined time window, each downlink signal block comprising at least one or more synchronization signals used for downlink synchronization, and one or more signals, one or more physical channels, or a combination thereof, comprising each downlink signal block comprising at least one of the plurality of downlink signal block bursts, which indicates transmission pattern information for the plurality of downlink signal block bursts.

Images