Beam management in direct communication link

Abstract

The present document relates to a communication method for efficiently managing beams of signals transmitted through a direct communication link, and a user equipment (UE) therefor. In the communication method, a first UE transmits, to a second UE, a physical control channel through a direct communication link and a physical shared channel corresponding to the physical control channel through the direct communication link. KR2025005683 Here, the physical control channel and the physical shared channel are transmitted through a beam indicated through the same indicator in the same time unit, and the physical control channel and the physical shared channel are transmitted through a beam corresponding to the indicator set for each time unit.

Description

Beam management on direct communication links

[0001] The following description relates to communication using a direct communication link between user equipment (UE), and more specifically, to a communication method that improves beam management of signals transmitted through a direct communication link, and to a user equipment therefor.

[0002] Wireless communication systems utilize a variety of technologies, including LTE, LTE-Advanced, and WiFi, and 5G is also included. The three main usage scenarios for 5G include (1) Enhanced Mobile Broadband (eMBB), (2) Massive Machine Type Communication (mMTC), and (3) Ultra-reliable and Low Latency Communications (URLLC). Some use cases may require optimization across multiple areas, while others may focus on just a single Key Performance Indicator (KPI). 5G supports these diverse use cases in a flexible and reliable manner.

[0003] Figure 1 shows the structure of a system for 5G communication.

[0004] Referring to FIG. 1, a Next Generation - Radio Access Network (NG-RAN) may include a base station (20) that provides user plane and control plane protocol termination to a UE (10). For example, the base station (20) may include a next generation Node B (gNB) and / or an evolved Node B (eNB). For example, the UE (10) may be fixed or mobile, and may be referred to by other terms such as a terminal, a mobile station (MS), a user terminal (UT), a subscriber station (SS), a mobile terminal (MT), a wireless device, etc. For example, the base station may be a fixed station that communicates with the UE (10), and may be referred to by other terms such as a base transceiver system (BTS), an access point, etc.

[0005] The example of Fig. 1 illustrates a case that includes only gNB. The base stations (20) can be connected to each other via Xn interfaces. The base stations (20) can be connected to a 5th generation core network (5G Core Network: 5GC) via an NG interface. More specifically, the base station (20) can be connected to an access and mobility management function (AMF) (30) via an NG-C interface, and can be connected to a user plane function (UPF) (30) via an NG-U interface.

[0006]

[0007] In the system for 5G communication as described above, a connection may be made between a UE (10) and a gNB via a Uu interface, and a connection may be made between UEs (10) via a PC5 interface, and a link via PC5 may be referred to as a side link. In the 5G communication system and its successor next-generation mobile communication, a communication method using a high frequency band (Frequency Range 2 or FR2) of 24 GHz or higher, unlike the existing communication frequency band (Frequency Range 1 or FR1), is being discussed.

[0008] In this type of FR2 communication method, it is required to form beams of signals and communicate them in consideration of high path loss, and many previous studies have been conducted on channels on the Uu interface in relation to beam management.

[0009] However, for the side link between UEs (10), a new beam management method may be required depending on the characteristics different from the beam management on the existing Uu interface.

[0010] In order to solve the above-described problem, one aspect of the present invention proposes a communication method and a user device therefor that improves the efficiency of beam management of signals transmitted through a direct communication link between UEs.

[0011] The technology proposed below is assumed to be applicable not only to the current 5G system but also to 6G and subsequent mobile communication systems, and therefore, the term 'side link' used in 5G can be referred to as a 'direct communication link' between UEs, and the concept of 'direct communication link' is assumed to be used as a term to refer to a link adopted to correspond to the side link between 5G UEs in 6G and subsequent standards.

[0012] In addition, terms such as PSSCH (Physical Sidelink Shared Channel), PSCCH (Physical Sidelink Control Channel), and PSFCH corresponding to data channels used in 5G may be referred to as terms such as 'physical shared channel', 'physical control channel', and 'physical feedback channel' transmitted through the above-described direct communication link.

[0013] In one aspect of the present invention, it is proposed to set up a physical control channel and a physical shared channel transmitted through a direct communication link between UEs to be transmitted through a beam indicated by the same indicator in the same time unit, but with the indicator configured for each time unit.

[0014] At this time, the term 'time unit' may correspond to 'slot', which is the basic time unit for signal transmission in 5G, but it assumes a concept corresponding to the term to be used in response to the 'slot' in 6G and subsequent next-generation mobile communication systems.

[0015] Additionally, depending on the embodiment, the 'time unit' may correspond to a 'sub-slot'.

[0016] The "indicator" that directs the beam can correspond to the "TCI (Transmission Configuration Indicator)" of 5G. However, this does not exclude the concept of an indicator that distinguishes the beam configuration of a transmission signal, based on other terms used in response to TCI in 6G and subsequent next-generation mobile communication standards.

[0017] The problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0018] In one aspect of the present invention for solving the above-described problem, a method for performing communication between a first user equipment (UE) and a second UE through a direct communication link in a mobile communication system is proposed, comprising: transmitting, to the second UE, a physical control channel through the direct communication link; and transmitting a physical shared channel corresponding to the physical control channel through the direct communication link, wherein the physical control channel and the physical shared channel are transmitted through a beam indicated by the same indicator in the same time unit, and the physical control channel and the physical shared channel are transmitted through a beam corresponding to the indicator set for each time unit.

[0019] A plurality of beams are configured for transmission of the physical control channel and the physical shared channel, and it is preferable to transmit the physical control channel and the physical shared channel through one beam corresponding to the indicator set for each time unit among the plurality of beams.

[0020] At this time, the above indicator can be set to be repeated at a predetermined cycle of the above time unit.

[0021] Additionally, the indicator may be set through an index-based modulo operation of the above time unit.

[0022] Additionally, the indicator may include a first indicator common to the entire time unit, and a second indicator additionally set to the first indicator for each time unit.

[0023] In addition, the method further includes selectively transmitting a repetitive signal for improving reception performance of at least one of the physical control channel and the physical shared channel through a first symbol within the time unit, wherein the first UE may be configured to omit the repetitive signal transmission in the second time unit based on a similarity between a first beam used in the first time unit among the time units and a second beam used in the second time unit.

[0024] The above time unit may correspond to a slot, and the above indicator may correspond to a Transmission Configuration Indicator (TCI).

[0025] Alternatively, the time unit may correspond to a sub-slot, each of which contains one or more symbols within the slot.

[0026] At this time, one physical shared channel and multiple physical control channels may be transmitted per slot.

[0027] In the above-described embodiment, when the TCI is set for each subslot, AGC (Automatic Gain Control) may also be transmitted for each subslot.

[0028] The above physical control channel may include a Physical Sidelink Control Channel (PSCCH), and the above physical shared channel may include a Physical Sidelink Shared Channel (PSSCH). However, the above-described embodiments assume that the concepts of physical control channels and physical shared channels corresponding to the above-described terms are included not only in 5G but also in 6G and subsequent standards.

[0029] Meanwhile, in another aspect of the present invention for solving the above-described problem, a method for performing communication between a second user equipment (UE) and a first UE through a direct communication link in a mobile communication system is proposed, comprising: receiving a physical control channel from the first UE through the direct communication link; and receiving a physical shared channel corresponding to the physical control channel through the direct communication link, wherein the physical control channel and the physical shared channel are received through a beam indicated by the same indicator in the same time unit, and the physical control channel and the physical shared channel are received through a beam corresponding to the indicator set for each time unit.

[0030] At this time, the method further includes selectively receiving a repetitive signal for improving reception performance of at least one of the physical control channel and the physical shared channel through the first symbol within the time unit, wherein the second UE may be configured to process the physical control channel and the physical shared channel based on the similarity between the first beam used in the first time unit among the time units and the second beam used in the second time unit, assuming that the repetitive signal is not received in the second time unit.

[0031] Meanwhile, in another aspect of the present invention, a first user equipment (UE) for performing communication with a second UE through a direct communication link in a mobile communication system is proposed, comprising: at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, wherein the operations include transmitting, to the second UE, a physical control channel through the direct communication link; and transmitting a physical shared channel corresponding to the physical control channel through the direct communication link, wherein the physical control channel and the physical shared channel are transmitted through a beam indicated by the same indicator in the same time unit, and the physical control channel and the physical shared channel are transmitted through a beam corresponding to the indicator set for each time unit.

[0032] According to the embodiments of the present invention as described above, a communication method based on beam management distinct from the Uu interface and a user device therefor can be implemented by taking into account the characteristics of a direct communication link between UEs.

[0033] Specifically, the physical control channel and the physical shared channel can be transmitted through beams indicated by the same indicator in the same time unit to prevent AGC problems and simplify transmission, and the beams can be configured by time unit to maintain beam diversity in applications such as V2X.

[0034] Meanwhile, depending on the embodiment, the trade-off relationship between signaling overhead and improved reception performance can be optimized through selective transmission of AGC according to the similarity between beams in consecutive time units.

[0035] The effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention belongs from the description below.

[0036] Figure 1 shows the structure of a system for 5G communication.

[0037] FIG. 2 is a diagram for explaining channels that can be used in sidelink communication according to embodiments of the present invention.

[0038] FIGS. 3 to 5 are drawings for explaining a beam management method on a Uu interface in comparison with embodiments of the present invention.

[0039] FIG. 6 is a diagram for explaining a method for performing communication through a direct communication link between UEs according to one embodiment of the present invention.

[0040] FIG. 7 and FIG. 8 are drawings for explaining the embodiment proposed in FIG. 6 in comparison with the case of the Uu interface of 5G.

[0041] FIG. 9 is a drawing for explaining an example of configuring a TCI in slot units according to one embodiment of the present invention.

[0042] FIG. 10 is a drawing for explaining a transmission omission method of AGC according to one embodiment of the present invention.

[0043] FIG. 11 is a drawing for explaining a method of configuring a TCI in subslot units according to one embodiment of the present invention.

[0044] FIG. 12 is a drawing for specifically explaining the AGC addition concept in the embodiment of FIG. 11.

[0045] FIG. 13 is a diagram for explaining a process of establishing a unicast link for performing direct communication between UEs according to one embodiment of the present invention.

[0046] Figure 14 illustrates a wireless device to which the present technology can be applied.

[0047] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In addition, in the drawings, parts irrelevant to the description have been omitted to clearly explain the present invention, and similar parts have been designated with similar reference numerals throughout the specification.

[0048] Throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0049]

[0050] As described above, one aspect of the present invention proposes a communication method and a user equipment for efficiently managing the beam of signals transmitted via a direct communication link between UEs. The proposed technology is assumed to be applicable not only to the current 5G system, but also to 6G and subsequent next-generation mobile communication systems. However, for ease of understanding, the following description will assume the current 5G system to avoid confusion.

[0051] First, we will look at channels that can be used in sidelink communication according to embodiments of the present invention.

[0052] FIG. 2 is a diagram for explaining channels that can be used in sidelink communication according to embodiments of the present invention.

[0053] The embodiment of FIG. 2 can be combined with various embodiments of the present invention. In various embodiments of the present invention, the "transmission mode" may be referred to as a "mode" or a "resource allocation mode." Hereinafter, for convenience of explanation, the transmission mode in LTE may be referred to as the LTE transmission mode, and the transmission mode in NR may be referred to as the NR resource allocation mode.

[0054] Specifically, (a) of FIG. 2 represents UE operations related to LTE transmission mode 1, LTE transmission mode 3, or NR resource allocation mode 1. For example, LTE transmission mode 1 can be applied to general SL communication, and LTE transmission mode 3 can be applied to V2X communication.

[0055] Meanwhile, (b) of FIG. 2 shows UE operation related to LTE transmission mode 2 or LTE transmission mode 4 or NR resource allocation mode 2.

[0056] Referring to (a) of FIG. 2, in LTE transmission mode 1, LTE transmission mode 3, or NR resource allocation mode 1, the base station may schedule SL resources to be used by the UE for SL transmission (S8000). For example, the base station may transmit information related to SL resources and / or information related to UL resources to the first UE. The UL resources may include PUCCH resources and / or PUSCH resources. In addition, the UL resources may be resources for reporting SL HARQ feedback to the base station.

[0057] A first UE may receive information related to a dynamic grant (DG) resource and / or information related to a configured grant (CG) resource from a base station. The CG resource may include a CG type 1 resource or a CG type 2 resource. In this specification, a DG resource may be a resource that a base station configures / allocates to the first UE via downlink control information (DCI). In addition, in this specification, a CG resource may be a (periodic) resource that a base station configures / allocates to the first UE via DCI and / or an RRC message. For example, in the case of a CG type 1 resource, the base station may transmit an RRC message including information related to the CG resource to the first UE. In the case of a CG type 2 resource, the base station may transmit an RRC message including information related to the CG resource to the first UE, and the base station may transmit a DCI related to activation or release of the CG resource to the first UE.

[0058] In step S8010, the first UE may transmit a PSCCH (e.g., Sidelink Control Information (SCI) or 1st-stage SCI) to the second UE based on the resource scheduling. In step S8020, the first UE may transmit a PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) related to the PSCCH to the second UE. In step S8030, the first UE may receive a PSFCH (Physical Sidelink Feedback Channel) related to the PSCCH / PSSCH from the second UE. For example, HARQ feedback information (e.g., NACK information or ACK information) may be received from the second UE via the PSFCH. In step S8040, the first UE may transmit / report HARQ feedback information to the base station via a PUCCH or a PUSCH. For example, the HARQ feedback information reported to the base station may be information generated by the first UE based on the HARQ feedback information received from the second UE. In addition, the HARQ feedback information reported to the base station may be information generated by the first UE based on a rule set in advance. The DCI may be DCI for scheduling the SL. The format of the DCI may be DCI format 3_0 or DCI format 3_1.

[0059] [Table 1] shows an example of DCI for SL scheduling.

[0060] Format 3_0- Resource pool index -roof (log2I) bits, whereIis the number of resource pools for transmission configured by the higher layer parametersl-TxPoolScheduling.- Time gap - 3 bits determined by higher layer parametersl-DCI-ToSL-Trans- HARQ process number - 4 bits- New data indicator - 1 bit- Lowest index of the subchannel allocation to the initial transmission -roof (log2(N SL subChannel)) bits- SCI format 1-A fields:- Frequency resource assignment.- Time resource assignment.- PSFCH-to-HARQ feedback timing indicator -roof (log2N ft_timing ) bits, where N ft_timingis the number of entries in the higher layer parametersl-PSFCH-ToPUCCH- PUCCH resource indicator - 3 bits.- Configuration index - 0 bit if the UE is not configured to monitor DCI format 3_0 with CRC scrambled by SL-CS-RNTI; otherwise 3 bits. If the UE is configured to monitor DCI format 3_0 with CRC scrambled by SL-CS-RNTI, this field is reserved for DCI format 3_0 with CRC scrambled by SL-RNTI.- Counter sidelink assignment index - 2 bits- 2 bits if the UE is configured withpdsch-HARQ-ACK-Codebook = dynamic- 2 bits if the UE is configured withpdsch-HARQ-ACK-Codebook = semi-static- Padding bits, if requiredFormat 3_1- Timing offset - 3 bits determined by higher layer parametersl-TimeOffsetEUTRA- Carrier indicator -3 bits.- Lowest index of the subchannel allocation to the initial transmission - roof (log2(N SLsubChannel) bits.- Frequency resource location of initial transmission and retransmission- Time gap between initial transmission and retransmission- SL index - 2 bits- SL SPS configuration index - 3 bits.- Activation / release indication - 1 bit.

[0061]

[0062] Referring to (b) of FIG. 2, in LTE transmission mode 2, LTE transmission mode 4, or NR resource allocation mode 2, the UE can determine SL transmission resources within SL resources configured by the base station / network or preset SL resources. The configured SL resources or preset SL resources may be a resource pool. For example, the UE can autonomously select or schedule resources for SL transmission. The UE can perform SL communication by selecting resources within the configured resource pool. For example, the UE can perform sensing and resource (re)selection procedures to select resources within a selection window. The sensing may be performed on a subchannel basis.

[0063] In step S8010, a first UE that has selected a resource within a resource pool can transmit a PSCCH (e.g., Sidelink Control Information (SCI) or 1st-stage SCI) to a second UE using the resource. In step S8020, the first UE can transmit a PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) related to the PSCCH to the second UE. In step S8030, the first UE can receive a PSFCH related to the PSCCH / PSSCH from the second UE.

[0064] Referring to (a) or (b) of FIG. 2, a first UE may transmit an SCI to a second UE on a PSCCH. Alternatively, the first UE may transmit two consecutive SCIs (e.g., 2-stage SCIs) to the second UE on the PSCCH and / or the PSSCH. In this case, the second UE may decode the two consecutive SCIs (e.g., 2-stage SCIs) to receive the PSSCH from the first UE. In this specification, an SCI transmitted on a PSCCH may be referred to as a 1st SCI, a 1st SCI, a 1st-stage SCI, or a 1st-stage SCI format, and an SCI transmitted on a PSSCH may be referred to as a 2nd SCI, a 2nd SCI, a 2nd-stage SCI, or a 2nd-stage SCI format. For example, a 1st-stage SCI format may include SCI format 1-A, and a 2nd-stage SCI format may include SCI format 2-A and / or SCI format 2-B.

[0065]

[0066] FIGS. 3 to 5 are drawings for explaining a beam management method on a Uu interface in comparison with embodiments of the present invention.

[0067] First, as illustrated in FIG. 3, multi-beam operation related to the PDCCH (Physical Downlink Control Channel) in 5G can be arranged such that each CORESET is associated with multiple SS (Synchronization Signal) sets. Each SS set (SS sets 1, 2, 3, etc. in FIG. 3) can correspond to each downlink transmission beam.

[0068] Meanwhile, TCI states can be set via RRC (Radio Resource Control) for each CORESET for PDCCH. In 5G, up to 64 TCI states can be specified.

[0069] Meanwhile, the base station can activate one of the multiple TCI states described above through the MAC (Medium Access Control) CE (Control Element). This activation command is received n+3 times after the command is received. Nsubframe slot It can be applied from the first slot after (3ms). For this purpose, it is desirable for the UE to monitor the PDCCH monitoring occasion of the SS set.

[0070] If the TCI state is not explicitly configured, the UE may assume the SSB beam of the corresponding CORESET.

[0071]

[0072] Next, we examine multi-beam operation related to PDSCH (Physical Downlink Shared Channel) in 5G as illustrated in Fig. 4.

[0073] First, for PDSCH, RRC can configure N TCI states (410), and in 5G, N can be set up to 64.

[0074] Meanwhile, the base station can activate some of the N TCI states through MAC CE (420), and in 5G, 8 TCI states can be activated as shown in Fig. 4. This can be done using a codepoint mapping method.

[0075] These activation commands are n+3N after the command is received. subframe slot It can be applied from the first slot after (3ms).

[0076] Next, the base station can indicate one of the activated TCI states via DCI (Downlink Control Information) (430). This can be indicated via the 3-bit 'Transmission Configuration Indication' item in the DCI field.

[0077] Figure 5 illustrates an operation of receiving a PDSCH by indicating TCI state 3 through the DCI described above (S510).

[0078] Specifically, FIG. 5 illustrates an operation of receiving a PDSCH through TCI state 3 indicated through the DCI after timeDurationForQCL after receiving the DCI through the PDCCH. If the time interval (t_offset) between the PDCCH reception and the PDSCH reception is greater than timeDurationForQCL, the UE may process the PDSCH assuming that it is received on a beam indicated by TCI state 3. If the time offset is smaller than timeDurationForQCL, the UE may receive / process the PDSCH assuming a default beam.

[0079]

[0080] As described above, in beam management for the Uu interface in 5G, different TCIs may be used for each CORESET even within the same slot, as illustrated in FIG. 3. Additionally, the PDCCH and its corresponding PDSCH may be configured with different TCIs.

[0081] However, if the above-described features are applied as they are to the direct communication link between UEs, i.e., the side link of 5G, overhead may increase due to redundant transmission of AGC (Automatic Gain Control) to improve reception performance as described later, and when considering the situation where the movement speed of UEs is fast, such as in vehicular communication, and assuming the use of multiple beams, an efficient beam management method different from the Uu interface is required.

[0082]

[0083] FIG. 6 is a diagram for explaining a method for performing communication through a direct communication link between UEs according to one embodiment of the present invention.

[0084] As illustrated in FIG. 6, UE1 can transmit a physical control channel (e.g., PSCCH of 5G) to UE2 via a direct communication link (e.g., side link of 5G) (S620), and transmit a physical shared channel (e.g., PSSCH of 5G) corresponding to the physical control channel (e.g., PSCCH of 5G) via the direct communication link (S630).

[0085] In the embodiments proposed below, unlike the case of the Uu interface described above, it is assumed that the physical control channel (e.g., PSCCH) and the physical shared channel (e.g., PSSCH) are transmitted through a beam indicated by the same indicator (e.g., TCI of 5G) in the same time unit (e.g., slot of 5G).

[0086] As described below, AGC can be transmitted in a transmission slot to improve reception performance at the receiver side when transmitting sidelink signals, specifically to measure reception power. In 5G, this AGC is transmitted via the first symbol of the slot and can typically be configured to replicate and transmit subsequent symbol signals.

[0087] In sidelink communication, a PSCCH and a corresponding PSSCH are transmitted simultaneously within one slot. If different transmission beams are used for the PSCCH and the PSSCH, there is a problem that AGC transmission may be required for different transmission beams within one slot. Accordingly, in the embodiments proposed below, it is assumed that the same transmission beam is used for the PSCCH and the PSSCH.

[0088] Under such assumptions, one embodiment of the present invention proposes that the indicator (e.g., TCI) is set (S610) for each time unit (e.g., slot) in common for the physical control channel (e.g., PSCCH) and the physical shared channel (e.g., PSSCH).

[0089] That is, using 5G as an example, the same TCI state is assigned to PSCCH and PSSCH transmitted in slot units, but the TCI state is set in each slot unit, thereby maintaining the use of multiple beams in sidelink communication and maintaining sidelink communication performance.

[0090]

[0091] FIG. 7 and FIG. 8 are drawings for explaining the embodiment proposed in FIG. 6 in comparison with the case of the Uu interface of 5G.

[0092] As illustrated in 710 of FIG. 7, in the NR Uu interface of 5G, beams can be formed for each CORESET, and accordingly, beams indicated by different TCIs (#1, #2) can be used for multiple PDCCHs (corresponding to CORESET 1, 2) transmitted in one slot, and also, a beam indicated by another TCI (#3) can be used for a PDSCH corresponding to the PDCCH.

[0093] In contrast, the beam management method proposed according to the present embodiment proposes that PSCCH and PSSCH are transmitted in slot units, as illustrated in 720 of FIG. 7, and that PSCCH / PSSCH transmitted through the same slot are transmitted through a beam indicated by the same TCI (#1).

[0094] In addition, as illustrated in 720 of FIG. 7, the TCI setting of such PSCCH / PSSCH can be configured on a slot-by-slot basis, and accordingly, an example is shown in which a beam indicated by a different TCI (#2) is configured for PSCCH / PSSCH in the subsequent slot.

[0095] Meanwhile, FIG. 8 is a diagram showing a situation in which it is advantageous to use multiple beams for signal transmission such as PSCCH / PSSCH in sidelink communication.

[0096] Communication through a direct communication link between UEs, such as the side link of 5G, is suitable for use in V2X (Vehicle-to-everything), and Fig. 8 illustrates a V2V communication situation assuming such V2X communication.

[0097] If only one beam is utilized for sidelink communication (810), it is difficult to quickly respond to rapidly changing beam performance changes in situations where UEs move at high speeds. That is, if a Beam Failure Recovery (BFR) operation is performed to switch to a different beam whenever beam performance deteriorates due to high-speed movement, processing may become unnecessarily complex.

[0098] In contrast, when UEs utilize multiple beams for sidelink communication (820), they can more flexibly cope with the high-speed movement situation described above. That is, even if the PSCCH / PSSCH transmitted via beam #1 in a specific slot is not successfully transmitted, beam diversity gain can be secured via the PSCCH / PSSCH transmitted via beam #2 in the subsequent slot.

[0099] FIG. 9 is a drawing for explaining an example of configuring a TCI in slot units according to one embodiment of the present invention.

[0100] In the embodiment illustrated in Fig. 9, an example is shown in which TCI is configured in slot units, and TCI configuration is repeated at regular intervals.

[0101] Specifically, in the embodiment of FIG. 9, it is assumed that a signal (910) including AGC, PSCCH, PSSCH, and transmission gap is transmitted through one slot. That is, within one slot, PSCCH and PSSCH are transmitted simultaneously through the same TCI.

[0102] In the example of Fig. 9, the concept is illustrated in which TCI#1, TCI#2, TCI#3, and TCI#4 are allocated and used in slots #1, #2, #3, and #4, respectively, and such TCI configuration can be configured to be repeated in a cycle of 4 slot units.

[0103] In another embodiment of the present invention, when K TCI states are configured, n is set based on slot index n. k The kth TCI state can be set to be activated and utilized in a slot satisfying =mod(n,k). That is, the TCI state to be activated can be determined based on a modulo operation of a time unit (e.g., a slot).

[0104] In another embodiment of the present invention, one anchor TCI state and one or more candidate TCI states are configured, and the candidate TCIs can be activated on a slot-by-slot basis, as in the embodiments described above. That is, in this embodiment, the TCI can be utilized as a concept including a first TCI common to all slots and a second TCI additionally set for each slot.

[0105] The UE can transmit PSCCH / PSSCH according to the TCI state set according to the embodiments described above.

[0106] FIG. 10 is a drawing for explaining a transmission omission method of AGC according to one embodiment of the present invention.

[0107] In the embodiment of FIG. 10, slot #1 (910), which includes AGC, PSCCH, PSSCH, and transmission interval, may be transmitted via a beam indicated by TCI #1, similarly to FIG. 9. In addition, as described above with respect to FIG. 9, slot #2 (10100) is transmitted via a beam indicated by TCI #2, illustrating the concept of TCI being configured on a slot-by-slot basis.

[0108] However, it is proposed that the transmitting UE (Tx UE) according to the present embodiment is configured to omit (1020) AGC transmission in the transmission of slot #2 when beam #1 indicated by TCI #1 and beam #2 indicated by TCI #2 are similar.

[0109] For this AGC omission mechanism, it is desirable that TCI states capable of AGC omission be pre-configured for each TCI state.

[0110] In this way, when a combination of TCI states for applying the AGC omission mechanism is specified, the receiving UE (Rx UE) can process the beam used for PSCCH / PSSCH reception, assuming that AGC is omitted in the corresponding slot.

[0111]

[0112] FIG. 11 is a drawing for explaining a method of configuring a TCI in subslot units according to one embodiment of the present invention.

[0113] In the embodiment described above with reference to FIG. 6, the concept of setting TCI by time unit was presented, and the embodiment illustrated in FIG. 11 shows a case where such time unit corresponds to a sub-slot, each of which includes one or more symbols within a slot.

[0114] As shown in 1110, 1120, and 1130 of FIG. 11, two TCIs (TCI #1, TCI #2) can be applied per slot, and each TCI is applied in units of sub-slots.

[0115] That is, K TCI states are configured, and the kth TCI state can be configured to be applied to the kth subslot (symbol group). In this case, multiple beams may be used for PSCCH reception.

[0116] 1110 of FIG. 11 illustrates a case in which one PSCCH and one PSSCH are transmitted in one slot, similar to 720 of FIG. 7, but unlike 720 of FIG. 7, TCI is configured in units of sub-slots. That is, if two sub-slots are included in one slot, two TCI states can be applied to the slot.

[0117] 1120 of FIG. 11 illustrates the concept of additionally transmitting PSCCH in a subsequent subslot, unlike 1110, and also additionally transmitting AGC.

[0118] 1130 of FIG. 11 illustrates a case where different PSSCHs are transmitted in subslot units, and corresponding PSCCHs are also different. In other words, 1130 of FIG. 11 can be viewed as an embodiment where the time unit is replaced with a subslot rather than a slot.

[0119]

[0120] FIG. 12 is a drawing for specifically explaining the AGC addition concept in the embodiment of FIG. 11.

[0121] In the embodiment described with reference to Fig. 11, a concept in which TCI is configured in subslot units is proposed.

[0122] In such a case, AGC for subsequent subslot transmission may be additionally transmitted even within one slot, as illustrated in FIG. 12.

[0123] For such intra-slot AGC additional transmission, it is desirable to pre-configure the target to which AGC addition will be applied for each combination of TCI states. The configuration of the TCI state combination for such AGC additional transmission may be identical to the configuration of the TCI state combination for AGC omission described above.

[0124] For example, in the embodiment of FIG. 12, if beam #1 used in a preceding sub-slot and beam #2 used in a subsequent sub-slot are different by a predetermined standard or more, the UE may transmit AGC in the subsequent sub-slot as well, and it is preferable that the necessity of additional AGC transmission for combinations of TCI states be preset in the form of a table, taking into account the degree of difference between beams.

[0125] This TCI state combination table can be utilized in the same way for AGC omission as described above in Fig. 10. That is, when the difference between beams is below a predetermined standard, when AGC transmission is omitted in a subsequent slot, this AGC omission-capable TCI state combination table based on the similarity of beams can be utilized.

[0126]

[0127] FIG. 13 is a diagram for explaining a process of establishing a unicast link for performing direct communication between UEs according to one embodiment of the present invention.

[0128] Specifically, 9000 of FIG. 13 illustrates a process in which UE1 and UE2 perform initial beam pairing before establishing a unicast link. Additionally, 9500 of FIG. 13 illustrates a process in which UE1 and UE2 perform initial beam pairing after establishing a unicast link.

[0129] In both procedures 9000 and 9500 of FIG. 13, UE 1, which is a Tx UE, and UE 2, which is an Rx UE, can determine a destination ID for transmitting / receiving a DCR (Direct Communication Request) message (S9010, S9020, S9510, S9520).

[0130] For the initial beam pairing performed prior to unicast link establishment, at 9000 in FIG. 13, UE 1 can repeat the process of sweeping multiple beams and transmitting within a single symbol a predetermined number of times (S9030). UE 2, which receives a signal in which multiple beams within a slot are swept in this way, can fix the reception beam within a single slot, change the reception beam on a slot-by-slot basis, determine the reception beam that best pairs with the transmission beam of UE 1, and feed back information about the Tx beam to UE 1 (S9040).

[0131] Through beam pairing like this, UE 1 can transmit a corresponding DCR message to UE 2 (S9050).

[0132] Meanwhile, for the initial beam pairing performed after the unicast link is established, beam pairing can be performed in the form of UE 1 transmitting one beam per symbol at 9500 of FIG. 13 (S9030a to S9030d). When beam management is performed through RS transmission on a symbol-by-symbol basis in this way, processing may be delayed compared to the method of transmitting multiple beams in one symbol as in 9000 of FIG. 13. However, the beam sweeping target is narrowed through the beam configuration between UE 1 and UE 2 after the unicast link is established, thereby reducing the delay.

[0133] Through beam sweeping like this, UE 2SMS can transmit a feedback signal for the Tx beam to UE 1 (S9540).

[0134] Through the initial beam pairing procedure described above, the activation target of the TCI state and the slot-specific application target can be specified as described above in FIG. 6 and subsequent embodiments.

[0135]

[0136] Figure 14 illustrates a wireless device to which the present technology can be applied.

[0137] Referring to FIG. 14, the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals via various wireless access technologies (e.g., LTE, NR). Here, the first wireless device (100) and the second wireless device (200) can correspond to UE 1 and UE 2 of FIG. 6, respectively.

[0138] A first wireless device (100) includes one or more processors (102) and one or more memories (104), and may further include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memories (104) and / or the transceivers (106), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (102) may process information in the memory (104) to generate first information / signal, and then transmit a wireless signal including the first information / signal via the transceiver (106). In addition, the processor (102) may receive a wireless signal including second information / signal via the transceiver (106), and then store information obtained from signal processing of the second information / signal in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may perform some or all of the processes controlled by the processor (102), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE E-UTRA, 5G NR). The transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals via one or more antennas (108). The transceiver (106) may include a transmitter and / or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit. In the present invention, a wireless device may also mean a communication modem / circuit / chip.

[0139] The second wireless device (200) includes one or more processors (202), one or more memories (204), and may further include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memories (204) and / or the transceivers (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (202) may process information in the memory (204) to generate third information / signals, and then transmit a wireless signal including the third information / signals via the transceivers (206). In addition, the processor (202) may receive a wireless signal including fourth information / signals via the transceivers (206), and then store information obtained from signal processing of the fourth information / signals in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may store software code including commands for performing some or all of the processes controlled by the processor (202) or performing the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed in this document. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE E-UTRA, 5G NR). The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via one or more antennas (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF unit. In the present invention, a wireless device may also mean a communication modem / circuit / chip.

[0140] Hereinafter, the hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and / or methods disclosed herein, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein.

[0141] One or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software configured to perform one or more processors (102, 202) or stored in one or more memories (104, 204) and executed by one or more processors (102, 202). The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions.

[0142] One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. The one or more memories (104, 204) may be configured as ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. The one or more memories (104, 204) may be located internally and / or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

[0143] One or more transceivers (106, 206) can transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or flowcharts of this document, to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts of this document, from one or more other devices. For example, one or more transceivers (106, 206) can be connected to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be coupled to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, or the like, as referred to in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein, via one or more antennas (108, 208). In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using one or more processors (102, 202).One or more transceivers (106, 206) may convert user data, control information, wireless signals / channels, etc. processed by one or more processors (102, 202) from baseband signals to RF band signals. For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or filter.

[0144]

[0145] The detailed description of the preferred embodiments of the present invention disclosed above has been provided to enable those skilled in the art to implement and practice the present invention. While the above description has been made with reference to preferred embodiments of the present invention, those skilled in the art will appreciate that various modifications and variations can be made to the present invention without departing from the scope of the present invention. For example, those skilled in the art can utilize the individual components described in the above-described embodiments in combination with each other.

[0146] Accordingly, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0147] The communication method through a direct communication link according to the embodiments of the present invention as described above and the user device therefor are suitable for use in a sidelink communication environment discussed in 3GPP, but can also be widely used for beam management between UEs in communication methods other than 3GPP.

Claims

1. In a method for performing communication between a first user equipment (UE) and a second UE through a direct communication link in a mobile communication system, Transmitting a physical control channel to the second UE through the direct communication link; Including transmitting a physical shared channel corresponding to the above physical control channel through the above direct communication link, The above physical control channel and the above physical shared channel are transmitted through a beam indicated by the same indicator in the same time unit, The above physical control channel and the above physical shared channel are transmitted through a beam corresponding to the indicator set for each time unit. Communication method.

2. In paragraph 1, A plurality of beams are configured for transmission of the above physical control channel and the above physical shared channel, Transmitting the physical control channel and the physical shared channel through one beam corresponding to the indicator set for each time unit among the plurality of beams. Communication method.

3. In paragraph 1, The above indicator is set to repeat at a predetermined cycle of the above time unit, Communication method.

4. In paragraph 1, The above indicator is set through an index-based modulo operation of the above time unit, Communication method.

5. In paragraph 1, The above instructions are, A first indicator common to the entire time unit, and Including a second indicator additionally set to the first indicator for each time unit, Communication method.

6. In paragraph 1, In addition, it includes selectively transmitting a repetitive signal for improving reception performance of at least one of the physical control channel and the physical shared channel through the first symbol within the time unit, The first UE is configured to omit the repetitive signal transmission in the second time unit based on the similarity between the first beam used in the first time unit among the time units and the second beam used in the second time unit. Communication method.

7. In paragraph 1, The above time unit corresponds to a slot, The above indicator corresponds to the Transmission Configuration Indicator (TCI). Communication method.

8. In paragraph 1, The above time unit corresponds to a sub-slot, each of which contains one or more symbols within the slot, The above indicator corresponds to the Transmission Configuration Indicator (TCI). Communication method.

9. In paragraph 8, One physical shared channel and multiple physical control channels are transmitted per the slot. Communication method.

10. In paragraph 8, When the TCI is set in the sub-slot unit, AGC (Automatic Gain Control) is transmitted in the sub-slot unit. Communication method.

11. In paragraph 1, The above physical control channel includes a PSCCH (Physical Sidelink Control Channel), The above physical shared channel includes PSSCH (Physical Sidelink Shared Channel). Communication method.

12. In a mobile communication system, a method for a second user equipment (UE) to perform communication with a first UE through a direct communication link, From the first UE, receive a physical control channel through the direct communication link; Including receiving a physical shared channel corresponding to the above physical control channel through the above direct communication link, The above physical control channel and the above physical shared channel are received through a beam indicated by the same indicator in the same time unit, The above physical control channel and the above physical shared channel are received through a beam corresponding to the indicator set for each time unit. Communication method.

13. In paragraph 12, In addition, it includes selectively receiving a repetitive signal for improving reception performance of one or more of the physical control channel and the physical shared channel through the first symbol within the time unit, The second UE is configured to process the physical control channel and the physical shared channel based on the similarity between the first beam used in the first time unit among the time units and the second beam used in the second time unit, assuming that the repetitive signal is not received in the second time unit. Communication method.

14. In a mobile communication system, a first user equipment (UE) that performs communication through a direct communication link with a second user equipment (UE), at least one processor; and At least one computer memory operably connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations; The above actions are, Transmitting a physical control channel to the second UE through the direct communication link; Including transmitting a physical shared channel corresponding to the above physical control channel through the above direct communication link, The above physical control channel and the above physical shared channel are transmitted through a beam indicated by the same indicator in the same time unit, A user device in which the above physical control channel and the above physical shared channel are transmitted through a beam corresponding to the indicator set for each time unit.

Images