Patent Application
20250220605
This disclosure relates to a wireless communication system.
Sidelink (SL) communication is a communication scheme in which a direct link is established between User Equipments (UEs) and the UEs exchange voice and data directly with each other without intervention of an evolved Node B (eNB). SL communication is under consideration as a solution to the overhead of an eNB caused by rapidly increasing data traffic. Vehicle-to-everything (V2X) refers to a communication technology through which a vehicle exchanges information with another vehicle, a pedestrian, an entity having an infrastructure (or infra) established therein, and so on. The V2X may be spread into 4 types, such as vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-network (V2N), and vehicle-to-pedestrian (V2P). The V2X communication may be provided via a PC5 interface and/or Uu interface.
Meanwhile, as a wider range of communication devices require larger communication capacities, the need for mobile broadband communication that is more enhanced than the existing Radio Access Technology (RAT) is rising. Accordingly, discussions are made on services and user equipment (UE) that are sensitive to reliability and latency. And, a next generation radio access technology that is based on the enhanced mobile broadband communication, massive Machine Type Communication (MTC), Ultra-Reliable and Low Latency Communication (URLLC), and so on, may be referred to as a new radio access technology (RAT) or new radio (NR). Vehicle-to-everything (V2X) communication may also be supported in NR.
According to an embodiment of the present disclosure, a method for performing, by a first device, wireless communication may be proposed. For example, the method may comprise: obtaining sidelink (SL) synchronization priority order information configured as global navigation satellite system (GNSS)-based synchronization or based station-based synchronization: selecting at least one synchronization reference, based on the SL synchronization priority order information: obtaining time synchronization from the at least one synchronization reference; and transmitting a sidelink synchronization signal block (S-SSB) including a physical sidelink broadcast channel (PSBCH), a sidelink primary synchronization signal (S-PSS), and a sidelink secondary synchronization signal (S-SSS), on an unlicensed band, based on the time synchronization.
According to an embodiment of the present disclosure, a first device performing wireless communication may be proposed. For example, the first device may comprise: at least one transceiver; at least one processor; and at least one memory operably connected to the at least one processor and storing instructions. For example, the instructions, based on being executed by the at least one processor, may cause the first device to perform operations. For example, the operations may comprise: obtaining sidelink (SL) synchronization priority order information configured as global navigation satellite system (GNSS)-based synchronization or based station-based synchronization: selecting at least one synchronization reference, based on the SL synchronization priority order information: obtaining time synchronization from the at least one synchronization reference; and transmitting a sidelink synchronization signal block (S-SSB) including a physical sidelink broadcast channel (PSBCH), a sidelink primary synchronization signal (S-PSS), and a sidelink secondary synchronization signal (S-SSS), on an unlicensed band, based on the time synchronization.
According to an embodiment of the present disclosure, a device adapted to control a first user equipment (UE) may be proposed. For example, the device may comprise: at least one processor; and at least one memory operably connected to the at least one processor and storing instructions. For example, the instructions, based on being executed by the at least one processor, may cause the first UE to perform operations. For example, the operations may comprise: obtaining sidelink (SL) synchronization priority order information configured as global navigation satellite system (GNSS)-based synchronization or based station-based synchronization: selecting at least one synchronization reference, based on the SL synchronization priority order information: obtaining time synchronization from the at least one synchronization reference; and transmitting a sidelink synchronization signal block (S-SSB) including a physical sidelink broadcast channel (PSBCH), a sidelink primary synchronization signal (S-PSS), and a sidelink secondary synchronization signal (S-SSS), on an unlicensed band, based on the time synchronization.
According to an embodiment of the present disclosure, a non-transitory computer-readable storage medium storing instructions may be proposed. For example, the instructions, based on being executed, may cause a first device to: obtain sidelink (SL) synchronization priority order information configured as global navigation satellite system (GNSS)-based synchronization or based station-based synchronization: select at least one synchronization reference, based on the SL synchronization priority order information; obtain time synchronization from the at least one synchronization reference; and transmit a sidelink synchronization signal block (S-SSB) including a physical sidelink broadcast channel (PSBCH), a sidelink primary synchronization signal (S-PSS), and a sidelink secondary synchronization signal (S-SSS), on an unlicensed band, based on the time synchronization.
According to an embodiment of the present disclosure, a method for performing, by a second device, wireless communication may be proposed. For example, the method may comprise: receiving, from a first device, a sidelink synchronization signal block (S-SSB) including a physical sidelink broadcast channel (PSBCH), a sidelink primary synchronization signal (S-PSS), and a sidelink secondary synchronization signal (S-SSS), on an unlicensed band, wherein the S-SSB is transmitted by the first device based on time synchronization obtained from at least one synchronization reference, wherein the at least one synchronization reference may be selected by the first device based on a sidelink (SL) synchronization priority order information, wherein the SL synchronization priority order information may be configured as global navigation satellite system (GNSS)-based synchronization or based station-based synchronization.
According to an embodiment of the present disclosure, a second device performing wireless communication may be proposed. For example, the second device may comprise: at least one transceiver: at least one processor; and at least one memory operably connected to the at least one processor and storing instructions. For example, the instructions, based on being executed by the at least one processor, may cause the second device to perform operations. For example, the operations may comprise: receiving, from a first device, a sidelink synchronization signal block (S-SSB) including a physical sidelink broadcast channel (PSBCH), a sidelink primary synchronization signal (S-PSS), and a sidelink secondary synchronization signal (S-SSS), on an unlicensed band, wherein the S-SSB may be transmitted by the first device based on time synchronization obtained from at least one synchronization reference, wherein the at least one synchronization reference may be selected by the first device based on a sidelink (SL) synchronization priority order information, wherein the SL synchronization priority order information may be configured as global navigation satellite system (GNSS)-based synchronization or based station-based synchronization.
The user equipment (UE) may efficiently perform SL communication.
In the present disclosure, “A or B” may mean “only A”, “only B” or “both A and B.” In other words, in the present disclosure, “A or B” may be interpreted as “A and/or B”. For example, in the present disclosure, “A, B, or C” may mean “only A”, “only B”, “only C”, or “any combination of A, B, C”.
A slash (/) or comma used in the present disclosure may mean “and/or”. For example, “A/B” may mean “A and/or B”. Accordingly, “A/B” may mean “only A”, “only B”, or “both A and B”. For example, “A, B, C” may mean “A, B, or C”.
In the present disclosure, “at least one of A and B” may mean “only A”, “only B”, or “both A and B”. In addition, in the present disclosure, the expression “at least one of A or B” or “at least one of A and/or B” may be interpreted as “at least one of A and B”.
In addition, in the present disclosure, “at least one of A, B, and C” may mean “only A”, “only B”, “only C”, or “any combination of A, B, and C”. In addition, “at least one of A, B, or C” or “at least one of A, B, and/or C” may mean “at least one of A, B, and C”.
In addition, a parenthesis used in the present disclosure may mean “for example”. Specifically, when indicated as “control information (PDCCH)”, it may mean that “PDCCH” is proposed as an example of the “control information”. In other words, the “control information” of the present disclosure is not limited to “PDCCH”, and “PDCCH” may be proposed as an example of the “control information”. In addition, when indicated as “control information (i.e., PDCCH)”, it may also mean that “PDCCH” is proposed as an example of the “control information”.
In the following description, ‘when, if, or in case of may be replaced with ‘based on’.
A technical feature described individually in one figure in the present disclosure may be individually implemented, or may be simultaneously implemented.
In the present disclosure, a higher layer parameter may be a parameter which is configured, pre-configured or pre-defined for a UE. For example, a base station or a network may transmit the higher layer parameter to the UE. For example, the higher layer parameter may be transmitted through radio resource control (RRC) signaling or medium access control (MAC) signaling.
The technology described below may be used in various wireless communication systems such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and so on. The CDMA may be implemented with a radio technology, such as universal terrestrial radio access (UTRA) or CDMA-2000. The TDMA may be implemented with a radio technology, such as global system for mobile communications (GSM)/general packet ratio service (GPRS)/enhanced data rate for GSM evolution (EDGE). The OFDMA may be implemented with a radio technology, such as institute of electrical and electronics engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, evolved UTRA (E-UTRA), and so on. IEEE 802.16m is an evolved version of IEEE 802.16e and provides backward compatibility with a system based on the IEEE 802.16e. The UTRA is part of a universal mobile telecommunication system (UMTS). 3rd generation partnership project (3GPP) long term evolution (LTE) is part of an evolved UMTS (E-UMTS) using the E-UTRA. The 3GPP LTE uses the OFDMA in a downlink and uses the SC-FDMA in an uplink. LTE-advanced (LTE-A) is an evolution of the LTE.
5G NR is a successive technology of LTE-A corresponding to a new Clean-slate type mobile communication system having the characteristics of high performance, low latency, high availability, and so on. 5G NR may use resources of all spectrum available for usage including low frequency bands of less than 1 GHz, middle frequency bands ranging from 1 GHz to 10 GHz, high frequency (millimeter waves) of 24 GHz or more, and so on.
For the sake of clarity, the description focuses on 5G NR, but the technical ideas of one embodiment of the present disclosure are not limited thereto.
For terms and techniques used herein that are not specifically described, reference may be made to wireless communication standards documents published prior to the filing of this specification.
Referring to
The embodiment of
Layers of a radio interface protocol between the UE and the network can be classified into a first layer (layer 1, L1), a second layer (layer 2, L2), and a third layer (layer 3, L3) based on the lower three layers of the open system interconnection (OSI) model that is well-known in the communication system. Among them, a physical (PHY) layer belonging to the first layer provides an information transfer service by using a physical channel, and a radio resource control (RRC) layer belonging to the third layer serves to control a radio resource between the UE and the network. For this, the RRC layer exchanges an RRC message between the UE and the BS.
Referring to
Between different physical layers, i.e., a physical layer of a transmitter and a physical layer of a receiver, data are transferred through the physical channel. The physical channel is modulated using an orthogonal frequency division multiplexing (OFDM) scheme, and utilizes time and frequency as a radio resource.
The MAC layer provides services to a radio link control (RLC) layer, which is a higher layer of the MAC layer, via a logical channel. The MAC layer provides a function of mapping multiple logical channels to multiple transport channels. The MAC layer also provides a function of logical channel multiplexing by mapping multiple logical channels to a single transport channel. The MAC layer provides data transfer services over logical channels.
The RLC layer performs concatenation, segmentation, and reassembly of Radio Link Control Service Data Unit (RLC SDU). In order to ensure diverse quality of service (Qos) required by a radio bearer (RB), the RLC layer provides three types of operation modes, i.e., a transparent mode (TM), an unacknowledged mode (UM), and an acknowledged mode (AM). An AM RLC provides error correction through an automatic repeat request (ARQ).
A radio resource control (RRC) layer is defined only in the control plane. The RRC layer serves to control the logical channel, the transport channel, and the physical channel in association with configuration, reconfiguration and release of RBs. The RB is a logical path provided by the first layer (i.e., the physical layer or the PHY layer) and the second layer (i.e., a MAC layer, an RLC layer, a packet data convergence protocol (PDCP) layer, and a service data adaptation protocol (SDAP) layer) for data delivery between the UE and the network.
Functions of a packet data convergence protocol (PDCP) layer in the user plane include user data delivery, header compression, and ciphering. Functions of a PDCP layer in the control plane include control-plane data delivery and ciphering/integrity protection.
A service data adaptation protocol (SDAP) layer is defined only in a user plane. The SDAP layer performs mapping between a Quality of Service (QOS) flow and a data radio bearer (DRB) and QoS flow ID (QFI) marking in both DL and UL packets.
The configuration of the RB implies a process for specifying a radio protocol layer and channel properties to provide a particular service and for determining respective detailed parameters and operations. The RB can be classified into two types, i.e., a signaling RB (SRB) and a data RB (DRB). The SRB is used as a path for transmitting an RRC message in the control plane. The DRB is used as a path for transmitting user data in the user plane.
When an RRC connection is established between an RRC layer of the UE and an RRC layer of the E-UTRAN, the UE is in an RRC_CONNECTED state, and, otherwise, the UE may be in an RRC_IDLE state. In case of the NR, an RRC_INACTIVE state is additionally defined, and a UE being in the RRC_INACTIVE state may maintain its connection with a core network whereas its connection with the BS is released.
Data is transmitted from the network to the UE through a downlink transport channel. Examples of the downlink transport channel include a broadcast channel (BCH) for transmitting system information and a downlink-shared channel (SCH) for transmitting user traffic or control messages. Traffic of downlink multicast or broadcast services or the control messages can be transmitted on the downlink-SCH or an additional downlink multicast channel (MCH). Data is transmitted from the UE to the network through an uplink transport channel. Examples of the uplink transport channel include a random access channel (RACH) for transmitting an initial control message and an uplink SCH for transmitting user traffic or control messages.
Examples of logical channels belonging to a higher channel of the transport channel and mapped onto the transport channels include a broadcast channel (BCCH), a paging control channel (PCCH), a common control channel (CCCH), a multicast control channel (MCCH), a multicast traffic channel (MTCH), etc.
Referring to
In case of using a normal CP, each slot may include 14 symbols. In case of using an extended CP, each slot may include 12 symbols. Herein, a symbol may include an OFDM symbol (or CP-OFDM symbol) and a Single Carrier-FDMA (SC-FDMA) symbol (or Discrete Fourier Transform-spread-OFDM (DFT-s-OFDM) symbol).
The following Table 1 shows the number of symbols per slot (Nslotsymb), the number of slots per frame (Nframe,uslot), and the number of slots per subframe (Nsubframe,uslot), according to an SCS configuration (u), when Normal CP is used.
Table 2 shows the number of symbols per slot, the number of slots per frame and the number of slots per subframe according to SCS, when Extended CP is used.
In an NR system, OFDM (A) numerologies (e.g., SCS, CP length, and so on) between multiple cells being integrate to one UE may be differently configured. Accordingly, a (absolute time) duration (or section) of a time resource (e.g., subframe, slot or TTI) (collectively referred to as a time unit (TU) for simplicity) being configured of the same number of symbols may be differently configured in the integrated cells.
In the NR, multiple numerologies or SCSs for supporting diverse 5G services may be supported. For example, in case an SCS is 15 kHz, a wide area of the conventional cellular bands may be supported, and, in case an SCS is 30 kHz/60 kHz a dense-urban, lower latency, wider carrier bandwidth may be supported. In case the SCS is 60 kHz or higher, a bandwidth that is greater than 24.25 GHz may be used in order to overcome phase noise.
An NR frequency band may be defined as two different types of frequency ranges. The two different types of frequency ranges may be FRI and FR2. The values of the frequency ranges may be changed (or varied), and, for example, the two different types of frequency ranges may be as shown below in Table 3. Among the frequency ranges that are used in an NR system, FRI may mean a “sub 6 GHz range”, and FR2 may mean an “above 6 GHz range” and may also be referred to as a millimeter wave (mmW).
As described above, the values of the frequency ranges in the NR system may be changed (or varied). For example, as shown below in Table 4, FRI may include a band within a range of 410 MHz to 7125 MHz. More specifically, FRI may include a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, and so on) and higher. For example, a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, and so on) and higher being included in FRI mat include an unlicensed band. The unlicensed band may be used for diverse purposes, e.g., the unlicensed band for vehicle-specific communication (e.g., automated driving).
Referring to
A carrier includes a plurality of subcarriers in a frequency domain. A Resource Block (RB) may be defined as a plurality of consecutive subcarriers (e.g., 12 subcarriers) in the frequency domain. A Bandwidth Part (BWP) may be defined as a plurality of consecutive (Physical) Resource Blocks ((P) RBs) in the frequency domain, and the BWP may correspond to one numerology (e.g., SCS, CP length, and so on). A carrier may include a maximum of N number BWPs (e.g., 5 BWPs). Data communication may be performed via an activated BWP. Each element may be referred to as a Resource Element (RE) within a resource grid and one complex symbol may be mapped to each element.
Hereinafter, a bandwidth part (BWP) and a carrier will be described.
The BWP may be a set of consecutive physical resource blocks (PRBs) in a given numerology. The PRB may be selected from consecutive sub-sets of common resource blocks (CRBs) for the given numerology on a given carrier
For example, the BWP may be at least any one of an active BWP, an initial BWP, and/or a default BWP. For example, the UE may not monitor downlink radio link quality in a DL BWP other than an active DL BWP on a primary cell (PCell). For example, the UE may not receive PDCCH, physical downlink shared channel (PDSCH), or channel state information-reference signal (CSI-RS) (excluding RRM) outside the active DL BWP. For example, the UE may not trigger a channel state information (CSI) report for the inactive DL BWP. For example, the UE may not transmit physical uplink control channel (PUCCH) or physical uplink shared channel (PUSCH) outside an active UL BWP. For example, in a downlink case, the initial BWP may be given as a consecutive RB set for a remaining minimum system information (RMSI) control resource set (CORESET) (configured by physical broadcast channel (PBCH)). For example, in an uplink case, the initial BWP may be given by system information block (SIB) for a random access procedure. For example, the default BWP may be configured by a higher layer. For example, an initial value of the default BWP may be an initial DL BWP. For energy saving, if the UE fails to detect downlink control information (DCI) during a specific period, the UE may switch the active BWP of the UE to the default BWP.
Meanwhile, the BWP may be defined for SL. The same SL BWP may be used in transmission and reception. For example, a transmitting UE may transmit an SL channel or an SL signal on a specific BWP, and a receiving UE may receive the SL channel or the SL signal on the specific BWP. In a licensed carrier, the SL BWP may be defined separately from a Uu BWP, and the SL BWP may have configuration signaling separate from the Uu BWP. For example, the UE may receive a configuration for the SL BWP from the BS/network. For example, the UE may receive a configuration for the Uu BWP from the BS/network. The SL BWP may be (pre-) configured in a carrier with respect to an out-of-coverage NR V2X UE and an RRC_IDLE UE. For the UE in the RRC_CONNECTED mode, at least one SL BWP may be activated in the carrier.
Referring to
The BWP may be configured by a point A, an offset NstartBWP from the point A, and a bandwidth NsizeBWP. For example, the point A may be an external reference point of a PRB of a carrier in which a subcarrier 0 of all numerologies (e.g., all numerologies supported by a network on that carrier) is aligned. For example, the offset may be a PRB interval between a lowest subcarrier and the point A in a given numerology. For example, the bandwidth may be the number of PRBs in the given numerology.
Hereinafter, V2X or SL communication will be described.
A sidelink synchronization signal (SLSS) may include a primary sidelink synchronization signal (PSSS) and a secondary sidelink synchronization signal (SSSS), as an SL-specific sequence. The PSSS may be referred to as a sidelink primary synchronization signal (S-PSS), and the SSSS may be referred to as a sidelink secondary synchronization signal (S-SSS). For example, length-127 M-sequences may be used for the S-PSS, and length-127 gold sequences may be used for the S-SSS. For example, a UE may use the S-PSS for initial signal detection and for synchronization acquisition. For example, the UE may use the S-PSS and the S-SSS for acquisition of detailed synchronization and for detection of a synchronization signal ID.
A physical sidelink broadcast channel (PSBCH) may be a (broadcast) channel for transmitting default (system) information which must be first known by the UE before SL signal transmission/reception. For example, the default information may be information related to SLSS, a duplex mode (DM), a time division duplex (TDD) uplink/downlink (UL/DL) configuration, information related to a resource pool, a type of an application related to the SLSS, a subframe offset, broadcast information, or the like. For example, for evaluation of PSBCH performance, in NR V2X, a payload size of the PSBCH may be 56 bits including 24-bit cyclic redundancy check (CRC).
The S-PSS, the S-SSS, and the PSBCH may be included in a block format (e.g., SL synchronization signal (SS)/PSBCH block, hereinafter, sidelink-synchronization signal block (S-SSB)) supporting periodical transmission. The S-SSB may have the same numerology (i.e., SCS and CP length) as a physical sidelink control channel (PSCCH)/physical sidelink shared channel (PSSCH) in a carrier, and a transmission bandwidth may exist within a (pre-) configured sidelink (SL) BWP. For example, the S-SSB may have a bandwidth of 11 resource blocks (RBs). For example, the PSBCH may exist across 11 RBs. In addition, a frequency position of the S-SSB may be (pre-) configured. Accordingly, the UE does not have to perform hypothesis detection at frequency to discover the S-SSB in the carrier.
For example, (a) of
For example, (b) of
Referring to (a) of
For example, the first UE may receive information related to dynamic grant (DG) resource(s) and/or information related to configured grant (CG) resource(s) from the base station. For example, the CG resource(s) may include CG type 1 resource(s) or CG type 2 resource(s). In the present disclosure, the DG resource(s) may be resource(s) configured/allocated by the base station to the first UE through a downlink control information (DCI). In the present disclosure, the CG resource(s) may be (periodic) resource(s) configured/allocated by the base station to the first UE through a DCI and/or an RRC message. For example, in the case of the CG type 1 resource(s), the base station may transmit an RRC message including information related to CG resource(s) to the first UE. For example, in the case of the CG type 2 resource(s), the base station may transmit an RRC message including information related to CG resource(s) to the first UE, and the base station may transmit a DCI related to activation or release of the CG resource(s) to the first UE.
In step S610, the first UE may transmit a PSCCH (e.g., sidelink control information (SCI) or 1st-stage SCI) to a second UE based on the resource scheduling. In step S620, 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 S630, the first UE may receive a PSFCH 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 through the PSFCH. In step S640, the first UE may transmit/report HARQ feedback information to the base station through the PUCCH or the 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. For example, the HARQ feedback information reported to the base station may be information generated by the first UE based on a pre-configured rule. For example, the DCI may be a DCI for SL scheduling. For example, a format of the DCI may be a DCI format 3_0 or a DCI format 3_1.
Referring to (b) of
Referring to (a) or (b) of
Hereinafter, an example of SCI format 1-A will be described.
SCI format 1-A is used for the scheduling of PSSCH and 2nd-stage-SCI on PSSCH.
The following information is transmitted by means of the SCI format 1-A:
Hereinafter, an example of SCI format 2-A will be described.
SCI format 2-A is used for the decoding of PSSCH, with HARQ operation when HARQ-ACK information includes ACK or NACK, when HARQ-ACK information includes only NACK, or when there is no feedback of HARQ-ACK information.
The following information is transmitted by means of the SCI format 2-A:
Hereinafter, an example of SCI format 2-B will be described.
SCI format 2-B is used for the decoding of PSSCH, with HARQ operation when HARQ-ACK information includes only NACK, or when there is no feedback of HARQ-ACK information.
The following information is transmitted by means of the SCI format 2-B:
Referring to (a) or (b) of
Referring to (a) of
Hereinafter, a UE procedure for determining a subset of resources to be reported to an higher layer in PSSCH resource selection in sidelink resource allocation mode 2 will be described.
In resource allocation mode 2, the higher layer can request the UE to determine a subset of resources from which the higher layer will select resources for PSSCH/PSCCH transmission. To trigger this procedure, in slot n, the higher layer provides the following parameters for this PSSCH/PSCCH transmission:
The following higher layer parameters affect this procedure:
sl-SelectionWindowList: internal parameter T2 min is set to the corresponding value from higher layer parameter sl-SelectionWindowList for the given value of prioTX.
The resource reservation interval, Prsvp_TX, if provided, is converted from units of msec to units of logical slots, resulting in Prsvp_TX′.
(t′0SL, t′1SL, t′2SL, . . . ) may denote the set of slots which belongs to the sidelink resource pool.
For example, a UE may select a set of candidate resources (Sa) based on Table 8. For example, when resource (re) selection is triggered, a UE may select a candidate resource set (Sa) based on Table 8. For example, when re-evaluation or pre-emption is triggered, a UE may select a candidate resource set (Sa) based on Table 8.
Meanwhile, in the conventional unlicensed spectrum (NR-U), a communication method between a UE and a base station is supported in an unlicensed band. In addition, a mechanism for supporting communication in an unlicensed band between sidelink UEs is planned to be supported in Rel-18.
In the present disclosure, a channel may refer to a set of frequency domain resources in which Listen-Before-Talk (LBT) is performed. In NR-U, the channel may refer to an LBT bandwidth with 20 MHz and may have the same meaning as an RB set. For example, the RB set may be defined in section 7 of 3GPP TS 38.214 V17.0.0.
For example, an RB set may be a basic unit which is a target of a channel sensing operation. For example, the channel sensing operation may include a listen before talk (LBT) operation.
For example, an RB set may be a basic unit which is a target of a channel sensing operation. For example, the channel sensing operation may include a listen before talk (LBT) operation.
For example, an RB set may be a basic unit which is a target of a channel sensing operation. For example, the channel sensing operation may include a listen before talk (LBT) operation.
In the present disclosure, channel occupancy (CO) may refer to time/frequency domain resources obtained by the base station or the UE after LBT success.
In the present disclosure, channel occupancy time (COT) may refer to time domain resources obtained by the base station or the UE after LBT success. It may be shared between the base station (or the UE) and the UE (or the base station) that obtained the CO, and this may be referred to as COT sharing. Depending on the initiating device, this may be referred to as gNB-initiated COT or UE-initiated COT.
Hereinafter, a wireless communication system supporting an unlicensed band/shared spectrum will be described.
In the following description, a cell operating in a licensed band (hereinafter, L-band) may be defined as an L-cell, and a carrier of the L-cell may be defined as a (DL/UL/SL) LCC. In addition, a cell operating in an unlicensed band (hereinafter, U-band) may be defined as a U-cell, and a carrier of the U-cell may be defined as a (DL/UL/SL) UCC. The carrier/carrier-frequency of a cell may refer to the operating frequency (e.g., center frequency) of the cell. A cell/carrier (e.g., CC) is commonly called a cell.
When the base station and the UE transmit and receive signals on carrier-aggregated LCC and UCC as shown in (a) of
Unless otherwise noted, the definitions below are applicable to the following terminologies used in the present disclosure.
Referring to
Table 9 shows an example of the channel access procedure (CAP) supported in NR-U.
Referring to Table 9, the LBT type or CAP for DL/UL/SL transmission may be defined. However, Table 9 is only an example, and a new type or CAP may be defined in a similar manner. For example, the type 1 (also referred to as Cat-4 LBT) may be a random back-off based channel access procedure. For example, in the case of Cat-4, the contention window may change. For example, the type 2 can be performed in case of COT sharing within COT acquired by the base station (gNB) or the UE.
Hereinafter, LBT-SubBand (SB) (or RB set) will be described.
In a wireless communication system supporting an unlicensed band, one cell (or carrier (e.g., CC)) or BWP configured for the UE may have a wideband having a larger bandwidth (BW) than in legacy LTE. However, a BW requiring CCA based on an independent LBT operation may be limited according to regulations. Let a subband (SB) in which LBT is individually performed be defined as an LBT-SB. Then, a plurality of LBT-SBs may be included in one wideband cell/BWP. A RB set included in an LBT-SB may be configured by higher-layer (e.g., RRC) signaling. Accordingly, one or more LBT-SBs may be included in one cell/BWP based on (i) the BW of the cell/BWP and (ii) RB set allocation information.
Referring to
Hereinafter, a channel access priority class (CAPC) will be described.
The CAPCs of MAC CEs and radio bearers may be fixed or configured to operate in FR1:
When selecting a CAPC of a DRB, the base station considers fairness between other traffic types and transmissions while considering 5QI of all QoS flows multiplexed to the corresponding DRB. Table 10 shows which CAPC should be used for standardized 5QI, that is, a CAPC to be used for a given QoS flow. For standardized 5QI, CAPCs are defined as shown in the table below, and for non-standardized 5QI, the CAPC with the best Qos characteristics should be used.
Hereinafter, a method of transmitting a downlink signal through an unlicensed band will be described. For example, a method of transmitting a downlink signal through an unlicensed band may be applied to a method of transmitting a sidelink signal through an unlicensed band.
The base station may perform one of the following channel access procedures (e.g., CAP) for downlink signal transmission in an unlicensed band.
In the type 1 DL CAP, the length of a time duration spanned by sensing slots sensed to be idle before transmission(s) may be random. The type 1 DL CAP may be applied to the following transmissions:
Referring to
Table 11 shows that mp, a minimum contention window (CW), a maximum CW, a maximum channel occupancy time (MCOT), and an allowed CW size, which are applied to the CAP, vary depending on channel access priority classes.
Referring to Table 12, a contention window size (CWS), a maximum COT value, etc. for each CAPC may be defined. For example, Td may be equal to Tf+mp*Tsl (Td=Tf+mp*Tsl).
The defer duration Td is configured in the following order: duration Tf (16 us)+mp consecutive sensing slot durations Tsl (9 us). Tf includes the sensing slot duration Tsl at the beginning of the 16 us duration.
The following relationship is satisfied: CWmin,p<=CWp<=CWmax,p. CWp may be configured by CWp=CWmin,p and updated before step 1 based on HARQ-ACK feedback (e.g., the ratio of ACK or NACK) for a previous DL burst (e.g., PDSCH) (CW size update). For example, CWp may be initialized to CWmin,p based on the HARQ-ACK feedback for the previous DL burst. Alternatively, CWp may be increased to the next higher allowed value or maintained as it is.
In the type 2 DL CAP, the length of a time duration spanned by sensing slots sensed to be idle before transmission(s) may be determined. The type 2 DL CAP is classified into type 2A/2B/2C DL CAPs.
The type 2A DL CAP may be applied to the following transmissions. In the type 2A DL CAP, the base station may perform transmission immediately after the channel is sensed to be idle at least for a sensing duration Tshort_dl=25 us. Herein, Tshort_dl includes the duration Tf (=16 us) and one sensing slot duration immediately after the duration Tf, where the duration Tf includes a sensing slot at the beginning thereof.
The type 2B DL CAP is applicable to transmission(s) performed by the base station after a gap of 16 us from transmission(s) by the UE within a shared channel occupancy time. In the type 2B DL CAP, the base station may perform transmission immediately after the channel is sensed to be idle for Tf=16 us. Tf includes a sensing slot within 9 us from the end of the duration. The type 2C DL CAP is applicable to transmission(s) performed by the base station after a maximum of 16 us from transmission(s) by the UE within the shared channel occupancy time. In the type 2C DL CAP, the base station does not perform channel sensing before performing transmission.
Hereinafter, a method of transmitting an uplink signal through an unlicensed band will be described. For example, a method of transmitting an uplink signal through an unlicensed band may be applied to a method of transmitting a sidelink signal through an unlicensed band.
The UE may perform type 1 or type 2 CAP for UL signal transmission in an unlicensed band. In general, the UE may perform the CAP (e.g., type 1 or type 2) configured by the base station for UL signal transmission. For example, a UL grant scheduling PUSCH transmission (e.g., DCI formats 0_0 and 0_1) may include CAP type indication information for the UE.
In the type 1 UL CAP, the length of a time duration spanned by sensing slots sensed to be idle before transmission(s) is random. The type 1 UL CAP may be applied to the following transmissions.
Referring to
Table 12 shows that mp, a minimum CW, a maximum CW, a maximum channel occupancy time (MCOT), and an allowed CW size, which are applied to the CAP, vary depending on channel access priority classes.
Referring to Table 12, a contention window size (CWS), a maximum COT value, etc. for each CAPC may be defined. For example, Td may be equal to Tf+mp*Tsl (Td=Tf+mp*Tsl).
The defer duration Td is configured in the following order: duration Tf (16 us)+mp consecutive sensing slot durations Tsl (9 us). Tf includes the sensing slot duration Tsl at the beginning of the 16 us duration.
The following relationship is satisfied: CWmin,p<=CWp<=CWmax,p. CWp may be configured by CWp=CWmin,p and updated before step 1 based on an explicit/implicit reception response for a previous UL burst (e.g., PUSCH) (CW size update). For example, CWp may be initialized to CWmin,p based on the explicit/implicit reception response for the previous UL burst. Alternatively, CWp may be increased to the next higher allowed value or maintained as it is.
In the type 2 UL CAP, the length of a time duration spanned by sensing slots sensed to be idle before transmission(s) may be determined. The type 2 UL CAP is classified into type 2A/2B/2C UL CAPs. In the type 2A UL CAP, the UE may perform transmission immediately after the channel is sensed to be idle at least for a sensing duration Tshort_dl=25 us. Herein, Tshort_dl includes the duration Tf (=16 us) and one sensing slot duration immediately after the duration Tf. In the type 2A UL CAP, Tf includes a sensing slot at the beginning thereof. In the type 2B UL CAP, the UE may perform transmission immediately after the channel is sensed to be idle for the sensing duration Tf=16 us. In the type 2B UL CAP, Tf includes a sensing slot within 9 us from the end of the duration. In the type 2C UL CAP, the UE does not perform channel sensing before performing transmission.
For example, according to the type 1 LBT-based NR-U operation, the UE having uplink data to be transmitted may select a CAPC mapped to 5QI of data, and the UE may perform the NR-U operation by applying parameters of the corresponding CACP (e.g., minimum contention window size, maximum contention window size, mp, etc.). For example, the UE may select a backoff counter (BC) after selecting a random value between the minimum CW and the maximum CW mapped to the CAPC. In this case, for example, the BC may be a positive integer less than or equal to the random value. The UE sensing a channel decreases the BC by 1 if the channel is idle. If the BC becomes zero and the UE detects that the channel is idle for the time Td (Td=Tf+mp*Tsl), the UE may attempt to transmit data by occupying the channel. For example, Tsl (=9 usec) is a basic sensing unit or sensing slots, and may include a measurement duration for at least 4 usec. For example, the front 9 usec of Tf (=16 usec) may be configured to be Tsl.
For example, according to the type 2 LBT-based NR-U operation, the UE may transmit data by performing the type 2 LBT (e.g., type 2A LBT, type 2B LBT, or type 2C LBT) within COT.
For example, the type 2A (also referred to as Cat-2 LBT (one shot LBT) or one-shot LBT) may be 25 usec one-shot LBT. In this case, transmission may start immediately after idle sensing for at least a 25 usec gap. The type 2A may be used to initiate transmission of SSB and non-unicast DL information. That is, the UE may sense a channel for 25 usec within COT, and if the channel is idle, the UE may attempt to transmit data by occupying the channel.
For example, the type 2B may be 16 usec one-shot LBT. In this case, transmission may start immediately after idle sensing for a 16 usec gap. That is, the UE may sense a channel for 16 usec within COT, and if the channel is idle, the UE may attempt to transmit data by occupying the channel.
For example, in the case of the type 2C (also referred to as Cat-1 LBT or No LBT), LBT may not be performed. In this case, transmission may start immediately after a gap of up to 16 usec and a channel may not be sensed before the transmission. The duration of the transmission may be up to 584 usec. The UE may attempt transmission after 16 usec without sensing, and the UE may perform transmission for up to 584 usec.
In a sidelink unlicensed band, the UE may perform a channel access operation based on Listen Before Talk (LBT). Before the UE accesses a channel in an unlicensed band, the UE should check whether the channel to be accessed is idle (e.g., a state in which UEs do not occupy the channel, a state in which UEs can access the corresponding channel and transmit data) or busy (e.g., a state in which the channel is occupied and data transmission/reception is performed on the corresponding channel, and the UE attempting to access the channel cannot transmit data while the channel is busy). That is, the operation in which the UE checks whether the channel is idle or busy may be referred to as Clear Channel Assessment (CCA), and the UE may check whether the channel is idle or busy for the CCA duration.
In this specification, the word “configuration or definition” may be interpreted as being (pre-) configured by a base station or network (via pre-defined signaling (e.g., SIB, MAC signaling, RRC signaling)). For example, “A may be configured” may include “a base station or network (pre-) configures/defines or informs a UE of A”. Alternatively, the word “configuration or definition” may be interpreted as being pre-configured or pre-defined by the system. For example, “A may be configured” may include “A is pre-configured/defined by the system”
Meanwhile, in a future system, a UE may perform a sidelink transmission and/or reception operation in an unlicensed band. For operations in an unlicensed band, depending on band-specific regulations or requirements, a UE's transmission may be preceded by a channel sensing operation (e.g., energy detection/measurement) for the channel to be used, a UE may perform a transmission in the unlicensed band only if, as a result of the channel sensing, the channel or RB set to be used is determined to be IDLE (e.g., if the measured energy is less than or equal to or greater than a certain threshold value), and, if, according to a result of the channel sensing, the channel or RB set to be used is determined to be BUSY (e.g., if the measured energy is greater than or equal to or greater than a certain threshold value), the UE may cancel all or part of the transmission in the unlicensed band.
Meanwhile, in operation in an unlicensed band, a UE may omit or simplify the channel sensing operation (i.e., make the channel sensing interval relatively small) within a certain time interval after a transmission for a certain time period, or conversely, after a certain time interval after the transmission, the UE may decide whether to transmit or not after performing the usual channel sensing operation.
On the other hand, in a transmission in an unlicensed band, depending on regulations or requirements, the size and/or power spectral density (PSD) of the time interval and/or frequency occupied region of the signal/channel transmitted by the UE may be greater than or equal to a certain level, respectively.
On the other hand, in an unlicensed band, in order to simplify the channel sensing, it may be informed through the channel occupancy time (COT) duration information that it occupies the channel obtained through the initial general channel sensing for a certain period of time, and the maximum value of the length of the COT duration may be set differently according to the priority value of a service or a data packet.
Meanwhile, the sidelink transmission in the unlicensed band may be in the form of transmission through a plurality of RBs spaced apart according to a specification. For uplink channel transmission in the unlicensed band, a UE may be provided by a base station with information about a single or multiple RB set(s) and a single or multiple interlaces, and the final transmission resource may be determined as the intersection of the RBs within the provided RB set(s) and the RBs corresponding to the provided interlaces.
Meanwhile, an interlace may be defined in a common RB (CRB) grid, wherein an interlace in the CRB grid may be determined as an RB set spaced 10 RBs apart at 15 kHz and an RB set spaced 5 RBs apart at 30 KHz, and the interlace index of each interlace may be determined based on the RB offset relative to CRB #0.
On the other hand, in the case of sidelink communication, sensing and/or resource (re) selection is performed in sub-channel units, which may require that the sub-channels be represented in the form of interlaced and/or RB sets. The advantage of this is that subchannel-based sensing operations and/or resource reservation methods may be reused as much as possible.
On the other hand, sidelink synchronization signals in the license band or ITS band are generated based on sequences of length 127, but in the case of interlaced structures, depending on the size of the RBs that comprises the RB set, there may be insufficient resources to map the traditional 127-long sequence as it is.
For example, in an unlicensed band, sidelink communications may be limited to cases where the synchronization source is GNSS. For example, sidelink communications in unlicensed bands may be limited to cases where the synchronization source is a base station (e.g., eNB or gNB).
For example, if the synchronization source is a base station, a UE may receive a synchronization signal transmitted by the base station for a licensed band and use it to derive slot boundaries for sidelink communications in an unlicensed band. For example, if the synchronization source is a base station, a UE may receive a synchronization signal transmitted by a base station for the unlicensed band to which the UE is to perform sidelink, and use it to derive slot boundaries for sidelink communications in the unlicensed band.
For example, in using the synchronization signal transmitted by a base station in the unlicensed band as described above, the base station may be a base station that corresponds to the target PLMN ID of a UE. For example, in using the synchronization signal transmitted by a base station in the unlicensed band, the base station may not correspond to the target PLMN ID of a UE, but the RSRP measurement based on the synchronization signal and/or PBCH DMRS transmitted by the base station may be greater than or equal to a specific level at the UE. The advantage of this may be that there may be no need for sidelink SSB transmissions and receptions on unlicensed bands. However, the circumstances under which sidelink communications may be performed may be limited.
For example, when transmitting a sidelink synchronization signal through a specific interlace within a specific RB set, a UE may map to an RE of 10 RBs by cutting 7 bits of the MSB and/or 7 bits of the LSB of a 127 long synchronization sequence. For example, when transmitting a sidelink synchronization signal through a specific interlace within a specific RB set, a UE may map to an RE of 9 RBs by cutting 19 bits of the MSB and/or 19 bits of the LSB of the 127-long synchronization sequence. For example, in the above, the UE may additionally cut X bits of MSBs and/or X bits of LSBs to secure a guard region. This may be useful in terms of power spectral density (PSD) boosting. For example, the value of X may be a value less than 10, such as 5 or 6, etc.
For example, when transmitting a sidelink synchronization signal through a specific interlace within a specific RB set, 1 RB to which a synchronization sequence of length 127 is mapped may be transmitted through 11 PRBs distributed within the RB set. For example, the spacing between the PRBs and/or the PRB positions at which the mapping of the 11 RBs is to start may be (pre-) configured per RB set and/or per SL BWP and/or per SL carrier and/or per subcarrier spacing (SCS). For example, the spacing between the PRBs may be positioned such that the 11 RBs in the RB set are (approximately) equally distributed. For example, the PRB spacing may be an integer value via rounding down for N/11 and/or an integer value via rounding for N/11, when the number of PRBs constituting the RB set is N. For example, when 11 RBs for the synchronization signal map to 11 non-contiguous PRBs in the RB set, the position of the starting PRB may be determined such that the synchronization signal is centered in the RB set. For example, when the 11 RBs for the synchronization signal map to 11 non-contiguous PRBs within the RB set, the starting PRB may be the first PRB in the RB set. For example, when the 11 RBs for the synchronization signal map to 11 non-contiguous PRBs in the RB set, the last PRB may be the last PRB of the RB set.
In embodiments of the present disclosure, the positions of the non-contiguous 11 PRBs may be determined differently depending on the location of the RB set and/or the location of the guard region.
For example, when transmitting a sidelink synchronization signal through a specific interlace within a specific RB set, the synchronization signal may be generated based on an M sequence of length 113. For example, the offset value for some component of the SL ID for the S-PSS sequence index may be changed to 37 or 38. For example, the 37 or 38 may be an approximation to a value for a third of the sequence length 113. For example, the fixed offset value for the S-PSS sequence index may be 18 or 19. Equation 1 is a representation of the above embodiment of generating an S-PSS sequence.
Equation 2 is a representation of the above embodiment for generating an S-SSS sequence.
In embodiments of the present disclosure, specific RB set and/or specific interlace may be (pre-) configured and/or predetermined per SL BWP and/or per resource pool, or may be selected by a UE, but information about the RB set and/or interlace may be indicated via PSBCH (e.g., embedded in content or indicated by PSBCH DMRS). For example, as described above, RB set and/or interlace candidates that can be indicated via PSBCH may be (pre-) configured.
On the other hand, as a way to satisfy the occupied channel bandwidth (OCB) requirement, increasing the number of RBs to which S-SSBs are mapped is proposed.
Equation 3 represents the above embodiment of generating an S-PSS sequence.
Equation 4 represents the above embodiment of generating an S-SSS sequence.
For example, the number of RBs for S-SSB for 15 kHz subcarrier spacing (SCS) may be 88 or 96. For example, the sequence length of the S-PSS and/or S-SSS in the above may be 1051 or 1151. For example, in generating the S-PSS for the 15 kHz SCS above, the value of C in Equation 3 may be 1051 or 1151, and/or the value of B may be 350 or 351 or 383 or 384, and/or the value of A may be 116 or 117 or 127 or 128. For example, the value of A may be 175 or 176 or 175 or 176.
For example, an S-PSS and/or S-SSS sequence may be mapped to include the lowest subcarrier of the S-SSB, or it may be mapped to include the highest subcarrier, or it may be mapped to be centered on the frequency region of the S-SSB. For example, depending on the mapping position of the S-SSB within the RB set, a guard region for the sequence may be placed on the side closer to the RB set boundary.
For example, the number of RBs for S-SSB for 30 kHz subcarrier spacing (SCS) may be 44 or 48. For example, the sequence length of the S-PSS and/or S-SSS in the above may be 523 or 571. For example, in generating the S-PSS for the 30 KHz SCS above, the value of C in Equation 3 may be 523 or 571, and/or the value of B may be 174 or 175 or 190 or 191, and/or the value of A may be 58 or 59 or 63 or 64. For example, the value of A may be 87 or 88 or 95 or 96.
For example, the S-PSS and/or S-SSS sequence may be mapped in a form where the lowest subcarrier of the S-SSB is included, or mapped in a form where the highest subcarrier is included, or mapped in the center of the frequency region of the S-SSB. For example, depending on the mapping position of the S-SSB within the RB set, the guard region for the sequence may be placed on the side closer to the RB set boundary. For example, in 30 KHz SCS, the length of the sequence may be determined to be 577, but the first or last symbol of the sequence may be punctured to fit the length of 48 RBs. For example, in the above case, the value of A could be 192 or 193, and the value of B could be 64 or 65.
For example, the number of RBs for S-SSB for 60 KHz subcarrier spacing (SCS) may be 22 or 24. For example, the sequence length of the S-PSS and/or S-SSS in the above may be 263 or 283. For example, in generating the S-PSS for the 60 KHz SCS above, the value of C in Equation 3 may be 263 or 283, and/or the value of B may be 87 or 88 or 94 or 95, and/or the value of A may be 29 or 30 or 31 or 32. For example, the value of A may be 43 or 44 or 47 or 48.
For example, the S-PSS and/or S-SSS sequence may be mapped in a form where the lowest subcarrier of the S-SSB is included, or mapped in a form where the highest subcarrier is included, or mapped in the center of the frequency region of the S-SSB. For example, depending on the mapping position of the S-SSB within the RB set, a guard region for the sequence may be placed on the side closer to the RB set boundary.
For example, the value of B can be a rounding down value, a rounding up value, or a rounding value for the length of the sequence divided by 3. For example, the value of A can be a rounding down value, a rounding up value, or a rounding value for the length of the sequence divided by 6. For example, the value of A can be a rounding down value, a rounding up value, or a rounding value for the value of B divided by 2.
For example, for 120 kHz subcarrier spacing (SCS), the number of RBs for S-SSB can be 11, in this case the S-SSB structure in the licensed band can be used as it is.
Meanwhile, as a method to satisfy the occupied channel bandwidth (OCB) requirement, it is proposed to repeat the S-SSB consisting of 11 RBs in terms of frequency. However, the above method may have a problem that the coverage of the SL communication may be limited due to the higher PAPR for the S-SSB transmission. For example, the S-SSBs repeated in the frequency region may be mapped to contiguous consecutive RBs and/or REs.
For example, the S-PSS and/or S-SSS mapping may be in the form of concatenating a plurality of sequences without guard regions and mapping the concatenated sequences to the center or low frequency region or high frequency region of an RB set to which a plurality of S-SSB repeats are mapped.
For example, the frequency region position to which the concatenated sequence is mapped may vary depending on the position of the S-SSB repeats in the RB set. For example, if the position of the S-SSB repeats in the RB set is close to the boundary of the RB set, the concatenated sequence may be mapped to be as far away from the boundary of the RB set as possible. For example, as a method for lowering the PAPR as described above, all or a portion of the S-PSS and/or S-SSS and/or PSBCH symbols may be multiplied by different scaling values per S-SSB repeat or per sequence repeat for all or a portion of the S-PSS and/or S-SSS and/or PSBCH symbols. For example, a single PSBCH may be mapped through rate-matching based on the number of total REs for the PSBCH for the S-SSB resources repeated above.
On the other hand, the OCB requirement may be temporarily omitted within the channel occupancy time (COT) interval. For example, a UE may perform channel access according to the channel access procedure for S-SSB, and for all or part of the symbols in the PSBCH, the UE may use an interlace structure and/or perform wideband transmission occupying more than 80% of the channel, subject to OCB requirements, and/or S-PSS and/or S-SSS may be transmitted based on 11 consecutive PRBs.
For example, in the above, at least the first symbol of the PSBCH or the first symbol of the S-SSB may be transmitted in a form that satisfies the OCB requirements. For example, in an unlicensed band and/or on a carrier with OCB requirements, the position of the S-PSS and/or S-SSS symbols may be changed to the end of the S-SSB. This may be because the first symbol of the S-SSB is a PSBCH, and if a UE has succeeded in the channel access for the PSBCH, the symbols to which the subsequent S-PSS and S-SSS will be transmitted are already in the COT duration.
Where, for a single S-SSB transmission, in a specific symbol, a transmission is performed with a transmission structure that complies with the OCB requirements (e.g., a wideband transmission that occupies 80% or more of the channel) and/or in a specific symbol, a transmission is performed with a transmission structure that omits the OCB requirements (e.g., a narrowband transmission that does not occupy 80% of the channel and/or occupies 2 MHz or more), a transient period may be required between the different transmission structures.
More specifically, a transient interval may be required when the frequency domain changes between transmissions and/or when the PSD changes, which can lead to signal distortion, resulting in poor detection performance for S-SSB.
For example, if a UE transmits PSBCH in a first transmission structure with OCB requirements, and/or transmits S-PSS and/or S-SSS and/or residual PSBCH in a second transmission structure that omits the OCB requirements, the transitional period may be designated within the PSBCH symbol region of the first transmission structure.
For example, if a UE transmits S-PSS and/or S-SSS in a second transmission structure that omits OCB requirements, and/or transmits a PSBCH in a first transmission structure with OCB requirements, then a transient period may be designated within the PSBCH symbol region of the first transmission structure.
For example, if a UE transmits a PSBCH in a first transmission structure according to the OCB requirements, and/or transmits S-PSS and/or S-SSS and/or residual PSBCH in a second transmission structure that omits the OCB requirements, the UE may organize the symbol structure of the S-SSB in the form of PSBCH/PSBCH/S-PSS/S-PSS/S-SSS/S-SSS/PSBCH/ . . . .
For example, if a UE transmits a PSBCH in a first transmission structure with OCB requirements, and/or transmits S-PSS and/or S-SSS and/or residual PSBCH in a second transmission structure that omits OCB requirements, the UE may add one more S-PSS and/or S-SSS symbol to the S-SSB structure. For example, in the above, the S-SSB structure may be in the form of PSBCH/S-PSS/S-PSS/S-PSS/S-SSS/S-SSS/PSBCH/ . . . .
For example, when a UE transmits a PSBCH in a first transmission structure according to the OCB requirements, and/or transmits S-PSS and/or S-SSS and/or residual PSBCH in a second transmission structure that omits the OCB requirements, the UE may map the S-PSS and/or S-SSS for all or part of the S-PSS and/or S-SSS symbols to the frequency region in the form of a COMB structure in RE units. For example, the COMB structure may be mapping the S-PSS and/or S-SSS to REs with an even index or an odd index, or it may be mapping the S-PSS and/or S-SSS to REs with an index that is derived by dividing the RE index by a predefined or (pre) configured COMB STEP and adding the remaining value to a zero or (pre) configured value. As an advantage to the above, as the actual synchronization reference signal is repeated on the time axis due to the COMB structure, some of the time repetitions may be used as transient periods and/or a minimum frequency occupancy region of 2 MHz may be obtained on the frequency region.
On the other hand, a UE may omit or simplify the channel sensing operation for a specific transmission, wherein the specific transmission may be one in which limit 1) the number of transmissions within 50 msec is 50 or less, and limit 2) the total length of transmission interval within 50 msec is 2,500 usec or less. For example, a UE may expect that when transmitting S-SSB, the above limits 1 and/or 2 are (pre) configured to be met for the S-SSB time resource. For example, a UE may expect that the limit 1 and/or limit 2 is (pre) configured to be met for the entire S-SSB time resource. For example, sl-TimeInterval and/or sl-NumSSB-WithinPeriod and/or sl-SSB-Time Allocation1 and/or sl-SSB-TimeAllocation2 and/or sl-SSB-TimeAllocation3 may be suitably (pre) configured such that limits 1 and 2 are met.
For example, the specific transmission for simplifying the sensing operation may be whose 3) DUTY CYCLE is at most 1/20. For example, the specific transmission may be such that the total percentage of active interval within a given period is no more than 1/20.
For example, sl-TimeInterval and/or sl-NumSSB-WithinPeriod and/or sl-SSB-TimeAllocation1 and/or sl-SSB-TimeAllocation2 and/or sl-SSB-TimeAllocation3 may be suitably (pre) configured such that limit 3 is met.
On the other hand, a UE may simplify the above sensing operation and apply it to S-SSB transmissions and/or PSFCH transmissions at the same time, and in this case, the UE may simplify the channel sensing operation only if the above simplification conditions are satisfied for both transmissions.
On the other hand, if the above simplification conditions are not satisfied for S-SSB transmissions and/or PSFCH transmissions, it may be necessary to cancel applying the simplified channel sensing operation for all or part of the transmissions. For example, if a UE determines that condition 1) and/or condition 2) and/or condition 3) above are not satisfied for S-SSB transmissions and/or PSFCH transmissions, the UE may preferentially cancel applying the simplified channel sensing operation for all or part of the PSFCH transmissions (enough to satisfy the above conditions), and/or perform channel sensing operation based on Type 1 channel access for the PSFCH transmission (if the PSFCH is outside the COT), and/or the UE may cancel the PSFCH transmission.
For example, if a UE determines that condition 1) and/or condition 2) and/or condition 3) is not satisfied for an S-SSB transmission and/or PSFCH transmission, the UE may preferentially cancel applying simplified channel sensing operation for the S-SSB transmission, and/or perform channel sensing operation based on Type 1 channel access for the S-SSB transmission (if the S-SSB is outside the COT), and/or cancel the S-SSB transmission. For example, the canceling of the S-SSB transmission may be limited to cases where the S-SSB transmission originates from additional S-SSB transmission resources (for the purpose of compensating for LBT failure).
For example, if the UE determines that condition 1) and/or condition 2) and/or condition 3) above are not satisfied for the S-SSB transmission and/or PSFCH transmission, and/or if it cancels applying the simplified channel sensing operation for the entire PSFCH transmission or the entire S-SSB transmission, the UE may further cancel applying the simplified channel sensing operation for all or part of the S-SSB transmission or PSFCH transmission, and/or perform channel sensing operation based on the Type 1 channel access procedure for all or part of the S-SSB transmission or PSFCH transmission, and/or the UE may cancel the transmission for all or part of the S-SSB transmission or PSFCH transmission.
For example, if a UE determines that the above conditions 1) and/or conditions 2) and/or conditions 3) are not satisfied for an S-SSB transmission and/or a PSFCH transmission, the UE may cancel applying the simplified channel sensing operation for all or part of the S-SSB transmission and/or the PSFCH transmission. For example, the channels and/or transmissions for which the application of the simplified channel sensing operation is to be canceled may be selected by the UE implementation, and/or may correspond to resources that are temporally earlier, and/or may correspond to resources that are temporally later.
For example, the maximum number of S-SSB time resources in an S-SSB period at 15 KHz SCS may be a value of 6 or less. For example, the above may be a value determined in a situation where the UE's transmission criteria satisfies limit 1 and/or limit 2 above. For example, in 15 kHz SCS, the maximum number of S-SSB time resources in an S-SSB period may be a value of 2 or less. For example, the above may be a value determined in a situation where the S-SSB transmission resource criteria satisfy limit 1 and/or limit 2 above. For example, the above may be the case where the sl-SSB-TimeAllocation3 is (pre) configured. For example, the maximum number of S-SSB time resources in an S-SSB period at 15 kHz SCS may be a value of 3 or less if sl-SSB-TimeAllocation3 is not configured.
For example, the maximum number of S-SSB time resources in an S-SSB period in 15 KHz SCS may be a value of 8 or less. For example, the above may be a value determined in a situation where the UE's transmission criteria satisfies limit 3 above. For example, the maximum number of S-SSB time resources in an S-SSB period at 15 kHz SCS may be a value of 2 or 3 or less. For example, the above may be a value determined in a situation where the S-SSB transmission resource criteria satisfies limit 3 above. For example, the above may be the case where sl-SSB-TimeAllocation3 is (pre) configured. For example, the maximum number of S-SSB time resources in an S-SSB period at 15 kHz SCS may be 4 or less if sl-SSB-TimeAllocation3 is not configured.
For example, in 30 kHz SCS, the maximum number of S-SSB time resources in an S-SSB period may be a value of 16 or less. For example, the above may be a value determined in a situation where the UE's transmission criteria satisfies limit 1 and/or limit 2 and/or limit 3 above. For example, in 15 kHz SCS, the maximum number of S-SSB time resources in an S-SSB period may be a value of 5 or 6 or less, wherein sl-SSB-TimeAllocationl and/or sl-SSB-TimeAllocation2 and/or sl-SSB-TimeAllocation3 may have different maximum values. For example, the above may be values determined in a situation where the above limit 1 and/or limit 2 and/or limit 3 are satisfied on an S-SSB transmission resource basis. For example, the above may be the case where the sl-SSB-TimeAllocation3 is (pre) configured. For example, the maximum number of S-SSB time resources in an S-SSB period at 30 kHz SCS may be a value of 8 or less if sl-SSB-TimeAllocation3 is not configured.
For example, in 60 KHz SCS, the maximum number of S-SSB time resources in an S-SSB period may be a value of 32 or less. For example, the above may be a value determined in a situation where the UE's transmission criteria satisfies limit 1 and/or limit 2 and/or limit 3 above. For example, in 15 kHz SCS, the maximum number of S-SSB time resources in an S-SSB period may be a value of 10 or 11 or less, wherein sl-SSB-TimeAllocation1 and/or sl-SSB-TimeAllocation2 and/or sl-SSB-TimeAllocation3 may have different maximum values. For example, the above may be values determined in a situation where the above limit 1 and/or limit 2 and/or limit 3 are satisfied on an S-SSB transmission resource basis. For example, the above may be the case where the sl-SSB-TimeAllocation3 is (pre) configured. For example, in 60 KHz SCS, the maximum number of S-SSB time resources in an S-SSB period may be 16 or less if sl-SSB-TimeAllocation3 is not configured.
For example, sl-SSB-TimeAllocation1 and/or sl-SSB-TimeAllocation2 and/or sl-SSB-TimeAllocation3 may overlap in time domain, in whole or in part. For example, sl-SSB-TimeAllocation3 may be the same as sl-SSB-TimeAllocation1, but the frequency resource area for S-SSBs may be different. For example, if a UE relays S-SSB transmitted in the time resource and/or frequency resource for sl-SSB-TimeAllocation3, it may relay S-SSB transmissions in the time domain of sl-SSB-TimeAllocation2 in the frequency domain corresponding to sl-SSB-TimeAllocation1 or in the frequency domain corresponding to sl-SSB-TimeAllocation3.
For example, if a UE fails in channel access for an S-SSB transmission, it may attempt to transmit by trying to channel access the next RB set containing S-SSB resources.
For example, a sidelink synchronization signal may be transmitted through all or some of the RBs corresponding to a plurality of interlaces within a single or a plurality of RB sets.
For example, the sequence length of the synchronization signals may remain 127, and the synchronization signals may be mapped to only some of the 127 REs for the RB, with the remaining REs being guard regions. For example, the locations of the guard regions may be located in a lower region and/or a higher region in terms of frequency. For example, for RBs corresponding to two interlaces in a specific RB set, a guard region may be configured for 57 or 56 REs from the lower region on the frequency region, and a guard region may be configured for 56 or 57 REs from the higher region on the frequency region, with a synchronization signal of 127 lengths mapped to the center of the frequency region.
For example, the sequence length of the synchronization signal may be 229 or 233 or 239, wherein the synchronization signal is mapped only to REs of a portion of the sequence length for the RB, and the remaining REs may be guard regions. For example, the locations of the guard regions may be located in a lower region and/or a higher region in terms of frequency. For example, the synchronization signal may be mapped to the center frequency region for the RBs and REs, and the guard regions may be mapped to the lower and higher regions of the frequency region, respectively, but the difference in the number of REs comprising the guard in the lower and higher regions may be zero or one.
For example, if the length of the sequence is 229, the offset value for some components of the SL ID for the S-PSS sequence index may change to 76 or 77, and the fixed offset value may be 37 or 38 or 39.
For example, if the length of the sequence is 233, the offset value for some components of the SL ID for the S-PSS sequence index may change to 77 or 78, and the fixed offset value may be 37 or 38 or 39.
For example, if the length of the sequence is 239, the offset value for some components of the SL ID for the S-PSS sequence index may change to 79 or 80, and the fixed offset value may be 38 or 39 or 40.
In embodiments of the present disclosure, specific RB set group and/or specific interlace group may be (pre-) configured per SL BWP and/or per resource pool, or may be predetermined or selected by a UE, but information about the RB set group and/or interlace group may be indicated via PSBCH (e.g., embedded in content or indicated by PSBCH DMRS).
In embodiments of the present disclosure, depending on the sequence seed value and/or SL ID value and/or index shift value, the RB set group and/or interlace group used for the synchronization signal may be different. This may be due to the fact that the suitable RB set-interlace group combination in terms of PAPR may be different. For example, the unit in which the RB set group and/or interlace group is configured or indicated may be in the form of a plurality of RB set indices and/or a plurality of interlace indices. For example, the RB offset or index difference between the RB sets comprising the RB set group may be (pre-) configured or predefined, and the index of the lowest RB set may be indicated or configured.
For example, the RB offset or index difference between interlaces comprising an interlace group may be (pre-) configured or predefined. For example, the index of the interlace with the lowest frequency or the interlace with the lowest index may be indicated or configured. For example, an RB set group and/or an interlace group candidate that may be indicated via PSBCH as described above may be (pre-) configured.
For example, an RB set group and/or interlace group to which the synchronization signal and/or PSBCH is mapped and/or transmitted may be different for each period of the S-SSB and/or each repetition within a period of the S-SSB. For example, frequency hopping may be applied to an RB set group and/or interlace group to which the synchronization signal and/or PSBCH is mapped and/or transmitted, depending on an index value for a period of the S-SSB and/or an index value for a repetition within a period of the S-SSB. For example, a plurality of RB sets for the mapping of the synchronization signals and/or PSBCH may be configured, wherein a UE may transmit a synchronization signal and/or PSBCH through the lowest or highest indexed RB set among the RB sets that are IDLE according to the channel sensing results. For example, a UE may select a resource to transmit only among the RB sets where the synchronization signals and/or PSBCHs are (pre-) configured to be allowed to be transmitted.
For example, if there is no guard region between RB sets, a UE may perform SL transmission only if the channel sensing result is IDLE for all RB sets.
Referring to
For example, interlaces with the same interlace index may be mapped to the same subchannel. For example, interlace 0 of RB set 1 and interlace 0 of RB set 2 in
For example, by transmitting an S-SSB based on at least one RB set as described above, the effect of improving the probability of successful transmission of the S-SSB may occur even if channel sensing (e.g., LBT operation) fails (e.g., if the result is BUSY). Further, if a receiving UE detects an S-SSB in a specific RB set, it may have the effect that the starting position of the SL BWP may be accurately determined based on the RB set in which the S-SSB is detected.
Referring to
In step S1430, the first device may perform channel sensing from a time point preceding the starting time point of the resource by a specific time interval, to the start time point. For example, the step S1430 may be a step performed only if the first device is performing communication based on a Type 2 LBT. For example, the channel sensing may comprise LBT operation.
For example, the embodiment of
For example, by transmitting an S-SSB based on at least one RB set as described above, the effect of improving the probability of successful transmission of the S-SSB may occur even if channel sensing (e.g., LBT operation) fails (e.g., if the result is BUSY). Further, if a receiving UE detects an S-SSB in a specific RB set, it may have the effect that the starting position of the SL BWP may be accurately determined based on the RB set in which the S-SSB is detected.
On the other hand, when the PRIMARY synchronization signal and the SECONDARY synchronization signal are transmitted in an interlaced manner, the actual transmission power may differ significantly due to the difference in MPR (maximum power reduction), etc., in this case, if PRIMARY synchronization signal and SECONDARY synchronization signal are mapped to adjacent symbols, a transitional period between the transmissions may be required, or the detection performance of the synchronization signal may be significantly reduced due to signal distortion during the transitional period.
For example, depending on whether the sidelink synchronization signals and channel transmissions are mapped to non-contiguous RBs in an interlaced manner or to contiguous RBs, the symbols to which the PRIMARY synchronization signal and/or SECONDARY synchronization signal and/or PSBCH are mapped may be different.
For example, when interlaced transmission is configured for a sidelink synchronization signal, the PRIMARY and SECONDARY synchronization signals may not be mapped to adjacent symbols, but may be mapped such that a specific time interval is maintained between them. For example, the specific time interval may be 1 or 2 symbols, and a UE may map/transmit PSBCH in the specific time interval. For example, the specific time interval may be 1 or 2 symbols, and a UE may map/transmit a PRIMARY synchronization signal and/or a SECONDARY synchronization signal in the specific time interval.
Meanwhile, in future systems, sidelink synchronization may be configured on a per-UE pair basis rather than configured in a cluster form for multiple UEs. For example, after a UE receives a sidelink synchronization signal and/or channel, it may not transmit information about it back to another UE. In other words, only between a UE that transmitted the sidelink synchronization signal/channel and a UE that received it, synchronization and data exchange may occur, and thus a receiving UE may omit the operation of transmitting the sidelink synchronization signal/channel.
For example, when a UE receives a sidelink synchronization signal and/or channel from another UE, the UE may be provided with a target SL ID (list) for matching as a synchronization source and/or similar information from a higher layer of the UE. For example, the manner in which the UE transmits the sidelink synchronization signals and/or channels may be different depending on the type of service and/or source ID and/or destination ID (list), etc. that the UE expects to transmit and/or receive.
For example, the transmission method being different may be an SL ID configuration being different and/or information about the different transmission method may be provided via a PSBCH. This allows a UE receiving a sidelink synchronization signal/channel to decide whether to synchronize to the synchronization signal according to the information indicated in the SL ID and/or PSBCH.
For example, a UE that has received a sidelink synchronization signal and/or channel and/or synchronized based on the synchronization signal/channel may transmit a response signal and/or channel back to the UE that transmitted the sidelink synchronization signal and/or PSBCH. For example, the response signal and/or channel may be determined based on the information provided in the SL ID and/or PSBCH used to generate the sidelink synchronization signal and/or channel.
For example, the response signal may be in the form of PSCCH/PSSCH and/or the source ID and/or the destination ID may be set to the SL ID and/or the ID provided in the PSBCH. For example, a UE that transmits a sidelink synchronization signal and/or channel may omit or stop transmitting the sidelink synchronization signal and/or channel when it determines that another UE has synchronized based on the synchronization signal/channel and/or when it receives a response signal for the sidelink synchronization signal/channel.
For example, the UE may transmit again the sidelink signal and/or channel if it has not received the sidelink signal and/or channel from the same synchronization UE for a certain period of time (e.g., by (re) starting the timer from the stop of the synchronization signal/channel) and/or if it has received a synchronization signal/channel resume transmission indicator from the UE.
On the other hand, S-SSB transmission through an interlace structure and/or non-contiguous RBs may or may not be supported depending on the capability of a UE. For example, if a UE does not have the UE capability for S-SSB transmission through an interlace structure and/or non-contiguous RBs, the UE may not perform SL operation on the SL carrier and/or SL BWP through which the S-SSB is transmitted. For example, if a UE does not have the UE capability for S-SSB transmission through an interlace structure and/or non-contiguous RBs, the UE may not select another UE as a synchronization source.
For example, in the above, a UE may select GNSS or eNB or gNB or base station as a synchronization source. For example, if a UE does not have a UE capability for S-SSB transmission through an interlace structure and/or non-contiguous RBs, the UE may omit the operation of relaying and/or transmitting S-SSB even if it has received S-SSB from another UE.
In embodiments of the present disclosure, using frequency resources used for mapping synchronization signals and guard regions for PSBCH mapping may be extended and applied to the ideas of the present disclosure.
On the other hand, a CAPC value for a PSBCH or a logical channel corresponding to a PSBCH may be set to the smallest value (meaning the most important). For example, a CAPC value for the synchronization signals S-PSS and/or S-SSS of an S-SSB may be (pre) configured to a specific value (e.g., 1 or 4). For example, a CAPC value for the synchronization signals S-PSS and/or S-SSS of an S-SSB may be selected by a UE (by a UE implementation). For example, the corresponding CAPC values for each channel and/or signal in an S-SSB may be different, and/or in the above situation, the representative CAPC value for the S-SSB may be set to the smallest CAPC value and/or the largest CAPC value and/or the CAPC value of a specific channel or signal (e.g., PSBCH and/or S-PSS and/or S-SSS).
Embodiments of the disclosure may be applied in any combination of the above, depending on whether the transmission is within or outside the channel occupancy time (COT). Embodiments of the present disclosure may be applied in different combinations of the above depending on the shape of the COT (e.g., whether it is semi-static or time-varying). Embodiments of the present disclosure may be applied in different combinations of the above, depending on the carrier, depending on the presence or absence of guards between RB sets, or depending on regulations.
The scheme for transmitting a synchronization signal and PSBCH in the embodiments of the present disclosure may be applied differently depending on the SL operating region and regulations.
In embodiments of the present disclosure, the scheme for transmitting a synchronization signal and PSBCH may be applied differently depending on the size of the subcarrier space. For example, at 15 kHz and 30 kHz, the synchronization signal and/or PSBCH may be mapped to discontinuous RBs, such as in an interlace structure, while at 60 kHz, the synchronization signal and/or PSBCH may be mapped to contiguous RBs.
In embodiments of the present disclosure, the scheme for transmitting a synchronization signal and PSBCH may be different for each S-SSB time resource (e.g., sl-SSB-TimeAllocation1, sl-SSB-TimeAllocation2, sl-SSB-TimeAllocation3).
For example, synchronization signal and/or PSBCH mapping schemes may be (pre-) configured per SL BWP and/or per SL carrier and/or per RB set and/or per S-SSB time resource.
The proposed method may be applied to the device described below. First, a processor 202 of a receiving UE may configure at least one BWP. Then, the processor 202 of the receiving UE may control a transceiver 206 of the receiving UE to receive a sidelink-related physical channel and/or a sidelink-related reference signal from a transmitting UE on the at least one BWP.
According to the prior art, SL communication in unlicensed bands is not possible because an operation of SL communication in an unlicensed band is not defined. According to one embodiment of the present disclosure, S-SSB may be transmitted in an unlicensed band, which has the effect of enabling synchronization between UEs, thus enabling SL communication to be performed.
Referring to
For example, the S-SSB may be transmitted based on at least one resource block (RB) set.
For example, the at least one RB set may be included within a channel occupancy time (COT) duration.
For example, additionally, the first device may transmit information related to the at least one RB set.
For example, the information related to the at least one RB set may be transmitted along with the S-SSB.
For example, the S-SSB may be transmitted based on at least one interlace in the at least one RB set.
For example, additionally, the first device may obtain information related to a COT duration. For example, the S-SSB may be transmitted based on the COT duration.
For example, obtaining information related to the COT duration may include: performing an initial channel sensing; and determining the COT duration based on the initial channel sensing.
For example, additionally, the first device may obtain information related to at least one RB set or information related to at least one interlace.
For example, additionally, the first device may perform channel sensing for a transmission of the S-SSB. For example, the S-SSB may be transmitted based on a result of the channel sensing being IDLE.
For example, the channel sensing may include a listen before talk (LBT) operation.
For example, the channel sensing may be performed from a time point preceding a time point of a resource for the transmission of the S-SSB by a specific time interval, to the time point of the resource.
For example, the channel sensing may be performed based on the resource for the transmission of the S-SSB being included within a COT duration.
The embodiments described above may be applied to various devices described below. First, a processor 102 of a first device 100 may obtain sidelink (SL) synchronization priority order information configured as global navigation satellite system (GNSS)-based synchronization or based station-based synchronization. And, the processor 102 of the first device 100 may select at least one synchronization reference, based on the SL synchronization priority order information. And, the processor 102 of the first device 100 may obtain time synchronization from the at least one synchronization reference. And, the processor 102 of the first device 100 may control a transceiver 106 to transmit a sidelink synchronization signal block (S-SSB) including a physical sidelink broadcast channel (PSBCH), a sidelink primary synchronization signal (S-PSS), and a sidelink secondary synchronization signal (S-SSS), on an unlicensed band, based on the time synchronization.
According to an embodiment of the present disclosure, a first device performing wireless communication may be proposed. For example, the first device may comprise: at least one transceiver: at least one processor; and at least one memory operably connected to the at least one processor and storing instructions. For example, the instructions, based on being executed by the at least one processor, may cause the first device to perform operations. For example, the operations may comprise: obtaining sidelink (SL) synchronization priority order information configured as global navigation satellite system (GNSS)-based synchronization or based station-based synchronization; selecting at least one synchronization reference, based on the SL synchronization priority order information: obtaining time synchronization from the at least one synchronization reference; and transmitting a sidelink synchronization signal block (S-SSB) including a physical sidelink broadcast channel (PSBCH), a sidelink primary synchronization signal (S-PSS), and a sidelink secondary synchronization signal (S-SSS), on an unlicensed band, based on the time synchronization.
For example, the S-SSB may be transmitted based on at least one resource block (RB) set.
For example, the at least one RB set may be included within a channel occupancy time (COT) duration.
For example, additionally, the first device may transmit information related to the at least one RB set.
For example, the information related to the at least one RB set may be transmitted along with the S-SSB.
For example, the S-SSB may be transmitted based on at least one interlace in the at least one RB set.
For example, additionally, the first device may obtain information related to a COT duration. For example, the S-SSB may be transmitted based on the COT duration.
For example, obtaining information related to the COT duration may include: performing an initial channel sensing; and determining the COT duration based on the initial channel sensing.
For example, additionally, the first device may obtain information related to at least one RB set or information related to at least one interlace.
For example, additionally, the first device may perform channel sensing for a transmission of the S-SSB. For example, the S-SSB may be transmitted based on a result of the channel sensing being IDLE.
For example, the channel sensing may include a listen before talk (LBT) operation.
For example, the channel sensing may be performed from a time point preceding a time point of a resource for the transmission of the S-SSB by a specific time interval, to the time point of the resource.
For example, the channel sensing may be performed based on the resource for the transmission of the S-SSB being included within a COT duration.
According to an embodiment of the present disclosure, a device adapted to control a first user equipment (UE) may be proposed. For example, the device may comprise: at least one processor; and at least one memory operably connected to the at least one processor and storing instructions. For example, the instructions, based on being executed by the at least one processor, may cause the first UE to perform operations. For example, the operations may comprise: obtaining sidelink (SL) synchronization priority order information configured as global navigation satellite system (GNSS)-based synchronization or based station-based synchronization: selecting at least one synchronization reference, based on the SL synchronization priority order information: obtaining time synchronization from the at least one synchronization reference; and transmitting a sidelink synchronization signal block (S-SSB) including a physical sidelink broadcast channel (PSBCH), a sidelink primary synchronization signal (S-PSS), and a sidelink secondary synchronization signal (S-SSS), on an unlicensed band, based on the time synchronization.
According to an embodiment of the present disclosure, a non-transitory computer-readable storage medium storing instructions may be proposed. For example, the instructions, based on being executed, may cause a first device to: obtain sidelink (SL) synchronization priority order information configured as global navigation satellite system (GNSS)-based synchronization or based station-based synchronization: select at least one synchronization reference, based on the SL synchronization priority order information; obtain time synchronization from the at least one synchronization reference; and transmit a sidelink synchronization signal block (S-SSB) including a physical sidelink broadcast channel (PSBCH), a sidelink primary synchronization signal (S-PSS), and a sidelink secondary synchronization signal (S-SSS), on an unlicensed band, based on the time synchronization.
Referring to
For example, the S-SSB may be received based on at least one resource block (RB) set.
The embodiments described above may be applied to various devices described below. First, a processor 202 of a second device 200 may control a transceiver 206 to receive, from a first device 100, a sidelink synchronization signal block (S-SSB) including a physical sidelink broadcast channel (PSBCH), a sidelink primary synchronization signal (S-PSS), and a sidelink secondary synchronization signal (S-SSS), on an unlicensed band. For example, the S-SSB may be transmitted by the first device 100 based on time synchronization obtained from at least one synchronization reference, the at least one synchronization reference may be selected by the first device 100 based on a sidelink (SL) synchronization priority order information, the SL synchronization priority order information may be configured as global navigation satellite system (GNSS)-based synchronization or based station-based synchronization.
According to an embodiment of the present disclosure, a second device performing wireless communication may be proposed. For example, the second device may comprise: at least one transceiver: at least one processor; and at least one memory operably connected to the at least one processor and storing instructions. For example, the instructions, based on being executed by the at least one processor, may cause the second device to perform operations. For example, the operations may comprise: receiving, from a first device, a sidelink synchronization signal block (S-SSB) including a physical sidelink broadcast channel (PSBCH), a sidelink primary synchronization signal (S-PSS), and a sidelink secondary synchronization signal (S-SSS), on an unlicensed band, wherein the S-SSB may be transmitted by the first device based on time synchronization obtained from at least one synchronization reference, wherein the at least one synchronization reference may be selected by the first device based on a sidelink (SL) synchronization priority order information, wherein the SL synchronization priority order information may be configured as global navigation satellite system (GNSS)-based synchronization or based station-based synchronization.
For example, the S-SSB may be received based on at least one resource block (RB) set.
Various embodiments of the present disclosure may be combined with each other.
Hereinafter, device(s) to which various embodiments of the present disclosure can be applied will be described.
The various descriptions, functions, procedures, proposals, methods, and/or operational flowcharts of the present disclosure described in this document may be applied to, without being limited to, a variety of fields requiring wireless communication/connection (e.g., 5G) between devices.
Hereinafter, a description will be given in more detail with reference to the drawings. In the following drawings/description, the same reference symbols may denote the same or corresponding hardware blocks, software blocks, or functional blocks unless described otherwise.
Referring to
Here, wireless communication technology implemented in wireless devices 100a to 100f of the present disclosure may include Narrowband Internet of Things for low-power communication in addition to LTE, NR, and 6G. In this case, for example, NB-IoT technology may be an example of Low Power Wide Area Network (LPWAN) technology and may be implemented as standards such as LTE Cat NB1, and/or LTE Cat NB2, and is not limited to the name described above. Additionally or alternatively, the wireless communication technology implemented in the wireless devices 100a to 100f of the present disclosure may perform communication based on LTE-M technology. In this case, as an example, the LTE-M technology may be an example of the LPWAN and may be called by various names including enhanced Machine Type Communication (eMTC), and the like. For example, the LTE-M technology may be implemented as at least any one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-Bandwidth Limited (non-BL), 5) LTE-MTC, 6) LTE Machine Type Communication, and/or 7) LTE M, and is not limited to the name described above. Additionally or alternatively, the wireless communication technology implemented in the wireless devices 100a to 100f of the present disclosure may include at least one of Bluetooth, Low Power Wide Area Network (LPWAN), and ZigBee considering the low-power communication, and is not limited to the name described above. As an example, the ZigBee technology may generate personal area networks (PAN) related to small/low-power digital communication based on various standards including IEEE 802.15.4, and the like, and may be called by various names.
The wireless devices 100a to 100f may be connected to the network 300 via the BSs 200. An AI technology may be applied to the wireless devices 100a to 100f and the wireless devices 100a to 100f may be connected to the AI server 400 via the network 300. The network 300 may be configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. Although the wireless devices 100a to 100f may communicate with each other through the BSs 200/network 300, the wireless devices 100a to 100f may perform direct communication (e.g., sidelink communication) with each other without passing through the BSs/network. For example, the vehicles 100b-1 and 100b-2 may perform direct communication (e.g. Vehicle-to-Vehicle (V2V)/Vehicle-to-everything (V2X) communication). The IoT device (e.g., a sensor) may perform direct communication with other IoT devices (e.g., sensors) or other wireless devices 100a to 100f.
Wireless communication/connections 150a, 150b, or 150c may be established between the wireless devices 100a to 100f/BS 200, or BS 200/BS 200. Herein, the wireless communication/connections may be established through various RATs (e.g., 5G NR) such as uplink/downlink communication 150a, sidelink communication 150b (or, D2D communication), or inter BS communication (e.g. relay, Integrated Access Backhaul (IAB)). The wireless devices and the BSs/the wireless devices may transmit/receive radio signals to/from each other through the wireless communication/connections 150a and 150b. For example, the wireless communication/connections 150a and 150b may transmit/receive signals through various physical channels. To this end, at least a part of various configuration information configuring processes, various signal processing processes (e.g., channel encoding/decoding, modulation/demodulation, and resource mapping/demapping), and resource allocating processes, for transmitting/receiving radio signals, may be performed based on the various proposals of the present disclosure.
Referring to
The first wireless device 100 may include one or more processors 102 and one or more memories 104 and additionally further include one or more transceivers 106 and/or one or more antennas 108. The processor(s) 102 may control the memory(s) 104 and/or the transceiver(s) 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(s) 102 may process information within the memory(s) 104 to generate first information/signals and then transmit radio signals including the first information/signals through the transceiver(s) 106. The processor(s) 102 may receive radio signals including second information/signals through the transceiver 106 and then store information obtained by processing the second information/signals in the memory(s) 104. The memory(s) 104 may be connected to the processor(s) 102 and may store a variety of information related to operations of the processor(s) 102. For example, the memory(s) 104 may store software code including commands for performing a part or the entirety of processes controlled by the processor(s) 102 or for performing the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. Herein, the processor(s) 102 and the memory(s) 104 may be a part of a communication modem/circuit/chip designed to implement RAT (e.g., LTE or NR). The transceiver(s) 106 may be connected to the processor(s) 102 and transmit and/or receive radio signals through one or more antennas 108. Each of the transceiver(s) 106 may include a transmitter and/or a receiver. The transceiver(s) 106 may be interchangeably used with Radio Frequency (RF) unit(s). In the present disclosure, the wireless device may represent a communication modem/circuit/chip.
The second wireless device 200 may include one or more processors 202 and one or more memories 204 and additionally further include one or more transceivers 206 and/or one or more antennas 208. The processor(s) 202 may control the memory(s) 204 and/or the transceiver(s) 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(s) 202 may process information within the memory(s) 204 to generate third information/signals and then transmit radio signals including the third information/signals through the transceiver(s) 206. The processor(s) 202 may receive radio signals including fourth information/signals through the transceiver(s) 106 and then store information obtained by processing the fourth information/signals in the memory(s) 204. The memory(s) 204 may be connected to the processor(s) 202 and may store a variety of information related to operations of the processor(s) 202. For example, the memory(s) 204 may store software code including commands for performing a part or the entirety of processes controlled by the processor(s) 202 or for performing the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. Herein, the processor(s) 202 and the memory(s) 204 may be a part of a communication modem/circuit/chip designed to implement RAT (e.g., LTE or NR). The transceiver(s) 206 may be connected to the processor(s) 202 and transmit and/or receive radio signals through one or more antennas 208. Each of the transceiver(s) 206 may include a transmitter and/or a receiver. The transceiver(s) 206 may be interchangeably used with RF unit(s). In the present disclosure, the wireless device may represent a communication modem/circuit/chip.
Hereinafter, hardware elements of the wireless devices 100 and 200 will be described more specifically. One or more protocol layers may be implemented by, without being limited to, one or more processors 102 and 202. For example, the one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, and SDAP). The one or more processors 102 and 202 may generate one or more Protocol Data Units (PDUs) and/or one or more Service Data Unit (SDUs) according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. The one or more processors 102 and 202 may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. The one or more processors 102 and 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document and provide the generated signals to the one or more transceivers 106 and 206. The one or more processors 102 and 202 may receive the signals (e.g., baseband signals) from the one or more transceivers 106 and 206 and acquire the PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document.
The one or more processors 102 and 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. The one or more processors 102 and 202 may be implemented by hardware, firmware, software, or a combination thereof. As an 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 the one or more processors 102 and 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 configured to include the modules, procedures, or functions. Firmware or software configured to perform the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document may be included in the one or more processors 102 and 202 or stored in the one or more memories 104 and 204 so as to be driven by the one or more processors 102 and 202. The descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document may be implemented using firmware or software in the form of code, commands, and/or a set of commands.
The one or more memories 104 and 204 may be connected to the one or more processors 102 and 202 and store various types of data, signals, messages, information, programs, code, instructions, and/or commands. The one or more memories 104 and 204 may be configured by Read-Only Memories (ROMs), Random Access Memories (RAMs), Electrically Erasable Programmable Read-Only Memories (EPROMs), flash memories, hard drives, registers, cash memories, computer-readable storage media, and/or combinations thereof. The one or more memories 104 and 204 may be located at the interior and/or exterior of the one or more processors 102 and 202. The one or more memories 104 and 204 may be connected to the one or more processors 102 and 202 through various technologies such as wired or wireless connection.
The one or more transceivers 106 and 206 may transmit user data, control information, and/or radio signals/channels, mentioned in the methods and/or operational flowcharts of this document, to one or more other devices. The one or more transceivers 106 and 206 may receive user data, control information, and/or radio signals/channels, mentioned in the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document, from one or more other devices. For example, the one or more transceivers 106 and 206 may be connected to the one or more processors 102 and 202 and transmit and receive radio signals. For example, the one or more processors 102 and 202 may perform control so that the one or more transceivers 106 and 206 may transmit user data, control information, or radio signals to one or more other devices. The one or more processors 102 and 202 may perform control so that the one or more transceivers 106 and 206 may receive user data, control information, or radio signals from one or more other devices. The one or more transceivers 106 and 206 may be connected to the one or more antennas 108 and 208 and the one or more transceivers 106 and 206 may be configured to transmit and receive user data, control information, and/or radio signals/channels, mentioned in the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document, through the one or more antennas 108 and 208. In this document, the one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). The one or more transceivers 106 and 206 may convert received radio signals/channels etc. from RF band signals into baseband signals in order to process received user data, control information, radio signals/channels, etc. using the one or more processors 102 and 202. The one or more transceivers 106 and 206 may convert the user data, control information, radio signals/channels, etc. processed using the one or more processors 102 and 202 from the base band signals into the RF band signals. To this end, the one or more transceivers 106 and 206 may include (analog) oscillators and/or filters.
Referring to
Codewords may be converted into radio signals via the signal processing circuit 1000 of
Specifically, the codewords may be converted into scrambled bit sequences by the scramblers 1010. Scramble sequences used for scrambling may be generated based on an initialization value, and the initialization value may include ID information of a wireless device. The scrambled bit sequences may be modulated to modulation symbol sequences by the modulators 1020. A modulation scheme may include pi/2-Binary Phase Shift Keying (pi/2-BPSK), m-Phase Shift Keying (m-PSK), and m-Quadrature Amplitude Modulation (m-QAM). Complex modulation symbol sequences may be mapped to one or more transport layers by the layer mapper 1030. Modulation symbols of each transport layer may be mapped (precoded) to corresponding antenna port(s) by the precoder 1040. Outputs z of the precoder 1040 may be obtained by multiplying outputs y of the layer mapper 1030 by an N*M precoding matrix W. Herein, N is the number of antenna ports and M is the number of transport layers. The precoder 1040 may perform precoding after performing transform precoding (e.g., DFT) for complex modulation symbols. Alternatively, the precoder 1040 may perform precoding without performing transform precoding.
The resource mappers 1050 may map modulation symbols of each antenna port to time-frequency resources. The time-frequency resources may include a plurality of symbols (e.g., a CP-OFDMA symbols and DFT-s-OFDMA symbols) in the time domain and a plurality of subcarriers in the frequency domain. The signal generators 1060 may generate radio signals from the mapped modulation symbols and the generated radio signals may be transmitted to other devices through each antenna. For this purpose, the signal generators 1060 may include Inverse Fast Fourier Transform (IFFT) modules, Cyclic Prefix (CP) inserters, Digital-to-Analog Converters (DACs), and frequency up-converters.
Signal processing procedures for a signal received in the wireless device may be configured in a reverse manner of the signal processing procedures 1010 to 1060 of
Referring to
The additional components 140 may be variously configured according to types of wireless devices. For example, the additional components 140 may include at least one of a power unit/battery, input/output (I/O) unit, a driving unit, and a computing unit. The wireless device may be implemented in the form of, without being limited to, the robot (100a of
In
Hereinafter, an example of implementing
Referring to
The communication unit 110 may transmit and receive signals (e.g., data and control signals) to and from other wireless devices or BSs. The control unit 120 may perform various operations by controlling constituent elements of the hand-held device 100. The control unit 120 may include an Application Processor (AP). The memory unit 130 may store data/parameters/programs/code/commands needed to drive the hand-held device 100. The memory unit 130 may store input/output data/information. The power supply unit 140a may supply power to the hand-held device 100 and include a wired/wireless charging circuit, a battery, etc. The interface unit 140b may support connection of the hand-held device 100 to other external devices. The interface unit 140b may include various ports (e.g., an audio I/O port and a video I/O port) for connection with external devices. The I/O unit 140c may input or output video information/signals, audio information/signals, data, and/or information input by a user. The I/O unit 140c may include a camera, a microphone, a user input unit, a display unit 140d, a speaker, and/or a haptic module.
As an example, in the case of data communication, the I/O unit 140c may acquire information/signals (e.g., touch, text, voice, images, or video) input by a user and the acquired information/signals may be stored in the memory unit 130. The communication unit 110 may convert the information/signals stored in the memory into radio signals and transmit the converted radio signals to other wireless devices directly or to a BS. The communication unit 110 may receive radio signals from other wireless devices or the BS and then restore the received radio signals into original information/signals. The restored information/signals may be stored in the memory unit 130 and may be output as various types (e.g., text, voice, images, video, or haptic) through the I/O unit 140c.
Referring to
The communication unit 110 may transmit and receive signals (e.g., data and control signals) to and from external devices such as other vehicles, BSs (e.g., gNBs and road side units), and servers. The control unit 120 may perform various operations by controlling elements of the vehicle or the autonomous vehicle 100. The control unit 120 may include an Electronic Control Unit (ECU). The driving unit 140a may cause the vehicle or the autonomous vehicle 100 to drive on a road. The driving unit 140a may include an engine, a motor, a powertrain, a wheel, a brake, a steering device, etc. The power supply unit 140b may supply power to the vehicle or the autonomous vehicle 100 and include a wired/wireless charging circuit, a battery, etc. The sensor unit 140c may acquire a vehicle state, ambient environment information, user information, etc. The sensor unit 140c may include an Inertial Measurement Unit (IMU) sensor, a collision sensor, a wheel sensor, a speed sensor, a slope sensor, a weight sensor, a heading sensor, a position module, a vehicle forward/backward sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illumination sensor, a pedal position sensor, etc. The autonomous driving unit 140d may implement technology for maintaining a lane on which a vehicle is driving, technology for automatically adjusting speed, such as adaptive cruise control, technology for autonomously driving along a determined path, technology for driving by automatically setting a path if a destination is set, and the like.
For example, the communication unit 110 may receive map data, traffic information data, etc. from an external server. The autonomous driving unit 140d may generate an autonomous driving path and a driving plan from the obtained data. The control unit 120 may control the driving unit 140a such that the vehicle or the autonomous vehicle 100 may move along the autonomous driving path according to the driving plan (e.g., speed/direction control). In the middle of autonomous driving, the communication unit 110 may aperiodically/periodically acquire recent traffic information data from the external server and acquire surrounding traffic information data from neighboring vehicles. In the middle of autonomous driving, the sensor unit 140c may obtain a vehicle state and/or surrounding environment information. The autonomous driving unit 140d may update the autonomous driving path and the driving plan based on the newly obtained data/information. The communication unit 110 may transfer information about a vehicle position, the autonomous driving path, and/or the driving plan to the external server. The external server may predict traffic information data using AI technology, etc., based on the information collected from vehicles or autonomous vehicles and provide the predicted traffic information data to the vehicles or the autonomous vehicles.
Claims in the present description can be combined in a various way. For instance, technical features in method claims of the present description can be combined to be implemented or performed in an apparatus, and technical features in apparatus claims can be combined to be implemented or performed in a method. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in an apparatus. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in a method.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0039065 | Mar 2022 | KR | national |
| 10-2022-0047048 | Apr 2022 | KR | national |
| 10-2022-0055740 | May 2022 | KR | national |
| 10-2022-0094101 | Jul 2022 | KR | national |
| 10-2022-0099543 | Aug 2022 | KR | national |
| 10-2022-0140452 | Oct 2022 | KR | national |
| 10-2022-0152802 | Nov 2022 | KR | national |
This application is the National Stage filing under 35 U.S.C. 371 of International Application No. PCT/KR2023/004182, filed on Mar. 29, 2023, which claims the benefit of earlier filing date and right of priority to Korean Application Nos. 10-2022-0039065, filed on Mar. 29, 2022, 10-2022-0047048, filed on Apr. 15, 2022, 10-2022-0055740, filed on May 4, 2022, 10-2022-0094101, filed on Jul. 28, 2022, 10-2022-0099543, filed on Aug. 9, 2022, 10-2022-0140452, filed on Oct. 27, 2022, 10-2022-0152802, filed on Nov. 15, 2022 and also claims the benefit of U.S. Provisional Application No. 63/416,908, filed on Oct. 17, 2022, the contents of which are all incorporated by reference herein in their entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2023/004182 | 3/29/2023 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63416908 | Oct 2022 | US |
