Patent Application
20230276462
The present application claims priority to a Korean patent application 10-2020-0065290, filed May 29, 2020, a Korean patent application 10-2020-0084807, filed Jul. 9, 2020 and a Korean patent application 10-2020-0105460, filed Aug. 21, 2020, the entire contents of which are incorporated herein for all purposes by this reference.
The present disclosure relates to a wireless communication system and, more particularly, to a method and device for sensing a resource for sidelink communication in a wireless communication system.
A wireless communication system is a multiple access system that supports communication of multiple users by sharing available system resources (e.g., a bandwidth, transmission power, etc.). Examples of multiple access systems include a code division multiple access (CDMA) system, a frequency division multiple access (FDMA) system, a time division multiple access (TDMA) system, an orthogonal frequency division multiple access (OFDMA) system, a single carrier frequency division multiple access (SC-FDMA) system, and a multi carrier frequency division multiple access (MC-FDMA) 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 object having an infrastructure (or infra) established therein, and so on. The V2X may be divided 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 (mMTC), 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). Herein, the NR may also support vehicle-to-everything (V2X) communication.
The present disclosure relates to a method and device for efficiently sensing a resource for sidelink communication in a wireless communication system.
The present disclosure relates to a method and device for efficiently sensing a resource for sidelink communication using beamforming in a wireless communication system.
The present disclosure relates to a method and device for sensing a resource using a feedback signal for sidelink communication in a wireless communication system.
The present disclosure relates to a method and device for notifying of a location of a data channel using a feedback channel for sidelink communication using beamforming in a wireless communication system.
The technical objects to be achieved in the present disclosure are not limited to the above-mentioned technical objects, and other technical objects that are not mentioned may be considered by those skilled in the art through the embodiments described below.
As an example of the present disclosure, a method of operating a terminal in a wireless communication system comprises receiving sidelink data through a physical sidelink shared channel (PSSCH) from another terminal, and transmitting a feedback signal for the sidelink data through a physical sidelink feedback channel (PSFCH). The feedback signal may comprise hybrid automatic repeat request (HARQ)-acknowledge (ACK)/negative-ACK (NACK) information corresponding to the sidelink data and information related to a location of the PSSCH, and the feedback signal may be transmitted using a plurality of beams.
As an example of the present disclosure, a method of operating a terminal in a wireless communication system may comprise receiving a feedback signal transmitted through a physical sidelink feedback channel (PSFCH) from one of other terminals performing sidelink communication, identifying information related to a location of a physical sidelink shared channel (PSSCH) corresponding to the PSFCH based on the feedback signal, and transmitting sidelink data using a selected resource based on the information. The feedback signal may comprise hybrid automatic repeat request (HARQ)-acknowledge (ACK)/negative-ACK (NACK) information corresponding to sidelink data transmitted between the other terminals and information related to a location of the PSSCH, and the feedback signal may be transmitted using a plurality of beams.
As an example of the present disclosure, a terminal in a wireless communication system may comprise a transceiver and a processor connected to the transceiver. The processor may perform control to receive sidelink data through a physical sidelink shared channel (PSSCH) from another terminal and to transmit a feedback signal for the sidelink data through a physical sidelink feedback channel (PSFCH). The feedback signal may comprise hybrid automatic repeat request (HARQ)-acknowledge (ACK)/negative-ACK (NACK) information corresponding to the sidelink data and information related to a location of the PSSCH, and the feedback signal may be transmitted using a plurality of beams.
As an example of the present disclosure, a terminal in a wireless communication system may comprise a transceiver and a processor connected to the transceiver. The processor may perform control to receive a feedback signal transmitted through a physical sidelink feedback channel (PSFCH) from one of other terminals performing sidelink communication, to identify information related to a location of a physical sidelink shared channel (PSSCH) corresponding to the PSFCH based on the feedback signal and to transmit sidelink data using a selected resource based on the information. The feedback signal may comprise hybrid automatic repeat request (HARQ)-acknowledge (ACK)/negative-ACK (NACK) information corresponding to sidelink data transmitted between the other terminals and information related to a location of the PSSCH, and the feedback signal is transmitted using a plurality of beams.
As an example of the present disclosure, a device may comprise at least one memory and at least one processor functionally connected to the at least one memory. The at least one processor may control the device to receive sidelink data through a physical sidelink shared channel (PSSCH) from another terminal and to transmit a feedback signal for the sidelink data through a physical sidelink feedback channel (PSFCH). The feedback signal comprises hybrid automatic repeat request (HARQ)-acknowledge (ACK)/negative-ACK (NACK) information corresponding to the sidelink data and information related to a location of the PSSCH, and the feedback signal may be transmitted using a plurality of beams.
As an example of the present disclosure, a non-transitory computer-readable medium storing at least one instruction may comprise the at least one instruction executable by a processor. The at least one instruction may instruct a device to receive sidelink data through a physical sidelink shared channel (PSSCH) from another terminal and to transmit a feedback signal for the sidelink data through a physical sidelink feedback channel (PSFCH). The feedback signal comprises hybrid automatic repeat request (HARQ)-acknowledge (ACK)/negative-ACK (NACK) information corresponding to the sidelink data and information related to a location of the PSSCH, and the feedback signal may be transmitted using a plurality of beams.
The above-described aspects of the present disclosure are merely some of the preferred embodiments of the present disclosure, and various embodiments reflecting the technical features of the present disclosure may be derived and understood by those of ordinary skill in the art based on the following detailed description of the disclosure.
As is apparent from the above description, the embodiments of the present disclosure have the following effects.
According to the present disclosure, it is possible to efficiently sense a resource in a situation where beamforming is applied for sidelink communication.
It will be appreciated by persons skilled in the art that that the effects that can be achieved through the embodiments of the present disclosure are not limited to those described above and other advantageous effects of the present disclosure will be more clearly understood from the following detailed description. That is, unintended effects according to implementation of the present disclosure may be derived by those skilled in the art from the embodiments of the present disclosure.
The accompanying drawings are provided to help understanding of the present disclosure, and may provide embodiments of the present disclosure together with a detailed description. However, the technical features of the present disclosure are not limited to specific drawings, and the features disclosed in each drawing may be combined with each other to constitute a new embodiment. Reference numerals in each drawing may refer to structural elements.
The embodiments of the present disclosure described below are combinations of elements and features of the present disclosure in specific forms. The elements or features may be considered selective unless otherwise mentioned. Each element or feature may be practiced without being combined with other elements or features. Further, an embodiment of the present disclosure may be constructed by combining parts of the elements and/or features. Operation orders described in embodiments of the present disclosure may be rearranged. Some constructions or elements of any one embodiment may be included in another embodiment and may be replaced with corresponding constructions or features of another embodiment.
In the description of the drawings, procedures or steps which render the scope of the present disclosure unnecessarily ambiguous will be omitted and procedures or steps which can be understood by those skilled in the art will be omitted.
Throughout the specification, when a certain portion “includes” or “comprises” a certain component, this indicates that other components are not excluded and may be further included unless otherwise noted. The terms “unit”, “-or/er” and “module” described in the specification indicate a unit for processing at least one function or operation, which may be implemented by hardware, software or a combination thereof. In addition, the terms “a or an”, “one”, “the” etc. may include a singular representation and a plural representation in the context of the present disclosure (more particularly, in the context of the following claims) unless indicated otherwise in the specification or unless context clearly indicates otherwise.
In the present specification, “A or B” may mean “only A”, “only B” or “both A and B.” In other words, in the present specification, “A or B” may be interpreted as “A and/or B”. For example, in the present specification, “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 specification 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 specification, “at least one of A and B” may mean “only A”, “only B”, or “both A and B”. In addition, in the present specification, 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 specification, “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 specification 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 specification is not limited to “PDCCH”, and “PDDCH” 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 specification 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 clarity in the description, the following description will mostly focus on LTE-A or 5G NR. However, technical features according to an embodiment of the present disclosure will not be limited only to this.
For terms and techniques not specifically described among terms and techniques used in the present disclosure, reference may be made to a wireless communication standard document published before the present disclosure is filed. For example, the following document may be referred to.
Communication System Applicable to the Present Disclosure
Referring to
Components of a system may be referred to differently according to an applied system standard. In the case of the LTE or LTE-A standard, the radio access network 102 may be referred to as an Evolved-UMTS Terrestrial Radio Access Network (E-UTRAN), and the core network 103 may be referred to as an evolved packet core (EPC). In this case, the core network 103 includes a Mobility Management Entity (MME), a Serving Gateway (S-GW), and a packet data network-gateway (P-GW). The MME has access information of the terminal or information on the capability of the terminal, and this information is mainly used for mobility management of the terminal. The S-GW is a gateway having an E-UTRAN as an endpoint, and the P-GW is a gateway having a packet data network (PDN) as an endpoint.
In the case of the 5G NR standard, the radio access network 102 may be referred to as an NG-RAN, and the core network 103 may be referred to as a 5GC (5G core). In this case, the core network 103 includes an access and mobility management function (AMF), a user plane function (UPF), and a session management function (SMF). The AMF provides a function for access and mobility management in units of terminals, the UPF performs a function of mutually transmitting data units between an upper data network and the radio access network 102, and the SMF provides a session management function.
The BSs 120 may be connected to one another via Xn interface. The BS 120 may be connected to one another via core network 103 and NG interface. More specifically, the BSs 130 may be connected to an access and mobility management function (AMF) via NG-C interface, and may be connected to a user plane function (UPF) via NG-U interface.
Referring to
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 enable to exchange 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 PI-TY layer) and the second layer (i.e., the MAC layer, the RLC layer, and the packet data convergence protocol (PDCP) 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.
The physical channel includes several OFDM symbols in a time domain and several sub-carriers in a frequency domain. One sub-frame includes a plurality of OFDM symbols in the time domain. A resource block is a unit of resource allocation, and consists of a plurality of OFDM symbols and a plurality of sub-carriers. Further, each subframe may use specific sub-carriers of specific OFDM symbols (e.g., a first OFDM symbol) of a corresponding subframe for a physical downlink control channel (PDCCH), i.e., an L1/L2 control channel. A transmission time interval (TTI) is a unit time of subframe transmission.
Radio Resource Structure
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).
In a case where a normal CP is used, a number of symbols per slot (Nslotsymb), a number slots per frame (Nframe,μslot), and a number of slots per subframe (Nsubframe,μslot) may be varied based on an SCS configuration (μ). For instance, SCS(=15*2μ), Nslotsymb, Nframe,μslot and Nsubframe,μslot are 15 KHz, 14, 10 and 1, respectively, when μ=0, are 30 KHz, 14, 20 and 2, respectively, when μ=1, are 60 KHz, 14, 40 and 4, respectively, when μ=2, are 120 KHz, 14, 80 and 8, respectively, when μ=3, or are 240 KHz, 14, 160 and 16, respectively, when μ=4. Meanwhile, in a case where an extended CP is used, SCS(=15*2μ), Nslotsymb, Nframe,μ and Nsubframe,μ are 60 KHz, 12, 40 and 2, respectively, when μ=2.
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 FR1 and FR2. The values of the frequency ranges may be changed (or varied), and, for example, frequency ranges corresponding to the FR1 and FR2 may be 450 MHz-6000 MHz and 24250 MHz-52600 MHz, respectively. Further, supportable SCSs is 15, 30 and 60 kHz for the FR1 and 60, 120, 240 kHz for the FR2. Among the frequency ranges that are used in an NR system, FR1 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, comparing to examples for the frequency ranges described above, FR1 may be defined to include a band within a range of 410 MHz to 7125 MHz. More specifically, FR1 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 FR1 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.
Meanwhile, a radio interface between a UE and another UE or a radio interface between the UE and a network may consist of an L1 layer, an L2 layer, and an L3 layer. In various embodiments of the present disclosure, the L1 layer may imply a physical layer. In addition, for example, the L2 layer may imply at least one of a MAC layer, an RLC layer, a PDCP layer, and an SDAP layer. In addition, for example, the L3 layer may imply an RRC layer.
Bandwidth Part (BWP)
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.
When using bandwidth adaptation (BA), a reception bandwidth and transmission bandwidth of a UE are not necessarily as large as a bandwidth of a cell, and the reception bandwidth and transmission bandwidth of the BS may be adjusted. For example, a network/BS may inform the UE of bandwidth adjustment. For example, the UE receive information/configuration for bandwidth adjustment from the network/BS. In this case, the UE may perform bandwidth adjustment based on the received information/configuration. For example, the bandwidth adjustment may include an increase/decrease of the bandwidth, a position change of the bandwidth, or a change in subcarrier spacing of the bandwidth.
For example, the bandwidth may be decreased during a period in which activity is low to save power. For example, the position of the bandwidth may move in a frequency domain. For example, the position of the bandwidth may move in the frequency domain to increase scheduling flexibility. For example, the subcarrier spacing of the bandwidth may be changed. For example, the subcarrier spacing of the bandwidth may be changed to allow a different service. A subset of a total cell bandwidth of a cell may be called a bandwidth part (BWP). The BA may be performed when the BS/network configures the BWP to the UE and the BS/network informs the UE of the BWP currently in an active state among the configured BWPs.
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, PDSCH, or 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 a Physical Uplink Control Channel (PUCCH) or a 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 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. 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.
V2X or Sidelink Communication
Sidelink Synchronization Signal (SLSS) and Synchronization Information
The 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 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, based on Table 1, the UE may generate an S-SS/PSBCH block (i.e., S-SSB), and the UE may transmit the S-SS/PSBCH block (i.e., S-SSB) by mapping it on a physical resource.
Synchronization Acquisition of SL Terminal
In TDMA and FDMA systems, accurate time and frequency synchronization is essential. Inaccurate time and frequency synchronization may lead to degradation of system performance due to inter-symbol interference (ISI) and inter-carrier interference (ICI). The same is true for V2X. For time/frequency synchronization in V2X, a sidelink synchronization signal (SLSS) may be used in the PHY layer, and master information block-sidelink-V2X (MIB-SL-V2X) may be used in the RLC layer.
Synchronization acquisition of an SL UE will be described below.
In TDMA and FDMA systems, accurate time and frequency synchronization is essential. Inaccurate time and frequency synchronization may lead to degradation of system performance due to inter-symbol interference (ISI) and inter-carrier interference (ICI). The same is true for V2X. For time/frequency synchronization in V2X, a sidelink synchronization signal (SLSS) may be used in the PHY layer, and master information block-sidelink-V2X (MIB-SL-V2X) may be used in the RLC layer.
Referring to
Alternatively, the UE may be synchronized with a BS directly or with another UE which has been time/frequency synchronized with the BS. For example, the BS may be an eNB or a gNB. For example, when the UE is in network coverage, the UE may receive synchronization information provided by the BS and may be directly synchronized with the BS. Thereafter, the UE may provide synchronization information to another neighboring UE. When a BS timing is set as a synchronization reference, the UE may follow a cell associated with a corresponding frequency (when within the cell coverage in the frequency), a primary cell, or a serving cell (when out of cell coverage in the frequency), for synchronization and DL measurement.
The BS (e.g., serving cell) may provide a synchronization configuration for a carrier used for V2X or SL communication. In this case, the UE may follow the synchronization configuration received from the BS. When the UE fails in detecting any cell in the carrier used for the V2X or SL communication and receiving the synchronization configuration from the serving cell, the UE may follow a predetermined synchronization configuration.
Alternatively, the UE may be synchronized with another UE which has not obtained synchronization information directly or indirectly from the BS or GNSS. A synchronization source and a preference may be preset for the UE. Alternatively, the synchronization source and the preference may be configured for the UE by a control message provided by the BS.
An SL synchronization source may be related to a synchronization priority. For example, the relationship between synchronization sources and synchronization priorities may be defined as shown in [Table 2] or [Table 3]. [Table 2] or [Table 3] is merely an example, and the relationship between synchronization sources and synchronization priorities may be defined in various manners.
In [Table 2] or [Table 3], P0 may represent a highest priority, and P6 may represent a lowest priority. In [Table 2] or [Table 3], the BS may include at least one of a gNB or an eNB.
Whether to use GNSS-based synchronization or eNB/gNB-based synchronization may be (pre)determined. In a single-carrier operation, the UE may derive its transmission timing from an available synchronization reference with the highest priority.
For example, the UE may (re)select a synchronization reference, and the UE may obtain synchronization from the synchronization reference. In addition, the UE may perform SL communication (e.g., PSCCH/PSSCH transmission/reception, physical sidelink feedback channel (PSFCH) transmission/reception, S-SSB transmission/reception, reference signal transmission/reception, etc.) based on the obtained synchronization.
For example,
For example,
Referring to
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.
Subsequently, 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. After then, the first UE may transmit a PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) related to the PSCCH to the second UE. After then, 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. After then, 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. Table 4 shows an example of a DCI for SL scheduling.
indicates data missing or illegible when filed
Referring to
Referring to
Table 6 shows an example of a 2° d-stage SCI format.
Referring to
Referring to
Specifically,
Hybrid Automatic Request (Harq) Procedure
SL HARQ feedback may be enabled for unicast. In this case, in a non-code block group (non-CBG) operation, when the receiving UE decodes a PSCCH directed to it and succeeds in decoding an RB related to the PSCCH, the receiving UE may generate an HARQ-ACK and transmit the HARQ-ACK to the transmitting UE. On the other hand, after the receiving UE decodes the PSCCH directed to it and fails in decoding the TB related to the PSCCH, the receiving UE may generate an HARQ-NACK and transmit the HARQ-NACK to the transmitting UE.
For example, SL HARQ feedback may be enabled for groupcast. For example, in a non-CBG operation, two HARQ feedback options may be supported for groupcast.
For example, when groupcast option 1 is used for SL HARQ feedback, all UEs performing groupcast communication may share PSFCH resources. For example, UEs belonging to the same group may transmit HARQ feedbacks in the same PSFCH resources.
For example, when groupcast option 2 is used for SL HARQ feedback, each UE performing groupcast communication may use different PSFCH resources for HARQ feedback transmission. For example, UEs belonging to the same group may transmit HARQ feedbacks in different PSFCH resources.
In the present disclosure, HARQ-ACK may be referred to as ACK, ACK information, or positive-ACK information, and HARQ-NACK may be referred to as NACK, NACK information, or negative-ACK information.
Hereinafter, the present disclosure relates to resource sensing for sidelink communication in a wireless communication system, and more particularly, to a technology for sensing a resource used by terminals performing sidelink communication using a directional beam.
In order to perform millimeter wave (mmWave) communication, the use of a directional beam is considered to offset attenuation caused by path loss. However, 3GPP Release-16 does not consider directional beam characteristics in a sidelink procedure for V2X communication. Accordingly, there may be difficulties in resource sensing of a terminal that desires to use a V2X service using sidelink technology.
After initial beam alignment for bidirectional transmit beamforming of all terminals participating in the service for the V2X service, in particular, the V2V service is completed, data communication of a third-party terminal may be performed while data communication is in progress. In this case, for the communication of the third-party terminal, acquisition of channel information used for data communication between two terminals is a very important procedure. As such a procedure, the 3GPP standard defines a sensing and selection procedure. According to the sensing and selection procedure, the third-party terminal may acquire information on a channel used by other terminals by receiving a PSCCH transmitted between other terminals. In this case, when signals of other terminals are beamformed, the third-party terminal may be in a situation as shown in
3GPP NR Release 16 standard defines channels such as PSCCH, PSSCH, PSFCH for sidelink operation. The PSCCH is a control channel for sidelink resource assignment and is used to transmit 1st-stage SCI, the PSSCH is a data transmission channel and is used to transmit 2nd-stage SCI, the PSFCH is a feedback information transmission channel and is used to transmit feedback information, that is, HARQ-ACK information, in a unicast mode and a groupcast mode. In addition, the 3GPP 38.213 standard document defines a procedure for sidelink HARQ-ACK transmission in clause 16.3. According to this, in order to transmit HARQ feedback on the PSSCH data packet received from multiple users during a period including up to 4 slots, a base station may transmit a plurality of multiplexed HARQ-ACKs using a PSFCH valid resource through the PSFCH. Using the above description, the terminal, which has received data through the PSSCH, may provide information for sensing to adjacent terminals according to the method shown in
According to various embodiments, the information for resource sensing included in the feedback signal may include information related to the resource used by the terminal A 1210-1 and the terminal B 1210-2, for example, information related to the PSSCH used to transmit sidelink data. Specifically, the information related to the PSSCH is information related to the location of the PSSCH, and may include information for estimating or predicting the location of the PSSCH or information indicating the PSSCH. The information related to the PSSCH may be expressed explicitly or implicitly. The terminal, which has received the feedback signal, may extract a signal including the information related to the PSSCH from the feedback signal, and estimate and identify the location of the PSSCH based on a value of the extracted signal or a combination of elements different from the extracted signal (e.g., the location where the signal is extracted within the feedback signal, another signal included in the feedback signal, etc.).
Referring to
In step S1303, the terminal transmits feedback signals including ACK/NACK and information related to the location of the PSSCH through a PSFCH. That is, the terminal feeds whether decoding is successful back to another terminal and, at the same time, transmits information on sensing of a adjacent terminal. In this case, according to various embodiments, the terminal transmits feedback signals using a plurality of transmit beams having different directions. In this case, the terminal may repeatedly transmit the feedback signal during a plurality of transmission instances (e.g., slots).
Referring to
In step S1403, the terminal identifies information related to the location of the PSSCH from the feedback signals. The terminal may identify information related to the location of the PSSCH in a manner corresponding to the structure of the information related to the location of the PSCCH. For example, the terminal may identify the information related to the location of the PSSCH based on at least one of a value and location of a signal including information related to the location of the PSCCH or a structure of the PSFCH.
In step S1405, the terminal determines a usable resource and performs sidelink communication. The terminal may estimate or identify the location of the PSSCH used for sidelink communication of other terminals based on the identified information, identify the other available resources and then perform sidelink using at least some of the identified resources. That is, the terminal may determine resources to be used by the other terminals based on the identified used resource and periodicity of sidelink communication and perform sidelink communication using at least some of the remaining resources except for the determined resources in a resource pool.
According to the embodiments described with reference to
In performing sidelink communication, the terminal, which has received the PSFCH, determines whether the received PSFCH is valid feedback based on a resource pool used to transmit the data, SCI and a transmission time point, in order to identify that the corresponding PSFCH is feedback on the PSSCH transmitted thereby. At this time, if a common configuration is applied to a starting subchannel and a source ID (e.g., PID) of the PSSCH transmitted in the resource pool and SCI, the location of the PSSCH resource of another terminal may be inferred. According to an embodiment, the information for sensing described with reference to
The SFRI may be received by a adjacent terminal to enable a resource selection operation. To this end, by using a directional beam used for millimeter wave communication, transmission of the SFRI may be possible in all directions or a plurality of directions. According to the hardware capability of the terminal, when beams may not be simultaneously formed in a plurality of directions or the SFRI is transmitted in more directions than the number of simultaneously formable beams, repetitive transmission through two or more HARQ transmission instances is required. For repetitive transmission, a slot-wise HARQ-ACK repetition function of the PSFCH transmitting HARQ-ACK may be used.
According to the current 5G NR standard, the number of HARQ-ACK repetitions is dependent on a PSFCH period. Since the current standard defines the value of the PSFCH period as {1, 2, 4}, a maximum of 4 repetitions is possible. In the case of omnidirectional transmission using beams having a granularity of 45 degrees as shown in
Variables used below to describe embodiments using the SFRI and parameters defined in the standards corresponding to the parameters are summarized as shown in Table 9 below.
When operating in unicast mode, the starting subchannel is 1, and the slot index for receiving the PSCCH/PSSCH within the PSFCH period is 2, the structure of the PSSCH and the PSFCH and an example of the SFRI are shown in
In table 10, Msubch,slotPSFCH is the number of RBs occupied by one slot and one subchannel, RPRB,CSPSFCH is the number of values expressible using one RB of the PSFCH, MID is group member identification information and is set to 0 in the case of unicast. In the example of Table 10, Msubch,slotPSFCH is 2. In the example of Table 10, code division multiplex (CDM) using four cyclic shift (CS) values is applied and thus RPRB,CSPSFCH is 8.
Referring to
In the PSSCH region 1610, the PSSCH is transmitted through subchannel #6 1612 of slot index 2 and starting subchannel index 1. Accordingly, in the PSFCH region 1620, ACK/NACK is transmitted through subchannel #6 1622 corresponding to subchannel #6 1612. In this case, subchannel #6 1622 includes eight resources 1630-1 divided by a combination of RB and CS. An index of a resource, to which ACK/NACK will be mapped, among the eight resources 1630-1 is based on PID and MID, and is, for example, determined to be (PID+MID)%RPRB,CSPSFCH. When PID is 6 and MID is 0, ACK/NACK is mapped to the resource 1631 of index 6. Since the resource 1632 corresponds to RB index 12 and CS index 3, ACK/NACK information is multiplied by CS #3 and then transmitted through RB #12.
In addition to ACK/NACK information, the SFRI is transmitted. Referring to Table 10, PID and start-Subchannel for the SFRI are fixed to ‘0’. The SFRI is dependent on the received PSSCH, and, accordingly, among the resources in slot #2 in which the PSSCH is received, the SFRI is transmitted through subchannel #2 1624 corresponding to the resource of starting subchannel index 0. Similar to subchannel #6 1622, subchannel #2 1624 includes eight resources 1630-2 divided by a combination of RB and CS. Among the eight resources 1630-2, the resource 1634 to which the SFRI will be mapped is determined by PID and MID, PID for the SFRI is 0, and MID for the SFRI is set based on the number of PSSCHs received in the corresponding slot. For example, the values 0, 1, . . . , RPRB,CSPSFCH−2, RPRB,CSPSFCH−1 of MID denote 1, 2, . . . , RPRB,CSPSFCH−1, RPRB,CSPSFCH PSSCHs, respectively. In the case of
As a result, in the PSFCH region 1620, by mapping signals multiplexed with CS #0 and CS #3 to RB #4 and RB #12, the SFRI and ACK/NACK are expressed. In other words, in the PSFCH symbol included in the PSFCH region 1620, that is, in the feedback signal, one sequence in which CS #3 is applied to RB #12 is transmitted for HARQ-ACK/NACK information and another sequence in which CS #0 is applied to RF #4 is transmitted for SFRI.
Accordingly, the terminal, which has transmitted the PSSCH, may identify the HARQ-ACK information determined using the SFRI and its source ID. In addition, the adjacent terminal, which has not transmitted the PSSCH, may identify the adjacent PSSCH transmission state by decoding a common resource in the PSFCH of every slot along with resource sensing, and perform resource selection. That is, the adjacent terminal may estimate the location and number of PSSCHs received by the terminal, which has transmitted the PSFCH, by detecting the SFRI using the fixed starting subchannel index and the fixed source ID value.
Referring to
Referring to
Referring to
In step S1903, the terminal identifies the subchannel for the SFRI among the resources in the PSFCH. A subchannel for the SFRI may be predefined. One subchannel for the SFRI may be defined per PSSCH slot. That is, when a plurality of PSSCH slots correspond to one PSFCH slot, subchannels for SFRI as many as the number of PSSCH slots may be allocated in the PSFCH. Accordingly, the terminal identifies the subchannel for the SFRI corresponding to the PSSCH slot corresponding to the ACK/NACK information. Alternatively, the terminal identifies a subchannel in the PSFCH slot corresponding to a predefined location among resources included in the slot in which the PSSCH is received.
In step S1905, the terminal selects a resource in the subchannel based on the number of PSSCHs. The subchannel for SFRI is selected based on the location of the slot in which the PSSCH is received, and, among the resources in the subchannel, the resource to which the SFRI will be mapped is determined based on the number of PSSCHs received in the corresponding slot. Here, the resource may be specified by the location of the RB in the subchannel and the applied CS value.
In step S1907, the terminal transmits a PSFCH including sequences indicating ACK/NACK information and an SFRI. That is, the terminal maps at least one sequence defined to indicate ACK/NACK information and a sequence defined to indicate the SFRI to selected resources, and then transmits a feedback signal including the sequences through the PSFCH. In this case, the PSFCH may be transmitted in different directions using a plurality of transmit beams.
With reference to
Similar to the above-described SFRI, the TRIV is transmitted through a feedback signal using a plurality of transmit beams based on a PSFCH repetition function. However, unlike the SFRI, the TRIV according to various embodiments requires a new PSFCH format different from the PSFCH format defined in the current standard. Before describing a specific embodiment, the TRIV will be described as follows.
If NMAX is 2, the TRIV has a length of 5 bits. A 5-bit TRIV may represent one of values of 0 to 31. The 32 values may be mapped to virtual resources having a structure similar to a resource used for PSFCH resource selection. For example, virtual resources to which TRIV values are mapped are shown in
For example, if the TRIV value is 12, and the PSSCH is received in slot #3, resource #6 2112 is selected to represent the TRIV. Since resource #6 2112 corresponds to RB #6 2126 among 12 RBs 2120, a sequence for expressing the TRIV is transmitted through RB #6 2126. At this time, since the TRIV is 12 and 12 is the first value among values mapped to resource #6 2112, CS #0 2132 is applied.
If NMAX is 3, the TRIV has a length of 9 bits. The TRIV having a length of 9 bits may have one of 0 to 511. In this case, since a larger number of values than 36 values that may be expressed through mapping with virtual resources as shown in
Referring to
In step S2403, the terminal identifies a subchannel set for a TRIV among the resources in the PSFCH. The TRIV is expressed using two or more subchannels, and may be transmitted through subchannels defined separately from subchannels for ACK/NACK information transmission. In other words, the TRIV may be transmitted in an area assigned to indicate the TRIV in the PSFCH. One subchannel set for the TRIV may be defined per PSSCH slot. Accordingly, when a plurality of PSSCH slots correspond to one PSFCH slot, subchannel sets for the TRIV as many as the number of PSSCH slots may be assigned in the PSFCH. Accordingly, the terminal identifies the subchannel set for the TRIV corresponding to the PSSCH slot corresponding to the ACK/NACK information.
In step S2405, the terminal selects at least one resource in the subchannel based on the TRIV value. The number of selected resources may vary depending on the range of the TRIV value. For example, when the TRIV value is 0 to 31, one resource may be selected from among the resources in the subchannel set. As another example, when the TRIV value is 0 to 511, two resources may be selected from among the resources in the subchannel set. When two resources are selected, the resources may be selected based on a mapping table defining a correspondence relationship between two indices and TRIV values.
In step S2407, the terminal transmits a PSFCH including sequences indicating ACK/NACK information and the TRIV. That is, the terminal maps at least one sequence defined to indicate ACK/NACK information and a sequence defined to indicate the TRIV to selected resources, and then transmits a feedback signal including the sequences through the PSFCH. In this case, the PSFCH may be transmitted in different directions using a plurality of transmit beams.
According to the above-described various embodiments, the terminal may obtain information on the location of the PSSCH through the feedback signal, and perform resource sensing and selection operations. The various embodiments described above may be applied in the following environment. Since the HARQ-ACK feedback operation is utilized, a mode to which the HARQ procedure is applied among sidelink communication modes (e.g., unicast mode and groupcast mode option 2) is required. In addition, terminals performing sidelink communication and terminals performing resource sensing belong to a terminal cluster sharing the same resource pool configuration. In one terminal cluster, PSFCH transmission time point, timing synchronization, sl-MultiReserveResource-r16, and sl-MaxNumPerReserve-r16 are identically configured. That is, in the operation of the resource pool, full flexibility is limited, and, within the terminal cluster using the same resource pool, the above-described techniques may be operated. To this end, transmission of a cell-specific parameter (e.g., limited-resource-pool-for-beam flag) that may notify that the proposed technique is available may be considered.
The various embodiments described above may be utilized as one method for solving a hidden node problem. Specifically, if the above-described embodiments are applied, without using separate control frames such as request to send (RTS) and clear to send (CTS), other terminals in the vicinity of the transmitting terminal and the receiving terminal may know information on reserved resources which are being used by the transmitting terminal and the receiving terminal and will be used in the future, thereby reducing the possibility of mutual resource collision. In addition, when the above-described embodiments are applied, the possibility of delaying transmission of an emergency message by a network allocation vector (NAV) deferring access of other media which do not directly participate in communication based on the ‘Duration’ field of a RTS, CTS and data frame may be reduced.
In the case of adopting the RTS/CTS frame exchange procedure used in IEEE 802.11, etc. to solve the hidden node problem in the V2X communication system, control frames (e.g., RTS frame, CTS frame) having a size of about 20 bytes and 14 bytes shall be exchanged before data transmission. Since the exchange of control frames occupies a large amount of transmission capacity, it may hinder achievement of a high data transmission rate. However, most safety-related messages transmitted in the V2X environment generally have a low transmission rate. In this case, the NAV field deferring access to other media based on the ‘Duration’ field of the RTS frame, the CTS frame, and the data frame may restrict the transmission of the emergency message of the media. In order to solve this problem, the technique using the HARQ feedback signal according to the various embodiments described above may be applied without using separate control frames such as RTS and CTS.
However, since information (e.g., SFRI, TRIV) related to the location of the PSSCH according to the above-described embodiments is transmitted through a common resource through the same PSFCH when terminal B 2510-2, which has received the PSSCH from terminal A 2510-1, transmits HARQ-ACK through the PSFCH, resource information occupied by the PSSCH may be propagated to adjacent terminals including terminal C 25103. In
Referring to
In step S2603, terminal B 2610-2 transmits a PSFCH including a feedback signal for the PSSCH. Since the PSFCH is transmitted using a plurality of transmit beams, it may also be received even by terminal C 2610-3. The feedback signal includes HARQ-ACK/NACK information mapped to identification information of terminal A 2610-1.
In step S2605, terminal C 2610-3 detects the location of the PSCCH resource of terminal A 2610-1 based on the SFRI included in the feedback signal. That is, terminal C 2610-3 extracts a signal mapped to a subchannel for the SFRI from the PSFCH, and identifies a RB, to which the signal is mapped, and the used CS value, thereby detecting the location and number of PSSCHs. Here, the location of the PSSCH includes the location of the PSSCH transmitted in step S2601 and the location of the PSSCH to be used in the future.
In step S2607, terminal A 2610-1 transmits the PSSCH through the reserved resource to terminal B 2610-2. Since terminal C 2610-3 has detected the location of the PSSCH through the PSFCH, a reserved resource may not be selected.
In step S2609, terminal C 2610-3 transmits a PSSCH to terminal B 2610-2. The PSSCH includes control information, and the control information includes a source ID and a destination ID. That is, terminal C 2610-3 may select a collision-free resource based on the sensing result using the PSFCH and transmit data through the selected resource.
Various embodiments of the present disclosure may be combined with each other.
Hereinafter, a device to which various embodiments of the present disclosure may be applied will be described. Although not limited thereto, various descriptions, functions, procedures, proposals, methods, and/or operation flowcharts disclosed in this document may be applied to various fields requiring wireless communication/connection (e.g., 5G) between devices.
Hereinafter, it will be described in more detail with reference to the drawings. In the following drawings/description, the same reference numerals may represent the same or corresponding hardware blocks, software blocks, or functional blocks, unless otherwise indicated.
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 through the base station 120. AI technology is applicable to the wireless devices 100a to 100f, and the wireless devices 100a to 100f may be connected to the AI server 100g through the network. The network may be configured using a 3G network, a 4G (e.g., LTE) network or a 5G (e.g., NR) network, etc. The wireless devices 100a to 100f may communicate with each other through the base stations 120a to 120e or perform direct communication (e.g., sidelink communication) without through the base stations 120a to 120e. For example, the vehicles 100b-1 and 100b-2 may perform direct communication (e.g., vehicle to vehicle (V2V)/vehicle to everything (V2X) communication). In addition, the IoT device 100f (e.g., a sensor) may perform direct communication with another IoT device (e.g., a sensor) or the other wireless devices 100a to 100f.
Wireless communications/connections 150a, 150b and 150c may be established between the wireless devices 100a to 100f/the base stations 120a to 120e and the base stations 120a to 120e/the base stations 120a to 120e. Here, wireless communication/connection may be established through various radio access technologies (e.g., 5G NR) such as uplink/downlink communication 150a, sidelink communication 150b (or D2D communication) or communication 150c between base stations (e.g., relay, integrated access backhaul (IAB). The wireless device and the base station/wireless device or the base station and the base station may transmit/receive radio signals to/from each other through wireless communication/connection 150a, 150b and 150c. For example, wireless communication/connection 150a, 150b and 150c may enable signal transmission/reception through various physical channels. To this end, based on the various proposals of the present disclosure, at least some of various configuration information setting processes for transmission/reception of radio signals, various signal processing procedures (e.g., channel encoding/decoding, modulation/demodulation, resource mapping/demapping, etc.), resource allocation processes, etc. may be performed.
Referring to
The first wireless device 200a may include one or more processors 202a and one or more memories 204a and may further include one or more transceivers 206a and/or one or more antennas 208a. The processor 202a may be configured to control the memory 204a and/or the transceiver 206a and to implement descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed herein. For example, the processor 202a may process information in the memory 204a to generate first information/signal and then transmit a radio signal including the first information/signal through the transceiver 206a. In addition, the processor 202a may receive a radio signal including second information/signal through the transceiver 206a and then store information obtained from signal processing of the second information/signal in the memory 204a. The memory 204a may be coupled with the processor 202a, and store a variety of information related to operation of the processor 202a. For example, the memory 204a may store software code including instructions for performing all or some of the processes controlled by the processor 202a or performing the descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed herein. Here, the processor 202a and the memory 204a may be part of a communication modem/circuit/chip designed to implement wireless communication technology (e.g., LTE or NR). The transceiver 206a may be coupled with the processor 202a to transmit and/or receive radio signals through one or more antennas 208a. The transceiver 206a may include a transmitter and/or a receiver. The transceiver 206a may be used interchangeably with a radio frequency (RF) unit. In the present disclosure, the wireless device may refer to a communication modem/circuit/chip.
The second wireless device 200b may perform wireless communications with the first wireless device 200a and may include one or more processors 202b and one or more memories 204b and may further include one or more transceivers 206b and/or one or more antennas 208b. The functions of the one or more processors 202b, one or more memories 204b, one or more transceivers 206b, and/or one or more antennas 208b are similar to those of one or more processors 202a, one or more memories 204a, one or more transceivers 206a and/or one or more antennas 208a of the first wireless device 200a.
Hereinafter, hardware elements of the wireless devices 200a and 200b will be described in greater detail. Without being limited thereto, one or more protocol layers may be implemented by one or more processors 202a and 202b. For example, one or more processors 202a and 202b may implement one or more layers (e.g., functional layers such as PHY (physical), MAC (media access control), RLC (radio link control), PDCP (packet data convergence protocol), RRC (radio resource control), SDAP (service data adaptation protocol)). One or more processors 202a and 202b may generate one or more protocol data units (PDUs), one or more service data unit (SDU), messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed herein. One or more processors 202a and 202b may generate PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and/or methods disclosed herein and provide the PDUs, SDUs, messages, control information, data or information to one or more transceivers 206a and 206b. One or more processors 202a and 202b may receive signals (e.g., baseband signals) from one or more transceivers 206a and 206b and acquire PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed herein.
One or more processors 202a and 202b may be referred to as controllers, microcontrollers, microprocessors or microcomputers. One or more processors 202a and 202b may be implemented by hardware, firmware, software or a combination thereof. For example, one or more application specific integrated circuits (ASICs), one or more digital signal processors (DSPs), one or more digital signal processing devices (DSPDs), programmable logic devices (PLDs) or one or more field programmable gate arrays (FPGAs) may be included in one or more processors 202a and 202b. The descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed herein may be implemented using firmware or software, and firmware or software may be implemented to include modules, procedures, functions, etc. Firmware or software configured to perform the descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed herein may be included in one or more processors 202a and 202b or stored in one or more memories 204a and 204b to be driven by one or more processors 202a and 202b. The descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed herein implemented using firmware or software in the form of code, a command and/or a set of commands.
One or more memories 204a and 204b may be coupled with one or more processors 202a and 202b to store various types of data, signals, messages, information, programs, code, instructions and/or commands One or more memories 204a and 204b may be composed of read only memories (ROMs), random access memories (RAMs), erasable programmable read only memories (EPROMs), flash memories, hard drives, registers, cache memories, computer-readable storage mediums and/or combinations thereof. One or more memories 204a and 204b may be located inside and/or outside one or more processors 202a and 202b. In addition, one or more memories 204a and 204b may be coupled with one or more processors 202a and 202b through various technologies such as wired or wireless connection.
One or more transceivers 206a and 206b may transmit user data, control information, radio signals/channels, etc. described in the methods and/or operational flowcharts of the present disclosure to one or more other apparatuses. One or more transceivers 206a and 206b may receive user data, control information, radio signals/channels, etc. described in the methods and/or operational flowcharts of the present disclosure from one or more other apparatuses. In addition, one or more transceivers 206a and 206b may be coupled with one or more antennas 208a and 208b, and may be configured to transmit/receive user data, control information, radio signals/channels, etc. described in the descriptions, functions, procedures, proposals, methods and/or operational flowcharts disclosed herein through one or more antennas 208a and 208b. In the present disclosure, one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). One or more transceivers 206a and 206b may convert the received radio signals/channels, etc. from RF band signals to baseband signals, in order to process the received user data, control information, radio signals/channels, etc. using one or more processors 202a and 202b. One or more transceivers 206a and 206b may convert the user data, control information, radio signals/channels processed using one or more processors 202a and 202b from baseband signals into RF band signals. To this end, one or more transceivers 206a and 206b may include (analog) oscillator and/or filters.
Referring to
Codewords may be converted into radio signals via the signal processing circuit 300 of
Specifically, the codewords may be converted into scrambled bit sequences by the scramblers 310. 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 320. 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 330. Modulation symbols of each transport layer may be mapped (precoded) to corresponding antenna port(s) by the precoder 340. Outputs z of the precoder 340 may be obtained by multiplying outputs y of the layer mapper 330 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 340 may perform precoding after performing transform precoding (e.g., DFT) for complex modulation symbols. Alternatively, the precoder 340 may perform precoding without performing transform precoding.
The resource mappers 350 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 360 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 360 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 of
Referring to
The communication unit 410 may include a communication circuit 412 and a transceiver(s) 414. The communication unit 410 may transmit and receive signals (e.g., data, control signals, etc.) to and from other wireless devices or base stations. For example, the communication circuit 412 may include one or more processors 202a and 202b and/or one or more memories 204a and 204b of
The control unit 420 may be composed of at least one processor set. For example, the control unit 420 may be composed of a set of a communication control processor, an application processor, an electronic control unit (ECU), a graphic processing processor, a memory control processor, etc. The control unit 420 may be electrically coupled with the communication unit 410, the memory unit 430 and the additional components 440 to control overall operation of the wireless device. For example, the control unit 420 may control electrical/mechanical operation of the wireless device based on a program/code/instruction/information stored in the memory unit 430. In addition, the control unit 420 may transmit the information stored in the memory unit 430 to the outside (e.g., another communication device) through the wireless/wired interface using the communication unit 410 over a wireless/wired interface or store information received from the outside (e.g., another communication device) through the wireless/wired interface using the communication unit 410 in the memory unit 430.
The memory unit 430 may be composed of a random access memory (RAM), a dynamic RAM (DRAM), a read only memory (ROM), a flash memory, a volatile memory, a non-volatile memory and/or a combination thereof. The memory unit 430 may store data/parameters/programs/codes/commands necessary to derive the wireless device 400. In addition, the memory unit 430 may store input/output data/information, etc.
The additional components 440 may be variously configured according to the types of the wireless devices. For example, the additional components 440 may include at least one of a power unit/battery, an input/output unit, a driving unit or a computing unit. Without being limited thereto, the wireless device 400 may be implemented in the form of the robot (
Referring to
The communication unit 510 may transmit and receive signals and the control unit 520 may control the hand-held device 500, and the memory unit 530 may store data and so on. The power supply unit 540a may supply power to the hand-held device 500 and include a wired/wireless charging circuit, a battery, etc. The interface unit 540b may support connection between the hand-held device 500 and another external device. The interface unit 540b may include various ports (e.g., an audio input/output port and a video input/output port) for connection with the external device. The input/output unit 540c may receive or output video information/signals, audio information/signals, data and/or user input information. The input/output unit 540c may include a camera, a microphone, a user input unit, a display 540d, a speaker and/or a haptic module.
For example, in case of data communication, the input/output unit 540c may acquire user input information/signal (e.g., touch, text, voice, image or video) from the user and store the user input information/signal in the memory unit 530. The communication unit 510 may convert the information/signal stored in the memory into a radio signal and transmit the converted radio signal to another wireless device directly or transmit the converted radio signal to a base station. In addition, the communication unit 510 may receive a radio signal from another wireless device or the base station and then restore the received radio signal into original information/signal. The restored information/signal may be stored in the memory unit 530 and then output through the input/output unit 540c in various forms (e.g., text, voice, image, video and haptic).
Referring to
The communication unit 610 may transmit and receive signals (e.g., data, control signals, etc.) to and from external devices such as another vehicle, a base station (e.g., a base station, a road side unit, etc.), and a server. The control unit 620 may control the elements of the car or autonomous driving car 600 to perform various operations. The control unit 620 may include an electronic control unit (ECU). The driving unit 640a may drive the car or autonomous driving car 600 on the ground. The driving unit 640a may include an engine, a motor, a power train, wheels, a brake, a steering device, etc. The power supply unit 640b may supply power to the car or autonomous driving car 600, and include a wired/wireless charging circuit, a battery, etc. The sensor unit 640c may obtain a vehicle state, surrounding environment information, user information, etc. The sensor unit 640c may include an inertial navigation unit (IMU) sensor, a collision sensor, a wheel sensor, a speed sensor, an inclination sensor, a weight sensor, a heading sensor, a position module, a vehicle forward/reverse 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 brake pedal position sensor, and so on. The autonomous driving sensor 640d may implement technology for maintaining a driving lane, technology for automatically controlling a speed such as adaptive cruise control, technology for automatically driving the car along a predetermined route, technology for automatically setting a route when a destination is set and driving the car, etc.
For example, the communication unit 610 may receive map data, traffic information data, etc. from an external server. The autonomous driving unit 640d may generate an autonomous driving route and a driving plan based on the acquired data. The control unit 620 may control the driving unit 640a (e.g., speed/direction control) such that the car or autonomous driving car 600 moves along the autonomous driving route according to the driving plane. During autonomous driving, the communication unit 610 may aperiodically/periodically acquire latest traffic information data from an external server and acquire surrounding traffic information data from neighboring cars. In addition, during autonomous driving, the sensor unit 640c may acquire a vehicle state and surrounding environment information. The autonomous driving unit 640d may update the autonomous driving route and the driving plan based on newly acquired data/information. The communication unit 610 may transmit information such as a vehicle location, an autonomous driving route, a driving plan, etc. to the external server. The external server may predict traffic information data using AI technology or the like based on the information collected from the cars or autonomous driving cars and provide the predicted traffic information data to the cars or autonomous driving cars.
Examples of the above-described proposed methods may be included as one of the implementation methods of the present disclosure and thus may be regarded as kinds of proposed methods. In addition, the above-described proposed methods may be independently implemented or some of the proposed methods may be combined (or merged). The rule may be defined such that the base station informs the UE of information on whether to apply the proposed methods (or information on the rules of the proposed methods) through a predefined signal (e.g., a physical layer signal or a higher layer signal).
Those skilled in the art will appreciate that the present disclosure may be carried out in other specific ways than those set forth herein without departing from the spirit and essential characteristics of the present disclosure. The above exemplary embodiments are therefore to be construed in all aspects as illustrative and not restrictive. The scope of the disclosure should be determined by the appended claims and their legal equivalents, not by the above description, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein. Moreover, it will be apparent that some claims referring to specific claims may be combined with another claims referring to the other claims other than the specific claims to constitute the embodiment or add new claims by means of amendment after the application is filed.
The embodiments of the present disclosure are applicable to various radio access systems. Examples of the various radio access systems include a 3rd generation partnership project (3GPP) or 3GPP2 system.
The embodiments of the present disclosure are applicable not only to the various radio access systems but also to all technical fields, to which the various radio access systems are applied. Further, the proposed methods are applicable to mmWave and THzWave communication systems using ultrahigh frequency bands.
Additionally, the embodiments of the present disclosure are applicable to various applications such as autonomous vehicles, drones and the like.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2020-0065290 | May 2020 | KR | national |
| 10-2020-0084807 | Jul 2020 | KR | national |
| 10-2020-0105460 | Aug 2020 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2021/006617 | 5/27/2021 | WO |
