Abstract: Methods, apparatuses, and systems described herein generally relate to a reference signal generation and mapping. For example, a method comprises determining a first set of antenna ports for a demodulation reference signal (DM-RS) transmission; determining, based on the first set, a frequency index associated with four adjacent resource elements, wherein the four adjacent resource elements correspond to two adjacent symbols in a time axis and to two adjacent subcarriers in a frequency axis; generating, based on a first orthogonal cover code and a second orthogonal cover code, a DM-RS associated with the first set of antenna ports; and transmitting, via a mapping to the four adjacent resource elements, the DM-RS associated with the first set of antenna ports.

Abstract: Exemplary embodiments provide a method and apparatus for transmitting data through a device-to-device (D2D) communication between user equipments (UEs), the method including: generating, at a first UE, first D2D data, the first D2D data corresponding to a transport block (TB) unit; and transmitting, from the first UE to a second UE, the first D2D data through at least one D2D communication resource, the at least one D2D communication resource being based on a sub-RPT (sub-resource pattern for transmission). An RPT defined in a D2D resource pool is configured based on the sub-RPT, and the sub-RPT indicates the at least one D2D communication resource for the transmission of the first D2D data among at least two D2D communication candidate resources.

Abstract: A method and apparatus for supporting a device-to-device (D2D) communication between user equipments (UEs) are provided. The method includes: receiving, at a UE, configuration information associated with a D2D data transmission resource, the configuration information including information of a D2D data allocation period and being transmitted from an evolved NodeB (eNB); determining, at the UE, a D2D data transmission resource offset and a period associated with a D2D data transmission resource bitmap in each D2D data allocation period, the D2D data transmission resource bitmap including at least one bit corresponding to bit value “1”; and determining a pool of subframes corresponding to the bit value “1” of the D2D data transmission resource bitmap, the period associated with the D2D data transmission resource bitmap including the pool of subframes, the pool of subframes corresponding to D2D data transmission resources through which a D2D data transmission is capable.

Abstract: One or more synchronization procedures in wireless communications are provided. A wireless user device may determine a global navigation satellite system (GNSS) as a synchronization reference source associated with a sidelink synchronization. The wireless user device may determine, based on the GNSS being the synchronization reference source associated with a sidelink synchronization and a subcarrier spacing index for sidelink, a slot number for sidelink communication. The wireless user device may transmit, based on the slot number, a sidelink synchronization signal from the wireless user device to a second wireless user device.

Abstract: Provided is a method and apparatus for receiving a reference signal. A wireless user device may determine, based on a synchronization signal (SS) block index and based on an index associated with a time interval, an initialization value associated with a reference signal for a physical broadcast channel (PBCH). The wireless user device may receive, based on the initialization value and based on a frequency domain shift value, the reference signal via at least one resource element (RE). The reference signal may be mapped, based on the frequency domain shift value, to the at least one RE. The wireless user device may receive the PBCH.

Abstract: One or more synchronization procedures in wireless communications are provided. A wireless user device may determine a global navigation satellite system (GNSS) as a synchronization reference source associated with a sidelink synchronization. The wireless user device may determine, based on the GNSS being the synchronization reference source associated with a sidelink synchronization and a subcarrier spacing index for sidelink, a slot number for sidelink communication. The wireless user device may transmit, based on the slot number, a sidelink synchronization signal from the wireless user device to a second wireless user device.

Abstract: Exemplary embodiments provide a method and apparatus for transmitting a synchronization signal for Device-to-Device (D2D) communication in a wireless communication system. With respect to a D2D synchronization source to transmit a synchronization signal for D2D communication, the method includes: generating a D2D Synchronization Signal (D2DSS); and transmitting, by a synchronization source, the D2DSS to a D2D reception (Rx) UE, wherein the D2DSS includes a Primary D2D Synchronization Signal (PD2DSS) generated based on information associated with the synchronization source.

Abstract: A method, apparatus, and system for generating and transmitting a physical broadcast channel (PBCH) are provided. A base station may perform a first scrambling process on PBCHs in a time period before a channel coding, and perform a second scrambling process after the channel coding. PHCH payloads and PBCH DMRS may provide information bits to be used in the scrambling processes.

Abstract: Disclosed is a method and apparatus for generating information indicating a synchronization signal (SS) block. A method comprises: determining a frequency resource associated with a wireless device; determining, by a base station and based on the determined frequency resource, whether to add or omit a first bitmap indicating a plurality of groups in which at least one synchronization signal (SS) block is transmitted: generating, based on the determining to add the first bitmap, system information comprising a parameter comprising: the first bitmap; and a second bitmap indicating a position of one or more transmission SS blocks in each of the plurality of groups; and transmitting, based on the position, the one or more transmission SS blocks each comprising a Physical Broadcast Channel (PBCH) and a synchronization signal.

Abstract: A communication method of a terminal with another terminal through a sidelink comprises: determining, by a first user device, one or more radio resource control (RRC) configurations comprising information of a demodulation reference signal (DMRS) for vehicle-to-everything (V2X) communication between user devices; determining, based on the one or more RRC configurations, a Physical Sidelink Control Channel (PSCCH) DMRS for a PSCCH; determining, based on a cyclic redundancy code of the PSCCH, an identifier; determining, based on the identifier, an initialization value associated with a Physical Sidelink Shared Channel (PSSCH) DMRS for a PSSCH; and via one or more orthogonal frequency division multiplexing (OFDM) symbols, transmitting, by the first user device to a second user device, the PSCCH DMRS and the PSSCH DMRS.

Abstract: A method of performing sidelink positioning in a wireless communication system according to an aspect of the present disclosure may include, as an operation of receiving, by a first UE, allocation information from a base station, receiving, by each of one or more UEs, the allocation information from the base station; transmitting, by the first UE, the received allocation information to a second UE; as an operation of receiving, by the first UE, an SL SRS from the second UE, receiving, by each of the one or more UEs, the SL SRS transmitted from the second UE, and performing measurement based on the received SL SRS; and as an operation of transmitting measurement information acquired based on the measurement to the base station, acquiring, by each of the one or more UEs, measurement information by performing measurement based on the SL SRS and transmitting the same to the base station.

Abstract: A sidelink positioning method may include, as an operation of receiving, by a first UE, respective allocation information on one or more UEs including the first UE from a base station, receiving, by each of the one or more UEs, the respective allocation information from the base station; transmitting, by the first UE, allocation information of the first UE and the respective allocation information on the one or more UEs to a second UE; as an operation of transmitting, by the first UE, a SL PRS to the second UE based on the allocation information of the first UE, receiving, by the second UE, an SL PRS from each of the one or more UEs based on the allocation information on the one or more UEs received from the first UE; and receiving, by the first UE, measurement information from the second UE.

Abstract: A method includes receiving, at a mobile device, resource pool configuration information, the resource pool configuration information comprising a bitmap to determine the resource pool and determining, for a period having a plurality of consecutive subframes, a first subset of subframes by excluding, from the plurality of consecutive subframes, subframes in which a sidelink synchronization signal (SLSS) resource is configured and subframes other than uplink subframes. The method also includes determining, for the period, a second subset of subframes by excluding, from the first subset of subframes, one or more subframes, wherein a quantity of the second subset of subframes corresponds to an integer multiple of a length of the bitmap, and determining, based on a plurality of repetitions of the bitmap, the resource pool for a sidelink transmission from the second subset of subframes.

Abstract: A communication method of a terminal with another terminal through a sidelink may provide information related to a demodulation reference signal (DMRS). A user device may demodulate a Physical Sidelink Control Channel (PSCCH) DMRS and a Physical Sidelink Shared Channel (PSSCH) DMRS, and may demodulate a PSCCH based on the demodulated PSCCH DMRS and demodulate a PSSCH based on the demodulated PSSCH DMRS.

Abstract: Exemplary embodiments provide a method and apparatus for transmitting a synchronization signal for Device-to-Device (D2D) communication in a wireless communication system. With respect to a D2D synchronization source to transmit a synchronization signal for D2D communication, the method includes: generating a D2D Synchronization Signal (D2DSS); and transmitting, by a synchronization source, the D2DSS to a D2D reception (Rx) UE, wherein the D2DSS includes a Primary D2D Synchronization Signal (PD2DSS) generated based on information associated with the synchronization source.

Abstract: A communication method of a terminal with another terminal through a sidelink comprises: determining, by a first user device, one or more radio resource control (RRC) configurations comprising information of a demodulation reference signal (DMRS) for vehicle-to-everything (V2X) communication between user devices; determining, based on the one or more RRC configurations, a Physical Sidelink Control Channel (PSCCH) DMRS for a PSCCH; determining, based on a cyclic redundancy code of the PSCCH, an identifier; determining, based on the identifier, an initialization value associated with a Physical Sidelink Shared Channel (PSSCH) DMRS for a PSSCH; and via one or more orthogonal frequency division multiplexing (OFDM) symbols, transmitting, by the first user device to a second user device, the PSCCH DMRS and the PSSCH DMRS.

Abstract: Disclosed is a method and apparatus for generating information indicating a synchronization signal (SS) block. A method comprises: determining a frequency resource associated with a wireless device; determining, by a base station and based on the determined frequency resource, whether to add or omit a first bitmap indicating a plurality of groups in which at least one synchronization signal (SS) block is transmitted: generating, based on the determining to add the first bitmap, system information comprising a parameter comprising: the first bitmap; and a second bitmap indicating a position of one or more transmission SS blocks in each of the plurality of groups; and transmitting, based on the position, the one or more transmission SS blocks each comprising a Physical Broadcast Channel (PBCH) and a synchronization signal.

Abstract: Disclosed is a method and apparatus for generating information indicating a synchronization signal (SS) block. A method comprises: determining a frequency resource associated with a wireless device; determining, by a base station and based on the determined frequency resource, whether to add or omit a first bitmap indicating a plurality of groups in which at least one synchronization signal (SS) block is transmitted: generating, based on the determining to add the first bitmap, system information comprising a parameter comprising: the first bitmap; and a second bitmap indicating a position of one or more transmission SS blocks in each of the plurality of groups; and transmitting, based on the position, the one or more transmission SS blocks each comprising a Physical Broadcast Channel (PBCH) and a synchronization signal.

Abstract: A method includes generating a first DM-RS for V2X communication and a second DM-RS for V2X communication, the first DM-RS for V2X communication being mapped in a first symbol in a first slot of a subframe, the second DM-RS for V2X communication being mapped in a second symbol in the first slot; generating a third DM-RS for V2X communication and a fourth DM-RS for V2X communication, the third DM-RS for V2X communication being mapped in a first symbol in a second slot of the subframe, the fourth DM-RS for V2X communication being mapped in a second symbol in the second slot; and transmitting the first DM-RS for V2X communication, the second DM-RS for V2X communication, the third DM-RS for V2X communication, and the fourth DM-RS for V2X communication. The first DM-RS is generated based on a first group-hopping, and the second DM-RS is generated based on a second group-hopping.

Abstract: Exemplary embodiments provide a method and apparatus for transmitting a synchronization signal for Device-to-Device (D2D) communication in a wireless communication system. The method includes: receiving, at a first UE, a D2D synchronization signal transmitted from a second UE, the D2D synchronization signal comprising a primary D2D synchronization signal (PD2DSS) and a secondary D2D synchronization signal (SD2DSS); determining a root index based on the received PD2DSS; and determining a type of a synchronization source based on the root index. The root index corresponds to an integer value X when the type of synchronization source is associated with D2DSSue_net. The root index corresponds to an integer value Y when the type of synchronization source is associated with D2DSSue_oon. Each of the integer value X and integer value Y is not an element of a set {25, 29, 34}.