A method of a base station (BS) for transmitting synchronization signals in a wireless communication system. The method comprises generating a primary synchronization signal (PSS) including one of multiple PSS sequences that is generated based on a M-sequence of length 127 in a frequency domain, wherein the PSS indicates part of cell identification (ID) information using a cyclic shift performed on the M-sequence generating the PSS; generating a secondary synchronization signal (SSS) including one of multiple SSS sequences that is generated based on multiple BPSK modulated M-sequences of length 127 in the frequency domain, wherein the SSS indicates the cell ID information using cyclic shifts performed on the M-sequences generating the SSS; and transmitting, to a user equipment (UE), the PSS and SSS over downlink channels.

The present invention discloses a method for a user equipment to receive system information in a wireless communication system. Particularly, the method is characterized in detecting a first synchronization signal block configured with a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS) and a Physical Broadcasting Channel (PBCH) at a specific frequency position, determining a presence or non-presence of system information corresponding to the first synchronization signal block within a first synchronization raster corresponding to a specific frequency position based on a system information indicator included in the PBCH, and if the system information corresponding to the first synchronization signal block is determined as not existing, determining a second synchronization raster having system information exist therein based on the system information indicator.

A base station receives, from a wireless device, at least one first measurement report of at least one synchronization signal of a cell. One or more channel state information reference signals (CSI-RSs) of the cell are selected based on: the at least one first measurement report; and a first antenna port of the one or more CSI-RSs being quasi-collocated with a second port of the at least one synchronization signal. At least one second measurement report of the one or more CSI-RSs is received. At least one first CSI-RS of the one or more CSI-RSs is selected based on the at least one second measurement report. A downlink control information initiating a random access procedure of the cell is transmitted. The random access procedure is based on the at least one first CSI-RS.

A method and apparatus for implementing reference signal transmissions in a wireless communication system. In one embodiment, the method includes the cell, transmission point (TP), or transmission and reception point (TRP) broadcasting a first RS periodically for measurement, wherein the first RS is transmitted at multiple occasions (or timings) in each period on different beams. The method also includes the cell, TP, or TRP transmitting a second RS to a UE for PDCCH demodulation, wherein the second RS is transmitted on multiple beams in a beam set of the UE in a subframe (or symbol) in which the PDCCH is transmitted.

A method for identifying a mobile cell causing interference by a terminal connected to a first mobile cell, according to one embodiment of the present invention, comprises the steps of: acquiring system information of a fixed base station to which the first mobile cell is connected through a backhaul interface; acquiring a physical cell identifier of a second mobile cell neighboring the first mobile cell by a cell search; determining whether the second mobile cell causes interference to the first mobile cell on the basis of the physical cell identifier of the second mobile cell and the system information of the fixed base station; and reporting the physical cell identifier of the second mobile cell to the first mobile cell if the interference to the first mobile cell is determined to be caused by the second mobile cell.

Provided are a method and a device whereby a synchronization signal is transmitted and received. One embodiment of the present invention involves using one of a plurality of cells (first cell hereinbelow) in order to transmit synchronization signal setting information of a cell (second cell hereinbelow) set in an unlicensed band of the plurality of cells. The synchronization signal is transmitted on the second cell, based on the synchronization signal setting information. The synchronization signal is used in order to acquire time and frequency synchronization with the second cell.

Provided are a method for a first device carrying out wireless communication, and a device supporting same. The method may comprise the steps of: receiving, from a base station, information on the number of sidelink synchronization signal blocks (S-SSBs) transmitted in an S-SSB period; and, on the basis of the information on the number of S-SSBs, transmitting, in the S-SSB period, one or more S-SSB including a sidelink primary synchronization signal (S-PSS), a sidelink secondary synchronization signal (S-SSS) and a physical sidelink broadcast channel (PSBCH). Here, the number of S-SSBs may be selected from among one or more element included in a set of the number of S-SSBs transmittable in the S-SSB period, wherein the set of the number of S-SSBs transmittable in the S-SSB period may be configured differently on the basis of sub-carrier spacing (SCS) and frequency range (FR).

A mobile station communicates with a base station controlling over a cell containing a plurality of sectors. The mobile station also receives, from a base station, data of synchronization channels which includes sector specific codes respectively corresponding to sector identification numbers for identifying the sectors. In addition, the mobile station performs synchronization detection with reference to the data of synchronization channels, where the data of the synchronization channels mapped to a plurality of predetermined symbols at intervals of a half period of a frame and a plurality of predetermined subcarriers are specific to respective sectors in the same cell and common among adjacent cells.

A method of performing cell search includes receiving a primary synchronization signal (PSS) comprising a primary synchronization code (PSC) and receiving a secondary synchronization signal (SSS) comprising a first secondary synchronization code (SSC) and a second SSC, wherein the SSS includes a first SSS and a second SSS, the first SSC and the second SSC are arranged in that order in the first SSS, and the second SSC and the first SSC are arranged in that order in the second SSS. Detection performance on synchronization signals can be improved, and cell search can be performed more reliably.

A method for performing a device-to-device (D2D) communication in a wireless communication system by a terminal, according to an embodiment of the present invention, comprises: a step for detecting a D2D synchronization signal from at least one synchronization source; a step of measuring a D2D reference signal received through the same subframe as that for the detected D2D synchronization signal; and a step of selecting synchronization reference UE from said at least one synchronization source according to whether a prescribed condition is satisfied, wherein said prescribed condition is satisfied if the measured result of the D2D reference signal satisfies a threshold value and an information element of a D2D channel linked with the D2D reference signal satisfying the threshold value is acquired.