Disclosed are a method for transmitting and receiving a synchronization signal in a wireless communication system supporting NarrowBand-Internet of Things (NB-IoT) and an apparatus therefor. Specifically, the method for transmitting and receiving a synchronization signal may include: receiving, from a base station, a narrowband synchronization signal; and performing a cell search procedure for the base station based on the narrowband synchronization signal, in which the narrowband synchronization signal may include a narrowband primary synchronization signal and a narrowband secondary synchronization signal, the narrowband primary synchronization signal and the narrowband secondary synchronization signal may be transmitted in different subframe, and the subframe in which the narrowband secondary synchronization signal is transmitted may be configured differently according to a type of a radio frame structure.

One embodiment of the invention describes a synchronization signal sending method applied to an unlicensed frequency band. To ensure transmission fairness, a network device performs listen before talk (LBT) before a start time for transmitting a synchronization signal, to determine whether a channel is busy or idle. When the channel is busy, the network device cannot transmit the synchronization signal at the expected start time for transmitting the synchronization signal. Therefore, the network device performs LBT again within a preset time length after the start time, and sends the synchronization signal when determining that the channel is idle by performing LBT again. When the channel is idle, the network device preempts a channel resource, and sends the synchronization signal the expected start time for transmitting the synchronization signal.

Various arrangements for performing uplink grant-free transmissions are presented herein. An instance of user equipment (UE) may determine data that is to be transmitted using a grant-free (GF) uplink transmission to a base station of a cellular network. The UE may select a first GF resource block and a second GF resource block. The UE may transmit GF transmissions that comprise: a data payload and a first pointer at the first GF resource block; and the data payload and a second pointer at the second GF resource block. The first pointer may refer to the second GF resource block, while the second pointer may refer to the first GP resource block.

The present invention provides an electronic device for mitigating inter-cell interference in a dynamic TDD environment, the electronic device including: at least one antenna array including antenna elements; and a processor configured to use the antenna array and form a plurality of reception beams having mutually different directions, wherein at least one processor may enable: a first beam pair link to be formed with a first transmission beam emitted from a first base station by using a first reception beam having a first direction; information about a first TDD pattern indicating a TDD sequence set in a serving cell formed by the first base station and information about a second TDD pattern indicating a TDD sequence set in an adjacent cell adjacent to a serving cell formed by a second base station to be acquired; a first portion of the first TDD pattern to be selected on the basis of the information about the first TDD pattern and the information about the second TDD pattern; the detection of whether interference has occurred in the first portion; and a second beam pair link to be formed with one among transmission beams emitted from the second base station by using a second reception beam having a second direction different from the first direction, when the interference is determined to have occurred.

A method by which a base station transmits a synchronization signal (SS) in a wireless communication system, according to one embodiment of the present invention, comprises the steps of: generating an SS including a primary synchronization signal (PSS) and a secondary synchronization signal (SSS); and transmitting the synchronization signal. A portion of the synchronization signal is transmitted in a region of a time interval corresponding to the cyclic prefix (CP) of the synchronization signal, and the portion of the synchronization signal includes the PSS and/or the SSS.

An apparatus for transmitting broadcasting signal using transmitter identification scaled by 4-bit injection level code and method using the same are disclosed. An apparatus for transmitting broadcasting signal according to an embodiment of the present invention includes a waveform generator configured to generate a host broadcasting signal; a transmitter identification signal generator configured to generate a transmitter identification signal for identifying a transmitter, the transmitter identification signal scaled by an injection level code; and a combiner configured to inject the transmitter identification signal into the host broadcasting signal in a time domain so that the transmitter identification signal is transmitted synchronously with the host broadcasting signal.

A precoding process is performed on a first baseband signal and a second baseband signal to generate a first precoding signal and a second precoding signal. A pilot signal is inserted into the first precoding signal and phase change is performed on the second precoding signal. A pilot signal is inserted into the phase changed second precoding signal, and phase change is further performed on the phase-changed second precoding signal with the pilot signal inserted.

A method by which a terminal reports channel state information (CSI) in a wireless communication system, according to one embodiment of the present invention, comprises the steps of: measuring interference through an interference measurement resource (IMR) set in a control area; and reporting, to a base station, CSI for the control area on the basis of the result of the interference measurement, wherein the CSI for the control area includes information on quality of a downlink control channel set through at least one control channel element (CCE) aggregation, and the information on the quality of the downlink control channel can include information on at least one CCE aggregation level preferred by the terminal in order to receive the downlink control channel. A UE is capable of communicating with at least one of another UE, a UE related to an autonomous driving vehicle, a base station or a network.

A method in a wireless device for reporting Channel State Information (CSI). The wireless device is comprised in a wireless communications system. The method includes receiving a CSI process configuration and a request for CSI information from a network node. The method further includes reporting CSI for one or more CSI processes. The CSI reflects the state of the channel for a CSI reference resource. According to the method, the CSI reference resource is determined based on the number of configured CSI processes. Related devices are also disclosed.

The apparatus may be a base station. The apparatus processes a first group of synchronization signals. The apparatus processes a second group of synchronization signals. The apparatus performs a first transmission by transmitting the processed first group of the synchronization signals in a first synchronization subframe. The apparatus performs a second transmission by transmitting the processed second group of the synchronization signals in a second synchronization subframe.