A method for transmitting a sounding reference signal (SRS) by a terminal comprises the steps of: receiving, from a base station, the number of SRS repetition symbols, group hopping patterns, sequence hopping patterns, pattern selection information, and hopping selection information; generating an SRS sequence by applying a group hopping pattern and a sequence hopping pattern selected according to the pattern selection information and the hopping selection information; and transmitting the SRS on the basis of the SRS sequence, wherein the group hopping patterns include a group hopping pattern calculated using the number of SRS repetition symbols, the sequence hopping patterns include a sequence hopping pattern calculated using the number of SRS repetition symbols, and the hopping selection information selects whether to activate group hopping and sequence hopping.

Provided in the present invention is a method for avoiding downlink interference between an indoor DAS system and a small base station, the steps comprising: step 1: determining an initial access RU, and establishing a signal strength table; step 2: the DAS system, by means of the chosen RU, attempts to establish a downlink with UE 1, and detects the signal to interference plus noise ratio (SINR) value of the downlink signal of UE 1, and comparing same with a preset threshold value γ.sub.1; step 3: UE 1 maintains one or a plurality of RU downlinks assigned thereto by the DAS system, during the communication process continuously detects an SINR value at a set time interval, and on the basis of whether same is greater than γ.sub.1, ensures a corresponding service quality.

Provided is a method for performing network assisted interference cancellation and suppression (NAICS) in user equipment (UE) in which a carrier aggregation (CA) is set. The method can comprise the steps of: receiving a UE capability request message; and transmitting UE capability information by responding to the UE capability request message. The UE capability information can include information related to an NAICS operation in a situation in which a CA is set. The method can comprise a step of receiving interference cancellation support information from a base station. The interference cancellation support information can include information on neighboring cells identified by respectively operating in one or more carriers which are selected by the base station on the basis of the transmitted UE capability information. The method can comprise a step of cancelling the interference received from the neighboring cells, on the basis of the information on the neighboring cells within the interference cancellation support information.

The present invention relates to a feedback information transmission method for supporting interference randomization in a wireless system and an apparatus using the same. The feedback information transmission method comprises the steps of: receiving, from a base station, information for an interference pattern including an inter-cell interference measurement reference signal, and a trigger condition for change in the interference pattern; measuring interference randomization gains on the basis of the inter-cell interference measurement reference signal; determining whether to request a change in the interference pattern on the basis of the interference randomization gains; requesting a change in the interference pattern to the base station, if it is determined to request a change in the interference pattern; and receiving, from the base station, the changed interference pattern and the changed trigger condition.

An eNB transmits a preamble signal including synchronization information before transmitting data in an unlicensed band where the synchronization information is in accordance with a licensed frequency band communication standard used in a primary cell (Pcell) provided by the eNB. The preamble signal is transmitted in accordance with a timing structure used in the Pcell using the licensed frequency band. The eNB provides a secondary cell (Scell) that has a service area that at least partially overlaps with a service area of the Pcell. The preamble signal provides synchronization information to a user equipment (UE) device for the Scell.

A user equipment having a first mechanism to obtain a control region size of a sub-frame of a cell, the user equipment having a processor; and a communications subsystem, wherein the processor and communications subsystem are configured to cooperate to: determine having a first mechanism to obtain a control region size of a sub-frame of the first cell, second cell, or both, whether the user equipment is within an area of the second cell; and utilize, a second mechanism to obtain a control region size of a sub-frame of the second cell while the user equipment is within the area of the second cell.

A small cell interference coordination method and wireless communication device includes obtaining mobile information of at least one of the small cells. Relative movement between the small cells is determined according to at least the movement information. A Doppler frequency shift of a signal between small cells is estimated according to the relative movement. An interference alignment policy between small cells is implemented according to the estimated Doppler frequency shift.

A method includes transmitting, at an access point configured to transmit data over an unlicensed band, a single message prior to transmitting data over a channel of the unlicensed band. The method further includes receiving, at the access point, a plurality of responses from a plurality of user equipment acknowledging the single message in response to the single message.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive downlink control information (DCI) that includes an indication of a null resource element pattern. The null resource element pattern may be indicated in the DCI using: a value of an antenna port field that also indicates one or more demodulation reference signal (DMRS) ports for the UE and a number of DMRS code-division multiplexing groups without data, or one or more zero power downlink reference signals. The UE may perform one or more demodulation interference measurements based at least in part on the null resource element pattern. The UE may demodulate a downlink communication based at least in part on performing the one or more demodulation interference measurements. Numerous other aspects are provided.

In accordance with various embodiments, an electron beam evaporator can comprise the following: a tubular target; an electron beam gun for producing at least one vapor source on a removal surface of the tubular target by means of an electron beam; wherein the removal surface is a ring-shaped axial end surface or a surface of the tubular target that extends conically or in a curved fashion from the free end edge.