The scheduling flexibility of CSI reference signals enables time and frequency synchronization using multiple non-zero CSI-RSs transmitted in the same subframe, or using CSI-RSs transmitted in the same subframe with other synchronization signals. Also, multiple synchronization signals may be scheduled in the same subframe to enable fine time and frequency synchronization without cell-specific reference signals.

In order to provide a transmission device and transmission method with which a response signal for random access preamble transmitted from a preamble transmission device is efficiently transmitted, setting unit in base station sets a first resource candidate group, which enables terminal capable of receiving a latch response transmitted by demodulation reference signal (DMRS) transmission to be selected, and a second resource candidate group, which enables terminal incapable of receiving a latch response transmitted by DMRS transmission but capable of receiving a latch response transmitted by cell-specific reference signal (CRS) transmission to be selected. Control unit selects DMRS transmission as the latch response transmission method when a resource in which latch preamble has been received is included in the first candidate group, but selects CRS transmission as the latch response transmission method when the resource is included in the second resource candidate group.

A base station can select orthogonal frequency-division multiplexing (OFDM) numerologies that define subcarrier spacing values based on attributes associated with one or more services that a user equipment (UE) is using. The base station can use the selected OFDM numerologies for transmission associated with the services. When the UE is using multiple services simultaneously, the base station can select the same or different OFDM numerologies for the multiple services.

A method for determining a position of a positioning device, for synchronization of positioning devices, and/or for synchronization of slave anchor electronic devices. The method is performed by a system having a master anchor electronic device, and a plurality of slave anchor electronic devices including a first slave anchor electronic device. The method includes broadcasting, from the master anchor electronic device, a first ultra-wide band (UWB) signal, at a first predetermined time. The method includes receiving, at the first slave anchor electronic device, the first UWB signal. The method includes determining, at the first slave anchor electronic device, a first transmission time based on the first UWB signal. The method includes broadcasting, from the first slave anchor electronic device, a second UWB signal at the first transmission time.

Aspects of the subject disclosure may include, for example, a process or apparatus for receiving, by a processing system including a processor, cell traffic reports for cells of a radio communication network, performing a reconfiguration analysis to identify reconfiguration information to reconfigure the radio communication network according to changing network conditions, and communicating the reconfiguration information defining a new cell configuration for the cells of the radio communication network and communicating information defining a new reconfiguration time for the cells to substantially synchronously switch to communicating according to the reconfiguration information. The receiving the cell traffic reports, the performing the reconfiguration analysis and the communicating the reconfiguration information occur in substantially real time. Other embodiments are disclosed.

Disclosed are a method for improving measurement performance of a terminal in a wireless communication system, and an apparatus therefor. Specifically, in a method wherein a terminal performs measurement in a wireless communication system, a method performed by the terminal comprises the steps of: receiving, from a serving base station, configuration information for measurement of a reference signal receive power (RSRP) and/or a reference signal received quality (RSRQ), wherein the configuration information includes port configuration information related to an antenna port to which a reference signal is transmitted and measurement configuration information related to a correlation between a cell-specific reference signal (CRS) and a re-synchronization signal (RSS) for the measurement; receiving the CRS and/or the RSS from a neighbor base station; calculating the RSRP and/or the RSRQ according to the configuration information by using the CRS and the RSS; and reporting the RSRP and/or the RSRQ to the serving base station.

The present invention provides methods for configuring and transmitting a positioning reference signal (PRS) used for estimating the location of a machine type communication (MTC) terminal in a wireless access system supporting machine type communication (MTC), and an apparatus for supporting the same. According to one embodiment of the present invention, a method for transmitting, by a base station, a positioning reference signal (PRS) used for estimating the location of a machine type communication (MTC) terminal in a wireless access system supporting MTC, comprises the steps of: repeating transmission of a physical downlink shared channel (PDSCH) including the same downlink data N times; and transmitting the PRS in a PRS subframe (SF), wherein when the PRS SF consists of a normal subframe (SF) and a multimedia broadcast multicast service single frequency network (MBSFN) SF, a normal cyclic prefix (CP) is used as a CP to be applied to the PRS, and when the PRS SF consists of only the MBSFN SF, a CP applied to the PRS may be an extended CP.

The present invention presents a method by which a base station notifies a terminal of information on a tone into which interference caused by surrounding cells greatly flows, and by which a terminal uses the information so as to efficiently remove the interference caused by the surrounding cells and to demodulate data channels, such that the method improves reception performance. Particularly, when the surrounding cells transmit cell-specific reference signals, the base station transmits, to the terminal, location information of the cell-specific reference signals transmitted by the surrounding cells, and the terminal demodulates the received data except for a data channel tone in which cell-specific reference signals of the surrounding cells greatly cause interference. The present invention can improve data reception performance by efficiently removing the interference caused by the surrounding cells.

A wireless device receives a control message configuring cell groups comprising a first cell group and a second cell group. The wireless device receives a control command causing the wireless device to transmit a random access preamble on a secondary cell in the secondary cell group. Transmission timing of the random access preamble is determined, at least in part, employing uplink subframe transmission timing of the primary cell or a stored timing advance value.

A first base station transmits to a second base station a first message. The first message comprises at least one parameter indicating the wireless device supports configuration of a plurality of cell groups. The first base station receives from the second base station a second message comprising first configuration parameters of a plurality of cells grouped into a first plurality of cell groups comprising a first cell group and a second cell group. The first base station transmits, to the wireless device, a third message comprising the first configuration parameters.