Abstract: Provided is an optical communication device including: a first channel card configured to convert an input first signal into a first optical signal and output the first optical signal to any one of a first MUX/DEMUX connected to a first optical line and a second MUX/DEMUX connected to a second optical line; a second channel card configured to convert an input second signal into a second optical signal and output the second optical signal to any one of the first MUX/DEMUX and the second MUX/DEMUX; and a controller configured to monitor states of the first optical line and the second optical line to determine a MUX/DEMUX from which the first optical signal and the second optical signal are respectively output, from among the first MUX/DEMUX and the second MUX/DEMUX.

Abstract: The disclosure provides a method of operating a distributed antenna system (DAS) interworking with a spectrum sharing system (SSS) including: transmitting, by a node unit of the DAS, DAS information to a management system entity (MSE); generating, by the MSE, linkage information based on the DAS information and radio service device (RSD) information received from at least one RSD of the SSS; transmitting, by the MSE, the interworking information to a system controller of the SSS; receiving, by the MSE, allocation information including a result of allocating shared radio resources to the DAS and the at least one RSD, respectively, according to the interworking information from the system controller; transmitting, by the MSE, the allocation information to the node unit; and operating, by the node unit, according to the allocation information.

Abstract: Provided is a communication repeater including a receiver configured to receive a plurality of test signals from a plurality of external communication devices and then receive a plurality of downlink signals from the plurality of external communication devices, and a digital signal processor configured to measure a delay time of each of the plurality of test signals and perform a delay synchronization process for the plurality of downlink signals, wherein the digital signal processor is configured to determine whether the plurality of downlink signals for which the delay synchronization process has been performed are synchronized, and perform synchronization restoration for a downlink signal having a synchronization error among the plurality of downlink signals, based on a result of the determining.

Abstract: A communication node included in a multi-antenna multi-carrier system, when precoding matrices corresponding to some subcarriers from among subcarriers allocated to another communication node connected to the communication node are input, obtains precoding matrices for at least some subcarriers from among the allocated subcarriers by performing spherical interpolation on the input precoding matrices, maps the obtained precoding matrices for the at least some subcarriers to the subcarriers allocated to the other communication node, and performs precoding on the plurality of vector signals using the mapped precoding matrices.

Abstract: Provided is an optical transceiver including: a controller configured to output firmware update data for updating firmware of another optical transceiver connected to the optical transceiver through an optical cable; and a transmitter configured to generate an optical signal by superposing input payload data and the firmware update data, and to transmit the optical signal to the other optical transceiver. According to embodiments, the firmware of a remote optical transceiver at a remote location is automatically updated without affecting payload data, which is information to be transmitted.

Abstract: Disclosed is a beacon-based positioning system. A beacon position in which a beacon is installable is defined in a target space, and a path loss model of radio frequency (RF) signals between all beacon positions and all observation positions of a scanner is determined. Among all possible installation plans for the beacon positions, an installation plan in which different beacon signals, whose RSSIs calculated using the path loss model have significant values, are received in a number greater than or equal to a minimum reference number and a total number of the beacons installed is minimum is determined as an optimal installation plan. The optimization problem of determining the optimal installation plan may be expressed by binary linear programming.

Abstract: A TSN-based distributed antenna system including a headend unit, one or more TSN switches, and one or more remote units and a fronthaul transport network constituted by the headend unit, the TSN switch, and the remote unit is provided. The packet-based fronthaul network constituted by the headend unit, the TSN switch, and the remote unit transmits traffic in a time-deterministic manner while minimizing packet loss through Ethernet to which TSN standards are applied.

Abstract: A method of combining compressed uplink signals according to one aspect of the present disclosure is a method of combining IQ data of uplink signals compressed without decompression by a block floating point compression method, a block scaling compression method, or a -law compression method.

Abstract: A fronthaul multiplexer according to one aspect of the present invention combines uplink packets in a compressed state that is received from two or more radio units so that the uplink packets are accumulated and combined immediately when received or the uplink packets are recompressed using a compressing method with high compression efficiency when stored in a memory in order to reduce a use amount of memory.

Abstract: According to one aspect of the disclosure, there is provided a mount bracket for installation of communication device in a structure, the mount bracket including: a bracket body coupled to the structure; a bracket base, to which the communication device is fixed, coupled to the bracket body and rotates to cover the bracket body; and a connection member provided at one end of the bracket body to rotatably connect the bracket base to the bracket body, wherein the bracket base includes an anti-detachment structure for preventing separation from the bracket body during rotation.

Abstract: Provided are a clock synchronization method performed between communication nodes included in a communication network, the clock synchronization method comprises receiving a synchronization source signal through any one of remaining communication nodes except for an uppermost communication node included in the communication network, generating a reference clock for clock synchronization from the received synchronization source signal and transmitting the generated reference clock through a first path including at least a portion reverse to a second path through which a downlink signal is transmitted in the communication network.

Abstract: Provided are a method of operating a communication system, the method comprises mapping some antennas selected from among a plurality of antennas of each of a plurality of first communication nodes and reception ports of a second communication node, combining uplink signals mapped to an identical reception port of the second communication node from among uplink signals received through the plurality of antennas, and transmitting the combined signals to the mapped reception ports of the second communication node, respectively.

Abstract: The present disclosure relates to a method of reducing a Peak to Average Power Ratio (PAPR) in a communication device, and more particularly, to a method of Crest Factor Reduction (CFR) processing of a signal in order to reduce a PAPR in a communication device such as a repeater. The communication device includes: a first CFR module configured generate a first processed signal by CFR processing an original signal; and a second CFR module configured generate a second processed signal by CFR processing the first processed signal, wherein the first processed signal is generated using a first sampling rate, and the second processed signal is generated using a second sampling rate. According to the disclosure, even a communication device with a low sampling rate may effectively remove a peak component of an input signal.

Abstract: Provided is a method of outputting a synchronization signal in a communication node comprising: receiving communication connection information from a terminal, identifying detectable position information of a synchronization signal block (SS block) included in the communication connection information, setting a position of the SS block based on the identified detectable position information, and outputting the SS block based on the set position.

Abstract: Provided is a base station signal monitoring system including: a plurality of optical transmission devices configured to transmit a base station signal; a measuring device configured to measure the base station signal according to a preset method; and a switch device, which is connected to the plurality of optical transmission devices and the measuring device, configured to switch connections between a plurality of input ports and a plurality of output ports so that the base station signal is transmitted from one of the plurality of optical transmission devices to the other one of the plurality of optical transmission devices or the measuring device.

Abstract: Provided are a method of operating a communication system using physical layer division, the method comprises extracting an initial random access signal from an uplink signal, in a first physical layer of a first communication node of the communication system reducing a data amount of the extracted initial random access signal in the first physical layer and calculating a time synchronization error using the initial random access signal with a reduced amount of data, in a second physical layer of a second communication node of the communication system.

Abstract: Provided is an optical communication system configured as an optical ring network including: a first optical communication device configured to transmit a first optical signal having a first wavelength in a first direction, and to transmit a second optical signal having a second wavelength in a second direction opposite to the first direction; and a second optical communication device configured to generate a first reflected signal by reflecting the first optical signal when the first optical signal is received, to generate a second reflected signal by reflecting the second optical signal when the second optical signal is received, and to transmit the first and second reflected signals to the first optical communication device, wherein the first optical communication device analyzes a connection state of the second optical communication device based on the first and second reflected signals.

Abstract: A distributed antenna system of the present invention implements duplication by a method of configuring a first headend unit and a second headend unit in an active state or in a standby state and connecting a hub unit or a remote unit to the first headend unit and the second headend unit and by a method of connecting, through a redundancy link, a hub unit or remote units of a branch group branched from and connected to each headend unit, activating the redundancy link according to the control of an active headend unit when an error occurs in a frame transmission path, and changing logical port states of a hub unit or remote units that cannot transmit frames due to the error in order to change the frame transmission path so that frame transmission is possible through the activated redundancy link.

Abstract: A method of operating a TDD-based interference cancellation repeater, the method comprises setting a compensation gain of a gain compensator differently in an uplink communication period and a downlink communication period, setting an optimal coefficient of an adaptive filter in the uplink communication period and an optimal coefficient of the adaptive filter in the downlink communication period the same, based on the set compensation gain of the gain compensator and removing an interference signal in the uplink communication period or the downlink communication period according to the set optimal coefficient of the adaptive filter.

Abstract: Provided are a base station signal matching device, and a base station interface unit and a distributed antenna system including the base station signal matching device. The base station signal matching device included in a distributed antenna system receiving a base station signal from at least one base station and transmitting the base station signal to at least one user terminal includes: a signal matching unit receiving a first base station signal from a corresponding base station and matching the first base station signal to be suitable for signal processing of the distributed antenna system; and a signal processing unit receiving the matched first base station signal from the signal matching unit, receiving a matched second base station signal from another base station signal matching device, and combining the matched first base station signal with the matched second base station signal.