Abstract: Provided are a laser diode driver for a multilevel optical signal and a multilevel optical signal transmission device including the same, wherein the laser diode driver includes: a clock generator configured to generate and output a clock signal; a first latch configured to delay output of data corresponding to a first timing of the clock signal from among data sequentially input at each data input period; a second latch configured to delay output of data corresponding to a second timing of the clock signal from among data sequentially input at each data input period; a first synchronization processor configured to output a signal corresponding to the data input by the first latch according to the clock signal; and a second synchronization processor configured to output a signal corresponding to the data input by the second latch according to the clock signal.

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 operating a repeater operating in a time division duplex (TDD) mode which comprises detecting a synchronization signal from a received signal, determining a type of a communication period based on the detected synchronization signal and controlling an operation of a signal linearizer based on the determined type of the communication period.

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: There is provided a method of processing uplink Ethernet packets of an aggregation node included in a distributed antenna system, the method includes: receiving a plurality of uplink Ethernet packets; summing the plurality of received uplink Ethernet packets; and transmitting the summed uplink Ethernet packets in an uplink direction.

Abstract: Provided is an optical transceiver including: a receiver configured to receive an optical transmission signal including wavelength information from another optical transceiver through a multiplexer/demultiplexer connected to the receiver; and a controller configured to identify a reception wavelength for communication with the other optical transceiver and to determine a wavelength corresponding to the reception wavelength as a transmission wavelength for communication with the other optical transceiver, based on the wavelength information included in the optical transmission signal.

Abstract: An optical communication device includes: a first multiplexer including a first transmitting port and a second transmitting port; a downstream wavelength analyzer configured to analyze first transmission light to recognize a first downstream wavelength corresponding to the first transmission light and analyze second transmission light to recognize a second downstream wavelength corresponding to the second transmission light; and a controller configured to generate a first control signal for allowing the first transmitting port to pass light corresponding to the first downstream wavelength and allowing the second transmitting port to pass light corresponding to the second downstream wavelength, and output the first control signal to the first multiplexer, wherein the first multiplexer, according to the first control signal, controls the first transmitting port to correspond to the first downstream wavelength and controls the second transmitting port to correspond to the second downstream wavelength.

Abstract: There is provided a method of processing uplink Ethernet packets of an aggregation node included in a distributed antenna system, the method includes: receiving a plurality of uplink Ethernet packets; summing the plurality of received uplink Ethernet packets; and transmitting the summed uplink Ethernet packets in an uplink direction.

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: 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: A technology related to a distributed antenna system is disclosed. In an exemplary embodiment, a distributed antenna system may include a master unit and a plurality of remote units. The master unit may be interfaced with a wireless communications network and perform a bidirectional simultaneous digital radio frequency distribution of a wireless signal. The plurality of remote units may be each coupled to the master unit, and each perform a wireless transmission or reception of a split radio frequency signal to or from terminals located within a coverage. The master unit and the plurality of remote units may transmit or receive digital radio frequency signals in a wavelet transform domain. The master unit may determine whether the digital radio frequency signal, transmitted by each of the remote units, is normal, and merge the digital radio frequency signals.

Abstract: The present disclosure provides a method of allocating shared radio resources in a spectrum shared system (SSS), the method including: obtaining, by a system controller of the SSS, identification information from at least one radio service device of the SSS and a node unit of a distributed antenna system (DAS); determining, by the system controller of the SSS, whether the at least one radio service device interoperates with the DAS based on the identification information; and allocating, by the system controller of the SSS, the shared radio resources to the at least one radio service device and the DAS, respectively, based on a result of the determining of interoperating.

Abstract: A synchronization method of a communication network, the synchronization method comprises monitoring a connection state of second communication nodes that are synchronized using a synchronization signal provided through a first communication node to which a synchronization source is connected, determining whether the number of the connected second communication nodes exceeds a reference value according to a result of the monitoring and switching a synchronization mode of at least one second communication node when the number of the second communication nodes exceeds a reference value.

Abstract: A communication system comprises a clock generator configured to generate a plurality of system clock signals used to synchronize components included in each of communication nodes in the communication system based on an external clock signal provided by an external clock source located outside the communication system and a physical layer configured to transmit any one of the generated system clock signals to a small cell communicatively connected to an end communication node of the communication system.

Abstract: A method of operating a repeater comprises detecting a synchronization signal from a received communication signal, identifying a time division duplex (TDD) switching pattern based on a power change of the communication signal over time and switching an uplink operation and a downlink operation of the repeater based on the detected synchronization signal and the TDD switching pattern.

Abstract: Provided is an optical transceiver including: a receiver configured to receive an optical transmission signal including wavelength information from another optical transceiver through a multiplexer/demultiplexer connected to the receiver; and a controller configured to identify a reception wavelength for communication with the other optical transceiver and to determine a wavelength corresponding to the reception wavelength as a transmission wavelength for communication with the other optical transceiver, based on the wavelength information included in the optical transmission signal.

Abstract: Provided are a method of synchronizing a communication network, the method comprising obtaining a quality parameter of at least two or more synchronization sources connected to communication nodes in a communication network and a capacity parameter of the communication nodes connected to the synchronization sources, selecting a synchronization source to be used for synchronization of the communication network from among the at least two or more synchronization sources, according to a priority based on the obtained quality parameter and capacity parameter and performing synchronization of the communication network using a synchronization signal provided from the selected synchronization source.

Abstract: The present disclosure provides a method of allocating shared radio resources in a spectrum shared system (SSS), the method including: obtaining, by a system controller of the SSS, identification information from at least one radio service device of the SSS and a node unit of a distributed antenna system (DAS); determining, by the system controller of the SSS, whether the at least one radio service device interoperates with the DAS based on the identification information; and allocating, by the system controller of the SSS, the shared radio resources to the at least one radio service device and the DAS, respectively, based on a result of the determining of interoperating.

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: The present disclosure provides a method of allocating shared radio resources in a spectrum shared system (SSS), the method including: obtaining, by a system controller of the SSS, identification information from at least one radio service device of the SSS and a node unit of a distributed antenna system (DAS); determining, by the system controller of the SSS, whether the at least one radio service device interoperates with the DAS based on the identification information; and allocating, by the system controller of the SSS, the shared radio resources to the at least one radio service device and the DAS, respectively, based on a result of the determining of interoperating.