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: 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 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.

Abstract: Provided is an SINR measurement method of a repeater, the SINR measurement method including: obtaining SSBs from a plurality of base stations; obtaining cross-correlation for each of PSS symbols included in the obtained SSBs; measuring noise power based on the obtained SSBs; obtaining signal power and interference signal power based on a dot product of the cross-correlation for each of the PSS symbols; and measuring the SINR based on the signal power, the interference signal power, and the noise power.

Abstract: A satellite signal relay system according to an embodiment of the inventive concept includes: a plurality of remote units configured to receive an analog satellite signal, to convert the analog satellite signal into a digital satellite signal, to generate a characteristic signal for the analog satellite signal, to generate a transmission frame based on the digital satellite signal and the characteristic signal, and to convert the transmission frame into an optical transmission frame; and a central unit configured to convert optical transmission frames received from the plurality of remote units into transmission frames through an optical transmission medium, respectively, to extract a digital satellite signal and a characteristic signal from each of the converted transmission frames, and to convert any one of the extracted digital satellite signals into an analog satellite signal based on the extracted characteristics signals.

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: A method of operating a communication device including a processor and a memory, the method comprises feeding back a downlink communication signal subjected to analog signal processing, generating signal modification information according to a comparison result of the fed-back downlink communication signal and a downlink communication signal before the analog signal processing, generating an interference cancellation signal for canceling interference occurring in an uplink communication signal by the downlink communication signal based on the generated signal modification information and canceling interference occurring in the uplink communication signal by using the generated interference cancellation signal.

Abstract: A method of operating a repeater comprises selecting some of adaptive filter coefficients among a plurality of adaptive filter coefficients of an adaptive filter used for interference cancellation, based on the size of a coefficient, generating a predicted interference signal using the selected adaptive filter coefficients and generating an interference-canceled communication signal from a received signal using the generated predicted interference signal.

Abstract: An automatic wavelength setting system for an optical communication device includes: an optical transceiver included in the optical communication device, the optical transceiver configured to generate and transmit first transmission light corresponding to a first wavelength, to analyze power of first reception light received after the transmission of the first transmission light, and when it is determined that the first transmission light is received as a result of the analysis, to generate and transmit second transmission light corresponding to a second wavelength; and an optical reflector, which is formed between the optical transceiver and a multiplexer, configured to transmit the first transmission light to the connected multiplexer when the first transmission light is an optical signal of a set wavelength, and to reflect and retransmit the first transmission light to the optical transceiver when the first transmission light is not the optical signal of the set wavelength.

Abstract: Provided are an interference cancellation repeater capable of selecting one of a plurality of adaptive filters based on a synchronization signal and canceling interference included in a received signal using the selected adaptive filter and a method of operation thereof.

Abstract: Provided are a synchronization signal detection method performed by a receiver including a processor and a memory, the synchronization signal detection method comprises calculating a PSS correlation value for a primary synchronization signal (PSS) included in a received signal, detecting a frequency offset for the PSS and a timing offset for sampling timing of the received signal and detecting the PSS based on the PSS correlation value, the frequency offset, and the timing offset.

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: Embodiments of a system and method for communicating acknowledgments in a wireless network are generally described herein. In some embodiments, a method of wirelessly communicating acknowledgements includes receiving a first signal on a first subchannel from a second wireless device. The method may include transmitting a block acknowledgement of the first signal on a subchannel. The first wireless communication device may not receive a block acknowledgement request to transmit the block acknowledgement. In some embodiments, a method of communicating block acknowledgements includes transmitting a first transmission to a first wireless device on a first subchannel and a second transmission to a second wireless device on a second subchannel The method may include receiving a first block acknowledgement from the first wireless device and a second block acknowledgement from second wireless device. The first and second block acknowledgement may be received on one of the first and second subchannels.

Abstract: Provided is an optical module assembly including: an optical module body in which an optical transceiver is built; a first connector coupled to one side of the optical module body to be connected to an optical transceiver in the optical module body; a second connector, in which an insertion hole for inserting an optical cable is formed and the optical cable is inserted into the insertion hole, connected to the first connector to connect the optical cable to the optical transceiver connected to the first connector; and a disconnection unit installed on the first connector and the second connector to release the connection between the first connector and the second connector by rotation.