Abstract: An analog distributed antenna system having a set of small cells as a signal source is provided. A proposed cellular communication system includes an upper small cell unit including upper protocol processors configured to process an upper first part of a protocol stack of a small cell, a lower small cell unit including lower protocol processors configured to process a remaining second part of the protocol stack of the small cell, and a first matching switch configured to respectively match the lower protocol processors to a plurality of remote units. According to one aspect, the cellular communication system includes a common controller configured to control activation of the plurality of upper protocol processors of the upper small cell unit and the plurality of lower protocol processors of the lower small cell unit according to a required service capacity and appropriately control an operation of the first matching switch.

Abstract: A communication device for power saving and a method for controlling power thereof are provided. The communication device includes a power amplifying unit and a control unit. The power amplifying unit generates an output signal obtained by amplifying a downlink signal, using a supply voltage, and outputs the output signal. The control unit determines a current state by comparing predetermined downlink reference information with output signal information on the output signal, and, if the current state is an active state as a comparison result, controls the supply voltage to correspond to the output signal information. Accordingly, power for amplifying a signal can be controlled according to communication traffic, thereby preventing consumption of unnecessary power.

Abstract: There is provided an optical signal monitoring device and an optical signal monitoring system of a wavelength division multiplexing based network including: an input unit configured to receive each of downlink signals and uplink signals; a wavelength division multiplexing filter configured to separate the downlink signals and the uplink signals by wavelength; an optical power measurement module configured to measure optical power of each signal separated by wavelength; and a controller configured to determine whether an optical signal is abnormal based on optical power information measured by the optical power measurement module.

Abstract: A distributed antenna system includes a plurality of head-end units for each receiving mobile communication signals from at least one corresponding base station, a hub unit communicatively coupled to the plurality of head-end units, and a plurality of remote units communicatively coupled to the hub unit, wherein the hub unit configured to distribute the mobile communication signals received from each of the plurality of head-end units to the plurality of remote units, wherein each of the plurality of remote units is remotely disposed to transmit the distributed mobile communication signals to a terminal in service coverage, and wherein the hub unit includes a mixing processing stage configured to perform digital mixing processing on the mobile communication signals respectively received from the plurality of head-end units, and a crest factor reduction (CFR) module disposed posterior to the mixing processing stage, with respect to a signal transmission direction.

Abstract: A passive intermodulation (PIM) measurement device for measuring a PIM in at least one of installation equipments and a distribution network within a distributed antenna system (DAS), the PIM measurement device included in a relay unit of the DAS, the PIM measurement device includes a pulse generation unit, a PIM detection unit and a controller. The pulse generation unit generates a two-tone pulse signal having frequencies different from each other. The PIM detection unit detects intermodulation (IM) signals fed back from the installation equipments or the distribution network in the DAS, corresponding to the propagation of the two-tone pulse signal. The controller detects PIM generation information in the DAS, based on the fed-back IM signal.

Abstract: A headend device includes a spectrum analysis unit configured to analyze a frequency spectrum of a plurality of base station signals to detect characteristic information of the plurality of the base station signals, a control unit configured to generate a control signal to control a power of the plurality of the base station signals on the basis of the characteristic information detected, and a plurality of RF units configured to receive at least one of the plurality of the base station signals and adjust the power of the base station signals received according to the control signal and output the power-adjusted base station signals.

Abstract: A wideband highly linear amplifier includes a plurality of pre-distortion units for respectively linearizing digital signals of a plurality of bands, a synthesis unit for synthesizing output signals of the pre-distortion units, a single amplifier for amplifying signals outputted from the synthesis unit, distribution units for respectively separating the signals for each of the plurality of bands from the output signals of the amplifier, a plurality of inverse compensation attenuators for respectively attenuating the separated signals for each of the plurality of bands, and a feedback path for respectively feeding the attenuated signals for each of the plurality of bands back into the pre-distortion unit of the corresponding band out of the plurality of the pre-distortion units.

Abstract: A signal processing device according to an exemplary embodiment of the inventive concept can integrate a power amplifier, a duplexer, and a linearizer as a module to improve the convenience of management and to improve flexibility and extensibility so as to be transformable corresponding to a change in system development concept.

Abstract: An interference cancellation repeater for canceling an interference signal included in an input signal including a first adaptive filter configured to generate a first estimated signal; a second adaptive filter configured to generate a second estimated signal; a first scaler configured to scale the first estimated signal based on a first scale factor determined according to a channel state; a second scaler configured to scale the second estimated signal based on a second scale factor determined according to the channel state; a first canceller configured to generate a first interference canceled signal based on the input signal and the scaled first estimated signal; and a second canceller configured to generate a second interference canceled signal based on the first interference canceled signal and the scaled second estimated signal.

Abstract: The present invention relates to a communication module assembly. The present invention is a communication module assembly which is electrically connected to a communication device and is supplied with power and signal, and can include a connection port unit that is supplied with the power and the signal from the communication device; a cable connection portion which is provided in the connection port unit, and to which cables electrically connected to the communication device is connected; a plurality of communication modules that is stacked on and connected to the connection port unit in a plug-in type; and a guide for guiding the communication module such that the communication modules are connected to the connection port unit in a central direction.

Abstract: Provided are a node unit including a queuing engine for multicasting Ethernet data, and a distributed antenna system including the same. The node unit is a node unit which is branch-connected to a plurality of lower nodes, and comprises: a media access control (MAC) module; and a queuing engine for interfacing Ethernet data between the MAC module and the plurality of branch-connected lower nodes, wherein the queuing engine multicasts Ethernet data received from the MAC module to the plurality of branch-connected lower nodes, transfers Ethernet data received from the plurality of branch-connected lower nodes to the MAC module, wherein the queuing engine comprises a buffer for buffering Ethernet data received from the plurality of branch-connected lower nodes, and outputting the buffered Ethernet data to the MAC module.

Abstract: According to an aspect of the inventive concept, there is provided an interference cancellation repeater for repeating a long term evolution (LTE) signal between a terminal and a base station, the interference cancellation repeater includes: an interference canceller configured to generate a restored LTE signal by canceling a feedback signal included in an input LTE signal; a sync signal detector configured to detect a first sync level which is a level with respect to a sync signal of the input LTE signal and a second sync level which is a level with respect to a sync signal of the restored LTE signal; and a gain controller configured to control a signal amplifier according to isolation calculated based on a difference between the first sync level and the second sync level.

Abstract: The present invention provides a distributed antenna system for automatically detecting an abnormally operating node unit. According to an embodiment of the present invention, a node unit of the distributed antenna system includes a signal input unit configured to receive and output first through n-th state information from n other node units connected to the node unit, where n is a natural number greater than or equal to 2; and a controller configured to analyze the first through n-th state information and to determine states of uplink signals respectively corresponding to the first through n-th state information. Each of the n other node units may analyze a signal received through a service antenna and generate the state information.

Abstract: An interference cancellation repeater according to the inventive concept includes: a first transmission/reception processing unit configured to adjust a gain of a radio frequency (RF) input signal input via a link antenna communicatively coupled to a base station; an interference canceller configured to cancel and output an interference signal from an output signal of the first transmission/reception processing unit; and a gain controller configured to extract a signal with constant magnitude regardless of a change in user traffic from the output signal of the interference canceller, and to adjust the gain of the RF input signal to a predetermined level by controlling the first transmission/reception processing unit based on the extracted signal.

Abstract: A distributed antenna system (DAS) according to an aspect of the inventive concept includes a first node unit for receiving first digital data in accordance with a digital interface standard from a base station, converting the first digital data into second digital data in accordance with a DAS frame standard, and a second node unit for receiving the second digital data from the first node unit, and restoring the first digital data based on the second digital data.

Abstract: An optical line testing device for measuring at least a cutting position of an optical line according to the present invention includes: a first wavelength tunable laser source configured to generate a first optical signal in which a plurality of wavelengths appear alternately and periodically; a second wavelength tunable laser source configured to generate a second optical signal which is identical to the first optical signal but has an adjustable delay time; and an interferometer configured to cause interference between a reflected optical signal, corresponding to the first optical signal, which is returning after having been emitted to the optical line, and the second optical signal to output an interference signal.

Abstract: An interference cancellation repeater configured to cancel an interference signal included in an input signal, the interference cancellation repeater including: a canceller configured to generate an interference canceled signal based on the input signal and an estimated signal; a digital filter configured to filter the interference canceled signal to generate an output signal; an interference signal detector configured to generate interference signal existence interval information using the input signal and the output signal; and an adaptive filter configured to receive the interference canceled signal and the output signal, and generate the estimated signal based on the interference signal existence interval information. Information of the signal existence section.

Abstract: According to an example embodiment of the inventive concept, a master unit for time division duplex includes a passive signal distributor for outputting, to a second node, a downlink signal input through a first node, and outputting, to the first node, an uplink signal input through a third node, and a signal transceiver for transmitting, to a remote unit, the downlink signal input from the second node, and outputting, to the third node, an uplink amplification signal received from the remote unit.

Abstract: A distributed antenna system includes a headend device for generating a downlink transmission signal by combining a plurality of downlink RF signals in different frequency bands, received from a plurality of base stations, and converting the downlink transmission signal into a downlink optical signal, a main remote device for receiving the downlink optical signal from the headend device, converting the downlink optical signal into the downlink transmission signal, and amplifying the plurality of downlink RF signals included in the downlink transmission signal, and a sub-remote device for receiving the downlink transmission signal distributed from the main remote device, and amplifying the plurality of downlink RF signals included in the received downlink transmission signal.

Abstract: A base station interface device including an interface board, which is located in a housing and determines an upper portion of a first surface as a first mounting location and an upper portion of a second surface opposite to the first surface as a second mounting location, including a relay connector wherein one end is exposed to the upper portion of the first surface and the other end is exposed to the upper portion of the second surface; a base station signal matching unit mounted on the first mounting location and including a first connector coupled to the one end of the relay connector; and a base station signal processing unit mounted on the second mounting location and including a second connector coupled to the other end of the relay connector.