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: There is provided a distributed antenna system includes a plurality of head-end units configured to receive mobile communication signals from at least one base station, a hub unit connected to each of the plurality of head-end units through a first transport medium, the hub unit distributing the mobile communication signals respectively received from the plurality of head-end units to a plurality of remote units connected thereto through a second transport medium, and the plurality of remote units remotely disposed to transmit the mobile communication signals to a terminal in a service coverage, wherein the hub unit includes a signal summer configured to digitally sum sub-band signals in a same mobile communication service band based on the mobile communication signals.

Abstract: A remote apparatus includes: a plurality of sub amplification units amplifying radio frequency (RF) signals of different frequency bands, respectively; a test signal generation unit generating test signals of a frequency band for any one sub amplification unit among the plurality of sub amplification units; a conversion unit converting intermodulation (IM) signals generated in response to the test signals into a plurality of conversion IM signals by using a conversion signal of which a frequency is swept; and a control unit determining a degree of an intermodulation distortion by the any one sub amplification unit based on signal levels of the plurality of the conversion IM signals.

Abstract: The present invention provides a method of optical transmission delay compensation of a system including a main unit and a remote unit, wherein the main unit and the remote unit are connected to each other through an optical transmission line, including: receiving a reference signal, by the remote unit, generated by the main unit through the optical transmission line; analog converting the reference signal and performing analog processing on the reference signal; converting the analog-processed reference signal into an RF signal and radiating the RF signal; and measuring a delay time until the reference signal is generated and radiated as the RF signal. Accordingly, it is possible to obtain an effect of preventing degradation of service quality due to interference by synchronizing remote units and improving the service quality.

Abstract: There is provided a first unit which constitutes a point-to-multipoint communication system and is connected to communicate with each of a plurality of second units. The first unit includes a control signal extraction unit, a signal switching unit and a controller. The control signal extraction unit extracts first control signals respectively transmitted from the plurality of second units. The signal switching unit includes a switching circuit, and selects any one of the first control signals respectively received through individual signal transmission lines. The controller receives the first control signal selected by the signal switching unit, determines an allocation ID to be allocated to a second unit corresponding to the selected first control signal based on the initial identification information of the selected first control signal, and controls the determined allocation ID to be transmitted to the corresponding second unit.

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: According to one mode of the inventive concept, an amplification device includes a first amplification unit configured to amplify an input signal when a power level of the input signal is within a first range, a second amplification unit configured to amplify the input signal when the power level of the input signal is within a second range, and an abnormality sensing unit configured to sense an occurrence of an abnormality in the second amplification unit. The abnormality sensing unit senses reverse power regarding an output of the second amplification unit to generate a sensed voltage and compares the sensed voltage with a reference voltage to sense whether an abnormality occurs in the second amplification unit.

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: The present invention relates to an optical time domain reflectometer using, as a optical source, a polymer wavelength tunable laser which tunes the wavelength of an optical signal by using polymer grating. The optical time domain reflectometer of the present invention tunes the wavelength of a polymer wavelength tunable laser that outputs a constant optical signal and inspects cutting, reflection, and damage of an optical line by separating an optical signal returning from the optical line by an optical filter having a specific central wavelength. Since a optical source having a constant light intensity is used, the present invention has an effect of reducing the nonlinear effect generated in an optical line.

Abstract: A wavelength-setting auxiliary device according to an embodiment of the inventive concept includes an optical wavelength analyzer configured to transmit a test signal having a first wavelength to an optical line terminal, and to execute a central wavelength detection algorithm based on a result of detecting power of a return signal for the test signal to set optical wavelength information of a tunable optical module, and a connector connected to the tunable optical module for interfacing data transmitted between the optical wavelength analyzer and the tunable optical module.

Abstract: There is provided a main unit and a distributed antenna system including the same. The main unit for constituting a distributed antenna system that receives a base station signal from at least one base station, transmits the base station signal to at least one user terminal, and includes a plurality of main units, the main unit includes: a first receiver for receiving a first group of base station signals; a second receiver for receiving a second group of base station signals from another main unit; a signal combiner for combining the first and second groups of base station signals; and a delay compensator for compensating for time delay corresponding to a path between the main unit and the other main unit with respect to the first group of base station signals before combining the first and second groups of base station signals.

Abstract: There is provided a distributed antenna system includes a plurality of head-end units configured to receive mobile communication signals from at least one base station, a hub unit connected to each of the plurality of head-end units through a first transport medium, the hub unit distributing the mobile communication signals respectively received from the plurality of head-end units to a plurality of remote units connected thereto through a second transport medium, and the plurality of remote units remotely disposed to transmit the mobile communication signals to a terminal in a service coverage, wherein the hub unit includes a signal summer configured to digitally sum sub-band signals in a same mobile communication service band based on the mobile communication signals.

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: According to an aspect of the inventive concept, there is provided an apparatus for processing an output signal of an analog-digital converter, includes: a first frequency conversion unit for converting a frequency of the output signal of the analog-digital converter so that a band where spurious components exist moves to a band where direct current components exist in the output signal of the analog-digital converter; a spurious component blocking unit for eliminating, from an output signal of the first frequency conversion unit, spurious components which have moved to the band where direct current components exist; and a second frequency conversion unit for restoring a frequency of an output signal of the spurious component blocking unit to the original frequency of the output signal of the analog-digital converter.

Abstract: A remote apparatus includes: a plurality of sub amplification units amplifying radio frequency (RF) signals of different frequency bands, respectively; a test signal generation unit generating test signals of a frequency band for any one sub amplification unit among the plurality of sub amplification units; a conversion unit converting intermodulation (IM) signals generated in response to the test signals into a plurality of conversion IM signals by using a conversion signal of which a frequency is swept; and a control unit determining a degree of an intermodulation distortion by the any one sub amplification unit based on signal levels of the plurality of the conversion IM signals.

Abstract: A peak cancellation-crest factor reduction (PC-CFR) device includes a clipping unit configured to output a clipping error signal by clipping amplitude values of a first baseband complex signal based on a predetermined threshold value; a peak value determination unit configured to receive the clipping error signal, and determine a first amplitude value as a peak value when the first amplitude value is greater than a second amplitude value input before the first amplitude value and a third amplitude value input after the first amplitude value among amplitude values of the clipping error signal; a cancellation pulse generator (CPG) allocation unit configured to allocate the peak value to a CPG; and a subtractor configured to subtract a cancellation pulse generated from the CPG from the first baseband complex signal and output a second baseband complex signal with a reduced peak-to-average power ratio (PAPR).

Abstract: There is provided a first unit which constitutes a point-to-multipoint communication system and is connected to communicate with each of a plurality of second units. The first unit includes a control signal extraction unit, a signal switching unit and a controller. The control signal extraction unit extracts first control signals respectively transmitted from the plurality of second units. The signal switching unit includes a switching circuit, and selects any one of the first control signals respectively received through individual signal transmission lines. The controller receives the first control signal selected by the signal switching unit, determines an allocation ID to be allocated to a second unit corresponding to the selected first control signal based on the initial identification information of the selected first control signal, and controls the determined allocation ID to be transmitted to the corresponding second unit.

Abstract: There is provided a digital data compression device including a domain converter configured to perform frequency domain conversion on input digital I/Q data and output coefficient data corresponding to the digital I/Q data; a data converter configured to receive the coefficient data output from the domain converter and convert the input coefficient data of Cartesian coordinates into coefficient data of polar coordinates; and a quantizer configured to quantize the coefficient data of the polar coordinates output from the data converter.

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.

Abstract: A data compression device includes an analog to digital converter (ADC) configured to convert an analog signal into a digital signal including in-phase and quadrature components; and a compressor configured to generate a 28-bit fixed-point digital signal in which bits of the in-phase and quadrature components are alternately arranged, generate an exponent bit string by comparing n most significant bits of a data bit string excluding two sign bits in the 28-bit fixed-point digital signal with preset mapping data, wherein the exponent bit string includes 4 bits, generate a mantissa bit string composed of 14 bits corresponding to up to 14th bit from a bit next to the n most significant bits of the data bit string, and generate a 20-bit floating point digital signal by combining the two sign bits, the exponent bit string, and the mantissa bit string, wherein n is a natural number equal to or greater than 2 and equal to or less than 12.