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: Provided are an optical relay system and a method for setting identification information of a remote device in an optical relay system. In particular, provided are an optical relay system and a method for setting identification information of a remote device in an optical relay system in which a donor device generates unique identification information of a remote device based on temporary identification information and characteristic information received from the remote device to automatically set identification information of the remote device, and as a result, the optical relay system can be normally implemented rapidly in initial installation of the optical relay system or a change of an optical relay system environment and convenience of a manager and reliability of a mobile communication service can be improved.

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: According to an embodiment of the inventive concept, an up-down converter includes a first mixer configured to convert an input radio frequency (RF) signal into an intermediate frequency (IF) signal using a first local signal; an IF filter configured to filter the IF signal converted by the first mixer; a second mixer configured to convert the IF signal, which has been filtered by the IF filter, into an output RF signal using a second local signal; and a local oscillator configured to control a frequency of the first local signal and the second local signal based on a frequency of the input RF signal.

Abstract: A head-end device according to an embodiment includes: a plurality of base station interfacing units configured to interface each of transmission/reception signals that are exchanged between the head-end device and a plurality of base stations; and a head-end control unit configured to receive an upper interfacing unit signal transmitted from an upper base station interfacing unit from among the plurality of base station interfacing units, and sequentially transmit the received upper interfacing unit signal to a lower base station interfacing unit.

Abstract: A repeater including an analog attenuator configured to attenuate an analog signal in response to a first control signal; an analog to digital converter (ADC) configured to convert the attenuated analog signal into a digital signal; a digital attenuator configured to attenuate the digital signal in response to a second control signal; and an attenuation controller configured to calculate average power and peak power of the attenuated digital signal, determine an attenuation value for each value of the calculated average power and peak power, and generate at least one of the first and second control signals based on the determined attenuation values.

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: 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: According to one or more embodiments of the present invention, a frame processing method of a distributed antenna system may include confirming whether a quality of service (QoS) tag exists in header information of a received frame; performing frame scheduling of the frame based on the QoS tag; and dropping or transmitting the frame according to a transmission priority according to a result of the frame scheduling.

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: 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: Provided is a multi-antenna relay device. The multi-antenna relay device having first to n-th (n is a natural number of 2 or more) channel formed between receiving antennas and transmitting antennas corresponding to each other, comprising: first to n-th channel interference cancellation units, respectively, included in a corresponding channel among the first to n-th channels and canceling first to n-th channel interference signals corresponding to signals radiated through the first to n-th channels from signal input into the corresponding channel in real time.

Abstract: The present invention, which relates to a multi-path communication device for sharing a feedback path for digital pre-distortion, includes: a DPD processing unit configured to output a plurality of pre-distorted signals by respectively pre-distorting a plurality of input signals, to output an nth control signal when an nth input signal is input, and to output an nth pre-distorted signal using an nth feedback signal input in response to the nth control signal; a power amplifying unit configured to amplify each of the plurality of pre-distorted signals and output a plurality of amplified signals; a signal combining unit configured to combine some of each of the plurality of amplified signals and output combined feedback signal; and a signal selection unit configured to select and output only the nth feedback signal from the combined feedback signal according to the input nth control signal, thereby preventing an increase in the size of a device and manufacturing cost thereof caused by a plurality of DPD feedbac

Abstract: There is provided a device for detecting LTE frame synchronization, including: a CP correlator calculating a correlation of a cyclic prefix (CP) included in each orthogonal frequency division multiplexing (OFDM) symbol of an LTE signal processed digital conversion; a frequency offset compensation unit compensating a frequency offset for a synchronization signal in the LTE signal by using a symbol frequency offset calculated based on the CP correlation; a synchronization signal correlation calculation unit performing a correlation calculation in a time domain with respect to the synchronization signal, of which the frequency offset is compensated, by considering a symbol start timing obtained based on the CP correlation; and a frame synchronization detection unit detecting the frame synchronization of the LTE signal based on a result of the correlation calculation for the synchronization signal.

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: An interference cancellation repeater includes: a first transmission/reception processing unit configured to convert a radio frequency (RF) input signal input via a link antenna communicatively coupled to a base station into a digital input signal; an interference canceller configured to cancel an interference signal from the digital input signal and to output an interference canceled signal; a second transmission/reception processing unit configured to convert the interference canceled signal into an RF output signal and to amplify the RF output signal; and a gain controller configured to detect a gain change of the interference cancellation repeater based on the interference canceled signal and to change a current gain of the interference cancellation repeater to a target gain by adjusting intensity of at least one of the RF input signal, the interference canceled signal, and the RF output signal when the gain change of the interference cancellation repeater is detected.

Abstract: The inventive concept relates to a distributed antenna system (DAS), and more particularly, to an uplink signal transmission operation of each of node units constituting a DAS. A node unit of a DAS includes a multiplexer configured to generate a single uplink signal by selectively outputting any one of m uplink signals received from m lower node units at an interval of a predetermined output time, where m is a positive integer greater than 1, and a down-sampler configured to output a transmission uplink signal by converting a sampling rate of the single uplink signal to correspond to a sampling rate of any one of the m uplink signals. Accordingly, it is possible to provide a DAS capable of processing and outputting, as one signal, uplink signals received from a plurality of remote units, without any error.

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: 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: An ethernet-based communication system is provided. The communication system comprises: a first unit configured to generate a reference clock signal by using an input first ethernet signal, multiplex the first ethernet signal and a second ethernet signal in response to the reference clock signal, and output the multiplexed ethernet signals; a second unit configured to generate the reference clock signal by using the multiplexed ethernet signals, separate the second ethernet signal from the multiplexed ethernet signals in response to the reference clock signal, and output the first ethernet signal; and a transmission medium for connecting the first and second units and transmitting the multiplexed ethernet signals from the first unit to the second unit.