Patent application number | Description | Published |
20080267266 | Pre-Equalization Apparatus and Method for Reducing Time Delay in On-Channel Repeater - Provided is a pre-equalization apparatus and method that can reduce time delay of an on-channel repeater. The pre-equalization apparatus reduces time delay in an on-channel repeater by generating modified filter coefficient from a given filter coefficient and a pre-equalization filter coefficient after an up-sampling process and filtering up-sampled signals. The pre-equalization apparatus includes: a baseband signal generating unit for forming a baseband signal by combining an inputted signal, field sync signal, and segment sync signal; a pilot adding unit for adding a pilot signal to the baseband signal; an up-sampling unit for up-sampling the baseband signal having the pilot signal; a pre-equalization filter coefficient generating unit for generating a pre-equalization filter coefficient; a modified filter coefficient generating unit for generating a modified filter coefficient by using the pre-equalization filter coefficient and a given filter coefficient; and a filtering unit for filtering the up-sampled signal by using the modified filter coefficient. | 10-30-2008 |
20080298295 | Apparatus and Method for Modulating of On-Channel Repeater - Provided is a modulating apparatus and method of an on-channel repeater. An object of the present invention is to provide a modulating apparatus of an on-channel repeater for reducing time delay by configuring and up-sampling a baseband signal, filtering the up-sampled baseband signal with an Equi-Ripple (ER) filter or in a window method, and converting the filtered baseband signal into an RF signal. The modulating apparatus includes: a baseband signal configuring unit for configuring a baseband, signal by combining an input field and a segment sync signal; a pilot adding unit for adding a pilot signal to the baseband signal; a filtering unit for filtering the baseband signal with the pilot signal; and an RF up-converting unit for up-converting the filtered signal into an RF signal. The present invention is used to form an on-channel repeating network in a transmitting system including a digital TV broadcasting system. | 12-04-2008 |
20090219088 | APPARATUS AND METHOD FOR CORRECTING NON-LINEAR DISTORTION BASED ON CHARACTERISTIC MODELING OF HIGH POWER AMPLIFIER - An apparatus for correcting a non-linear distortion includes a pre-distorter for pre-distorting a transmit signal inputted from an external apparatus based on pre-distortion characteristics outputted from a pre-distortion characteristic predictor; a modulator for modulating the pre-distorted signal to thereby generate a modulated signal; a frequency up-converter for up-converting a frequency of the modulated signal to thereby generate an up-converted signal; a high power amplifier for amplifying the up-converted signal to a high power amplified signal; a frequency down-converter for down-converting a frequency of the high power amplified signal, thereby generate a down-converted signal; a demodulator for demodulating the down-converted signal, to thereby generate a demodulated signal; a high power amplifying characteristic predictor for predicting characteristics of the high power amplifier based on the pre-distorted signal and the demodulated signal; and a pre-distortion characteristic predictor for predicting the pre-distortion characteristics based on the pre-distorted signal and the predicted high power amplifying characteristics. | 09-03-2009 |
20090286473 | ON-CHANNEL REPEATER AND ON-CHANNEL REPEATING METHOD - Provided is an on-channel repeater, which includes a receiver for receiving radio frequency (RF) signals; a subtractor for subtracting replica from the RF signals to thereby produce output signals of the subtractor; a repeating process unit for performing a repeating process onto the output signals of the subtractor; and a replica generator for calculating replica based on the output signals of the subtractor and the signals obtained after repeating process performed thereon and feeding the replica back to the subtractor. | 11-19-2009 |
20100210205 | On-channel Repeater for Feedback Capable of Removing Feedback Signals Based on Pilot Partitioning and Method Thereof - Provided is an on-channel repeater capable of removing feedback signals based on pilot partitioning, which can efficiently remove a feedback signal by quickly coping with even a situation in which a feedback channel changes rapidly, by reducing a filter-coefficient update interval, i.e., increasing the number of times of filter-coefficient creation, through pilot partitioning, and a method thereof. The on-channel repeater includes: a receiver for receiving a signal; a subtractor for subtracting a replica of a feedback signal from the signal received in the receiver to remove the feedback signal; a replica creator for creating a filter coefficient using pilot partitioning, creating a replica of the feedback signal using the created filter coefficient, and feeding back the created replica to the subtractor; and a transmitter for transmitting an output signal of the subtractor. | 08-19-2010 |
20100221998 | ON-CHANNEL REPEATER AND ON-CHANNEL REPEATING METHOD - Provided are an on-channel repeater and method for increasing output of the on-channel repeater by removing feed-back signals caused by low isolation of transmission/reception antennas. The on-channel repeater includes: a receiver for receiving RF signals and converting the RF signals into baseband signals; a subtractor for subtracting replicas of feedback signals from the received signal; an inverse channel estimator for estimating inverse of a reception channel and generating a filter tab coefficients; a first adaptive filter for compensating for channel distortion of the subtracted signal; a transmitter for converting the signals whose channel distortion is compensated into an RF signal and performing radio transmission; a down-converter for down-converting the RF signal converted by the transmitter into the baseband signal; and a replica generator for calculating replicas and feeding back the replicas to the subtractor. The present invention is applied to the on-channel repeater. | 09-02-2010 |
20100297935 | APPARATUS AND METHOD FOR SYNCHRONIZING FREQUENCY IN DISTRIBUTED REPEATER - Provided is a frequency synchronizing apparatus and method that can synchronize center frequency of radio frequency (RF) transmission signals among distributed repeaters using identical signals as mother signals by reflecting sampling information acquired in a timing recovery process of reception signals transmitted from a main transmitter or other repeaters. The apparatus for synchronizing frequency in distributed repeaters includes: a timing recoverer for compensating sampling timing offset of reception signals; an intermediate frequency (IF) timing offset information reflector for applying the sampling timing offset information extracted in the timing recoverer to digital-to-analog conversion; and a radio frequency (RF) timing offset information reflector for applying the sampling timing offset information extracted in the timing recoverer to RF up-conversion as a reference signal. | 11-25-2010 |
20100310023 | APPARATUS AND METHOD FOR ESTIMATING INVERSE CHANNEL OF REPEATER'S RECEIVING CHANNEL - Provided is an apparatus and method for estimating inverse channel of a repeater's receiving channel, which ensures stability and causality by generating a time-domain filter coefficient having information on an inverse channel of repeater's receiving channel from a signal transmitted from a main transmitter or another repeater. The apparatus includes: a channel estimator for estimating a channel established by a transmission path from a received signal; an inverse minimum phase filter coefficient generator for generating inverse channel of a minimum phase channel from the estimated channel, and converting the inverse channel of the minimum phase channel into a time-domain filter coefficient; an inverse group delay filter coefficient generator for generating a time-domain filter coefficient by using the estimated channel and the minimum phase channel; and a combiner for generating an inverse channel of a receiving channel in a time domain by combining the filter coefficient and the filter coefficient. | 12-09-2010 |
20100311323 | ON-CHANNEL REPEATER AND ON-CHANNEL REPEATING METHOD - Provided are an on-channel repeater and an on-channel repeating method. The on-channel repeater includes: a receiving means for receiving a Radio Frequency (RF) signal; a subtracting means for subtracting a replica of feedback signals from the signal received by the receiving means; a replica generating means for calculating the replica based on the signal acquired from the subtraction in the subtracting means and feeding back the replica to the subtracting means; an inverse channel estimating means for estimating inverse of a reception channel based on the signal acquired from the subtraction in the subtracting means and generating filter tab coefficients; a first adaptive filtering means for compensating for channel distortion of the signal subtracted by the subtracting means based on the filter tab coefficients generated in the inverse channel estimating means; and a transmitting means for converting a signal whose channel distortion is compensated by the first adaptive filtering means into an RF signal and performing radio transmission. | 12-09-2010 |
20100321577 | DISTRIBUTED REPEATER AND DISTRIBUTED REPEATING METHOD THEREOF - Provided are a distributed repeater for repeating output signals identical to input signals through a channel different from that of main transmitter signals but identical to channels of other distributed repeaters, and a distributed repeating method thereof. The distributed repeater includes: a pre-processing unit configured to receive a radio frequency (RF) signal transmitted from an external device and demodulate the RF signal into a baseband signal; an equalizer configured to equalize the baseband signal to correct a distortion occurring on a transmission channel; an identification signal generation and insertion unit configured to generate an identification signal for identification of the distributed repeater and network conditioning, and insert the identification signal in the equalized baseband signal; and a post-processing unit configured to convert the baseband signal from the identification signal generation and insertion unit into an RF signal, and send the RF signal. | 12-23-2010 |