Abstract:
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.
Abstract:
Provided are an apparatus and method for compensating a feedback path distortion in a digital broadcasting signal. The apparatus for improving a performance of a pre-equalizer in a transmitter of a digital broadcasting system having a feedback path for adaptively generating a filter coefficient of the pre-equalizer, includes a reference signal generator for generating a reference radio frequency (RF) signal, a feedback path estimator for estimating transmission band characteristic information for the feedback path based on the reference RF signal generated from the reference signal generator, and a feedback path compensator for compensating a demodulated signal transferred through the feedback path based on the estimated transmission band characteristic information from the feedback path estimator and generating a filter coefficient of the pre-equalizer.
Abstract:
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.
Abstract:
Provided are hierarchical modulation apparatus and method using a pilot signal and an apparatus and method for receiving a hierarchically modulated signal. The hierarchical modulation apparatus comprises a first encoder encoding a first layer signal sequence, a second encoder encoding a second layer signal sequence, a pilot inserting unit inserting a pilot signal into the signal sequence encoded by the second encoder, and a hierarchical modulator modulating the signals output from the first encoder and the pilot inserting unit and combining the modulated signals.
Abstract:
Provided is an electronic program guide (EPG) service using an EPG extensible markup language (XML) in a digital audio broadcasting (DAB)/digital multimedia broad casting (DMB) system, and more particularly, a voice-enabled EPG provision method which enables a user to listen to desired program information without looking at a screen or a liquid crystal display (LCD) panel or make a desired input by voice or through other interfaces while watching a broadcasting program by adding a voice input/output function to an EPG service. In this method, a tag for an interactive voice input/output function, i.e., an interactive dialog between a user and a system, is added or extended to an EPG XML which was designed to provide a text or screen-based EPG service. Therefore, the DAB/DMB system can have the voice input/output function in addition to text and graphics output functions. These functions enable a user to listen to or view desired program information through a screen, by voice, or in an integrated mode of the screen and voice while on the move.
Abstract:
Provided is an apparatus and method for providing customized public transportation information in a Digital Multimedia Broadcasting (DMB) terminal. In a transmitter of the DMB terminal, a data collecting/sorting unit collects public transportation information from a traffic information collector, and sorts the collected public transportation information into static data and dynamic data according to time variance. A transmission processing unit transmits the static data periodically and the dynamic data in real time.
Abstract:
Provided is a digital broadcasting service, more particularly, a method for providing a Web service that can simultaneously input/output speech data along with visual data by integrating speech Web data with broadcasting Web sites (BWS) provided for a multimedia broadcasting in a digital multimedia broadcasting (DMB) system configured based on a digital audio broadcasting (DAB), and an apparatus thereof . The method for synchronizing visual data with speech data includes the steps of : a) generating a visual Web document; b) generating a speech Web document including synchronization tags related to the visual Web document; and c) identifying the speech Web document and the visual Web document based on a sub-channel or a directory and transmitting the speech Web document and the visual Web document independently.
Abstract:
Provided are a method of estimating an encoder for dual stream transmission, and an encoder using the same. The method includes the steps of : a) setting up the number of memories required for an encoder, a free distance condition for robust data, and a free distance condition for mixed stream of robust data and normal data; b) obtaining 1/2 rate encoder combinations that sustain backward compatibility with a typical trellis encoder; c) obtaining encoder combinations H that satisfy the free distance condition for the robust data and the free distance condition for the mixed stream from the 1/2 rate encoder combinations; d) obtaining relations between memories and input/output signals, which satisfy the encoder combinations H; and e) configuring an encoder according to the obtained relation between the memories and the input/output signals.
Abstract:
Provided is a method for searching for an optimal coder suitable to a dual stream transmission method of a DTV transceiving apparatus, and an encoder and a decoder employing the optimal coder searching method. The optimal coder searching method includes the steps of: a) determining a mixed pattern of normal stream and robust stream; b) determining a trellis structure of the robust stream which is applied to the mixed pattern based on how coders are connected; c) forming a dual stream trellis by mixing a trellis of the normal stream, which is a normal stream trellis, and a trellis of the robust stream, which is a robust stream trellis; d) computing a free distance at departing points of the dual stream trellis structure based on a dual stream free distance computation termination condition; and e) determining the optimal coder based on the free distance.
Abstract:
The present invention provides an apparatus for transforming a terrestrial digital multimedia broadcasting (DMB) stream. The transformation apparatus includes a program specific information (PSI) extracting unit extracting PSI of a first stream and transmitting the first stream to a time code extracting unit a PSI analyzing unit analyzing the PSI of the first stream and acquiring construction information thereof; a PSI modifying unit for modifying the PSI information based on PSI modification information; the time code extracting unit for extracting time code information from the first stream based on stream information; a time code modifying unit for modifying a time code of a second stream based on the time code information; a stream erasing unit for erasing a stream piece of the first stream based on stream erasing information from the user; and a multiplexing unit for multiplexing the modified PSI, the modified first stream and the modified second stream.