Abstract:
Provided is an on-channel repeater and method thereof. The on-channel repeating apparatus includes: a receiving unit for receiving a Radio Frequency (RF) broadcast signal; a demodulating unit for converting the RF signal into a baseband signal; an equalizing unit for equalizing the baseband signal to generate an equalized baseband signal; a modulating unit for converting the equalized baseband signal into an RF signal; and a transmitting unit for transmitting the RF signal.
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:
Provided is a frequency synchronizing apparatus and method that can synchronize frequencies between receiving signals and transmitting signals by extracting a carrier error and sampling timing error information in a synchronization process of the receiving signal from a main transmitter or another repeater and reflecting them in the transmitting signal in an on-channel repeater. The apparatus includes a carrier recovery means for compensating a carrier frequency error of a receiving signal; a timing recovery means for compensating a sampling timing error of the receiving signal; a carrier error reflecting means for reflecting the carrier frequency error extracted from the carrier recovery means to a transmitting signal; and a timing error reflecting means for reflecting the sampling timing error extracted from the timing recovery means to the transmitting signal. The present invention is used to form an on-channel repeating network in any transmission system including a digital television broadcasting system.
Abstract:
Provided are a Vestigial Side Band (VSB) Digital Television (DTV) transmitter and receiver based on the Advanced Television System Committee (ATSC) A/53, and a method thereof. The present invention provides 8-VSB DTV transmitter and receiver that can improve reception performance of the receiver by transmitting and double streams formed of normal data and robust data without increasing an average power level, regardless of the ratio of the normal data and robust data, by including an encoding unit for performing 16-state trellis coding on the robust data when a data stream includes robust data, and a method thereof.
Abstract:
Se proporcionan un transmisor y un receptor de Television Digital (DTV) de Banda Lateral Residual (VSB) basados en el A/53 del Comite de Sistema de Television Avanzado (ATSC) y un metodo para los mismos. La presente invencion proporciona un transmisor y un receptor DTV de 8-VSB que puede mejorar el funcionamiento de la recepcion del receptor mediante transmitir y recibir los datos robustos mezclados con P-2VSB, E-4VSB y/o E-8VSB. El transmisor DTV incluye un medio de entrada para recibir un flujo de datos de video digitales incluyendo los datos normales y los datos robustos, un medio de codificacion para codificar el flujo de datos de video digitales y un medio de transmision para modular y transmitir una senal de salida de los medios de codificacion, en donde los medios de codificacion realizan la codificacion trellis de los datos robustos mediante mezclar y usar una pluralidad de metodos.
Abstract:
Provided are an on-channel repeater and a method thereof. The on-channel repeater can extract reception channel information from signals transmitted from a main transmitter or another repeater, compensate for channel distortion caused on a transmission channel by inversely reflecting the extracted reception channel information to the received signals, and transmit the channel-distortion compensated signals through the same channel as a reception channel, and a method thereof. The on-channel repeater includes: a receiver for receiving RF signals transmitted from outside; a down-converter for down-converting the received RF signals into signals of a desired band; a channel-estimator for estimating an inverse value of a reception channel based on the down-converted signals; an adaptation filter for compensating for channel distortion by using a filter having the inverse value of the estimated reception channel; an up-converter for up-converting the channel distortion-compensated signals into RF signals; and a transmitter for transmitting the up-converted RF signals.
Abstract:
Provided is a demodulation apparatus capable of reducing time delay of an on-channel repeater in a terrestrial digital television (TV) broadcasting system and a demodulation method thereof. The demodulation method includes the steps of a) converting an analogue intermediate frequency (IF) signal into a digital IF signal; b) generating an in-phase (I) signal and a quadrature (Q) signal by converting the frequency of the digital IF signals and down-converting the frequencies of the pilot components of the I and Q signals so that the center frequencies of the I and Q signals could be shifted to 0; c) filtering the down-converted I and Q signals and maximizing signal-to-noise -ratio; d) up-converting the filtered I and Q signals into baseband signals in which the center frequencies of the filtered I and Q signals are placed in baseband and shifting the frequency of the pilot components of the filtered I and Q signals to 0; and e) adding up the up-converted I and Q signals to restore the signals into baseband signals for broadcasting.
Abstract:
The present invention relates to a Vestigial Side Band (VSB) Digital Television (DTV) in agreement with the DTV standards (A/53) of the Advanced Television System Committee (ATSC), and to a method thereof. More particularly, it provides 4-VSB DTV transceiver that improves reception performance of a receiver by transmitting and receiving dual streams formed of normal data and robust data without increasing average power, regardless of a mixing ratio of the normal and robust data. The 4-VSB DTV transceiver of the present research includes an encoding unit for encoding the robust data to be mapped to one of two groups having 4 levels {-5, -3, 1, 7} and {-7, -1, 3, 5}.
Abstract:
In a channel equalizer applicable to a digital television receiver, a forward filter and a backward filter perform filtering to an input signal and a predetermined signal. A Viterbi decoder corrects errors during a transmission procedure in a blind mode. A training symbol storing block stores training symbols. An output signal of the Viterbi decoder and symbols are provided to the backward filter in accordance with a blind mode or a training mode. A Kalman gain is calculated in a Kalman gain calculating block and an error signal is calculated by comparing an equalized signal, symbols, and the output signal of the Viterbi decoder with one another. A tap coefficient is updated by using the calculated error signal and the Kalman gain.