摘要:
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.
摘要:
Provided is a modulation apparatus that can reduce time delay of on-channel repeaters in a terrestrial digital television broadcasting system. The time delay is caused by a filter during the modulation operation in the on-channel repeaters. The modulation apparatus of the present research includes: a baseband signal forming unit for forming a baseband signal by combining the output signals of an equalization unit with the pre-defined field/segment synchronization signals in the on-channel repeaters; a pilot inserting unit for inserting a pilot signal to the baseband signal; an up-sampling unit for up-sampling the baseband signal with the pilot signal; a VSB filtering unit for filtering the up-sampled baseband signal based on a Window technique and/or an Equi-Ripple filter to thereby form an in-phase (I) signal and a quadrature (Q) signal; an up-converting unit for up-converting the frequencies of the filtered I and Q signals to frequencies of an intermediate frequency (IF) band; an adding unit for adding the up-converted I and Q signals and converting a resultant signal into a digital VSB signal of the IF band; and a digital-to-analogue converting unit for converting the digital signal of the IF band to an analogue signal.
摘要:
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.
摘要:
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.
摘要:
Provided is a channel equalizing apparatus and method for improving channel equalization performance in an Orthogonal Frequency Division Multiplexing (OFDM) reception system applied to digital broadcasting or a communication system. The apparatus, includes: a channel estimating unit for performing channel estimation by using a pilot signal of a frequency domain; a digital filtering unit for changing a characteristic of a channel in a time domain based on an estimated channel estimation result; and a channel equalizing unit for performing channel equalization of a frequency domain on the signal after changing the channel characteristic.
摘要:
Provided is a Vestigial Side Band Digital Television (DTV) transmitter/receiver based on Advanced Television System Committee A/53. The invention provides DTV transmitter/receiver having a dual stream structure through generation of robust data which has a transmission rate a fourth as fast as that of normal data, and a method thereof. The DTV transmitter includes: input means for receiving digital video data stream including normal and robust data; encoding means for performing ¼ rate coding on the digital video data stream so that one bit can be transmitted through two symbols; and transmitting means for modulating/transmitting output signals of the encoding means. This invention can reduce SNR and satisfy TOV of robust data by performing additional FEC on robust data, transmitting/receiving ¼ rate coded robust data, which are capable of transmitting one-bit data for two symbols, and improving decoding ability of an equalizer and a trellis decoder of a DTV receiver.
摘要:
Provided is a system and method for transmitting and receiving 3D video based on digital broadcasting. The system includes: an encoder for generating 2D ES and 3D supplementary ES by encoding 2D video and 3D supplementary data; a packetizer for generating 2D video PES and 3D supplementary PES by packetizing the 2D video ES and the 3D supplementary ES; a PSI generator for generating a PSI; a TS generator for generating 2D video TS and 3D supplementary TS for the 2D video PES and the 3D supplementary PES; a multiplexer for multiplexing the transport streams to transmit the 2D video TS as a normal stream and transmit the 3D supplementary TS, the PSI TS and 3D video synch data TS as robust stream; and a modulator for modulating the multiplexed TS according to a DTV specification and transmitting the modulated TS.
摘要:
Provided are an apparatus and method for selecting an optimal signal using auxiliary equalization in a diversity receiver. The optimal signal selecting apparatus includes: a plurality of sync recovery units for extracting sync information from baseband signals, which are candidate signals, except a baseband signal selected as a current optimal signal a plurality of auxiliary equalizers for channel-equalizing the candidate signals based on the extracted sync information; a plurality of SNR measuring units for measuring signal-to-noise ratios (SNRs) of the candidate signals inputted to the auxiliary equalizers and the candidates signals equalized in the auxiliary equalizers; and an optimal signal selector for selecting an optimal candidate signal from the candidate signals by using the extracted sync information and the measured SNRs, and replacing the optimal signal with the optimal candidate signal when reception quality of the current optimal signal is poor.
摘要:
Provided are encoding and decoding methods for a single-view video or a multi-view video and apparatuses thereof. The multi-view encoding method includes performing motion and disparity estimation based on a base image, a supplementary image, and a reference image, generating residual data using the reference image and the motion and disparity estimated data, down sampling the residual data, and transforming and quantizing the down sampled residual data using a discrete cosine transformation (DCT) method.
摘要:
Provided are an apparatus and method for synchronizing a timing clock between a transmission signal and a reception signal. The apparatus for synchronizing a timing clock includes a timing restorer configured to restore a timing clock based on a digital input data; and a timing clock synchronizer configured to synchronize the timing clock based on timing information and a timing restoration signal restored in the timing restorer.