Patent ID: 7809048

Claim:
An on-channel repeating apparatus for an Advanced Television System Committee (ATSC) terrestrial digital TV broadcasting service, in which a terrestrial digital television broadcast signal is repeated over an on-channel, the on-channel repeating apparatus comprising: a receiving unit for receiving a Radio Frequency (RF) broadcast signal from a main transmitter; a frequency downlink converting unit for converting the received RF broadcast signal into an intermediate frequency (IF) signal based on a first reference frequency; a demodulating unit for converting the converted IF signal into a baseband signal; an equalizing unit for removing a predetermined signal generated between the main transmitter and the on-channel repeater from the converted baseband signal, wherein the predetermined signal includes a noise signal and a multi-path signal generated due to a transmission channel between the main transmitter and the on-channel repeating apparatus, and a feedback signal generated due to low isolation of transmission or reception antennas; a modulating unit for converting the baseband signal received directly from the equalizing unit, into an IF signal; a frequency uplink converting unit for converting the IF signal into a RF broadcast signal based on a second reference frequency; a high power amplifying unit for amplifying and repeating the converted RF broadcast signal; a transmitting unit for transmitting the RF broadcast signal outputted from the high power amplifying unit; and a signal synchronizing unit for generating the first reference frequency to provide the generated first reference frequency for the IF downlink converting unit to the demodulating unit which shifts the IF signal to the baseband signal, and generating the second reference frequency based on the first reference frequency to provide the generated second reference frequency for the RF uplink converting unit such that the transmission/reception signal are frequency-and-phase synchronized.