Abstract: A phase error corrector for an HDTV reception system, which can correct data level errors by reducing phase errors coming from local oscillators, includes a gain and offset adjustment unit for adjusting a gain and an offset of incoming I data, a Hilbert transform filter for performing a Hilbert transform filtering of the I data received from the gain and offset adjustment unit for generating Q data, a log LUT for producing logarithmic values of the I data and the Q data received from the gain and offset adjustment unit and the Hilbert transform filter into a logI value and a logQ value respectively, a complex multiplexer for generating a corrected I value and a corrected Q value having their errors corrected out of the logI value and the logQ value received from the log LUT, a phase error detector for detecting phase errors from the corrected I value and the corrected Q value received from the complex multiplexer, and a loop filter for accumulating phase errors received from the phase error detector and apply

Abstract: An NTSC interference detector is disclosed which includes an NTSC extracting filter for extracting an NTSC signal component from a received I-channel signal; a comparing portion for integrating the NTSC signal output from the NTSC extracting filter for a predetermined period and deciding whether the NTSC signal component is above a first reference value or not; and a control signal generator for adding the signal output from the comparing portion for every horizontal sync, deciding the presence or absence of NTSC interference according to a second reference value, and outputting a control signal according to the presence or absence of NTSC interference, thereby accomplishing a precise detection of NTSC interference.

Abstract: An ATM multiplexing system comprising a plurality of ATM cell input circuits, each of which stores a cell stream incoming from a corresponding input stage and absorbs and removes instantaneous displacement of the incoming cells, a priority encoder for receiving simultaneously FIFO storage level information from the ATM cell input circuits and determining a priority for processing first an input stage with the largest number of stored cells, the FIFO storage level information including the number of the cells stored in the ATM cell input circuits, a link table processing circuit for receiving output headers from the priority encoder and input port numbers corresponding to the received headers and outputting changed headers corresponding to the received headers, an ATM cell output circuit for receiving the changed headers and link information from the link table processing circuit, determining a cell transmission order according to a service priority and performing a header assembling function for perfect cell

Abstract: A cochannel interference filter for a HDTV transmission system comprising a post-comb filter. The post-comb filter comprises first and second feedforward circuits. The first feedforward circuit includes a first adder and a first delay circuit. The first adder has a first input connected to an output of a data clock recovery circuit. The first delay circuit has an input connected to the output of the data clock recovery circuit and an output connected to a second input of the first adder. The second feedforward circuit includes a second adder and a second delay circuit. The second adder has a first input connected to an output of the first adder. The second delay circuit has an input connected to the output of the first adder and an output connected to a second input of the second adder. Also, the post-comb filter comprises third and fourth feedforward circuits. The third feedforward circuit includes a third adder and a third delay circuit.

Abstract: A NTSC/HDTV community receiving system having a microcomputer, HDTV and NTSC tuners and NTSC and HDTV intermediate frequency detectors. The system includes an A/D converter for converting HDTV and NTSC intermediate frequency signals into digital signals and a demodulator for demodulating a NTSC frame color signal into an original state and demodulating the resultant digital HDTV signal from the A/D converter into a base band level state. A first comb filter removes a NTSC interference signal from the demodulated HDTV signal and extracts a NTSC line color signal from the resultant digital NTSC signal from the A/D converter, and a second comb filter extracts a motion coefficient, the NTSC frame color signal and a NTSC frame luminance signal from the resultant digital NTSC signal from the A/D converter and the NTSC line color signal from the first cob filter.