Kalman-viterbi joint channel equalizer

A VSB signal receiving system, comprising:

• a tuner for receiving an RF signal from an antenna and synchronizing the RF signal with a local oscillation signal to transform the RF signal into an IF signal;
• an NTSC removing filter for removing an NTSC component from the IF signal to prevent degradation of an HDTV due to the NTSC component;
• an equalizer for removing multi-path distortion generated in a transmission channel by equalizing the input signal;
• a phase tracer for removing phase noise from the equalized signal;
• a trellis decoder for performing trellis decoding with respect to an output signal of the phase tracer and outputting a decoded signal;
• a data de-interleaver for performing reverse interleaving to the decoded signal;
• an RS decoder for performing Reed-Solomon decoding to the output signal of the data de-interleaver so as to generate error-corrected bit streams;
• and
• a de-randomizer for providing the output signal of the RS decoder to other elements of the VSB signal receiving system,
• wherein the equalizer further comprises:
• a forward filter and a backward filter for receiving an input signal and a predetermined signal and performing filtering to the signals;
• a Viterbi decoder for correcting errors during a transmission procedure in a blind mode;
• a training symbol storing block for storing training symbols;
• a switching block for classifying the output signal of the Viterbi decoder and symbols in accordance with a training mode and the blind mode and inputting the output signal of the Viterbi decoder and symbols into the backward filter;
• a Kalman gain calculating block for receiving input signals of the forward filter and the backward filter and calculating a Kalman gain;
• an error signal calculating block for calculating an error signal by comparing an equalized signal, symbols, and the output signal of the Viterbi decoder with one another;
• and
• a tap coefficient updating block for updating a tap coefficient of the filters by using the calculated error signal and the Kalman gain.