Complex adaptive channel equalizer for digital VSB receiver

摘要

PURPOSE: A device for equalizing a complex adaptive channel of a VSB(Vestigial Sideband) receiver is provided to output an I channel signal and a Q channel signal as complex signals, and to update coefficients of each signal for minimizing differences between a transmitted symbol value and an output value of an adaptive channel equalizer, thereby improving a capacity of a digital VSB receiving system. CONSTITUTION: The first multiplier(110) multiplies a received signal by the first local carrier signal to demodulate the multiplied signal to an I channel signal. The first LPF(Low Pass Filter)(120) removes a high frequency component from the I channel signal. The first A/D converter(130) performs a discrete cosine transform process for the I channel signal. The second multiplier(140) multiplies a received signal by the second local carrier signal to demodulate the multiplied signal to a Q channel signal. The second LPF(150) removes a high frequency component from the Q channel signal. The second A/D converter(160) performs a discrete cosine transform process for the Q channel signal. A complex adaptive channel equalizer(170) equalizes the I channel signal and the Q channel signal as complex signals having a real number and an imaginary number. An adder(180) adds an output of the complex adaptive channel equalizer to a discrete symbol, and outputs the added symbol to the complex adaptive channel equalizer.