Patent ID: 6680985
Filing Date: 2004-01-20
Classification: H04L

Abstract:
A quadrature amplitude modulation (QAM) decoding device for use in decoding a QAM signal comprising:an equalizer that equalizes the QAM signal using a plurality of tap weights to produce an equalized signal; a demodulator coupled to the equalizer that demodulates the equalized signal to produce a demodulated signal; an amplifier coupled to the demodulator that amplifies the demodulated signal based on a voltage bias and a gain factor; an analog-to-digital converter coupled to the amplifier and adapted to produce a digital signal; a symbol decoder coupled to the analog-to-digital converter and adapted to decode the digital signal; a gain compensation circuit coupled to the analog-to-digital converter and to the amplifier that sets the gain factor for the amplifier using the digital signal; a voltage bias compensation circuit coupled to the analog-to-digital converter and to the amplifier that sets the voltage bias for the amplifier using the digital signal; and an equalizer weight calculation circuit coupled to the analog-to-digital circuit and to the equalizer that calculates updates for the tap weights based on the digital signal.