Patent ID: 6268767
Filing Date: 2001-07-31
Classification: H04L

Abstract:
A quadrature amplitude modulation (QAM) type demodulator comprising:an analog-to-digital converter receiving an input signal and producing a first signal,a baseband conversion circuit being electrically coupled to the analog-to-digital converter and receiving the first signal and producing a baseband signal,a carrier recovery circuit being electrically coupled to the baseband conversion circuit and receiving the baseband signal and producing a QAM signal,a symbol decision circuit being electrically coupled to the carrier recovery circuit and receiving the QAM signal and producing a recovered bit stream output signal,a forward error correction circuit being electrically coupled to and receiving the output signal from the symbol decision circuit and producing a demodulated data output signal and a plurality of error signals, anda dual bit error rate (BER) estimator circuit being electrically coupled to the forward error correction circuit and receiving the plurality of error signals and producing a BER output signal.