Channel equalizing and carrier recovery system for home phoneline networking alliance receiver and method thereof

Abstract

A channel equalizing and carrier recovery system for home phoneline networking alliance (HomePNA) receiver and method thereof are provided. The channel equalizing system includes a frequency diverse quadrature amplitude modulation (FD-QAM) equalizer and a quadrature amplitude modulation (QAM) equalizer. The FD-QAM equalizer receives an FD-QAM signal, determines FD-QAM tap coefficients, and equalizes the FD-QAM signal using the FD-QAM tap coefficients. The QAM equalizer receives a QAM signal, determines QAM tap coefficients, and equalizes the QAM signal using the QAM tap coefficients. The QAM equalizer receives the FD-QAM signal and determines the QAM tap coefficients during a predetermined header period. The carrier recovery circuit includes a phase detector, a loop filter, and a numerically controlled oscillator (NCO). The phase detector uses a phase difference between a reception symbol and a decision signal of the reception symbol as an instantaneous phase difference when the reception symbol is a data symbol of an FD-QAM signal or a symbol of a QAM signal, uses '0' as the instantaneous phase difference when the reception symbol is a zero symbol of the FD-QAM signal, averages instantaneous phase differences during a predetermined period or time, and outputs the result of averaging. The loop filter filters the output signal of the phase detector. The NCO generates an oscillation signal having a variable phase in response to an output signal of the loop filter so that a phase error of a reception signal can be controlled.