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.