Echo cancellation with reference signal generator and reliable receiving schemes for intersymbol interference

For adaptive echo cancellation (EC) in full-duplex two-wire data transmission, the problem of double-talk which disturbs adaptation procedure always exists since the far-end signal appears continuously. To provide reliable adaptation, an EC with a decision-directed reference signal generator (RSG) is proposed. Additionally, the intersymbol interference (ISI) is another problem. Fortunately, for an EC with far-end RSG, information on the pulse shape dispersion in the transmission channel is included in the RSG and is helpful for reducing the effect of the dispersive channel. Some methods which sufficiently make use of this information are proposed to provide optimal reception and decoding, and hence a lower bit error rate is obtained