METHOD OF PROVIDING ADAPTIVE ECHO CANCELLATION IN TRANSMISSION OF DIGITAL INFORMATION IN DEPLEX AND APPARATUS FOR PERFORMING THE METHOD

摘要

The transmitter(s) sends coded data symbols and a detector receives data symbols over the dulpex line from remote source. Between the transmit and receive paths, the balance filter is connected to substract a signal (y(t)) from the signal input (W(t) + L(t)) from a hybrid coupler. A quantifying unit connected in the receive path estimates the data symbols sent over the duplex line from the remote. A digital reference level(v(k)) stored by a memory is applied to a multiplier for combination with the estimated value(ak). An error signal (ak), representing the difference between the sampled signal (r(k)) applied to the quantifying unit and the reference level, is formed by a first summing circuit.