| 摘要 |
<p>A method and digital hybrid circuit apparatus is disclosed for connecting a near end subscriber to a far end subscriber with the near end subscriber providing a digital input signal Vs which undesirably contains an interfering echo signal e(T). This signal is transmitted to a connected far end subscriber which far end subscriber provides a far end digital input signal VRX for reception by the near end subscriber. In order to eliminate the echo signal, first HA(f) and second HB(f) programmable coefficient digital filters have an input to receive the far end digital signal with the outputs of the filters coupled to an input of an adder 12, 16 with one input of each adder to receive the near end input signal, means 20 is provided for programming each of the filters with a different set of coefficients and logic means 25 are coupled to the output of the adders for comparing the average power output of each of the adders and means for selecting that filter and adder which provides the lowest value of average power and to employ those coefficients in filter HA(f) to thereby provide an output signal to be transmitted to the far end subscriber which contains a minimum level of the interfering echo signal. <IMAGE></p> |
