| 摘要 |
<p>Echo-cancelling method in the passband, i.e. on the whole Nyquist band of the transmitted signal, for two-wire full-duplex phase-modulation data transmission system, apt to generate, modulate and add together an in-phase component and a quadrature component of the baseband equivalent echo-signal, thus obtaining a passband equivalent echo signal to be subtracted from the signal at the receiving side upstream the receiving device. The error signal obtained in this way is still used for the recursive updating of the coefficients present in the expressions of said in-phase and quadrature components. The device which carries out this method is composed of four adaptive transversal digital filters (FT) and two adders (53, 54) for the generation of the two baseband echo-signal components, two modulators (MOD 3, MOD 4) and an adder (55) for generating the passband equivalent echo-signal.</p> |
