Fremgangsmate og anordning for maling av ekkoparametere pa telefonlinjer

摘要

A test signal is injected on the line (L) and the corresponding return signal produced by the line itself as an effect of the echo is detected. A signal having lenticular envelope is used as test signal and is generated preferably starting from a first sinusoid with a first given frequency modulated in amplitude with a second sinusoid having a second given frequency, lower than the aforesaid first given frequency.