Echo suppression circuit with controlled delay line - is regulated by magnitude of modulating echo and adding delayed signal to undelayed signal

摘要

The echo suppression circuit suppresses echos modulating signals in carrier wave telecommunications. It operates by removing part of the distorted signal, delaying it and adding it back to the original. - A demodulator demodulates the modulating signal and interference signals lying outside the transmission band. The demodulator output passes to a handpass filter (BP) that suppresses the modulating signal but allows interference signals lying within a given frequency band to pass through a rectifier. The rectifier output is used to control an optimiser that controls the delay elements in the delay line such that the rectifier output is minimised