Echo cancellation device includes stages for filtering, amplifying converting received radio frequency signal, eliminating echo from received signal, and outputting signal towards transmitter antenna

摘要

The device includes a first stage for filtering the adjustment level of a received radio frequency signal, a second stage for eliminating echo in the received and filtered signal, a third stage for filtering, amplifying and converting the output signal of the second stage, and a fourth stage for outputting sampled signal to a transmitter antenna. A receiving antenna acquires the radio frequency signal. The output of the third stage is fed to the transmitter antenna. The output of the fourth stage is fed to the transmitter antenna as a second entry based on a referred digital procedure and amplitude characterization of the main echo and sub echo in the received signal.