1. A signal identification method comprising: receiving an incoming signal divided into a plurality of incoming frames; receiving an outgoing signal divided into a plurality of outgoing frames; extracting outgoing features from a current frame of the plurality of outgoing frames; extracting incoming features from a first previous frame of the plurality of incoming frames; calculating first feature distances based on corresponding the outgoing features from the current frame and the incoming features from the first previous frame; deriving a first similarity score based on the first feature distances; extracting incoming features from a second previous frame of the plurality of incoming frames; calculating second feature distances based on corresponding the outgoing features from the current frame and the incoming features from the second previous frame; deriving a second similarity score based on the second feature distances; and determining whether the incoming signal includes an echo of the outgoing signal based on the first similarity score and the second similarity score.