ATEIS ECS - Manual (Page 25)

ECS MANUAL
Version EN.1
25
AEC WITH TWO DEVICES
Schematic:
In a system without video codec, each side receives the incoming signal called "far-end",
coming from the other side. Without AEC, this signal contains the audio sources of the other side
(microphones, and maybe PC, DVD, etc) and the echo due to the acoustic reflections on the other
side.
The idea of the AEC is to send a proper signal to the other side.
The AEC simulates the local reflections, and removes them from the signal to be sent.
The AEC component modifies the signal of the local microphone by using the far-end signal as
reference.
This is an example of a standard point to point system:
On the both sides, there is an AEC component on the microphones, in order to send a proper
signal to the other side. The reference signal of the AEC is the signal coming from the other side,
called far-end signal.