CS6403
60.0
40.0
ERLE
20.0
0.3
Speech Training Signal
0.0
0.0
0.0
2.0
4.0
6.0
Seconds
-0.3
8.0
Figure 1. Typical ERLE Convergence Characteristics
Echo Canceller Characteristics
The typical Echo Return-Loss Enhancement
(ERLE) convergence characteristics for the
CS6403 are illustrated in the above diagram
under the following conditions:
• Echo-canceller length: 512 taps
• Echo-canceller initial conditions: zeroed filter
taps, updates disabled until t=0.125s
• Sampling rate: 8 kHz
• Echo path (including microphone, speaker,
and amplifiers):
- spectrally flat
- linear
- duration < 64 ms
- noise free
- time invariant
• Near-end high-pass filter: enabled
• Pre-emphasis filter: enabled
• Graded-beta profile: 64 echo-canceller filter
taps processed per 2x reduction in update gain
• Training signal: speech, full scale
• Unlimited S/(N+D) on linear ADC
Note:
Many of these conditions may be
significantly different in real
applications, resulting in significantly
different measured ERLE performance.
8
DS192PP6