PSB4860HV4.1 Lantiq, PSB4860HV4.1 Datasheet - Page 39

• Manufacturer Part Number: PSB4860HV4.1
• Manufacturer: Lantiq

Specifications of PSB4860HV4.1

• Lead Free Status / Rohs Status: Supplier Unconfirmed

Figure 20 Speech Comparator - Interdependence of Parameters
According to figure 19, a compromise between the reserve GD and the decrement rate
PD has to be made: a smaller reserve (GD) above the level enhancement G requires a
longer time to decrease (PD). It is easy to overshout the other side but the
intercommunication is harder because after the end of the speech, the level of the
estimated echo has to be exceeded. In contrast, with a higher reserve (GD*) it is harder
to overshout continuous speech or tones, but a faster intercommunication is supported
because of a stronger decrement (PD*).
Two pairs of coefficients, GDS/PDS when speech is detected, and GDN/PDN in case of
noise, offer a different echo handling for speech and non-speech. With speech, even if
very strong resonances are present, the performance will not be worsened by the high
GDS needed. Only when speech is detected, a high reserve prevents clipping.
The time ∆
comparator are switched to the “noise” values. If both sets of the parameters are equal,
ET has no effect.
Table 5
Parameter # of bytes Range
G
GDS
Data Sheet
dB
t
Speech Comparator Parameters
1
1
(determined by parameter ET) after speech ends, the parameters of the
RX-noise
GD*
GD
RX-Speech
– 48 to + 48 dB
0 to 48 dB
G
PD*
∆
t
39
Comment
Base Gain
Gain Reserve (Speech)
G
PD
t
PSB 4860
2000-01-14