FPGA Central

Hi

When a speech or audio signal is sent through a GSM or CDMA cellular phone,
what is the maximum audio frequency that is encoded by the codec? For
example, 4kHz is considered as the cutoff for a plain old telephone system.
GSM uses a CELP based encoder (?) ,so the number may be related to the
standard. Any approximate figures would be appreciated.

TIA,
Siddharth

Hello Siddharth,
Actually 4kHz is a real hard cutoff for POTS lines. They usually roll off at
3.2 or 3.4 kHz. Cellular vocoders aren't very different from POTS lines in
their frequency response limits

Clay
..


"Siddharth Mathur" <smathur@removethis.softhome.net> wrote in message
news:bnrf7q$l9j$1@oasis.ccit.arizona.edu...
> Hi
>
> When a speech or audio signal is sent through a GSM or CDMA cellular
phone,
> what is the maximum audio frequency that is encoded by the codec? For
> example, 4kHz is considered as the cutoff for a plain old telephone
system.
> GSM uses a CELP based encoder (?) ,so the number may be related to the
> standard. Any approximate figures would be appreciated.
>
> TIA,
> Siddharth
>
>