Hi Adrian,
This blog post compares a bunch of different modems at the 2% BER
operating point:
http://www.rowetel.com/?p=4663
Given all things being equal (e.g. sync overheads, bit rate etc) PSK is
about 3dB better than 4FSK at the 2% BER point. In practice real world
PSK modems tend to
Hi Andrew,
Sounds like you're very close. The lsp_to_lpc() function is actually
much simpler than the encode side. IIRC it's just a big polynomial
multiplication, but this routine uses a method that clocks an impulse
thru 2nd order filters formed by the odd and even LSP pairs.
The output
Hi,
I was able to perform some field measurements on Sunday to compare the
performance of the 4FSK modem and the QPSK modem in the 433 MHz ISM
band.
My transmitter was set to 1 mW output power into a 2 dBi gain antenna
located at approx. 21 meters above ground on one of the buildings in
my city.
Hi Everyone,
I'm working on a speech vocoder and have so far been able to use a combination
of SPTK and codec2 functions to achieve most of this. However I'm confused as I
want to be able to control the order of the lpc coefficients in real-time as a
parameter but my LSP_to_LPC seems to have
