software for generating FSK modulated signals

hi

I have to generate signals with data encoded in them using FSK, 1300Hz
for mark and 2100Hz for space with a baud rate of 1200. i dont have an
FSK modulator so is there any software that could do this over voice
modem ?

i dont have any backgound of DSP so i would really be thankful for you
help or any other relavent information.

Somia

On 23 May 2005 04:11:09 -0700, "Somia" <somia_iqbal@yahoo.com> wrote:

>hi
>
>I have to generate signals with data encoded in them using FSK, 1300Hz
>for mark and 2100Hz for space with a baud rate of 1200. i dont have an
>FSK modulator so is there any software that could do this over voice
>modem ?

   I'm sure there are Windoze calls to send data and control signals
to the modem, but generating the tones is pretty easy, use a
phase-accumulator digital oscillator (which then drives a sine
function or lookup), it changes frequency instantly, maintains phase
between frequency changes, bla bla bla. The transmitter is the easier
part of an FSK modem.

>i dont have any backgound of DSP so i would really be thankful for you
>help or any other relavent information.
>
>Somia

-----
http://mindspring.com/~benbradley

A good article is to be found on page 331...389 of:

     Digital Signal Processing Applications with the TMS320 Family -
       - Theory, Algorithms and Implementations, Volume 2"

The article:

     "Implementation of an FSK modem using the TMS320C17"

was written by:

    Al Lovrich and Raj Chirayil.

The book was printed in 1990 by Texas Instruments.  It may still be
available as a download.

It worked for me (in spite of me).  It is a good combo of what it does & how
it does it, with supporting mathematics and sample code.  Once you get the
picture, it is easy to convert to other sample rates, baud rates, carrier
frequencies, languages & CPU's.

Jim Adamthwaite