Hallo Adnan,

ok, you only need to fabricate the sinus tones.

Data given by you, namely:

Data signal frequencies

The mark (logical 1) frequency shall be 1200 +/- 100 Hz and the space (logical 0) frequency shall be 2200 +/- 100 Hz.

Data signal-off level

he maximum power in the frequency bands from 1100 Hz to 1300 Hz and 2100 Hz to 2300Hz in the signal-off state shall not exceed -50 dBm.

Data transmission rate

The data transmission rate shall be 1200 +/- 50 bits per second.

confuses me a bit. If transmission rate shall be 1200 bits per second, then the two sinus tones will last 1/1200 sec = 833.3µsec. That's exactly one period of 1200Hz tone ('Mark'), but 1.833 periods of 2200Hz tone ('Space'). Is this intended with your application??

To the fabrication of sinus tones:

In most cases a square wave is produced, which afterwards undergoes a certain low pass filtering. I have seen many FSK projects some decades ago, where this filtering was accomplished by the help of only one simple RC-filter. Then, the edges got only rounded knees. But a pure sinus is something different...

Another way to fabricate a 'sinus' tone is to make a symmetrical triangle wave by the help of two simple operational amplifiers and to let the signal afterwards pass through a limiter consisting of germanium diodes. Then the curve looks very similar like sinus, even without extense low pass filtering.

If, on the other hand, you need a pure sinus, then chips like XR2206, ICL8038 or even higher sophisticated ones should be used. An alternative could be the generation of sinus by the help of microcontroller using look-up table in combination with simple DAC, similar to the recommendation shown in the following post:

http://www.8052.com/forum/read.phtml?id=48128

But then the micro is obstructed by rather stupid work...

Try to find out how your sinus tones actually should look like. Is a pure sinus needed, or is a square wave with rounded knees acceptable? Each methode has its pros and cons, and it depends on your needs, what you need.

Kai