Well, because it is a uni project they dont allow as to use any other components but the ones in the lab and plus we have to do build everything from scratch, so i have to build both the transmitter and reciever.

 

It is a regenerative detectors (the Colpitts) followed by multiple analog amplifier stages made by biasing CMOS inverters in their linear mode (don't use "B" series CMOS here), followed by a 32768 Hz bandpass crystal filter, then another detector. It takes 500 ms or more for the crystal to respond to the incoming signal because of its high Q, so the transmitter needs to transmit for a minimum of about one second.

This circuit is sold in wireless doorbells here in Thailand (coming down from China) and they seem to work pretty well. One mode uses different crystal oscillator frequencies (32768 Hz and I think the other is 38 kHz) creating two non-interferring channels.

As Bill said, as long as the power is low, you can probably get away with using it almost anywhere in the world. Of course, keeping the duty cycle low (a one second pulse a few times a day, for example) is also a good idea.