[abeD]

I know for one of my college classes we had to make an IR receiver transmitter for a robot we were using and we could control the frequency at which we broadcasted the signal and would just make a good enough filter so that the phototransistors would only see close to this frequency. If you are allowed to do something like this you would get no interference from anyone else (as long as there not on the same frequency but you can ask them and can change your's accordingly if your setup allows it)

I haven't read the specifics of what your allowed to use but this consists of a simple IR LED's and some phototransistors which I don't think are against the rules.

I am also not on a team anymore so I haven't seen the receiver board or any spec sheets for it.