Robust RF Links

[dhouston]

The most important thing is to use FSK modulation. This is analogous to FM (Frequency Modulation) and is inherently more noise immune than ASK (analogous to AM). FSK hardware tens to cost 4-5 times ASK.

I have no idea what noise frequencies you will encounter but imagine that it's very broadband. Still, you might be well served by transmitters/receivers that can be tuned over a very broad range. This might give you a chance to find a band that has less noise than others.

• http://www.hoperf.com/rf_fsk/rf_transmitter.htm
• http://www.hoperf.com/rf_fsk/rf_receiver.htm

You should also use highly directional antennas on both ends. You can purchase printed circuit yagis but they tend to be available only for certain frequencies. Here are the results of a search:

• http://www.bing.com/search?q=printed+yagi&form=OSDSRC

One other thing to consider, if you have line-of-sight, is using either IR or a modulated laser pointer.

• http://www.instructables.com/id/Laser-Transceiver/