Hello Steve,
Since I still receive noise..I decide to use Holtek encoder/decoder which is HT12E/HT12D. I construct the circuit following your advice and connect all data pins at HT12E/HT12D to port A0-PortA3.The decoder works fine but the encoder have a little bit problem.That's why I'm not receiving any signal because When I check OSC pin at encoder using logic probe,it show logic low at OSC 1 and show nothing at OSC 2.For your Information, I put 1M resistor between these 2 pins. Don't know what's really happen with my encoder. If you have any idea about the problem..can you please share it with me??