In order to decode a signal like that, you would need a secondary processor. You might want to take a look at Digi's Programmable XBee modules, which include a Freescale HCS08 processor for additional code that you write. The adafruit page says that it, "requires careful timing to grab the data."
There's sample code on the Digi web page titled, "Developing Timer-Based, Bit-Banged Pulses with the Programmable XBee".