I didn't think the US had DAB, but something else incompatible. That article suggests that is the case - it's just a digital stream in the spare bandwidth of FM. Their digital TV is similar, they don't really have the concept of multiplexes, everybody just gets to broadcast one channel exactly as they did under analogue.
Wohnort appears to agree that the two aren't compatible http://www.wohnort.org/dab/usa.html
I think you'll be lucky to find a radio which supports this system as well as DAB+.