If by pdu you mean protocol data unit(what i get when I google "pdu"), then thats a protocol not a character set. If you mean ETSI GSM 03.38(some character set i get when I google "pdu to ascii") then here is a list of pdu characters to their corresponding unicode characters. Then it is a simple matter to convert from unicode to ascii. Remember... google is your friend.
vegaseat commented: thanks for the note +14
Andrew Wiggin commented: I love your quotes. +2