I use matlab to simulate 2-1multibit modulation ,but the result is not correct, I found the digital error correction circuit is not clear? can you help me, or who can sent me a 2-1 multibit  modulation (include the digital correction circuit) . or give me some advise or reference paper.
Thanks you a lot!!!

      (if you have the model , can you sent to me : f-jh3@sohu.com)