delay receiver / BER

can any one help me to find how I fixe delay receiver of the error rate calculation bloc knowing that I use a viterbi decoder in my model. the problem is that when I delete the channel AWGN bloc, the error rate BER is not ZERO!!! I think that is related to the parameter delay receiver of the error rate calculation bloc. here is my model: http://www.mediafire.com/?dqeis9qabkactct