In GMSK BER analysis, the BER curve with respect to EbNo is constant through out for any value of EbNo . Please ,Can anyone help in sorting out this problem

The BER curve should not be constant ,it should fall as the EbNo value increases. We have used Bernoulli generator,gmsk modulator and demodulator, error rate calculation from simulink library. I have attached a mdl file to which I am getting error.It is a part of my final year project. Please , someone help.