Hello Abhilash Achanta,
As far as your query is concerned i would agree with Aabid on this. It has been rightly mentioned that bit error rate 1 means the transmission quality is poor i.e corrupted information is being received which means the probability of error is maximum which is 100% in your case and as a result the Q-factor is also reduced to minimum value.
You may check various parameters of your design to set the bit error rate as low as possible. I hope you find it helpful.
Regards
Burhan