Hi Jyoti Raina,
I AGREE to points of Dhiman as he said Your results are as expected, because when the Q-factor will go high the BER will definitely become low. and BER of near to value 1 is not acceptable.
BER of value greater than 10^-07 is not acceptable .
I will also ask you to reduce transmitter power because 10 dbm is very high, You should reduce transmitter power to upto 4 dbm.
Here i am attaching 32 channel CSRZ WDM SYSTEM for long haul communication system.
Sometimes we could change the filter order and bandwidth to get better results.
Hope my response could help you.