hello Mohamed Abouseif Sir ,
thanks for the reply…
unfortunately my system is 32 bit so i am working on optisystem 13,32 bit version.
I want to ask you one thing,the 4-QAM OFDM example given in the examples set works just fine but when i make changes in QAM sequence generator and detector(making no of bits per symbol to 4 i.e making it 16-QAM,keeping other components as it is.),I receive very bad constellation and bit error rate increases to high of 0.45 from 0.
please find attachment.
please help me in this regard!!!