Hi Khadija Omran
such results like Q.F =0 and Min. BER =1, this is always a very plain case of either your signal is not reaching the receiver; or that your system parameters are not getting supported by the system. Eg.your system design supports a maximum bit rate of 5Gbps and you are trying to simulate at the bit rate of say, 10 or 20 Gbps, so the results which you are getting can be easily expected.
You can connect visualisers at various points of your system to check the signal in its traversal path. In case the connection is okay, the there is definitely something wrong with the parameters you have taken.
Regards
Naazira.