Hi Dhiman,
In order to use BER analyzer, you would have to acquire the binary input data. To do this, first you have to use a PSK decoder in each of the parallel branches. Then you can use a parallel to serial converter component to form the input data from the two parallel branches. After that, you just have to connect the input binary sequence to the upper input, the electrical signal created by passing binary input through a NRZ component to the middle input, and the output binary pulses (created by NRZ pulse generators) from the output to the lower input of the BER analyzer.
Regards