ber rate for QPSK different from theoretical values

Hi,

I am trying to simulate BER for QPSK transceiver.

I am using example " commqpsktxrx " and bertool to plot ber.

What I observe is that the BER plot deviates from the theoretical values.

Can some one guide why is this happenening?.

[Tamir Suliman]

please post your script values figures and results !