How to simulate High Power Amplifier(HPA), like Solid State Power Amplifier (SSPA) I cannot understand how to simulate Solid State Power Amplifier (SSPA). When I directly write the Rap's SSPA model in Matlab, it does not produce BER of OFDM like published papers by other researchers'. Even no change is observed between BER with and without SSPA. But theoretically there should be significant changes between these (for low nonlinear parameter r, Asat). I have seen several matlab code in Matlab fileexchange, but those could not produce BER like published papers.  What is the wrong in my code given below.

Please help me out.
The model works fine.  You need to slow down and check your (or someone else's? ) steps.  I just worked through one pass of this, without pskmod, and only one value was high enough voltage to push the model into a nonlinear region.  Work through it step by step, you'll see that your x values are too low in magnitude to really get out of the linear region.  The x values have to approach A to get distortion.