My question is, Why do we usually use baseband in simulation rather than passband? however, if we want to test our simulated idea in real environment, it must be sometimes in passband !!
So, should simulation in baseband give the same results if we made it in passband? for term of BER, MSE and so on
Here is an example as asked in the first comments,
In baseband, Suppose you have ofdm system, with $s$ is the $n^{th}$ block with N symbol, when performing N-by-N FFT to get $x = FFT^Hs $, after adding a CP as guard interval with length P, we will have $M = x + P$ is the transmitted signal as baseband.
But in Passband, we will not transmit the $M$ as it's, we will have additional process when having $M$, this process is summarized conversion --> matches filter --> carrier modulation by multiplying (.*exp(-j*2*pifct), fc is the carrier frequency t is the time period, and them transmit real part of this results, then in the receiver side, we follow the inverse of these steps till getting the baseband signal $M$ then, both passband and baseband will follow the same steps.
Thank you