# Simulation at Baseband or Passband

A naive question I guess. Would it make a difference in the results when a system is simulated at Baseband or at Passband. If I have a plot of a BER vs SNR curve that has been plotted at Baseband, will the same change if I perform the simulation at Passband with a carrier frequency of 2.4GHz? AFAIK, it should not make a difference, but I would like to know if what I am thinking is correct.

Another question is that if I have two signals from two transmitters and add these signals at the receiver, does it make a difference if these two signals are passband or baseband. Do the results vary? Since Passband simulation consumes a lot of time, would it be correct if I simulate the behavior at Baseband and assume that the result would be almost the same at the Passband?

• Lab Exercise 1: Bandpass signals & White Gaussian Noise Simulation %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % 1. Band-pass signal simulation %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % Sampling period and frequency Ts=0.001; fs=1/Ts; % Duration of signal t=[-511:512]*Ts; % Carrier frequency fc=200; % Bandwidth B=100; % Baseband message signal m=sinc(B/pit); % Bandpass signal s=m.*cos(2*pifc*t); % Plot time-domain signal figure, plot(t,s),title('Sample bandpass signal') axis tight % Power spectrum using FFT FFTsize = 1024; spec = fftshift(abs(fft(s,FFTsize)).^2); freq = [-fs/2: fs/FFTsize: fs/2]; freq – dilara Mar 3 '17 at 8:26