I am trying to simulate the effects of quantization of an ADC on different waveforms (e.g. QPSK,8PSK) in Simulink. For the case of QPSK the default BER curve would be generated with 2 bits per symbol and would have the characteristic waterfall shape. If someone added one more bit per symbol; would that simply add 6.02dB gain in the system? E.g. if for 2 bits/symbol to achieve around 10e-4 BER we would require around 11dB SNR with 3bits/symbols the SNR would become around 5?
Since the above sounds very simplistic, a more drastic approach would be to employ a quantisation mechanism.
From here: How can I mimic this ADC for a given resolution, sampling rate and input with MATLAB or Python? and other literature seems that rounding is the way to simulate quantization.
How would someone introduce quantization effects on matlab generated QPSK symbols (e.g. 0.7071 + 0.7071j) so to replicate the effects of different bit lengths?