How do I determine the MDS and sensitivity of the AD9361 and in general a receiver based on a non-ideal IQ demodulator? For instance sensitivity S=-174 +NF +10log(BW) + S/N of detector to meet BER. But this assumes an ideal IQ demodulator. So if my receiver requires a detector SNR of 5 to meet my BER with an ideal IQ demodulator, how do I now determine the sensitivity if I factor in an 17.8 % EVM (SNR of 15)? And if I use a digital quadrature error correction algorithm (QMC) can I recapture or come close to achieving the sensitivity of the receiver with an ideal IQ demodulator?

QEC error correction algorithm takes care of this imbalance between IQ. For AD9361 Quadrature gain and phase error are 2% and 2 degree typ respectively. The impact of this will be much less than a dB in terms of SNR.