MIMO-BICM with imperfect channel state information: EXIT chart analysis and LDPC code optimization

We investigate MIMO systems employing bit-interleaved coded modulation and iterative decoding with imperfect channel estimates. An optimum soft demodulator for this scenario with i.i.d. Rayleigh fading was recently proposed by Sadough et al. We extend the optimum demodulator to correlated channel models and provide a code-independent performance comparison of this demodulator and the conventional (mismatched) demodulator for different symbol mappings by means of EXIT charts. Furthermore, we describe optimized LDPC code designs for these demodulators and verify the EXIT chart results in terms of bit error rate simulations.