Performance analysis for bit-interleaved space-time coded modulation with iterative decoding

Iteratively decoded bit-interleaved space-time coded modulation (BI-STCM) greatly lowers bit error rate (BER) over fast Rayleigh fading multiple-input multiple-output (MIMO) channels. We develop a general, tight and efficient theoretical error-free feedback bound (EF bound) to analyze the asymptotic BER when the receiver has either perfect or imperfect channel state information (CSI). The convergence to the EF bound and the accuracy of the prediction are verified by simulation for both cases. With the best rate 1/2 4-state convolutional code and the 16-QAM modified set partitioning labeling, the BER of 10^-6 can be achieved at E_b/N₀ = 1.6 dB with 2 transmit and 2 receive antennas for the case of perfect CSI.