Performance analysis of the bit-interleaved coded modulation using turbo equalization with single carrier frequency domain equalization over fast fading channels

摘要

The performance of the bit-interleaved coded modulation using turbo equalization with single carrier frequency domain equalization (BICM TE-SC-FDE) over frequency-selective fading channels with the residual inter-symbol interference (ISI) is investigated. We focus on the impact of the residual ISI on the convergence behavior using the extrinsic information transfer (EXIT) chart. We first exhibit that the residual ISI impacts not only the error floor but also the convergence behavior of the BICM TE-SC-FDE. Then, we show that the Gaussian assumption of the soft information within the TE-SC-FDE, with or without the residual ISI, can accurately track the flow of the extrinsic information in the iterative procedure. We exhibit through simulation the accuracy of the EXIT chart in predicting the transfer function of the equalizer. We show that the product of the transmit block length and Doppler spread is a key parameter affecting the convergence behavior of the TE-SC-FDE with the residual ISI. The accuracy of our EXIT chart prediction is verified by simulation.