Iterative Channel Estimation and Decoding of the Block Markov Superposition Transmission with Doppler Diversity

The focus of this paper is the high mobility coded wireless communication system with Doppler diversity. In order to improve the bit-error-rate (BER) performance, we combine the systematic block Markov superposition transmission (BMST) with Doppler diversity, resulting in BMST-DD, where the systematic BMST is a recently proposed rate-compatible coding scheme. In the BMST-DD system, to reduce the performance loss caused by the channel estimation error, we propose an iterative channel estimation and decoding technique for the fast time-varying fading channels. In the iteration process, the recovered symbols are fed back to the channel estimator as the new pilot symbols to improve the accuracy of the channel state information (CSI) estimation. Numerical results show that the mutual information increases with the increase of the speed due to Doppler diversity, and that the BER performance of the BMST-DD system can be improved by the iteration between the channel estimator and the decoder.