Block Markov superposition transmission for high-speed railway wireless communication systems

Abstract

Ahstract-The focus of this paper is coded orthogonal frequen cy division multiplexing (OFDM) system for high-speed railway wireless communication based on block Markov superposition transmission (BMST). The effect of Doppler spreading destroys the orthogonality among subcarriers, resulting in intercarrier interference (leI) in the OFDM systems. In order to mitigate the leI and get the soft information easily, we present a simple soft output algorithm based on zero forcing (ZF) equalization, and the soft information is given to the soft-in soft-out (SISO) demapper. We combine the OFDM system with BMST code, which can be easily designed for any given code rate with a predictable performance lower bound. Based on the iterative sliding-window decoding algorithm, BMST scheme outperforms the convolutional code (eC) scheme in the OFDM system for quadrature phase-shift keying (QPSK) and 16-quadrature ampli tude modulation (QAM). Numerical results show that the BMST OFDM system performs well over doubly selective channels. IndexTerms-Block Markov superposition transmis sion (BMST), doubly selective channels, high-speed railway, iterative sliding-window decoding, orthogonal frequency division multiplexing (OFDM), zero forcing equalization.

Transformer-Based Detection for Highly Mobile Coded OFDM Systems

“…Thus, a soft demapper is needed between the detector and the channel decoder. We have already studied the mobile coded OFDM system with a flexible coding scheme called block Markov superposition transmission (BMST) [ 1 , 2 ]. In this paper, we still focus on the mobile coded OFDM system.…”

“…Example 4. In this example, a [2,1] 512 regular LDPC code is used. The BER performance of the coded OFDM with the type of detector at 1.0 bits/symbol/subcarrier spectral efficiency is depicted in Figure 8.…”