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A new multiple-input multiple-output system, referred to as transceive spatial modulation (TRSM), which integrates transmit spatial modulation (SM) and receive SM. In the TRSM system, information bits are carried by the conventional amplitude-phase modulation as well as by the indices of both the transmit and the receive antennas. To improve the bit-error-rate performance, block Markov superposition transmission (BMST) is applied to the TRSM, resulting in BMST-TRSM, where BMST is a recently proposed coding scheme and can be easily designed according to the spectral efficiency requirement. To reduce the computational complexity, a layered (suboptimal) soft detection algorithm is presented, which delivers a list of candidate spatial points (antenna combinations) first. Numerical results show that the proposed TRSM system performs well over the Rayleigh fading channels.

With the development of technology, QR codes play an important role in information exchange. In order to work out the problem of uneven illumination in automatic sorting in logistics systems, an adaptive method in binarization is presented. The proposed method defines the block windows’ size adaptively for local binarization based on the traits of the QR code. It takes advantage of integral images to calculate the sum of gray values in a block. The method can binarize the QR code with high quality and speed under uneven illumination. Compared with several existing algorithms, it is shown that the proposed method is more effective. The experimental results validate that the proposed method has a higher recognition accuracy and is more efficient in binarization.

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.