Compressed image transmission in precoded OFDM VLC systems

Abstract

In this paper, a compressed image transmission scheme is proposed in a precoded orthogonal frequency division multiplexing (OFDM)-based visible light communication (VLC) system. First, an image is divided into sub-block images; then, each block image is sampled by block-based compressive sensing (BCS) based on the Hadamard sparse basis matrix with a partial DCT measurement matrix. The resulting data are transformed into bit stream, which is transmitted in a DFT precoded OFDM-based VLC. We propose an integrated end-to-end OFDM-based VLC system platform, including BCS, quantization, VLC link, and OFDM transmission. The simulation results prove the effectiveness of the proposed simulation platform. The bit error rate (BER) and peak signal-to-noise ratio (PSNR) performances of the simulation platform are evaluated as well. The simulation results show that different images result in different BER and PSNR performances in the proposed precoded OFDM-VLC system. The larger the information entropy of images, the better the PSNR and BER performances. In addition, the PAPR of the DFT precoded OFDM can be significantly reduced compared to that of the conventional OFDM for compressed image data.