Secure Image Transmission in Wireless OFDM Systems Using Secure Block Compression-Encryption and Symbol Scrambling

Abstract

In this paper, a joint compression-encryption and symbol scrambling scheme is proposed for orthogonal frequency-division multiplexing (OFDM) systems for image date. First, in the compressionencryption phase, the original image data is fist divided into sub-blocks and then an secure image block compressive sensing (BCS) is applied to resulting image data, in which a chaotic sparse basis matrix and a chaotic measurement matrix based on the discrete cosine transform (DCT) are used. Secondly, the resulting secure CS data is transform into binary phase shift keying (BPSK) symbols and then a chaotic scrambling operation is applied to the obtained BPSK symbols. The simulation results show that the proposed secure BCS scheme can achieve better peak signal-to-nose ratio (PSNR) performance than that of the conventional chaotic measurement method. The simulation results also show that a good trade-off performance of signals between PSNR and computational complexity can be achieved when the proper sub block size of image is adopted. In addition, the performances of the BPSK OFDM signal, which is generated from the secure BCS of the image, are evaluated over AWGN and multipath fading channels. The simulation results show that the proposed scheme not only achieve effective secure block compressive sensing and achieve secure transmission in physical layer. The security of the transmitted image data is enhanced by the joint compression-encryption and symbol scrambling. INDEX TERMS Compressive sensing, security, chaos theory, OFDM.

Compressed image transmission in precoded OFDM VLC systems

“…Each image block is measured using (1) or (2). The DCT measurement matrix B Φ can be constructed using the following method [10]. First, we generated a chaotic sequence from a logistic map expressed as follows [21]: ,…”

“…Howev-2 er, these BCS schemes do not consider the transmission performance of the compressed image data in communication systems. In [10], a compressed image transmission scheme based on block CS was proposed for OFDM systems. In the proposed scheme, compression and encryption were achieved simultaneously.…”

Performance Enhancement of Bit-Level XOR Compressed Image OFDM Transmission Systems

“…In this section, the BCS scheme [17] based on sparse discrete cosine transform (DCT) matrix with a partial DCT measurement matrix is introduced, and then an end-to-end compressed image transmission scheme is presented.…”

“…Similar to [17], a partial chaotic DCT matrix is utilized to serve as the measurement matrix in the BCS scheme. A conventional DCT matrix can be expressed as…”

“…In [10], the authors studied the compressed image OFDM transmission based on the well-known EZW or SPIHT algorithms. en to reduce the computational complexity of CS, the block compressed sensing (BCS) method was proposed [13][14][15][16][17]. In [15], the transmission performance of the block compressed-sensed image data over a wireless channel was researched, and the simulation results show that BCS with a proper block size can greatly reduce the computational complexity with a slight peak signal-to-noise ratio (PSNR) performance loss.…”