Abstract
Nowadays, there are massive demands on the broadband multimedia services. Data security in today's world is an essential issue in different aspects of life such as marketing services, defense, financial, and health care. Modulation schemes, channel coding, diversity techniques, etc., are types of physical layer security methods, which are used to ensure the data from unauthorized access. In addition, various cryptographic techniques are usually used to secure data transmission between sender and the intended receiver. The combination of cryptographic techniques and physical layer security schemes makes it better for transferring multimedia data through unsecure or potentially risky communication (wired and wireless) path. Many chaotic-based encryption algorithms have been suggested to ensure confidentiality and security for multimedia data over an insecure wireless channel. Cryptography techniques do not involve any system complexity but add a little computation complexity. Use of advanced processors mitigates the computational burden. In this paper, we have discussed efficient transmission of an encrypted color image through a multiple-input multiple-output-orthogonal frequency division multiplexing (MIMO-OFDM) system over a Rayleigh fading with an additive white Gaussian noise channel. Four schemes of chaotic-based encryption are employed. Both 2 x 2MIMO - OFDMand4 x 4MIMO - OFDM wireless communication systems are presented. Peak signal-to-noise ratio metric is used to evaluate the quality of the received image at different signal-to-noise ratios. Other metrics such as number of changing pixel rate, unified averaged changed intensity, correlation coefficient, entropy, and histogram are evaluated.