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—The performance of the noncoherent differential chaos-shift-keying (DCSK) communication system over a mul-tipath fading channel with delay spread is evaluated. Analytical expressions of the bit error rates are derived under the assumption of an independent Rayleigh fading two-ray channel model. Analytical and simulated results are presented and compared.(More)
—In this paper, exact analytical expressions for the bit error rates (BERs) in a multiple-access chaos-based digital communication system are derived. Comparisons are made with those obtained using traditional approximation methods which assume a Gaussian distribution for the conditional decision parameter. The obtained results are compared to the results(More)
—In this paper, we propose a generalized correlation-delay-shift-keying (GCDSK) scheme for noncoherent chaos-based communications. In the proposed scheme, several delayed versions of a chaotic signal are first produced. Some of them will be modulated by the binary data to be transmitted. The delayed signals will then be added to the original chaotic signal(More)
We analyze the performance of cooperative communication systems with opportunistic decode-and-forward for relaying and selection combining receiver at the destination. We derive an exact closed-form expression for the outage of the system over dissimilar Nakagami fading channels. Also, we study its asymptotic outage performance, based on which the optimum(More)
Recently, the increasing demand for telemedicine services has raised interest in the use of medical image protection technology. Conventional block ciphers are poorly suited to image protection due to the size of image data and increasing demand for real-time teleradiology and other online telehealth applications. To meet this challenge, this paper presents(More)
In this paper, efficient LDPC block-code decoders/simulators which run on graphics processing units (GPUs) are proposed. We also implement the decoder for the LDPC convolutional code (LDPCCC). The LDPCCC is derived from a predesigned quasi-cyclic LDPC block code with good error performance. Compared to the decoder based on the randomly constructed LDPCCC(More)
—In this paper, a multiple access (MA) technique is proposed for chaos-based communication systems, in which chaotic reference signals are transmitted followed by the information bearing signals. Chaotic reference signals modulated by a binary training sequence are sent periodically. The same chaotic signals are then modulated by the binary data and(More)