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Chaotic systems have been shown to have interesting properties for the generation of spreading sequences in various spread-spectrum applications. The aim of this paper is to exploit the topological features of a time-delay system with appropriate non-linearity to propose sequences having good correlation properties. A novel family of chaotic sequences is proposed as spreading sequences using the Poincare...
In this paper, a study of the differential chaos shift keying for discrete time implementations is proposed. Then we analysed the performance of this modulation system. A new approach is considered to compute an exact bit error rate expression. The idea of this approach is to compute the probability density function of the chaotic bit energy and to integrate the bit error rate over all possible values...
In this paper, we propose a new color image encryption technique using two multidimensional chaotic maps: a three dimensional chaotic map for the key expansion and a two dimensional chaotic map for the generation of two chaotic lookup tables. The experimental results demonstrate that the distributions of red, green and blue surfaces of the encrypted image have a random-like behavior. Simulations show...
In this paper, we propose a new approach to compute the exact bit error rate expression for asynchronous chaos-based DS-CDMA system over multipath channel. Perfect estimation of the channel coefficients with the associated delays and chaos synchronization are assumed. A simple RAKE receiver structure is considered. A stationary multipath channel with constant gain is assumed. An asynchronous multi-user...
UWB technology possesses some important characteristics such as the robustness in multipath channel, the low probability of detection and interception, the relative simplicity of the systems, and the protected communication assured by UWB signals more difficult to detect that classic signals. The use of chaos for the UWB communications is put in this paper under survey with a more particular interest...
In this paper we propose a new system for achieving synchronization in asynchronous multi-user chaos-based DS-CDMA. The synchronization is made through a binary code used as a pilot signal and the chaotic signal used as spreading data sequence. The study of this process is evaluated under the assumption of an additive white Gaussian noise channel. The probability of detection and probability of false...
In this paper, an extension of the existing chaotic digital modulation named chaotic cyclic attractors shift keying (CCASK) is proposed, which uses different orders of chaotic cyclic attractors to modulate the information. The new scheme is analysed under a discrete-time domain, and the noise performance in AWGN channel is simulated, and also calculated in a mixed analytic-numerical way, under some...
The coherent reception of direct sequence-code division multiple access (DS-CDMA) is considered, when chaotic sequences are used instead of conventional pseudo-noise (PN) spreading code. A piecewise linear map (PWL) is used as chaotic spreading sequence (CSS). Additive white Gaussian noise channel (AWGN) is assumed. An analytical expression of the bit error rate in the single user case is presented.
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