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This paper presents a new technique, based on trigonometric transforms, to solve the peak to average power ratio (PAPR) problem associated with orthogonal frequency division multiplexing (OFDM) signals. In the proposed technique, both the in-phase and in-quadrature components of the OFDM signals after the inverse fast Fourier transform (IFFT) are transformed using either the discrete sine transform...
This paper presents a new approach for peak to average power ratio (PAPR) reduction in orthogonal frequency division multiplexing (OFDM) systems. This approach is based on the chaotic Baker map. It is known that OFDM transmitted signals are in complex format, having in-phase and in-quadrature components. If a chaotic randomization process is performed on each component, separately, prior to transmission,...
In this paper, A quantization based method for digital image watermarking is presented here. This method is based on inserting a watermark bit into the coarsest scale wavelet coefficients. A three level image decomposition is used in the paper. This watermarking technique is blind requiring neither the original image nor any side information in the watermark recovery process. It is computationally...
In this paper, we propose an SVD-based watermarking scheme in complex wavelet domain for color video. Video watermarking is well known as the process of embedding copyright information in video bit streams. It has been proposed in recent years to solve the problem of illegal manipulation and distribution of digital video. In this study, an effective, robust and imperceptible video watermarking algorithm...
This paper presents an efficient SVD based image Steganography approach. This approach aims at increasing the fidelity of the images after data embedding. Rather than embedding data in the singular values of the images, the image Left singular vectors are used for this purpose. The objective of this approach is to reduce the embedding errors as well as to maintain the image fidelity. Several solutions...
In this paper, a wide band antenna is proposed for ground-penetrating radar (GPR) system. This antenna consists of dipole antenna housed in a rectangular conducting reflector whose inner walls are coated by an absorbing material. The coating is composed of a number of layers with a conductivity profile designed to achieve the minimum voltage standing wave ratio (VSWR) of the dipole antenna over the...
In this paper the bandwidth of a single layer microstrip patch antenna is enhanced by using multi-resonance technique without significantly enlarging the size of the proposed antenna. In this work the validity of the design concept is demonstrated by two examples with 51.4% and 56.8% bandwidths. In the first example multiple resonances are achieved by overlapping three square patches of different...
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