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In this paper, we propose a new approach to estimate the low-frequency oscillatory modes in power system by using Total Least Square-Estimation of Signal Parameters employing rotational invariance technique (TLS-ESPRIT) based on Least Mean Squares Sign-Data (LMSSD) Adaptive filtering. LMSSD adaptive filtering reduces the effect of Additive White Gaussian Noise (AWGN) from the signal. The proposed...
This paper demonstrates an innovative variable fractional rate Digital Down Converter(DDC) architecture for satellite communication where the carrier frequency and output sample rate can be changed dynamically at run time. The proposed algorithm is highly modular and generic so that the DDC can decimate by any fractional ratio i.e. the ADC sampling rate may be any integer or non-integer multiple of...
The orthogonal frequency-division multiplexing (OFDM) which has underlying sensing and spectrum shaping capabilities, is indeed well suited to fulfill the requirements of next generation communications. In a multipath environment, bit error rate (BER) is dominated by few subcarriers with small amplitudes because of the deep fades. This requires employing forward error correction (FEC) method on the...
This paper describes the design and baseband processing of a low cost real-time RF channel emulator for the testing of wireless communication systems. It incorporates six independent Rayleigh / Rician fading blocks based on the method of exact Doppler spread (MEDS), an additive white Gaussian noise (AWGN) generator based on the Box-Muller method and programmable delay blocks for up to six multipath...
In the paper, operation algorithms of the N-OFDM modem for channels with the Additive White Gaussian Noise (AWGN) are considered. The algorithms are based on the Hartley transform under the optimal demodulation by the estimation of the received signals amplitudes using the Cauchy method. The experimental results for interference immunity estimation are provided for different values of spacing frequencies...
This paper analyzes the reverse link performance of wireless networks in presence of co-channel interference on AWGN and Rayleigh fading channels and M-QAM modulation schemes. Simple and precise close-form analytic expressions for mean symbol error probability are derived. The proposed expressions of the analytic model developed to evaluate the performance of those systems are verified by the results...
Dynamic spectrum access (DSA) has seen a growing interest in recent years due to spectrum scarcity. Cognitive radio is a necessary component to enable DSA. One key requirement for cognitive radio is the ability to blindly detect the presence of signals in time and frequency. One popular method for blind detection is computing a power spectral density estimate using the Welch periodogram. The Welch...
A Poisson-Gaussian (PG) denoising method for inservice insulator image is proposed. The existing spatial-based method can avoid the preserve more detail information than the transform-based method. Various transforms have been used for image denoising. However, the transforms have disadvantages such as aliasing and lack of directional selectivity. Meanwhile, the conventional redundant transform-based...
Compressed sensing represents an interesting approach in signal processing and reconstruction. The theory involves a surprising number of branches of mathematics: linear algebra, functional analysis, convex and non-convex optimization, nonlinear approximation theory and probability. In general, the applications of compressed sensing can be found (or searched) wherever it is possible to express the...
The reasons of G.fast technology transmission rate limitations when working on domestic TPP type telephone multi-pair cable are considered. The maximum G.fast system achievable transmission rate on TPP type cables in the absence of noise and distortion is determined. The estimation of the influence of interference and crosstalk to the achievable G.fast system transmission rate is given. The necessity...
Electromagnetic interference can cause severe degradation of the performance of wireless communication systems. In order to predict or handle the performance degradation, methods for calculating the impact of the interference is needed. However, for a communication system that is subjected to several impulsive interference sources, the performance is hard to calculate exactly. In addition, using standard...
Electromagnetic interference can degrade radio receiver severely. For this purpose, there is a need to monitor and quantify interference incidents in radio frequency bands. With this goal, a detection method is developed that is intended to be used in a portable detection system for interference detection in frequency bands, where radio transmissions are sporadically appearing. The method is used...
In this article, we study Fast Independent Component Analysis (FastICA) algorithm for resolving closely spaced sinusoids embedded in noise. We generated closely spaced sinusoid signals embedded in noise using open source IT++ libraries. The closely spaced sinusoids signals were randomly generated with minimum frequency separation of [0.05 ∗ Fs : 0.2 ∗ Fs]. Simulations were performed to resolve closely...
In this paper are presented the results obtained after of evaluating three techniques of blind detection of spectrum holes used in Cognitive Radio (CR). The techniques evaluated correspond to the general technique of detection of energy levels, the method LAD BASED and the technique based on forward methods. The operation of these techniques was tested in simulation scenarios of a telecommunications...
Image quality assessment (IQA) plays a crucial role in monitoring quality control in image communication systems, and in benchmarking and optimizing parameters in enhancement algorithms. The full-reference IQA metrics require a good-quality reference image, obtaining which may not be practical in real-life applications. This paper, therefore, proposes a no-reference IQA metric based on the hypothesis...
Laser phase noise degrades the bit-error-ratio (BER) performance after forward-error correction (FEC), so-called post-FEC BER. In order to suppress phase noise, we introduce iterative decoding between a decoder for carrier-phase estimation and an FEC decoder. The simulation results show that the post-FEC BER performance is improved by 0.8 dB by using the iterative decoder.
Target segmentation of synthetic aperture radar (SAR) images is one of the challenging problems in SAR image interpretation, which often serves as a processing step for SAR target recognition. Target segmentation tries to separate the target from the background thus eliminating the interference of background noises or clutters. However, the segmentation may also discard a part of the target characteristics...
The primary objective of the presented work is to exploit the power of modified empirical mode decomposition (M-EMD) for the denoising of ECG signals. It is well known that the ECG signals get corrupted by a number of noises during the recording process. Especially, during wireless ECG recording and ambulatory patient monitoring, the signal gets corrupted by additive white Gaussian noise (AWGN). Over...
This paper proposes an efficient algorithm for noise level estimation in still images. The images are assumed to be corrupted by additive white Gaussian noise. The proposed method relies on block-based image segmentation and Gaussian filtering to estimate the standard deviation of Gaussian noise. The proposed method employs adaptive image segmentation, where the size of segmentation blocks is derived...
Noise estimation is crucial in many image processing algorithms such as image denoising. Conventionally, the noise is assumed as signal-independent additive white Gaussian process. However, for the real raw-data of imaging sensors, the present noise is better modeled as signal-dependent noise. In this work, we propose an efficient image sensor noise estimation method based on iterative re-weighted...
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