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This letter presents a new filtering scheme based on contrast enhancement within the filtering window for removing the random valued impulse noise. The application of a nonlinear function for increasing the difference between a noise-free and noisy pixels results in efficient detection of noisy pixels. As the performance of a filtering system, in general,(More)
For proper and efficient design of wireless sensor network, minimum energy consumption within the sensors and a longer lifespan of sensor network has been posing a serious challenge for the engineers and scientists. Clustering infrastructure which allows efficient use of available resource has great potential in solving the problems of resource limited(More)
As the performance of the filtering system depends upon the accuracy of the noise detection scheme, in this paper we present a new scheme for impulse noise detection based on the local contents of the selected spatial window. In the proposed scheme we also use a noise estimator to decide the number of iterations during the first pass of the filtering. The(More)
Most of the cost functions used for blind equalization are nonconvex and nonlinear functions of tap weights, when implemented using linear transversal filter structures. Therefore, a blind equalization scheme with a nonlinear structure that can form nonconvex decision regions is desirable. The efficacy of complex-valued feedforward neural networks for blind(More)
In this paper, a reliable spectrum sensing scheme based on sample covariance matrix of received signal at secondary user is proposed. The reliability in terms of sufficient protection to primary user (PU) from the interference caused by secondary user (SU). The energy based spectrum sensing method is highly vulnerable at noise uncertainty and covariance(More)
Nonlinear techniques have recently assumed significance as they are able to suppress non-Gaussian and signal dependent noise to preserve important signal elements such as edges and fine details and eliminate degradations occurring during signal formation or transmission through nonlinear channels. Among nonlinear techniques, the fuzzy logic based approaches(More)
—Orthogonal Frequency Division Multiplexing (OFDM) systems are very sensitive to carrier frequency offset (CFO), caused by either frequency differences between transmitter and receiver local oscillators or by frequency selective channels. The CFO disturbs the orthogonality among subcarriers of OFDM system and results intercarrier interference (ICI), which(More)
The non-local means (NLM) algorithm uses the self-similarity or repeated patterns present in images for denoising. NLM algorithm has been extensively researched due to its effectiveness and simplicity. In conventional NLM algorithm, the size of the search window is kept fixed for each pixel. Ideally, the search window size must optimally vary from region to(More)