Spectrum sensing is an essential problem in cognitive radio communication system. This paper presents covariance based spectrum sensing on the test bed of cognitive radio system. A series of tests show that the detection performance of Covariance Based spectrum sensing technique is not liable to be affected by the noise uncertainty in practical application and meets the need of the system priml...

Oscillators are rarely strictly periodic but rather fluctuate irregularly over time. The fluctuations arise from the combined influences of the fluctuating environment, i.e. external noise due to the environmental perturbations or stochastic variations of externally set parameters, intrinsically random nature of chemical reactions, i.e. internal noise due to random transitions among discrete ch...

This paper presents a comparison study of performances and characteristics of three advanced state observers, including the high-gain observers, the sliding-mode observers and the extended state observers. These observers were originally proposed to address the dependence of the classical observers, such as the Kalman Filter and the Luenberger Observer, on the accurate mathematical representati...

One critical issue in the context of image restoration is the problem of noise removal while keeping the integrity of relevant image information. Denoising is a crucial step to increase image conspicuity and to improve the performances of all the processings needed for quantitative imaging analysis. The method proposed in this paper is based on an optimized version of the Non Local (NL) Means a...

The amplitude, frequency and phase of a biased and noisy sum of two complex exponential sinusoidal signals are estimated via new algebraic techniques providing a robust estimation within a fraction of the signal period. The methods that are popular today do not seem able to achieve such performances. The efficiency of our approach is illustrated by several computer simulations.

A new method for the determination of electric signal time-shifts is introduced. As the Kolmogorov-Smirnov test, it is based on the comparison of the cumulative distribution functions of the reference signal with the test signal. This method is very fast and thus well suited for on-line applications. It is robust to noise and its performances in terms of precision are excellent for shift times ...