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The increasing request of bandwidth for multimedia advanced services is one of the major issues of modern wireless systems. The spectrum shortage has been faced in several ways; among others the cognitive radio approach, aiming to exploit the unused spectrum resources already assigned to incumbent users, is maybe the most known. However, even if its application has been extensively proposed for wireless...
In cognitive radio networks, spectrum sensing plays a crucial role in the discovery of spectrum opportunities for secondary systems (or unlicensed systems). The performance of spectrum sensing is characterized by both accuracy and efficiency, and more importantly the time taken to make a decision and also the complexity involved in doing so. In this work we propose a simple detection technique based...
Very long wave (> 14μm) infrared quantum cascade detectors based on III-V materials are presented. Thanks to the optimum design of electron transport mechanism, high detectivity is obtained without decreasing device responsivity. For the 14.2 μm QCD, a work temperature up to 82K is obtained with a peak responsivity about 0.95 mA/W and detectivity of 1×108 Jones. Peak responsivities is 2.34 mA/W...
Traditionally, multiple speaker tracking consists of two stages, namely, 1) detection of location measurements, followed by 2) a multiple object tracking approach. In general, these two steps are performed separately, and the tracking performance is highly dependent on the measurement detection rate. The performance of the widely used Steered Response Power (SRP)-based measurement detectors, however,...
We consider a network composed of a finite set of communicating nodes that send individual particles to each other, and each particle can carry binary information. Though our main motivation is related to communications in nanonetworks with electrons that carry magnetic spin as the bipolar information, one can also imagine that the particles may be molecules that use chirality to convey information...
The design of a hi-Q resonant RF cavity with coupled detection scheme and associated instrumentation is reported for studying quantum vacuum within the framework of Quantum Electrodynamics (QED), the quantum theory of interaction of matter with radiation. Although this system could possibly serve in any general QED, cavity QED and RF applications in the range of a few GHz, the design was specifically...
In this paper we extend our previous work on strategies for automatically constructing noise resilient SVM detectors from click through data for large scale concept-based image retrieval. First, search log data is used in conjunction with Information Retrieval (IR) models to score images with respect to each concept. The IR models evaluated in this work include Vector Space Models (VSM), BM25 and...
Interest on anomaly detection for hyperspectral images is increasingly growing the last decades due to the diversity of applications that aims for detecting small distinctive objects dispersed in a large geographic zone, without any prior knowledge about the scene. In addition to the absence of prior knowledge, many problems are particularly challenging for the anomaly detection such as the differentiation...
This works makes a brief review of the current situation, first principles and objectives of Cognitive Radio, as well as, measurements of the electromagnetic environment in the 800–900 MHz UHF Band are carried out in a specific indoor environment in order to analyze and discover spectrum holes to be used by a cognitive receiver for creating white spaces in the selected site, in accordance with its...
In order to get an enhanced image and for extracting useful information, an image is first converted into digital form and after that various operations are performed on it. Image edge detection is one of the most important preprocessing step in image processing. In this paper, we compare various traditional edge detection methods such as Canny, Prewitt, Robert and Sobel. Also we propose edge detection...
Image preprocessing is required for texture poor, low-contrast images to enable the functionality of local feature detection algorithms. This is especially true in built environment. We propose a novel image enhancement procedure that conserves the core ‘signal’ in images, while enriching its environment by damping non-essential parts of the signal. Proposed image enhancement method is examined with...
An adaptive circuit is proposed to adjust CDR loop bandwidth based on different jitter spectral profile for better jitter performance. The preventional lock detector (PLD) is employed to achieve better jitter suppression ability without jitter tolerance (JTOL) degradation. The proposed circuit enhances the jitter suppression by 14.14 dB at an 8-MHz sinusoidal jitter source. This adaptive block is...
As speech enhancement for impact noise, it is important to detect the impact noise activity. However, since the impact noise suddenly occurs by hitting an object, a snap and clapping, the impact noise activity cannot be detected easy. Therefore, this paper proposes the impact noise activity detector based on 4th order cumulant. The continuous duration of impact noise is shorter than the one of speech...
This paper compares the performance of the zero forcing (ZF), minimum mean-squared error (MMSE), and MMSE-initialized CMA+AMA equalizers using SOQPSK-TG over multipath channels captured during channel sounding experiments at Edwards AFB. The ZF and MMSE equalizers are data-aided and are based on estimates of the channel conditions derived from the preamble and ASM bits included in each iNET packet...
The palmprint recognition has become a focus in biological recognition and image processing fields. In this process, the features extraction (with particular attention to palmprint principal line extraction) is especially important. Although a lot of work has been reported, the representation of palmprint is still an open issue. In this paper we propose a simple, efficient, and accurate palmprint...
Various methods for detecting the fiducial points of the pulse wave signals are discussed. A new simple detector of the fiducial points based on the application of the first derivative operator, set of nonlinear transformations and adaptive threshold is described. The efficiency of various detectors of the beat points of pulse wave signal in the presence of interferences of various origins and intensities...
India's future science vision emphasizes planetary explorations for better understanding of the universe, finding new domains of material resources, energy, environmental systems and habitat. Mars has a special significance of having many similarities with Earth. Methane Sensor for Mars (MSM) is one of the significant payloads of India's first mars mission. The prime objective of the proposed Methane...
This paper presents a novel approach for Voice Activity Detection (VAD), based on the sparse representation of an input noisy speech over a learned dictionary. For this purpose, we first generate sparse representations of the input noisy speech by Orthogonal Matching Pursuit (OMP) sparse decomposition method with an over-complete speech dictionary learned from clean speech using K-SVD. We then propose...
The paper addresses the problem of target detection embedded in a disturbance composed of a low rank Gaussian clutter and a white Gaussian noise. In this context, it is interesting to use an adaptive version of the Low Rank Normalized Matched Filter detector, denoted LR-ANMF, which is a function of the estimation of the projector onto the clutter subspace. In this paper, we show that the LR-ANMF detector...
Infrared Focal Plane Arrays have been developed with reductions in pixel size below the Nyquist limit imposed by the optical systems Point Spread Function (PSF). These smaller sub diffraction limited pixels allows spatial oversampling of the image. We show that oversampling the PSF allows improved fidelity in imaging, resulting in sensitivity improvements due to pixel correlation, reduced false alarm...
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